Collecting & Shipping Samples
These guidelines should be followed for all types of plant samples.
- Fill out the accompanying Plant Diagnostic Checksheet (PDF) as completely as possible.
- Send a plentiful amount of FRESH plant material, it is best to include the entire plant when possible. Dig (do not pull) up the plant and ship as soon as possible.
- Send a sample characteristic of the problem that exhibits a range of symptoms.
- DO NOT ADD WATER OR WET PAPER TOWELS TO THE SAMPLE!
- Seal the plant material in a plastic bag and pack in a crush-proof container.
- Send only one type of sample in each bag.
- Send information in a separate plastic bag.
- Include necessary payment with sample.
- Send samples on or before Wednesday in order to avoid weekend storage at the post office
Specific Collection Guidelines
All samples should be sent in a plastic bag with a few air holes cut in it.
- Crops / Annual plants: Send entire plants, including roots and soil. Carefully dig the plants up. Send several plants showing a range of symptoms. Seal the roots in a plastic bag and place the entire sample in a larger plastic bag. DO NOT ADD WATER.
- Tree Wilt Diseases: Collect several branches ½ to 1 inch in diameter and about 12 inches long. The samples should be in the process of wilting but not dead.
- Trees / Shrubs (foliage diseases, cankers, and fruit rots): Collect several branches 10-12 inches long (or fruit) showing a range of symptoms.
- Turf: Samples should be 6 inches square by 4 inches deep. Collect the sample near the margin of the affected area so that a range of diseased and healthy tissue is included.
Nematode Collection Guidelines
- Diagnostic sampling for initial detection of a nematode problem: Separate samples from healthy and affected areas are essential for a reliable diagnosis of nematode damage. Collect several soil and root cores to a depth of 6 to 8 inches from the margin of the affected area. The soil cores should be bulked, mixed, and subsampled. Repeat the sampling process nearby in the healthy area. Submit 1 pint of soil and roots. Include the plants if possible.
- Advisory sampling for management purposes (for soybean cyst):
- Collect samples prior to planting.
- Divide the field into sections based on soil type and cropping history.
- From each section collect at least five soil cores taken at a depth of 6 to 8 inches.
- The soil cores should be bulked, mixed, and subsampled.
- Submit 1 pint of soil.
- Sampling for pine wilt:
- Collect a branch at least 2 inches in diameter and 6 to 8 inches long from adjacent to the trunk of the tree.
- Place sample in plastic bag immediately after collection and keep cool until shipping.
- Do not add water to the sample.
- Mail early in the week (Monday – Wednesday).
- Allow 1-2 weeks for a reply.
There will be a $5.00 diagnostic surcharge per plant or cost of individual test fee ($10 to $20). Samples not submitted through the County extension office will have a additional overhead surcharge. Distance diagnostics – no charge.