University of Illinois Plant Clinic

Boxwood Blight Information (Not found in Illinois)

2012-02-15T14:09:00.000-08:00

This blog is in response to all the questions that I have been receiving about a newly discovered disease in the US called Boxwood Blight (Cylindrocladium pseudonaviculatum). This disease has not been found in Illinois, but has been found in other locations in the US:

Date Confirmed in US Location___

10/26/2011 Surry County, North Carolina

10/26/2011                 Middlesex, Fairfield, Hartford,
                                    New London Counties,
                                    Connecticut

11/01/2011 Carroll County, Virginia

12/13/2011 Providence County, Rhode Island

12/14/2011 Prince Georges County, Maryland

12/19/2011 Barnstable County, Massachusetts

12/20/2011 Washington County, Oregon

12/23/2011 Westchester County, New York

1/24/2012 Lancaster County, Pennsylvania

Detection: http://www.nh.gov/agric/divisions/plant_industry/boxwood-blight.htm

Survey Status of Boxwood Blight; Leaf and Stem Blight

http://pest.ceris.purdue.edu/map.php?code=FBBJCXR

Boxwood Blight (Cylindrocladium pseudonaviculatum)

History:

•This disease was 1st described in UK –mid 1990’s

•2002 found in New Zealand and disease was named in UK

•Since 2002, this disease was reported throughout Europe

Host: Buxus species

1). Initial Symptoms dark to light brown spots/lesions on leaves. Leaves turn brown/straw colored and defoliation occurs quickly

2). Also infects stems with distinctive dark brown to black lesions (leads to plant death)

3.) Does not appear to affect roots

CONSIDERED A SERIOUS DISEASE

Key: DETECTION and DESTROY
Fungicides do not appear promising, but research is ongoing

If you suspect this disease on boxwood, please send a sample to a NPDN Plant Diagnostic Lab near you.

For additional information and pictures of Boxwood Blight, here is a list of informational websites:

Boxwood Blight -A New Disease for Connecticut and the US

NPDN Pest Alert A Boxwood Blight New to the US, Cylindrocladium pseudonaviculatum

Boxwood Blight - A New Disease of Boxwoods

NC Pest Alert - "The Box Blight"

A Boxwood Blight - New to US

The "Box blight" pathogen

Boxwood Blight

Boxwood Blight Alert

A Double Coconut Palm Problem in Illinois?

2012-01-27T13:51:00.000-08:00

No, it is not very, often that we receive a palm sample at the U of I Plant Clinic. We are used to seeing corn and soybeans, as well as spruce, pine, oak, maple, and other tree problems. But, recently, we received a sample of a double coconut palm from a conservatory.

This palm has been declining since at least July (These pictures were taken in July 2011), but recently symptoms have appeared to be serious. This client submitted leaf and root samples to the University of Illinois Plant Clinic. The double coconut sample submitted to the U of I Plant Clinic was examined for the presence of disease pathogens as well as signs of insects and none were found on the sample submitted. The root sample that was submitted did not appear to be rotted. The problem was concluded to be abiotic (no disease).

I am very, fortunate to have received help from University of Florida– IFAS, Fort Lauderdale Research and Education Center experts such as Monica L. Elliott, Ph.D. and Timothy Broschat, Ph.D. After receiving pictures as well as soil/tissue nutrient analysis, they provided the U of I Plant Clinic with the following information:

"The leaf that has already expanded has physiological issues. In photo “A”, there is a yellow clear line across the entire expanse of leaf about half way down from the leaflet tips – that is an indication of a one time stress during the leaf development – could be cold, could be very mild boron deficiency – hard to say exactly the problem. These palms are very, very slow growing. I don’t remember how many leaves they produce a year, but it isn’t very many, so a leaf is in development for months, not days. The necrotic leaflets on the one side of the expanded leaf are physiological, not pathogenic – but it is difficult to know exactly what caused the damage. Same for most of the necrotic leaflet tips on the younger, expanded leaf.

Picture A- showing "yellow clear line across the entire expanse of leaf about half way down from the leaflet tips"

The leaf that is emerging in photo “B”: those spots could very well be pathogenic in origin. Usually, when I see a halo around a lesion, I suspect pathogen and not physiological. But, as shown, I can draw a diagonal line through those “spots”, which again is more likely to be indicative of physiological than pathogenic cause. And, you can observe necrotic leaflet tips, which would be physiological and not pathological." -Monica L. Elliott, Ph.D.

Photo B- "showing a diagonal line of “spots”

"I had responded earlier about the soil and leaf analyses not suggesting anything nutritional, but after seeing these photos, I agree with Monica that this looks physiological. This is not typical of phytotoxicities, which tend to result in marginal or tip necrosis on all, but the youngest leaf or if systemic, distortion, or tip necrosis of the spear leaf. This suggests to me a possible temperature problem though it is not typical chilling injury, which affects older leaves more than the newly emerging leaf. Perhaps cold irrigation water? These symptoms are similar to something that was common on Dracaena marginata back in the early 1980s, but after years of working on it, we were never able to pinpoint its cause. We were able to rule out nutritional deficiencies such as boron and calcium, which would be the most likely candidates." - Timothy Broschat, Ph.D.

Dear Sweet Basil, You Have Problems...Basially Yours, The U of I Plant Clinic

2012-01-10T09:41:00.000-08:00

After working on projects and presentations, it was very, exciting to receive a sweet basil sample at the U of I Plant Clinic. It arrived on my birthday, which made this sample even sweeter.

This basil had been growing in a greenhouse system of 12 foot channels and 4 inch offsets with water-flow, similar to a hydroponic operation; however the root plugs of the plants appeared to be encased in a soil mixture. These growers had first experienced problems 4 weeks ago. Luckily, this submitter had included information with his plant sample that provided some much needed clues as to the demise of their sweet basil.

Unfortunately, the temperature in the greenhouse had dipped down below 50 degrees F overnight, at least once. Basil is very, sensitive to cold temperatures and should be grown at temperatures of around 55 to 60 degrees F. We suspected that most of the necrotic areas seen on the leaves were due to cold injury; however we still needed to keep an open mind; as other issues could be lurking.

As routine, I try to rule out problems on ALL parts of the plant, even if they don't appear to be an issue at first glance. I scanned some of the plant parts under the dissecting scope and checked for bacterial ooze under the microscope. There were no signs of bacterial disease.

Dr. Babadoost, U of I Fruit and Vegetable Pathologist happen to peek his head into the lab and I asked him to take a look at the basil sample. He was concerned with a fungal disease on basil, which has recently been a major issue in Illinois, called downy mildew. For more information on downy mildew in basil, you can go to the following links:
Downy mildew wants to ruin your summer
Downy mildew poses a threat to Illinois basil crop

Luckily, we found no sign of any fungal diseases, such as Downy mildew, on this sample. Dr. Babadoost and I agreed that the sample had signs of abiotic injury (most likely cold injury) as well as some insect and possible virus symptoms. The plants had also been without water for about 15 hours and the heat was turned up to 80 degrees F (I assume to warm the greenhouse). These factors could have also caused some plant stress symptoms.

My next stop was the office of Dr. Weinzierl, U of I Extension, Fruit and Vegetable Entomologist. He looked at the sample and found a few leaves with possible thrip feeding. When these leaves were examined under the scope, there were still a few thrips present. By the way, thrips are very, small and can be very, tricky to find! Dr. Weinzerl said that he did not recommend any treatment, as the thrip injury to the basil did not appear to be threatening the crop at this time. Thrips can be one of those pests you don't want to have in the greenhouse, because infestations can be very, difficult to control.

The small, tan circles on leaves are thrip feeding. The darker areas are suspected cold injury.

But, the plot thickens.......I still needed to test suspect plant tissue from this sample for a virus. I happen to have an Agdia Inc. test strip that would test for the presence of INSV, impatiens necrotic spot virus. This test was requested by the grower, but also, one of the few viruses that I could find know to be a problem in basil.

Two red lines on the test strip indicated that some of the plants in this sample tested positive for INSV (impatiens necrotic spot virus). The recommendation was to rogue all of the plants that appeared to have viral symptoms immediately. But, guess the insect vector of INSV? THRIPS! This may change the previous recommendation of no treatment for thrips.

The moral of the story is there could be multiple problems with a sample. Many questions come to my mind. How long were some of these plants infected with INSV? Did the cold, heat, or water stress bring on the virus symptoms? The fact of the matter is that these plants should "grow out of abiotic injury"; however, if they do not, it is possible that the plants may face further complications from the virus infection or other possible factors not seen in the sample submitted.

Aspergillis ear rot and Aflatoxin in Corn as well as other ear rots that cause mycotoxins

2011-12-13T14:08:00.000-08:00

Aspergillus ear rot, as well as other ear rots were an issue in some areas of Illinois in 2011. Some areas experienced hot and dry weather or STRESS after silking, which are favorable conditions for Aspergillus ear rot as well as Fusarium ear rot. Other areas, which were lucky enough to get some rain after flowering, may have had a risk of Diplodia ear rot, especially if it was a problem in previous years. In most cases, injury by birds or insects (as seen in the pictures below), allow entry of ear rot fungal pathogens. Often times, fields that are corn on corn and have reduced tillage allow for the build up of and survival of the ear rot fungi, where it awaits for the right conditions to flourish on a injured or stressed corn crop.

Picture taken by Angela Peltier, U of I Extension Commercial Crop Educator. Kernals infected with Aspergillus (greenish fungus) as well as Diplodia (white fungus) and possibly Fusarium (starburst pattern on kernal) are present.

Picture taken by Angela Peltier, U of I Extension Commercial Crop Educator. Kernals infected with Aspergillus (greenish fungus) as well as Diplodia (white fungus) and possibly Fusarium (starburst pattern on kernal) are present.


Picture taken by Angela Peltier, U of I Extension Commercial Crop Educator. Kernals infected with Aspergillus are present.

