Practice Abstract 37 - Stem and bulb nematode – sampling and testing seed

Short title (native language): 
Stem and bulb nematode – sampling and testing seed

Short summary for practitioners (native language): 
Before sending a seed sample for testing it is important that a representative sample is taken from the seed bulk.
Sampling:
If possible, take samples when seed arrives in the store, but if seed is already in store sample using a spear;
Collect 20 random samples from across the seed lot. Size of samples should be roughly equal and bulked to form a single composite sample of at least 1200 grams. Reducing the number of samples or weight of the composite sample will reduce detection of nematodes, potentially leading to false negative results. Send 1200 grams of seed to a specialist laboratory for stem nematode analysis;
If seed is from more than one field, consider taking a separate sample of seed from each field prior to bulking in order to collect a representative sample;
If an issue in a field is suspected, store and sample seed from it separately.
Testing:
Laboratories should test at least 600 grams of seed per sample received;
Test three replicates of 200 grams per sample;
Reducing the weight of sample tested may reduce detection of nematodes, potentially leading to false negative results;
If nematodes are detected, field and broad beans should not be grown in the rotation for ten years.
A ‘Clear’ test is an indication, not a guarantee, that the crop or seed will be free of nematodes. Low levels of infestation may be below the limit of detection of the test. Testing services are offered at www.pgro.org