| Popis: |
One acre of sweet corn was planted on 27 Jun near University Park (Centre Co.), with rows 2.5 ft apart. The design was a RCB with 5 blocks per treatment. Plots (treatments within blocks) were two rows wide by 34 ft long, with three untreated rows between each treated pair of rows. Blocks were separated lengthwise by 10-ft alleyways. Sprays were delivered with a highclearance sprayer with two nozzles/row, set at tassel height, at a 45° downward angle. Sprays were applied at 72 gpa, with nozzle pressure at 64 psi, a tractor speed of 1.8 mph, and using TX-SS 10 nozzles from the Tee Jet company. Infestation of the planks in the “pre-tassel” stage (tassel visible but prior to anthesis) with ECB was 8% and with FAW larvae 44%. Anthesis was first observed on 20 Aug, and the first silks were observed on 22 Aug. The first spray was applied on 18 Aug. Additional sprays were applied on 22, 26, 29 Aug and 3 Sep. At harvest (11 Sep), 20 ears were picked randomly from each plot. For each ear, the numbers of ECB, FAW, and CEW were noted. For each 20-ear sample/plot, the proportions of the sample with insect damage at the tip, side, and shank were calculated. |