In response to this outbreak, Angela Peltier authored the following article: Corn ear molds make an appearance in western Illinois

Aspergillus flavus and Aspergillus parasiticus, the fungal pathogens that causes Aspergillus ear rot, produces a very, dangerous mycotoxin that is considered to be a major carcinogen! The FDA regulates the allowable amount of this toxin in grain for food or feed and less than 20 ppb (parts per billion) is the allowable amount of the toxin in grain intended for human consumption and immature animals. At the U of I Plant Clinic, one of the diagnostic tests that we use to detect the fungal growth of Aspergillus flavus, is put a black light over the corn ear in a dark room. The black light will cause corn kernals infected with Aspergillus flavus to glow in the dark.

Some other diagnostic techniques used to diagnose ear rots involve "plating" infected corn kernels on agar to allow the fungal ear rot pathogens to grow. Identification can be made by spore and fungus morphology.

Aspergillus sp. are not the only fungal ear rot pathogens to produce mycotoxins in corn. For more information on Aspergillus ear rot, see the following link: http://cropdisease.cropsci.illinois.edu/corn/Aspergillusearrot.html

Other ear rots that can cause mycotoxins:

Fusarium ear rot, often characterized by a starburst pattern on corn kernals, caused by Fusarium moniliforme, F. proliferatum, and F. subglutinans can also produce a mycotoxin called Fumonisin. For more information, see the following link: http://cropdisease.cropsci.illinois.edu/corn/Fusariumkernelandearrot.html
Gibberella ear rot, often characterized by a reddish mold first on the ear tip, then spreads downward, caused by Gibberella zeae (=Fusarium graminearum) also produces multiple mycotoxins. For more information, see the following link: http://cropdisease.cropsci.illinois.edu/corn/GibberellaRedearrot.html

In Illinois, to get an accurate test for the concentration of mycotoxins in grain, you can send samples to the Illinois Department of Agriculture CENTRALIA ANIMAL DISEASE LABORATORY

Please call them for further instructions and information.

For more information, contact:
Illinois Department of Agriculture
Centralia Animal Disease Laboratory
9732 Shattuc Road
Centralia, IL 62801-5858
618.532.6701
TDD: 217.524.6858
FAX: 618.532.1195

Need some information on ear rots and grain storage?
Check out this link to another 2011 article written by Dr. Suzanne Bissonnette: Look at Your Ears-Crop, Stock and Ledger

Seed collecting, Treatments, and Storage

2011-12-02T07:24:00.000-08:00

This weeks University of Illinois Plant Clinic blog was brought to you by:
Mike Kwiatek, University of Illinois Horticulture Student and Plant Clinic Student Worker

If you haven’t started collecting seeds yet, it may not be too late. Seed collecting is a fun pastime that provides you with plants for the following years to come, lets you share favorite varieties with friends, and saves you some money for the next season. Many home gardeners collect seed and some even participate in seed exchanges, which allow gardeners to meet and share some of their collected seeds with other gardeners. If you’re interested in participating in a seed exchange, look to community newsletters, local co-ops, and organic food stores; as they often play host to these events.

When collecting seed, consider choosing from plants that looked their best this year. Try to avoid collecting seeds from plants that are known to be hybrids. Lastly, be aware, that for many plants, the plants that will grow from your collected seeds, may not look exactly like the plants that grew the previous year.

There are two main types of seeds: dry seeds and those that come from moist fruit. Vegetables such as beans and ornamental plants such as cosmos or zinnias will produce dry seeds, which can be treated for disease, dried, and stored. Seed should always be harvested when dry. Those seeds that come from moist fruit, can be scooped out once the fruit has fully ripened, washed in a strainer, or sieved to remove any mucilage; then can be treated, dried, and stored. If dealing with squash or pumpkin seeds, a strainer alone will likely not be sufficient to remove the stringy mass that surrounds seeds.

After the collecting seed, it is very important to treat the seeds in order to reduce seedling infection or death caused by bacterial diseases like Xanthomonas and fungal diseases such as Alternaria. Seed treatments will vary by plant species. Plants like eggplant, tomato, pepper, carrot, spinach, lettuce, celery, cabbage, turnips, radishes, broccoli, and related vegetables should be treated with hot water. (See the following link for more details http://en.wikipedia.org/wiki/Cruciferous_vegetables). Vegetables like squash, gourds, pumpkins, watermelons, asparagus, as well as flowers like zinnias, should undergo a chlorine treatment.

Hot water treatment

Place washed seed in a cotton bag, nylon bag, or wrap it in cheesecloth. Warm the seeds for about 10 minutes in a 100F (37C) degree water. Drop the bag into water that is 118-125 degrees Fahrenheit (47-51C) for 15-30 minutes, depending on treatment (See the following link for more details:

http://ohioline.osu.edu/hyg-fact/3000/pdf/3085.pdf ) . Place the bags of seed in cool water for about 5 minutes after the set period of time and then, place them on a screen or newspaper to dry.

Bleach Treatment

Make a solution of 20% bleach, 80% water, and surfactant (dish soap will be adequate). A simple way to do this is by mixing 1/4 cup bleach to 1 cup water, and then add a drop or two of dish soap to this mixture. Place the seeds in this solution for one minute and mix. Then pour this mixture through a strainer and rinse the seeds well with water. Place the seeds on newspaper or a screen and allow them to dry.

Storage

When your seeds have completely dried, place them in paper bags or envelopes, label them properly, and store them in a cool, dry place. Adding a piece of paper towel or a napkin to the envelope or bag will help ensure dryness. You may choose to store the bags in the bottom drawer of your refrigerator. If you do this, you may wish to place all envelopes or paper bags in a plastic bag with 1-2 pieces of paper towel. This will ensure that if any spills occur, your seeds will be safe.

Another helpful web Source:

http://web.extension.illinois.edu/cook/downloads/8584.pdf

A Trip to Muir Woods and the Effect of Phytophthora ramorum (Sudden Oak Death)

2011-11-22T14:18:00.000-08:00

Thanks to the National Plant Diagnostic Network (NPDN) meeting, I was able to make my first trip to California. In addition to some awesome, diagnostic workshops and meetings, we were able to choose one of four field trips/tours. It was a very, hard decision, but I chose: Phytophthora ramorum-Redwoods Tour-
Marin County.

Basically, on the this tour, we were taken to the site where Sudden Oak Death (P. ramorum) was first discovered in the United States.

"Since the early 1990s, oaks and tanoaks have been dying in the coastal counties of California. Since then, other types of plants have been found to be infected or associated with this disease, referred to as Sudden Oak Death (SOD), ramorum leaf blight or ramorum dieback. Phytophthora ramorum is the pathogen that causes these diseases. Sudden Oak Death was first reported in 1995 in Mill Valley (Marin County) on tanoak. Since that time, the pathogen has been confirmed on various native hosts in fourteen coastal California counties (Marin, Santa Cruz, Sonoma, Napa, San Mateo, Monterey, Santa Clara, Mendocino, Solano, Alameda, Contra Costa, Humboldt, Lake, and San Francisco), and in Curry County, Oregon. Through ongoing surveys, APHIS-PPQ continues to define the extent of the pathogen’s distribution in the US and limit its artificial spread beyond infected areas through quarantine and a public education program." -USDA-APHIS

Case Study: Sudden Oak Death /ramorum blight caused by Phytophthora ramorum

This tour included a visit to Muir Woods!

There is an abundance of information and stories that could come from Muir Woods, but the one I would like to share is that of the trees located there. The large live trees located at Muir Woods mostly consist of coastal redwoods; however, there are some scattered Douglas Firs there. The tallest coastal redwood stands 258 feet tall ("A six foot person stacked 45 times"). The average coastal redwood is 600 to 800 years old and the oldest is 1200 years old. -Now, that is old! In the understory of these magnificent trees are tanoaks.

Unfortunately, many of the tanoaks in Muir Woods are infected with Phytophthora ramorum or SOD (Sudden Oak Death). Most of the trees are dying. To a plant pathologist the story may end here. We took many pictures, so that we would have record of the symptoms of tragedy, in the hope that we can catch it before it enters our State, like Illinois. What I did not realize, is how much this disease is affecting the ecosystem of Muir woods.

Note the dark, cankers on the tanoaks, which are symptoms of Sudden Oak Death caused the the fungal pathogen, Phytophthora ramorum. For more information, go to: http://www.suddenoakdeath.org/

If the tanoaks die-then there are no acorns...
If there are no acorns, then there will be no food for the forest rats.....
If the forest rats have no food, then they could possibly die, and then the endangered spotted owls will have no food....

And so, there are many ecological studies taking place to study the many ecosystems, like this one at Muir Woods.

In most of the pictures, the browning foliage belongs to dying tanoaks in Muir Woods.

I wish I could end my story here, but the horror of it is, this fungal disease pathogen, P. ramorum, not only affects oaks, but also has been found to infect over 200 plant hosts and counting....
http://www.aphis.usda.gov/plant_health/plant_pest_info/pram/downloads/pdf_files/usdaprlist.pdf

Here is how you can prevent the spread of this pathogen to your "neck of the woods": http://www.aphis.usda.gov/publications/plant_health/content/printable_version/SBR_StopTheSpread.pdf

Greenhouse Poinsettias with Pythium root rot

2011-11-18T14:31:00.000-08:00

When these plants were examined, the roots appeared to be rotted. When the root tissue was examined under the microscope, there were oospores present. This is a sign of Pythium root rot. The visual symptoms of the poinsettia roots also appeared to be those associated with Pythium root rot at various stages of infection.

Pythium can be introduced to plants by infested crop debris in the greenhouse, transplanting infected cuttings, or recycling potting mix or containers. In addition, in some cases, this pathogen can be introduced by contaminated irrigation water. The problem could also be that the potting medium is not draining properly. Remember, environmental conditions can cause soils not to dry out properly.

This disease is favored by high soil temperatures. Another thing that seems to favor this disease is high soluble salts in the root substrate. I also read where excess fertilization can promote the growth of Pythium.

