We inoculate V5 plants by cutting the terminal bud and placing a pipette tip with Sclerotinia culture on that tip. We measure the progress of the lesion as it grows down the plant. Daily evaluations for ten days yield good correlation with field resistance in standard varieties. The advantage of this technique is that plants are exposed to inoculum for the same length of time no matter what their maturity group. Because we are measuring tolerance and not true resistance results from this test are variable and we recommend 10 replications.
Cost for this test is $5.50 per replication. 10 replications are recommended.
If it is helpful to breeders we can maintain plant that appear resistant in these tests and take them to maturity in the greenhouse in order to harvest seed.
.A pipette tip is used to inoculate the terminal bud of plants with Sclerotinia. The lesion grows at different rates on varieties depending on their relative susceptibility to the fungus.