Insect Control in Late Snap Beans, 1983

Snap beans were planted at the Plateau Experiment Station, Crossville, Tenn. in 38-in. rows on 11 July. Plots were four rows by 20 ft with one untreated row between plots. Treatments, applied 16 Aug. were replicated five times in a randomized complete block design. Sprays were applied with a 2-gal compressed air hand sprayer at 50 gal/acre when pin beans were present. Dusts were applied by the cheesecloth shaker method. Rainfall was 0.2-inch within 18 h after treatment with a total of 1.22-in for the 14-day period after treatment. One treated row per plot was sampled by taking five sweeps along the row with a 15-in diameter insect net. A different row was sampled on each date to minimize plant damage. Diathane 80W at 1.6 lb (AI)/acre was applied on 4, 11, 17, and 24 Aug. to all plots for bean rust control. There were 6.2 leafhoppers (LH), 0.8 Mexican bean beetle adults (MBB), and 0.2 green cloverworms (GCW) per five sweeps before treatment. The middle two rows were machine harvested on 30 Aug. A subsample (ca. 2 lb) of beans was rated for damaged pods.