Good sanitation is the best defense against this disease. Make sure that the potting mix is sterile and disinfect work surfaces. Unfortunately, once Pythium infection takes place, control of the pathogen can be very difficult. Disease development can be reduced by lowering pH to 5.5 or below; however, this can cause nutrient disorders to develop in plants.

There are fungicides that can be used to help manage this disease. In Illinois, the Commercial Landscape and Turfgrass Pest Management Handbook lists fungicides that can be used for root rot. You can also refer to the report on disease to find out which fungicides are used against Pythium:
http://ipm.illinois.edu/diseases/rpds/615.pdf

A preventative fungicide application may be necessary the following year, in addition to improved sanitation.

Other very, helpful links:
http://ncsupdicblog.blogspot.com/2011_01_01_archive.html
http://www.negreenhouseupdate.info/index.php/diseases/296-poinsettia-pythium-root-rot
http://www.gpnmag.com/Don%E2%80%99t-Expect-Pythium-Root-Rot-to-Always-Act-the-Same-article2958
http://www.chasehorticulturalresearch.com/pages/ChaseArticles/45PythiumRootRotonPoinsettias.pdf

Downy Mildew on Impatiens in Illinois

2011-11-04T14:41:00.001-07:00

In October, 2011, there were several reports of downy mildew on garden impatiens (Impatiens walleriana). This disease was first reported in the U.S. in 1942, but recently several sources say this disease has been confirmed on impatiens in coastal southern California, northeastern Illinois, northern Indiana, Cape Cod in Massachusetts, Long Island and upstate New York. If you think that you experienced this disease in your garden, there are no worries of it infecting other plants. However, it is very, important that you remove and destroy infected plants. There is still a chance that this disease pathogen could overwinter and infect impatiens the following year. I have read that New Guinea impatiens have resistance to this disease and can be a considered a choice that can be planted in an infected area. End of the season fungicides are not recommended. Watch for this disease next year! Keep a careful watch on impatiens and catch this disease in the early stages and remove infected plants immediately! Fungicides can provide some protection, but will not protect impatiens for the entire season.

Several weeks ago, we received an email from from Diane Anderson saying that this downy mildew had infected most of the impatiens at the University of Illinois Trial Gardens. In the next several pictures you can see just how devastating downy mildew can be, if impatiens have been infected.

Symptoms of downy mildew of impatiens have been described as: "yellowish or pale-green foliage, downward curled leaves, leaf distortion, white to light-gray fuzz on leaf undersides, new leaves that are small or discolored (yellow or pale green), flowers buds that fail to form and stunted growth".

The plant pathogen that causes downy mildew is an oomycete and is spreads by oospores as seen below.

For more information on Down mildew of impatiens, you can check out the following websites:

Downy Mildew causing problems on impatiens in the Landscape

Check impatiens for downy mildew

It's Back

http://www.ballhort.com/Landscapers/Tips.aspx

End of the Season, "My Spruce is Dying" -Cytospora Canker

2011-10-28T14:35:00.000-07:00

The U of I Plant Clinic has been receiving calls and samples from clients because their spruce is dying. We received one sample that consisted of just spruce branches. There were no signs of disease on these branches. Unfortunately, there were no needles included with the sample, but the client did include a CD with several pictures. I called him to get further information on what may be going on with his trees. On the phone, he said that some of his spruces were dying and he was afraid that whatever was killing them might spread to his other trees. He continued to tell me he had a row of spruces on his property that were 15 to 20 years old. One of the spruces had already died. Travis Cleveland, U of I Extension, PSEP (also an urban tree expert) and I both examined his pictures, which were included with his sample. I suspected Cytospora canker and Travis suspected an injury at the base of the tree. I told the client to please check for "oozing cankers" or white sap on the trunks or the branches of his spruce trees, because this is a sign of a fungal disease called, Cytospora canker. In addition, I wanted him to check for any possible injury at the base of his trees.

Here are the pictures he later sent to me via email:

Note the twine/plastic girdling the base of the tree.

As it turns out, Travis and I both were correct. A few trees that had been described by the client as "runts" or smaller trees had twine/plastic left on the base of the tree when planted. As these trees grew, the twine/plastic girdled the base of the spruce, causing tree death. Other trees did not have an injury at the base, but must have been stressed, because they were clearly infected with Cytospora canker. You can see in these pictures where the white sap is running out cankered areas on the trunk. These oozing cankers are sometimes confused with bird droppings. Some things that may have stressed these trees: heat, drought, clay soils, ???? If branches are infected with Cytospora canker, they may die, and you can trim/destroy them. However, if the trunk of the tree becomes infected with Cytospora canker...... that can be bad news! Cankers on the trunk/stem of a spruce can cause tree death.

The Cytospora fungus invades weakened or stressed wood. We can't always determine the cause of stress from the lab, but any site or environmental conditions that are not good for the species could be the actual cause of the problem. Spruces do not do well in hot, dry, poorly drained soil with high clay content. Sometimes problems do not develop on spruce until roots outgrow the area, grow into poor soil, or until weather stress aggravates the situation. Fungicides are not effective. You need to help tree vitality by pruning out dead wood now, watering in periods of drought lasting two weeks, and fertilizing in the fall or early spring with a balanced tree fertilizer. If you can determine the cause of stress, of course, correct that as well. A fact sheet on Cytospora Canker of spruce can be found at the following link:
Cytospora Canker

The Difference Between Bacterial and Fungal Plant Pathogens

2011-08-15T14:11:00.000-07:00

(This week's blog brought to you by: Diane Plewa (U of I Plant Clinic Student Worker)

The most common pathogens we see at the U of I Plant Clinic are fungi. However, there are plenty of bacteria that can cause problems for plants, and one of the first things we do is try to determine if we’re looking at a fungal or bacterial disease.

There are two ways for us to determine what kind of plant pathogen (fungi or bacteria) we’re dealing with: looking at the disease symptoms displayed by the plant and using the microscope to check for fungal spores or bacterial oozing. When we look at the plant’s symptoms, there are a few that tend to indicate a bacterial infection. Yellow haloing around lesions on leaves is one sign of bacterial disease (though there are several fungi that can cause similar symptoms). Bacterial lesions tend to be limited by veins in the leaves. We also suspect bacteria when we find sticky exudate or stringy ooze in diseased tissue.

Bacterial lesions on pumpkin and pepper. Photo credit: U of I Plant Clinic.

Fungal lesions usually aren’t surrounded by yellow halos. They may manifest as round, oval, or irregular necrotic areas. Some lesions will have a characteristic “bulls eye” appearance. Under a dissecting microscope or strong hand-lens, fungal fruiting bodies (which contain spores) may be observed.

Clockwise from upper right: Fungal lesions on peony; Fungal lesions on hosta; Magnified fungal fruiting structures on spruce. Photo credit: D. Plewa

Identification of the actual pathogen is done by the appearance of the spore and its fruiting body for fungi. Using a compound microscope, we can observe the actual fungal spores.

A microscopic view of a few common fungal spores. Photo credit: D. Plewa

While an individual bacterium is too small for us to see, we can see masses of bacteria known as “bacterial ooze” or “bacterial streaming.” Many bacteria, as well as viruses, can be identified using an ELISA immunostrip assay. You are unable to see a virus particle under a compound microscope.

Bacterial streaming observed under the microscope. Photo credit: D. Plewa

An ELISA immunostrip assay indicating the presence of the bacteria Xanthomonas campestris. Photo credit: D. Plewa

Lightning Only Strikes a Tree Once?

2011-08-05T13:22:00.000-07:00

This week's blog brought to you by: Mike Kwiatek (U of I Plant Clinic Student Worker)

Any tree can be hit by lightning, but oaks, elm, maple, poplar, ash, spruce, fir, pine and tulip trees are known to be prone to lightning strikes. As they are trees that grow large and tower over the forest canopy damage is not uncommon from the forces of nature. Water and sap in a tree provide a conduit for the lightning as it travels toward the ground. As the lightning travels through the tree, water and sap boil, gases inside the tree expand, and often the wood and bark of the tree can split or commonly explode. When the bark is wet, damage is usually less severe as lightning will travel more along the outside.

Trees struck by lightning can survive many years after a lightning strike, but this is based on the extent of the damage and the treatment of the tree afterward. Most trees that die from lightning strikes years later die as a result of infection or infestation by insects. When pruning can be done to remedy damage, it is suggested. Lightning strikes can be extremely stressful to trees so it is advised that trees be watered in times of drought and fertilized in fall. Do not paint the wound, this can do more damage than good.

To prevent lightning damage a lightning protection system may be installed. Protection systems consist of a series of copper cables attached to the tree’s highest branches and grounded a safe distance from the tree. If lightning strikes the tree, the current flows down the cables to ground. If interested in a lightning protection system, consult with an arborist although the damage may already be done.

During the summer at times of drought leaf abscission may also occur in response to heat stress but we do not suspect that this is the main issue. This issue should also, however, be resolved by watering in times of drought. Fertilize the tree in early fall.

Which trees are less likely to be hit by lightning? -beech, birch, and horsechestnut

For additional information, see http://joa.isa-arbor.com/request.asp?JournalID=1&ArticleID=1862&Type=2

How We Identify Corn Leaf Diseases (Goss's wilt, Gray Leaf Spot, Common Rust and Physoderma brown spot) at the U of I Plant Clinic

2011-07-29T15:00:00.000-07:00

In the last week, we had a high number of corn leaf samples submitted to the U of I Plant Clinic. Most of are interested in knowing if their corn is infected with Goss's wilt, a bacterial disease showing up in many fields this growing season in Illinois. For more information on Goss's wilt, you can go to the following links:
Goss's wilt spreads across Illinois
Goss's wilt of Corn

After a corn leaf sample is "checked-in" to the Plant Clinic by our awesome secretary, Deb, they are evaluated for disease. One of the first steps is to "check for ooze". If leaves are showing symptomology of a bacterial leaf disease, a cross-section is cut from the leaf tissue and examined under a microscope for bacterial streaming as seen in the picture below:

Bacterial ooze or streaming that can be seen under a microscope.

