Control in Dryland Barley, 1987

Chemicals were evaluated in 2 dryland barley fields. Field 1 was planted with a 7-inch Hoe drill at a seeding rate of 60 lb/acre in clay loam soil. Field 2 was planted with a 10-inch Hoe drill at the same rate in clay loam soil. Both fields were planted the first week of May and had been previously planted in barley. Plots measured 10 by 20 ft and were arranged in a 5 by 5 Latin square. Treatments were applied in water with a CO2-pressurized backpack sprayer calibrated to deliver 20.5 gal/acre at 20 psi. The hand-held spray boom was equipped with TeeJet (8002) flat-fan nozzles and produced a 5-ft spray swath. Field 1 was treated 12 Jun and Field 2 was treated 25 Jun. BWM densities were estimated by placing the long edge of a 13- by 91/2- by 2-inch aluminum pan on the soil at a 45° angle adjacent to the plant crowns. One row-ft of barley was tapped 10 times with a 12-inch ruler, and mites knocked into the pan were counted. Five sampling locations were chosen randomly in each plot for each count. Counts were transformed by log(x + 1). Numbers in the table are actual means.