The trial was planted in a field of CB46, and fertility and pests were managed by the grower in the same manner as the field. Descriptions of the entries are provided in Table 1, and data are presented in Table 2. Stand counts were made approximately two weeks after planting on July 16th. The stand was assessed as the number of plants per two-foot length. Twelve replicate counts were averaged. We evaluated aphid and lygus damage on August 16th, and we also scouted for diseases but observed none. The grower had made one insecticide treatment prior to our data collection. For lygus, we took 10 sweeps from four locations in each plot and counted the lygus. Data were averaged and are presented as a 10-sweep count. For aphids, we used a rating scale from 0 to 10 that accounted for visible crown damage and aphid incidence (over at least 50 percent of the plant population). Overall, aphid pressure was low.
The beans were cut on October 15th, and we harvested on November 8th. All twelve rows of each variety were cut and harvested for yield analysis. We evaluated harvest samples for 100-seed weight (a measure of seed size) and lygus stings. The data represent the average of five replicate 100-seed samples. The advanced breeding line CB2 outperformed the other varieties at this trial location. It has stronger nematode resistance compared to the industry standard, CB46, so potentially nematode pressure was impacting the yield of other varieties at this location. The aim is to register CB2 this year, putting it on the path for commercial use. CB77 is a newly registered, aphid-resistant line that also performed well at the trial. Pending approval from the CA Crop Improvement Association, CB77 will be available for certified seed production this year.
We would like to thank our cooperating grower and the CA Dry Bean Advisory Board for assistance with statewide research prioritization.