If we see come bacterial streaming, we have immediately been testing the area showing symptoms, with an ELISA ImmunoStrip quick strip test for the bacteria, Clavibacter, which is the Genus of the bacterial pathogen that causes the disease, Goss's wilt (Clavibacter michiganensis). If the sample does not test positive for Clavibacter, we assume that it is Stewart's wilt.

Corn leaf sample that has been found to show microscopic, bacterial streaming.

Corn leaf tissue is ground up, put in the special bag with buffer solution, and a test strip is placed upright in the bag.


Two red lines means that the corn sample was positive for Goss's wilt.

Other corn leaf diseases that we have been finding are as follows:


Lesion of Common leaf rust (Puccinia sorghi) of corn.


Common leaf rust (Puccinia sorghi) pustule as seen under a compound scope. Picture taken by Mike Meyer.


Spores from Common leaf rust (Puccinia sorghi) as seen under a microscope. Picture taken by Mike Meyer.


Gray leaf spot (Cercospora zeae-maydis) lesion.

Gray leaf spot (Cercospora zeae-maydis) fruiting structures as seen under a compound scope.

Gray leaf spot (Cercospora zeae-maydis) fruiting structure with spores as seen under a microscope.

Cercospora zeae-maydis spores as seen under a microscope.


Physoderma (Physoderma maydis) brown spot (Sorry no other spore pictures available at this time)

Therefore, bacterial disease diagnosis is based on whether or not bacterial oozing is present as well as an ELISA ImmunoStrip quick strip test for Clavibacter reads as positive or negative.

Fungal disease diagnosis are based on morphology of fungal fruiting structures and spores that are observed under a compound scope and microscope.

Where are the Cicadas Now? An Update on the Great Southern Brood

2011-07-21T17:29:00.000-07:00

By: Jean Burridge,
Certified Illinois Arborist, and U of I Plant Clinic Volunteer

This has been an emergence year for periodical cicada in much of the southern part of the state. (See Phil Nixon's article in Home, Yard, and Garden Pest Newsletter, Issue 2). After thirteen years of subterranean existence, adults surfaced in late spring. Males sang, females listened; eggs were laid. Female cicadas possess a saw-like ovipositor, which they use to cut slits in twigs and small branches. They then insert their eggs into the wounds. The eggs will hatch in late summer, and the nymphs will drop to the ground and disappear into the earth. By August, an aggregation of insects so large and impressive that it has its own name (like Ann Arbor) will exist only inside the twigs of trees. Magicicada, indeed.

This feat of compression is not without cost. If you live in an area that is home to the brood, you may be seeing damage to trees, shrubs, or even perennials. Large trees look bedraggled – a bad hair year about sums it up. Trees that have been badly hit will have a fringe of dangling twigs. Weakened branches may snap immediately, or hang on until wind or ice loading finishes them off.

The loss of apical dominance in an injured branch results in bushy unbalanced growth, as a host of lateral buds vie to replace the lost leader. The damage – broken branches, oviposition scars and aberrant growth – will be visible for years.

It is too late to protect trees at this time. Native trees have co-evolved with cicadas – large trees usually grow out of their injuries and are not permanently harmed. Anything you can do to relieve stress would be helpful; water during dry spells and fertilize in the fall.

Small trees or shrubs can succumb to this death of a thousand cuts; they may need to be replaced. If an emergence is anticipated, it is best to delay planting new trees until ovipositon has ceased.

Biologists suspect that periodical cicadas may have evolved to emerge on a thirteen or seventeen year cycle, in part because these are prime numbers. (Such protracted phenomena are very difficult for biochronologists to isolate – see Zivkovik. Mathematicians have modeled cicada broods – see Lehmann-Ziebarth et al.) Cicadas on this schedule can evade their predators, whose reproductive cycle cannot track them effectively. Animals who grew fat on cicadas have offspring who partake of no such abundance. When the brood reappears, there are no extra mouths to greet it. There is one animal, however – Homo sapiens - that is fully capable of exploiting a thirteen year interval. The Great Southern Brood will rise from the earth in 2024; be prepared….

Lehmann-Ziebarth, Nicholas , et al. “Evolution of Periodicity in Periodical Cicadas”. Ecology 86 (12) 2005. pp 3200-3211. http://www.math.wisc.edu/~milewski/Paul_Milewski,_Professor_of_Mathematics/Publications_files/cicadas.pdf Web. 7/14/2011.

Nixon, Phil. “Periodical Cicada”. Home, Yard and Garden Pest Report Issue 2, May 2 2011. http://hyg.ipm.illinois.edu/article.php?id=263 Web. 7/14/2011

Zivkovik, Bora. “Centuries to Solve the Secrets of Cicadas”. http:www.scientificamerican.com/blog/post.cfm?id=too-hard-for-science-bora-zivkovil-2011-05-16. Web. 7/14/2011

The Corpse Flower is Blooming at the U of I Conservatory!

2011-07-15T17:18:00.000-07:00

Excitement has been in the air at the U of I Plant Biology Conservatory as they anxiously await the bloom of the Titan arum or Corpse Flower. It is 10 years old and is blooming for the very, first time right now! It also is expected to be stinky, when the bloom opens! The U of I Plant Biology Conservatory has recently extended it's hours for the public to see this flower.

If you are unable to visit, you can see it on the live webcam !

Everyone at the U of I Plant Clinic was very excited about the bloom of this stinky flower. In fact, we made sure the U of I Plant Clinic was "in on the action", by sending one of our students to visit the flower at the U of I Conservatory and wave to us from the webcam (Oh, yeah........ and put up a sign with a message from the U of I Plant Clinic)!

The "UI Plant Clinic "hearts" Titan"

The Titan and other plants can be seen at the U of I Plant Biology Greenhouse

Pictures of the Titan arum can be seen on the U of I Conservatory's Facebook Page

For more information, check out this fact sheet at U of I Plant Biology Greenhouse Plant Highlights

Press Releases:

Rare 'corpse flower' about to bloom at U of I Greenhouse

Rare Flower Expected to Bloom at UI

Seeds of Collaboration: Illinois Titan Arum Traces Roots to UW

A Few Tomato Diseases Seen at the U of I Plant Clinic this Week and How to Manage Them.

2011-07-08T14:09:00.000-07:00

We confirmed 2 tomato samples from Cook County Illinois with TMV (Tobacco Mosaic Virus). More information about this disease can be found at: TMV - UMN.edu

How to manage TMV:
Rouge out the affected plants and sterilize pruning equipment. The virus is soil-borne, so crop rotation should be used to reduce the levels of inoculum. Avoid planting tomatoes, potatoes, peppers, and other solanaceous crops in the affected area for several years. Control solanaceous weeds, including jimpson weed as well as nightshade. Resistant varieties of tomato are available.

Septoria leaf blight is one of the most common diseases of tomato. I have also two samples of tomatoes infected with this disease this week. A University of Illinois publication about this and other tomato leaf diseases can be found at Tomato leaf diseases - UIUC.edu.

How to manage Septoria leaf blight:
Due to the wet weather earlier this season, Septoria leaf spot has been particularly severe. To control Septoria leaf spot in the current growing season, remove infected plant parts and consider spraying weekly with an approved fungicide (or just accept losses). Be sure to avoid overhead irrigation which spreads disease, and stake plants to improve air circulation within the canopy. At the end of this season destroy all plant material. Rotate to a non-host crop next year. Products containing chlorothalonil (Bravo or Terranil, or others), copper, mancozeb (Dithane or pencozeb), or maneb are registered for use on tomato. Be sure to abide by the label you choose, especially the days between spraying and harvest. Additionally, saving seed from season to season may increase disease because seed infection is possible with Septoria lycopersici.

Frogeye leaf spot or Phyllosticta leaf spot in Soybean? Easily confused?

2011-07-01T15:35:00.000-07:00

A few weeks ago, there was an email floating around from "Ag Industry" that was claiming that frogeye leafspot, Cercospora sojina, had been found in soybeans. This just did not seem possible to me, especially on leaves, from early vegetative growth stages on soybean, but never say never.

Several hundred plant samples later, I had forgotten about the frogeye leaf spot claim, until I was looking at a sample of 20 soybean leaves that had been collected from the Soybean Rust Sentinel Plot in Richland County, Illinois.

Then, the memory came flooding back to me when my Graduate Student asked me, "Is this frogeye leafspot?" as she leaned over my shoulder, while I was carefully looking at each leaf from the Richland Soybean Sentinel Plot under the dissecting scope. I said, "No, this is PHYLLOSTICTA LEAF SPOT", Phyllosticta sojicola, as I pointed out to her that the lesions had black, round fruiting structures within necrotic lesions, which can be easily seen with some magnification. Also seen at this link: APS: Phyllosticta leaf spot with pycnidia

But, I told her that the early infection of Phyllosticta leaf spot sure could look like the lesions of frogeye leaf spot! Both of these diseases are easily distinguished under a scope. Phyllosticta lesions will eventually grow, as the disease develops, and become "V-shaped" within soybean veins. Phyllosticia leaf spot is not usually considered to be a serious disease.

I told Dr. Carl Bradly, University of Illinois Crop Sciences, Field Crop Plant Pathology, Extension Specialist, this story and he agreed with me that these two diseases could be confused. In fact, he reminded me that he had written an article about this very subject in the The Bulletin in 2007: Similar Symptoms on Soybean: Phyllosticta Leaf Spot Vs. Frogeye Leaf Spot

A lot of attention has recently been given to frogeye leafspot, since this pathogen has been found to have reduced sensitivity to fungicides in Tennessee. For more information: http://bulletin.ipm.illinois.edu/article.php?id=1429

For this reason, it is probably a good idea that frogeye leaf spot is correctly diagnosed.

Spruce and Pine damage- {Herbicide (Imprelis -DuPont) or Evironmental Factors}?

