Plant Disease or Disorders
1. Complete a PPDC specimen form (available from your OSU Extension office or at http://www.ag.ohio-state.edu/~plantdoc/cweppdc/cweppdc.html, or send a letter with inquirer's name, address, telephone, and information about the sample. Include the location of the plants affected (ie. field, landscape, nursery, etc), part of plant and number of plants affected, when the damage occurred and description of symptoms. Name the type and cultivar of affected plants, previous crop if applicable, amount of sun & moisture in that area, and soil type. List rates and amounts of pesticides and fertilizers applied.
2. Select material showing the symptoms, in different stages of decline. Do not send dead samples, unless accompanied with normal and progressively declining samples. Shake off excess water before packaging.
3. Send entire plant including roots if the whole plant is affected. Dig the plant and place the roots and attached soil in plastic. Do not send wet plants, nor put leaves or soft tissue in plastic, as they rot quickly.
4. If only local parts of the plant are affected (leaf spots, cankers or swelling), send several sections of affected plants.
Nematode Samples
Most nematodes are detected through soil samples which should be taken from May to October when soil temperatures are at least 50 F. at a six inch depth. Do not sample very wet or dry soils. Samples should be taken from problem areas of the field. Using a 1" soil sampling tube, trowel or shovel take at least 20 samples at a six inch depth from each sampling area (approximately 1 acre). Mix the samples in a bucket and place one quart of soil in a plastic bag. Dig feeder roots to include in the sample if plants are growing in the area. NEVER ALLOW THE SAMPLE TO BECOME DRY OR HOT.
Weed or Plant Identification
1. Complete a PPDC specimen form (available from your OSU Extension office or at http://www.ag.ohio-state.edu/~plantdoc/cweppdc/ cweppdc.html, or send a letter with inquirer's name, address, telephone, and information about the sample. Include the location of the plant- (ie. field, landscape, nursery, etc), number of that plant seen in each location, previous crop if applicable, amount of sun & moisture in that area, and soil type.
2. Identification of a plant requires an entire plantor a representative portion of the plant. If possible, include flowers or seeds. If none exist at time of inquiry, describe the flowers seen earlier.
Packaging and Delivery of Specimens
1. Select specimens fresh from the field, carefully shake off excess moisture, and pack tightly in a strong box. Pack any leaf tissue in newspaper or foil not plastic to allow the air to circulate. Pack tightly so the samples do not rattle in the box.
2. Send overnight mail services, or mail early in the week to avoid layovers at the postoffice. Herbicide Injury Symptoms
1. Remember that the PPDC can not test plant material for chemical evidence of a substance in a plant. The PPDC evaluates the symptoms of the plants and information provided, then determines if the pesticide/chemical applied could have caused the observed symptoms. For chemical testing, contact your OSU Extension agent for these specialized laboratories.
2. Complete a PPDC specimen form (available from your OSU Extension office or at http://www.ag.ohio-state.edu/~plantdoc/cweppdc/cweppdc.html, or send a letter with inquirer's name, address, telephone, and information about the sample. Include the location of the plants affected (ie. field, landscape, nursery, etc), part of plant and number of plants affected, when the damage occurred, and description of symptoms. Name the type and cultivar of affected plants, previous crop, amount of sun & moisture in that area, and the soil type. Describe the local weather when the symptoms appeared and the dates, rates, and amounts of pesticides and fertilizers applied.
3. Select material showing the symptoms, in different stages of decline. Do not send dead samples, unless accompanied with normal and progressively declining samples.
4. Send entire plant if the whole plant is affected. Dig the plant and place the roots and attached soil in plastic, so that the sample stays fresh. Soybeans especially, dry quickly. Do not send wet plants, nor put leaves or soft tissue in plastic, as they rot quickly.
5. If only local parts of the plant are affected(branches of trees, shrubs), send several sections of affected plants.
PLEASE INCLUDE AS MUCH INFORMATION AS POSSIBLE. PHOTO'S ARE VERY HELPFUL ALSO.
Fees: The PPDC charges a nominal fee for identification. Contact your Extension agent or see the fees posted on our website.
Mail samples to:
Plant and Pest Diagnostic Clinic
110 Kottman Hall
2021 Coffey Road
Columbus, OH 43210
614-292-5006