Testing Procedures
for BMPs for Producing Clean Nursery Stock

2.3.  Testing strategy

Either direct testing of roots with immunoassay test strips (3.1) or individual plant sampling/baiting (3.2) can be used to test individual symptomatic plants. If test plants are highly infected, either method should provide positive results. Baiting will be a more sensitive test if relatively few roots are infected.

Use bench testing of leachate (3.4) to monitor batches of container-grown plants for quality control purposes. Prioritize your testing to emphasize higher-risk plants, considering the risk factors in Table 1. For example, 2 year-old Salvia plants grown from root divisions that originated in cultivated landscapes would have a very high risk (and should generally not found in a nursery following the BMPs), compared with 6 month-old grasses grown from clean seed.

Typical Phytophthora lesions on pear baits generally do not require further confirmation if the purpose of baiting is to detect infected plants. If pear baits develop atypical lesions that do not match typical Phytophthora or Pythium lesions, you may either presume that the test is positive or submit baits to a qualified lab for confirmation.