2011-06-24T12:18:00.000-07:00

Several States have now reported evergreen injury (mainly spruce and white pine) due to either, herbicide or environmental factors.

Symptoms include: wilted, necrotic, yellow, needles; needle death, wilting of new shoots; desiccated and drooping candles; twisting and distorted shoots

These are pictures of a spruce sample where a lawn herbicide was applied on the property; however we never received confirmation of exactly what chemistry was used; therefore, we could not make a definite diagnosis.

One of the main topics of discussion is the injury of spruce and white pine, in some cases, which has been linked to to the herbicide, Imprelis (DuPont). Imprelis is a newly, released lawn herbicide with excellent soil activity. It is also important to note, that not all spruce and white pines have been injured in areas where Imprelis herbicide has been applied.

Be aware that all herbicides with good, soil activity could be a potential danger to evergreens and broadleaf ornamentals, if root uptake occurs.

DuPont Imprelis Label: http://www2.dupont.com/Professional_Products/en_US/assets/downloads/pdfs/H65717.pdf

The Imprelis label states: “Do not apply this product directly to, or allow to be under, ornamental ground covers, foliage plants, flowers, nearby crops or other desirable plants; or to the soil where potentially sensitive plants will be planted during the same season. Do not exceed specified application rates for any area and particular care should be taken within the dripline of trees and shrubs.” In addition, the Imprelis label states that grass clippings are not to be used as mulch or put into compost piles.

DuPont has made a statement. See more in the link below:
http://www.ksuturf.org/blog/2011/06/possible-herbicide-injury-to-spruces-and-pines/

Here are some other links to fact sheets, blogs, and pictures with further information on this topic.

Purdue fact sheet: http://www.ppdl.purdue.edu/PPDL/hot11/6-10.html

Ohio: http://www.osugarden.com/2011/06/imprelis-herbicide-may-injure.html

Penn State: http://extension.psu.edu/greenindustry/giec/news/2011/heads-up-spruce-and-pine-injury

Michigan State: http://expeng.anr.msu.edu/news/article/imprelis_herbicide_injury_to_evergreens

Iowa State: http://iaturf.blogspot.com/2011/06/imprelis-damage-on-trees.html

There have been several other reports of evergreen injury (spruce) linked with herbicides that contain (2, 4-D, Mecoprop and Dicamba) as well as "auxin" or phenoxy herbicides.

Why is this herbicide injury happening this growing season? Could environment or weather be a factor? There is speculation that spruce may be stressed from the drought of last fall and could be more susceptible to injury of all kind (diseases, insects, and herbicides). There was alot of rain this season that could move chemicals to roots of plants for uptake. In addition, was it a coincidence that symptoms started to occur when there was a sudden temperature fluctuation from low 40 degrees F to 90 degrees F?

Lastly, there have been reports of some of these same evergreen symptoms in areas where NO HERBICIDES have been applied. Late freezes can cause death of new growth. It possible that hot, dry winds or "tornado like winds", as well as a cold to hot temperature extreme can cause evergreens, such as spruces, to have uniform candle dieback or dessication of needles.

Since the environment could be to blame for some of the same symptoms described on spruce, you have to very, careful before you jump to the conclusion of herbicide injury. However, it appears that the "twisting" and "distortion" of evergreen seems to be a common symptom of suspected herbicide injury cases.

Any Reports of Areas or Entire Corn Fields (V5-V7) that are Completely Purple?

2011-06-17T14:47:00.000-07:00

Well, a month ago, we were received reports of white in corn fields. Some Southern Illinois growers were "spotting" white on leaves (Holcus spot), while others were trying to solve the mystery of white corn plants in Central Illinois. For more on this you can refer to my May 19th blog: Everyone is Talking about White Corn

Now, Northern Illinois (Ottawa and Southeast of Mendota) must need " have a turn" to have a corn, color issue, but this time, their color is purple. Today, I was asked if there had been any reports of areas or entire corn fields (V5-V7) that were purple. I had no additional information, nor pictures, but I asked some of the U of I Crop Science Extension Specialists if they had heard of any reports of "purple corn fields" and I asked what, in their opinion, could cause a large area of corn, growing in moderate to high temperatures, beyond a growth stage of V5, to become purple?

Dr. Mike Gray, U of I Crop Sciences Extension Entomologist:

"I have not heard of any reports. Because of the clumped distribution of insects within a field -- it is unlikely that an entire field showing purple discoloration is insect related. However, some insect feeding (e.g. grape colaspis and/or white grubs) that prune root hairs on seedling corn plants can lead to purple discoloration on plants. The mechanism -- poorer absorption of nutrients (especially phosphorus) by the root systems."

Corn Insects - A Diagnostic Guide

Dr. Fabian Fernandez, U of I Crop Sciences Soil Fertility and Plant Nutrition Extension Specialist

"I have not had any reports. Would it be possible to get a picture of the field and a close up on the plant? Purpling of corn leaves is typical for phosphorus deficiency, but often the problem is observed with younger plants when it’s very wet or cool. I suspect if they are seeing this at V5-7, and is due to phosphorus, the field is either very deficient in phosphorus, or something terribly wrong is going on with the root system that is not allowing plants to take up phosphorus. Both situations seem very unlikely to me because 1)it is not very common to see entire fields completely phosphorus-deficient and 2) if the problem is related to the roots there are other nutrients that would show deficiencies too, making for very sorry-looking plants. Again, if you can get a couple of pictures, that would be beneficial."

Nutrient Deficiency Symptoms in Corn (Identification)

Dr. Aaron Hager, U of I Crop Sciences Weed Science Extension Specialist

I was lucky enough to have Dr. Hager looking at 7 crop samples, with potential herbicide injury, today at the U of I Plant Clinic. In passing, in the hallway, I quickly asked him his thoughts on purple corn. He said that some herbicides can cause corn to turn purple. However, it is very, unlikely for an entire field to show symptoms for very, long. For example, glyphosate may cause purple leaves in corn, but it will not stay purple, in time, it could become "smoked".

Purple Corn May Indicate Herbicide Injury

As noted by Dr. Nafziger, in his comments below, other herbicides can cause injury by limiting root growth, but they just are not used that much anymore.

Dr. Emerson Nafziger, U of I Crop Science Agronomic Extension

"The “proximate cause” of purple corn is sugar accumulation. This can arise from P deficiency, since P is needed for sugar transport. In young plants, though, it usually results from inability of the root system to grow out into the soil around the base of the plant. Sugars accumulate when roots can’t grow, and the anthocyanin pigment then forms.

We’ve heard of some of this in areas where the surface soil is dry this year (I wrote about it in this week’s Bulletin) -The Bulletin: What Crops Need Now If it’s only in parts of the field, it will often be in places where the surface soil dried out before nodal roots could penetrate. Sometimes it can be in heavier soils as well, where the sidewall that forms during planting dries to form a barrier.

So I’d suggest looking first at root growth. In some cases the seminal roots will have grown more than normal, but at some point they just can’t support the plant anymore. If the field recently had rain, the problem will likely go away very quickly. If the crop is still purple several days after rainfall, then other possible causes need to be looked at. But since we don’t use many herbicides that limit root growth anymore, there aren’t that many causes to consider."

The Agronomist that is dealing with the issue of corn turning purple made the following comment after receiving the above information and consulting further with Dr. Fabian Fernandez:

"We have been extremely wet, and I wonder if this problem is related to saturated soils. I am beginning to think so. Dr Fernandez also mentions extremely low P levels. In one area that I see the purpling, this is a possibility, in another, it is a field that is extremely HIGH in P."

Anthracnose Leaf Blight on Corn: Crop Disease of the Week at the U of I Plant Clinic!!

2011-06-10T07:45:00.000-07:00

The sample of the week was Anthracnose leaf blight of corn! The U of I Plant Clinic confirmed this fungal leaf blight on several corn samples. As you can see in the pictures below, this disease is being observed at various corn growth stages. The fungus, Colletotrichum graminicola that causes Anthracnose requires wet and cloudy weather, which is just what the weatherman has ordered for the past several weeks.

Anthracnose leaf symptoms will vary among corn hybrids. The lower leaves are usually affected first because this disease is lurking in corn residue, which means corn on corn is more at risk. However, RESISTANCE is the key with this disease. If you are seeing this in your field, I would check your hybrid's susceptibility to Anthracnose. No need to worry too much at this time, if you are seeing this disease in your fields now. Research has shown that this disease should not extend to far up the plant beyond the V6 growth stage. Also, just because you are seeing Anthracnose leaf blight now, does not necessarily mean your corn has been sentenced to a stalk rot death. So, fungicides are not warranted at this time. For more information on Fungicides at Early Growth Stages, go to this link: http://bulletin.ipm.illinois.edu/article.php?id=1284

So, I think the underlying question on some of our client's mind was if this disease was killing corn seedlings, because many of our clients included a blighted corn seedling with their sample...just like the one below

Each of these blighted corn seedlings (like the one above) had roots that consisted of oospores, which tells me that our friend (or enemy), Pythium made it's debut on these roots and caused seedling blight or even death on many of the corn seedlings that were examined at the U of I Plant Clinic. So, Anthracnose was not the culprit of the demise of corn seedlings. In other cases, corn death occurred because corn roots were under water for a long enough period that caused root tissue to became oxygen deprived.

Some of the older corn plants that I examined did show signs Pythium on primary roots, but I am very happy to report that new, healthy roots had grown and the corn was quickly "growing out" of the root rot, thanks to the recent onset of better growing conditions!

For more information on Anthracnose leaf blight, you can check out the following links:

http://bulletin.ipm.illinois.edu/article.php?id=1337
http://bulletin.ipm.illinois.edu/pastpest/articles/200211m.html

Organic Pesticide Toxicity Problems

2011-06-04T11:50:00.000-07:00

The U of I Plant Clinic recently received 2 tomato samples with injury from organic fungicide and insecticides.

