Submitting Samples of Problematic Plants to the Extension Plant Diagnostic Clinic lateral branches.

It’s still too cold outside to get the garden going, but it’s a great time of year to make plans for new plantings this spring. It’s also a good time to consider your possibilities in case your plants don’t grow the way they should after spending all that time planning. Have you ever wondered why a favorite plant seems to look sick and just isn’t doing very well? Have you ever spent a lot of time, energy and money on plants, only to watch them die? There are many reasons a plant may decline or die. It could be a biotic problem, caused by a living organism such as an insect, fungus, bacteria, virus or nematode. The problem could also be abiotic in nature, such as a nutritional disorder, weather damage, mechanical or chemical injury. The University of Missouri Extension Plant Diagnostic Clinic exists to help you with these problems. With a properly submitted sample and detailed background, we are able to diagnose your plant problem and give you useful management information.

Unfortunately, there are times when the diagnostic process can be complicated by the multitude of factors that can lead to a decline in plant health. For example, a plant that is completely dead may have many different fungi growing on it, making it difficult or impossible to identify a specific fungus that originally caused the plant damage. Perhaps the plant was made more susceptible to attack by factors such as a poor planting site for growth. Because of this, the condition of the plant sample and the background information you submit to the diagnostic lab is very important. Our ability to provide you with a rapid, accurate diagnosis and effective management recommendations depends on it. The following information may be very useful when you are submitting plant materials for diagnosis.

Try not to wait until a plant is completely dead. Whenever possible, include sample plants or plant parts showing a range of symptoms from mild to severe. Include a healthy example for comparison when possible. Include enough of the plant to indicate clearly whether the symptoms are occurring on old or new growth. Symptoms observed on plant shoots or leaves often originate with damage to the lower stem or roots of the plant, so it’s best to send entire plants, including the roots when feasible. With larger specimens, collect a sample that includes the transition zone between healthy and affected plant tissues. You can call us at 573-882-3019 for information on sample collection to test for specific diseases.

Fresh samples should be wrapped in dry paper to absorb excess moisture and placed in a plastic bag. If roots are included, insert the root and soil ball in a plastic bag and tie around the stem to avoid soil contact with leaves while in transit. Then, wrap the entire sample in dry paper or paper towels and place in a plastic bag. Do not add moisture to packing materials. Pack samples firmly in a sturdy shipping container that will prevent crushing in transit.

Forms can be found at the clinic website, http://agebb.missouri.edu/pdc/, or should be available from your local county extension office. We have a form that’s specific for plant disease identification. Please fill out form as completely as possible. Detailed information the plant species, variety, plant age, location, planting site, symptoms, timeframe for symptom development, problem distribution and severity, recent weather and chemicals used is very helpful in diagnosis. If you are unable to obtain our form, please send the sample and relevant information to:

You are welcome to bring samples to our lab in person. We are located in the basement of Mumford Hall on the UMC campus. If you would like to mail samples to us, please do so early in the week. Always use at least first class mail. A next day service or delivery in person is the best way to assure that the sample arrives in good order. Cucurbit plants (melons, squash etc.) are very perishable and should always be sent by next day service. If you are unable to send samples right away, or need to wait until Monday, keep samples fresh and cool in the refrigerator. Never leave them in a vehicle on a hot day or in a bag in direct sunlight.

In addition to plant problem diagnosis, we also identify insects, spiders, mites, weeds and other plants, and provide management recommendations. There is a $15.00 fee for general diagnosis, which applies to most samples. Some samples require an additional $10.00 fee when additional testing such as pathogen isolation means extra time and lab supplies. You can also find additional information about the plant diagnostic clinic, specific plant diseases, sample submission and our services and fees at http://agebb.missouri.edu/pdc/. If you’ve got any questions, please call us at 573-882-3019. You can also email us at plantclinic@missouri.edu.

Simeon Wright, Plant Diagnostic Lab Coordinator 573-882-3019