The first sample was from a Commercial organic grower with a hoop house operation. A copper product (not specified), which is often used an organic fungicide, was applied. If the copper product is applied improperly or in cool, wet conditions (the copper product is not allowed to dry) plant injury can result. Here is a link for more information:
http://www.oardc.ohio-state.edu/fruitpathology/organic/grape/organic.html

In this picture, you can see the plant injury that resulted from the application of the copper product.

The next sample was submitted from a home grower. When, his sample was found to be free of disease and had no signs of insect injury, I gave him a call to get more information. I told him that his tomato leaves had symptoms (interveinal necrosis) that looked very similar to that of chemical phytotoxity; however he had not indicated that he had used any chemicals on his plants, on the information provided with the sample. But, on the phone he told me that he had "thew down" an organic pesticide on the soil that consisted of Eugenol and Thyme oils. This could also cause injury to plants if not applied correctly. Only the lower leaves of his tomato plant were affected, which led me to believe that the injury had come from the application of the organic pesticide.

My purpose of this blog, is to bring awareness when applying pesticides. No matter if it is an organic or conventional pesticide, you still should always read the label and follow use directions. Often times, pesticides that are considered organic have a greater potential to cause plant injury. Luckily, if plants are not severely injured, new growth will come, and the plant will "grow-out" of these symptoms.

Have You Ever Wondered How We Culture and Isolate for Oak Wilt?

2011-05-27T12:34:00.000-07:00

This week the students at the U of I Plant Clinic learned how to culture and isolate the fungal pathogen, Ceratocystis fagacearum, that causes oak wilt in oak trees.

When someone suspects that their oak tree is dying from oak wilt, they can send a sample to the U of I Plant Clinic. We usually suggest that they sample from areas of the trees that are showing symptoms typical of oak wilt as well as wood that may show streaking or darkening of vascular tissue (see pictures below). We would like the sample to consist of several 1 to 2 foot long branches with at least the diameter the size of a thumb.

Some oak leaves showing a symptoms of oak wilt.

Dark streaking of the wood caused by the oak wilt fungal pathogen.

Here students at the U of I Plant Clinic:
1. Take notes on the condition of the oak sample.
2. Label agar plates with sample number, date, type of agar, and OW (Oak Wilt)
3. The bark is peeled back from the end of the branch, so that the wood is exposed under a sterile hood.
4. They flame their knife and notch the wood into tiny wood chips, which remain attached to the branch.
5. Then, they flame their tweezers and pick off wood chips.
6. These wood chips are placed, very quickly, (to avoid any unwanted contamination) into PDA -Potato Dextrose Agar, plates under a sterile hood.

The agar plates are stored on a shelf in our lab, with their paperwork. They are kept there for up to 7 to 10 days to allow time for the fungal isolates to grow.

If we were successful at isolation of the oak wilt fungus, the above pictures show what it would look like growing in our PDA culture plates.

Lastly, we take clear tape and place it on top of the fungus to "catch spores". This clear tape is placed onto a microscope slide with a drop of water on it. If the oak tree is infected with oak wilt (oak wilt positive), we will see the chains of spores that is seen in the picture above. If none of these spores can be found, the oak sample will be considered "oak wilt negative". (Picture above taken by Travis Cleveland)

For more information on oak wilt, you can refer to: http://ipm.illinois.edu/diseases/rpds/618.pdf

Everyone is Talking about Corn that has Turned White......

2011-05-19T12:38:00.000-07:00

There have been several reports of corn turning white in different parts of Illinois.

One of those reports from Southern Illinois (not yet confirmed at the U of I Plant Clinic) refers to the possibility of Holcus spot in corn. Holcus spot is caused by a bacterial pathogen and can be easily confused with paraquat (herbicide) injury. Holcus spot is difficult to diagnose because the bacteria may not be readily found within the lesion. Holcus spot has a wide host range and can infect foxtail millet, pearl millet, Sudan grass, broom corn, Johnson grass, wheat, and sorghum. This disease is not a major problem in corn, but it is not commonly found. For additional information, you can go to: http://cropdisease.cropsci.illinois.edu/corn/holcusspot.html

These are pictures of suspect Holcus spot or paraquat injury from another sample that was previously submitted to the U of I Plant Clinic:

Now, the next issue that is causing "quite the buzz" among agronomists and consultants is the issue of corn turning white in the field. I was lucky enough to find a case of this and I did take pictures. I am not sure what may be causing this and I am unable to investigate further on this particular case, as I do not have any information on what chemicals (herbicide or insecticide) that have been applied to or near this corn field. This picture was taken in a field south of I-72. There does not seem to be a pattern. As you can see in the pictures below, these plants were found in areas of the field that had been waterlogged.

Dr. Aaron Hager,

Associate Professor of Weed Science, has had a few reports of this, but is not sure there has been anything consistent in each instance. Some wonder about herbicide injury (which is possible), although there have been reports of this occurring in fields where no herbicide as yet been applied. He suspects the weather/wet soils might also be contributing to this.

You are always welcome to submit a sample to the U of I Plant Clinic, where we and Dr. Hager will fully examine the white, corn plants. We will also need a very extensive history of the field, which includes all chemicals applied to the field.

So, You Want to Grow Grapes..........

2011-05-12T09:35:00.000-07:00

I have recently had some grape questions. Luckily, Dr. Elizabeth Wahle, Horticulture Specialist has some advice, for those wanting to start growing grapes.

"All grapes have numerous disease and insect problems and there should be a commitment to a spray program. If you plan on managing the pruning and pest management for good fruit quality, then grapes would be an attractive addition to any home. If not, it can turn ugly fast!"

http://ohioline.osu.edu/b919/index.html (Midwest Grape Production Guide)

Here are a few grape diseases that affect fruit quality:

Powdery Mildew of Grape (Picture by NC Jones)

Grape Black Rot and Anthracnose

Just wanted to let you know about the great, commercial and home grape production as well as other fruit resources available, thanks to Dr. Elizabeth Wahle, Horticulture Specialist, located out of Edwardsville, IL. These links are taken directly from her website. They are as follows:

COMMERCIAL GRAPE GROWERS

Commercial Grape Nurseries

Commercial Vinyard Suppliers

All you need to know to grow grapes!
Midwest Grape Production Guide

HOME FRUIT PRODUCTION

Growing Fruit for Home Use

Midwest Home Fruit Production Guide

Other U of I Extension information on Grapes:
http://urbanext.illinois.edu/hortanswers/plantdetail.cfm?PlantID=284&PlantTypeID=7

Do you want to take grapes or other fruits to the market?
http://web.extension.illinois.edu/edwardsvillecenter/foodcrophort2801.html

PLANT: CSI (How Plant Problem Investigation Works at the U of I Plant Clinic)

2011-05-04T11:11:00.000-07:00

When I first started, I have a couple of tough, plant samples that I was working on. Now, my definition of a "tough, plant problem" can mean one of following:
A. It's not a disease (I am a plant pathologist) Suzanne Bissonnette is a plant pathologist too; however she plays the role of an entomologist on TV! Ha ha!
B. The plant is exhibiting symptoms that could be attributed to a variety of problems (we just have to rule of some of these problems out).
C. The plant has a variety of problems that is contributing to the symptoms that are exhibited.
D. I don't know what the "heck" is going on!

I was helping to consult with Richard Hentschel, Extension Educator Horticulture, on a difficult plant issue (that could be an entirely different blog in itself), and in the flurry of emails back and forth between myself and his client, he mentioned that this whole process of plant diagnosis was much like, "Plant CSI". I liked that analogy and Richard, you inspired me to write this blog : )

Plant Crime Scence Evidence: Dead or yellowing plant parts/not normal plant symptoms <invision yellow crime scence tape placed around the plant sample>

Unfortunately, we are unable to come to the "plant scene", but alot of times, we want you to send us pictures of the "plant scene". Then, we recommend that you send the "Plant Crime Scene Evidence" to the lab: U of I Plant Clinic

First, we do an "initial walk-through" to get an overall feel for the injured plant scene. Luckily, we don't have to worry about touching things! Now, we can make some theories of diagnosis based on visual plant symptoms.

Here we don't swab or collect fingerprints, hair, or dried blood (that is why I am a plant doctor, not a medical doctor). We look for signs of fungal diseases, nematodes, chemical injury, environmental injury, or insects.

We do try to document all of this "evidence". And, of course, we are very careful to preserve this plant evidence in it's current form by using refridgeration or even watering (if we have an entire plant). Sometimes, we even document the "plant crime scene" by taking pictures, sketches, but no video walk throughs are necessary.

Next, we take the plant sample to the scopes (dissecting scope and microscope) to collect potential evidence. We don't use a swab, but we do use tweezers, as well as other tools such as pruners, knives, and razor blades. Here are some things we may find on the plant sample in question: fungal structures, fungal spores, bacterial oozing, nematodes, insect exoskeletons, insect frass, insect webbing, insect feeding, or even nematodes. Depending on the plant symptoms, we could also use assays or quick strip tests involving ELISA or PCR! Then, I guess you could say we tag, log, and package it!

If we can't find any of these things above (signs of disease or insect), now that is when it can get tricky! It could be an environmental, nutrient, or pesticide injury situation.

In this case, we may need to rely on documents such as soil tests, water analysis, or pesticide application log.

Don't forget, once we have a plant sample in hand, we reserve the right to call or email a grower, and perform a full interrogation! No, we don't ask them were the plant was on the night in question, but we may ask them questions such as:
When was it planted?
What pesticides have been applied?
When were the pesticides applied?
Have you had a soil test?
What fertilizer has been applied?
What was the rate of fertilzer applied?
What has the weather been like?
How long have you had this problem?
In what kind of site is this plant growing?
Was it planted correctly?
What is planted in this area before?
What is the soil type?
What is the condition of the nearby plants?
How old is the plant?
What is the pattern of the affected plants?
What is the name of the plant species?
Are you a homeowner or a commercial grower?
Just to name a few.................................................

When all of the evidence is collected and research has been done (books and internet), it goes straight to the lead detective or in our case, the head diagnostician (that's me). If I need too, I can also consult with experts. Now, I don't deal with experts in blood pattern spatter, trajectory determination, serology (blood and bodily fluides), but rather deal with campus specialists that can help me in more specific areas such as crop, fruit, and vegetable pathology or entomology.

Some Plant CSI's only work in the field - these are Extension Educators or Consultants. They help to collect the evidence and they pass it to our forensic lab - The U of I Plant Clinic!

Based on these procedures, we can hopefully, MAKE A PLANT DIAGNOSIS!

I Smell Field Crop Root Rots

2011-04-27T08:55:00.000-07:00


Fusarium and Gibberella Root Rot


Pythium oospores on wheat

Soybean Phytophthora

Phytophthora sporangia found on those soybeans above

Root and Crown rot of Red Clover

I Just Looked Into The Plant Clinic Crystal Ball: I See Root Rot In Our Future!

2011-04-27T08:48:00.000-07:00

Last year, on the days that I worked at the Plant Clinic, I looked at many plant samples that had root rot, thanks to last year's wet spring. I fear that this spring is even worse, especially in the southern part of Illinois. What do I expect to see?

PYTHIUM ROOT ROTS


Pythium root rot of mums

OOSPORES of Pythium

PHYTOPHTHORA


Phytophthora of Yew


Phytophthora of Raspberry

THIELAVIOPSIS ROOT ROT


Thielaviopsis root rot on Impatiens


Thielaviopsis root rot on Holly


Thielaviopsis spores

RHIZOCTONIA ROOT ROT

(some Rhizoctonia favors hot and dry conditions)


Rhizoctonia on Vinca Minor


Rhizoctonia mycelium

Early Corn Up in Central Illinois - Good or Bad?

2011-04-21T18:22:00.000-07:00

Many on Twitter are saying that 9 percent of the corn has been planted in Central Illinois. Many of this early planted corn is emerging. After the recent down pour of rains, this corn is struggling to "hang in there". This field's stand appeared to look OK...........

But, obviously, these fields near Route 48 have a tendency to pond in areas and a replant in those areas will most likely be necessary.

These plants are a little yellow thanks to the recent cool temps and wind blown. However, they don't look too stripped, considering this field is not too far from the area where train cars were blown off the track after the recent tornado-like winds.

So, what are some issues this early corn is facing in Illinois now?

Wireworms?
neglecting-to-scout-for-wireworms-may-be-a-mistake

Saturated soil conditions coupled with cool weather could be perfect for lingering seedling diseases. Just how well with these corn roots be able to cope?

When fields finally dry, corn planting resumes, and later corn emerges, cutworm damage could be a concern thanks to recent high catches of cutworm moths:
intense-captures-of-black-cutworm-moths-reported-in-illinois

Will The Oak Galls Kill My Tree?

2011-04-17T19:20:00.000-07:00

When I was able to teach the IPM (Integrated Pest Management) section of the Master Gardener Training in Champaign, IL, one of the pests that I used as an example was oak gall. I was stunned to learn that most of the Master Gardener trainees there were not familiar with oak gall. To be honest, I can't go a week without getting asked about oak galls in my neck of the woods. In the last several years, the wasp species that causes various oak galls in oaks have been on the rise in the St. Louis, MO and Springfield, IL vecinity. In these "hot spots", if trees are present along a road, you can easily identify oak trees by their sometimes, obvious galls protruding from their limbs.

Here is a great fact sheet about oak galls: http://web.extension.illinois.edu/southern/downloads/24689.pdf

Spring is here and homeowners are starting to work in their yards. If their oaks are plagued with oak galls, they "stick out like a sore thumb" right now, because oaks have not leafed out. The most common question that we hear is: "Will the oak galls kill my tree(s)?" The answer is NO, the oak galls will not kill your tree. Phil Nixon, University of Illinois Extension Entomologist says that it is sometimes very hard for someone to believe this when their oak tree is just thick with oak galls. Oak galls can girdle and kill branches, which in turn, can cause them to fall to the ground, and make them lethal weapons when hit by a lawn mower.

Here is a specific example to help explain why a tree infected with oak galls might die.

I went to church and was asked what to do about the oak on the church's property that was infected with oak gall. Here is the poor tree:

This is probably the worst case of oak gall that I have seen. Why might this be? Why is this oak so loaded with oak galls? When trees are stressed, they can be more susceptible to insects and diseases. So, I took a good look at this particular oak and asked myself, "What might be stressing this tree?".

The first thing that came to my mind was the stress of cars parking under this oak. This could compact the soil near this tree, as well as possibly damage roots. Also, I am sure that this tree has not been fertilized.

In my area, pin oaks seem to be more infected with oak gall. Pin oaks are notorious for being affected by iron chlorosis: http://web.extension.illinois.edu/forestry/publications/pdf/forest_health/UIUC_Iron_Chlorosis.pdf
Basically, something is causing the iron not to be available to the plant, and causes the leaves to be lighter green in color and have dark, green veins. Here is a picture of a pin oak with iron chlorois from the ISU Plant Disease Clinic:

Iron chlorosis is just one more possible stress on an oak that could be causing them to be more vulnerable to infection by the oak gall wasp. Other possible stresses to an oak tree could be: improper planting, planted near construction or concrete, drought, too much water, mower damage, overfertilization, underfertilization, improper pruning, and so on.

In conclusion, if an oak tree has oak gall and it dies, it probably did not die due to just the oak gall. It most likely died because of multiple issues: stresses or disease, along with the oak gall infection.

Lawn Problems: Where do I start?

2011-04-11T09:43:00.000-07:00

First, I would like to start out with the disclaimer: I AM NOT A TURF EXPERT, however, I have been asked to help with a few turf problems. Many think they can just throw out some grass seed in their yard, and a lush, green, lawn will grow. But sometimes, it's not that easy.

Here is an example of one of the problems that I recently helped to solve. This is a commercial site, where experts were called in to produce an estabishment of grass. So, this is not your everyday lawn, however, the basical principles are the same here. Finally, after 2 years of not getting the growth of grass that they wanted, they began to call as many experts as they could to try to get to the bottom of why they could not get a good establishment of grass.

The very first question that I asked was if this site consisted of alot of clay, and their answer was, "Yes, there could be some clay there." The next question that I asked was if they had a soil test. Their answer was, "We just took soil samples." I said that I did not want to go any further without seeing their soil test results. It was too bad that they did not soil sample 2 years previously, when this grass was first planted, because I just found out that the soil tests revealed that they had soils with a pH of 8! Turf grows best at a pH of 6 - 7. They will now need to add sulfur to try to raise the pH.

Here is a good website to help with site preparation in lawns-
http://urbanext.illinois.edu/lawnchallenge/lesson3.html

Here is a list of soil testing labs in Illinois-
http://urbanext.illinois.edu/soiltest/

Here is a website that explains other problems in turf-
http://urbanext.illinois.edu/lawntalk/weeds.cfm

Here a factsheet on spring lawn care-
http://web.extension.illinois.edu/springfieldcenter/downloads/9010.pdf

I really like this "oldie, but goodie" article by Sandy Mason-(fall is an ideal time to seed a lawn)
http://web.extension.illinois.edu/champaign/homeowners/040904.html

And The First Plant Sample Submitted to the Plant Clinic is..... (insert Drum roll here)..... Pine Wilt Disease

2011-04-01T08:22:00.000-07:00

This little critter and his friends killed a windbreak of 30 pines. This is a pinewood nematode.

This pinewood nematode is in the vascular system of a pine (like the picture above) and is causing the disease Pine wilt. This, in turn, will lead to a dead pine.

The pinewood nematode "hitches a ride" on the pine sawyer beetle. These beetles devour pine trees in the spring and can infect a pine near you. Pines under stress are more prone to be killed by the pinewood nematode. Depending on the size of the pine tree, it can take 1 to 2 years for it to die from the infection of the pinewood nematode.

Here are some great web resources to learn more about pinewood nematode and Pine wilt disease:
http://web.aces.uiuc.edu/vista/pdf_pubs/1104.pdf
http://urbanext.illinois.edu/hortanswers/detailproblem.cfm?PathogenID=19
http://urbanext.illinois.edu/focus/pinewilt.cfm
http://hyg.ipm.illinois.edu/pastpest/200613a.html

If you suspect that your pine (usually not white pine) has Pine wilt disease, you are welcome to send a sample to the University of Illinois Plant Clinic. There is a $15 dollar fee. Please send several foot long branches that are 2 -3 inches in diameter. Be sure they are from an area of the pine that is showing symptoms, but is not dead!

If your pine is diagnosed with Pine wilt, the tree will need to be removed immediately in order to avoid the infection of other pine trees!

Going to Plant Trees? Check This Out First!

2011-03-24T08:17:00.000-07:00

So, what do all of these tree pictures have in common? In my past Extension days, I made a few tree calls and this is what I found. These business and homeowners wanted to know what was wrong with their trees? Was it a disease or an insect? I had to be the bearer of bad news and let them know that these trees were not planted correctly!

If you look at the base of a tree, there should be a flare or the tree’s root collar should be above the ground. If you look at the base of a tree and it goes directly into the ground, it is planted too deeply (like the last 4 pictures). Also, remember to remove any burlap or wire baskets before planting a tree. If a tree is planted incorrectly, it may survive several years; however, eventually, it will gradually start to decline. Tree decline intinsifies during time of stress like last year's weather (extreme wet, then dry) or other problems such as cars driving on roots or construction near roots. Tree decline may look like the last 3 pictures in this blog.

Another problem that I have encountered is girdling roots (Look at the first 3 pictures). In some instances, if you look near the base of a declining tree, you can see roots growing in a circular pattern. But, in other cases, you can’t see any signs of strangling or girdling roots. When planting a tree, make sure roots are not winding around and spread them out in a wide hole. If a tree has girdling roots, naturally this will choke the tree and not allow nutrients to properly flow up into a tree. Strangling roots will also cause a gradual decline of a tree.

So, please plant a tree this spring, but do it correctly! There is nothing much you can do for a tree in decline due to incorrect planting!

Here is a great factsheet to use as a guide: http://web.extension.illinois.edu/winnebago/downloads/706.pdf

Can You Hear the Crabgrass Germinating?

2011-03-18T09:14:00.000-07:00

Even if you don't claim to be an expert at identifying weed species, most people know that those big dead patches in the lawn are crabgrass. Those unsightly, crabgrass patches are becoming even, more noticable in my neighborhood, due to spring, greening of turf. Everytime I see a crabgrass patch, I think of a local client that called our Extension office repeatedly with questions on how to control crabgrass. He had officially declared crabgrass, "Arch Enemy #1", and he was going to do everything in his power to defeat it! I know he is not alone in his fight with crabgrass!

The reason I chose this topic today is because crabgrass seeds will begin to germinate during the spring and early summer when soil temperatures start reaching 60 degrees F for five consecutive days. I think Central Illinois soils are approaching these conditions very soon. Also, according to David Robson,

"Pre-emergence chemicals should be applied one to two weeks prior to the time when soil temperatures reach 50 degrees F for three consecutive days. For this reason, in a typical year crabgrass applications should be applied by April 1 for best control in central Illinois. Add a week or two as you move farther north, and subtract a week or two going south." So, get ready!!!!!! Last year, there were alot of issues with pre-emergence chemical control of crabgrass, because of the wet spring conditions!

Some helpful tips for controlling crabgrass (outlined in helpful Extension website links below):

Your mowing height should be over 2 inches!
Light, frequent waterings may help your lawn, but it also promotes growth of crabgrass!
If applying a pre-emergence herbicide, timing is critical when controlling crabgrass!

If you get frustrated with your crabrgrass control fight, remember this:

CRABGRASS IS AN ANNUAL PLANT, SO IT WILL DIE WHEN TEMPERATURE DROP IN THE FALL! But, you must plan your attack the following spring : )

Here are some University of Illinois Extension links that may help you with our fight against crabgrass:

http://urbanext.illinois.edu/gardenerscorner/issue_04/04_spring_06.html

http://urbanext.illinois.edu/lawntalk/managing_crabgrass_in_home_lawns.cfm

http://urbanext.illinois.edu/lawnchallenge/lesson6b.html

GOOD LUCK, my friends!

Spring is Coming and so are Those Plant Problems: Winter Burn of Boxwood

2011-03-11T11:49:00.000-08:00

The boxwood shrub on the right seems to be showing signs of winter burn. This browning can show up when temperatures start to warm up after winter. Basically, winter burn can occur on all plants that have their foliage exposed in the winter, such as: some conifers (pines and spruces), boxwood, holly, and rhododendrons. I have been seeing signs winter burn on pine windbreaks.

Winter burn or dead foliage is not a result of cold temperature injury or disease. Basically, plants transpire or release water from foliage (photosynthesis) and a higher rate of water loss from foliage may result in high winds. If the ground is frozen or dry, these plants are unable to replace this water loss. The result is can be dehydration, foliar damage (winter burn), or even death.

What can you do about winter burn?

1.) When landscaping, choose plants that are less likely to be prone to winterburn

2.) Avoid planting conifers, boxwood, holly, and rhododendrons in areas that have high wind exposure

3.) You could put up a wind break to protect the plant

4.) You could wrap small plants in burlap or other material to protect from wind and water loss

5.) Products called "antitranspirants" can be applied to winter burn prone plants, but there is no research available, that I know of, that would prove their effectiveness.

Boxwoods can be pruned in the spring in order to remove any injury that has resulted in the winter.

Women Changing the Face of Agricuture Conference

2011-03-07T14:34:00.000-08:00

The Women Changing the Face of Agriculture Conference was held on March 4th, 2011 at the Bone Student Center-ISU, Normal, IL. We had several participate from the University of Illinois College of ACES, and this is a picture of our "Intigrated Pest Management team" which was represented by those who work in Crop Sciences as well as the Illinois History Survey. Believe it or not, we have an insect, plant disease, and weed chick represented here! From left to right: Kelly Estes, State Survey Coordinator, Illinois Cooperative Agriculture Pest Survey, Stephanie Porter, Visiting Plant Diagnostic Outreach Coordinator/Plant Clinic Dianostician, Crop Sciences, Michelle Wiesbrook, Pesticide Safet Specialist, Crop Sciences...and not wanting to be in the picture is Suzanne Bissonnette, IPM Coordinator/Plant Clinic, U of I Extension.

At the conference, we were able to visit with several girls that were interested in a career in agriculture. Their ages seem to range from a Freshmen in High School to Sophomore in College. After chatting with the girls, we tried to get a feel for what interests they had. To our surprise, many were interested in Animal Science; however many were undecided on what they wanted to do with their lives.

I think we learned alot not only from the girls that attended this conference, but alot about each other! I learned that Kelly Estes,who showed animals and was active in 4-H, was an Animal Science major until she was a Junior in College and then changed to a Crop Science major after taking an Entomology class. Stephanie Porter had her heart set on Biotechnology, but later changed her concentration to Plant Pathology, after having completing a Plant Disease course. Michelle Wiesbrook, raised on the farm, had her mind set on NOT pursuing a career in agriculture, but was steered into the ag business field by her local ag teacher, and later learned she was interested in Weed Science. Suzanne Bissonnette, was a city girl, started out in Pre-Med, and later switched over to a Plant Pathology doctoral degree, which then led her to her career in agriculture. We all realized that we ended up in careers that we could of never imagined! Who would of ever thought that we would like bugs, fungus, and weeds?

From these experiences, we illistrated to the girls in attendance, that it is OK not to know what career path to take, but recommended that they take alot of different courses and, if possible, experience some different internships to figure out exactly what they like....and, more importantly, what they don't like.

The U of I Plant Clinic: Change

2011-02-25T13:10:00.000-08:00

This article was taken from the U of I Home, Yard, and Garden Pest Newsletter Written by Nancy Pataky (Former University of Illinois Plant Clinic Director) July 30, 2010

Thank You and Farewell
This is my last article for the Home, Yard, and Garden Pest Newsletter. I want to take this opportunity to thank my loyal readers, as well as those who are new to the newsletter, for taking the time to read and question what we have to say. I am about to start my next phase of life--retirement. Some say I am too young to retire. I certainly feel that I am too young. Still, I have worked as the Plant Clinic Coordinator, Plant Clinic Assistant Director, and Plant Clinic Director for over 30 years now, so obviously I am not too young to retire. There are parts of the job I will not miss, mostly related to grants, forms, and reports. I will definitely miss interacting with clients and trying to help growers with plant disease problems.

The first image in this article is not my young replacement. In fact, that happens to be me near the beginning of my career when I was told that if I worked at the University of Illinois Plant Clinic for 5 years, then I could probably move on to bigger things. I enjoyed those first 5 years and the 25 additional years that followed. The second image is me as well, but in November of 2009.

From Stephanie Porter:

We will never be able to replace Nancy Pataky, but we hope to continue her legacy at the University of Illinois Plant Clinic. With much change across the state with the reorganization of the University of Illinois Extension, there also has been change in the managment of the University of Illinois Plant Clinic. The following will be diagnosing and supervising at the Plant Clinic:

Stephanie Porter

Stephanie Porter was hired in February as the Visiting Plant Diagnostic Outreach Specialist-Crop Sciences. She will serve as a plant diagnostician at the University of Illinois Plant Clinic, collaborate with departmental Extension Specialists to diagnose plant health problems and provide management recommendations, and manage the database for plant disease (NPDN), insect and weed identification, and interface with counterparts in the North Central Plant Diagnostic Network. Additionally, Stephanie will develop short courses and outreach for plant diagnostics as outlined in the NIFA-Extension IPM (E-IPM) grant.

Suzanne Bissonnette

Suzanne Bissonnette was hired in August as the U. of I. Extension, Plant Clinic and IPM Coordinator. Her primary responsibilities are to centralize IPM educational outreach, diagnostics, and programming within the context of a virtual Center of Extension IPM outreach and provide program leadership for the NIFA Extension IPM (E-IPM) Illinois program, and the NPDN grant program as supports

the Plant Clinic operation. She will provide leadership and deliver educational

programming that includes the content areas of: plant disease and pest diagnostics

and management; chemical, biological, cultural and physical pest control methods; rural and urban pest management. As coordinator, Suzanne is responsible for the supervision of the operation of the University of Illinois Plant Clinic.

You Might be a Plant Diagnostician/Plant Pathologist......

2011-02-18T14:55:00.000-08:00

If you answer yes, to most of the below questions, you just might make a good Plant Diagnostician or Plant Pathologist. And, yes, most of the following questions are based on my personal experience.

1. Was one of your favorite cartoons, "Scooby-Doo", and did you enjoy solving the mysteries?

2. Did Santa bring you a microscope as a child, and you liked it better than your "Cabbage Patch and Strawberry Shortcake" dolls?

3. Do you think outside the "Disease Triangle", instead of thinking "outside the box"?

4. Do you enjoy fungus? (enough said)

5. Have you taken more pictures of plant problems, than pictures of your own children?

6. Do you wake up in the middle of the night in a cold sweat, because you had a nightmare that 2 million plant samples have been submitted to the Plant Clinic and you have to diagnose all their problems by the end of the week?

7. Do you go on family trips to the zoo, and get yelled at by your spouse for spending too much time looking at the lesions on foliage near the lion's cage?

8. Can you identify plants by their plant diseases?

9. In Graduate school, were you referred to as a "fungi killer" by the Mycology students?

10. If given the choice between a vacation to a tropical paradise and a trip to National Plant Diagnostic Network (NPDN) meeting......what would you choose?

Welcome to the University of Illinois Plant Clinic Blog!

2011-02-17T13:21:00.000-08:00