Corn Rootworm Control in Field Corn, 1990

Abstract

Abstract Experimental plots measuring 37 rows × 30.5 m (100 ft) were planted at Rich-a-Lu farm in East Aurora, N.Y., on 2 May with a 2-row corn planter at 77,500 seeds/ha (31,000/acre), and fertilized with 181.4 kg (400 lb) of 10-10-10 fertilizer banded at planting. Soils were silt loam with 4% organic matter. Adult beetle counts averaged between 4 and 6 beetles/plant during the 1989 oviposition period in this field. Each treatment was a single row by 30.5 m (100 ft). Thirty-seven treatments were replicated 4 times in a complete randomized block design. Supplimental nitrogen was provided with a preplant incorporated application of tons manure/acre. Granular insecticides were applied at planting (AP) with Noble granular applicators mounted on the planter, and at cultivation with a Noble granular applicator mounted on a 2 wheel pushcart. Cultivation treatments were applied on 20 Jun and followed by a 2 inch cultivation using a single row cultivator with C-shanked shovels. All treatments were cultivated to eliminate the effect of cultivation on the different treatments. Corn growth stage at cultivation was S-2. Stand counts were taken on 50 row ft on 20 Jun. Five plants in each row were dug and the roots washed before rating root damage using the Iowa 1—6 root rating scale on 2 Aug. Treatments were mechanically harvested on 24 Sep with a single row silage chopper (New Holland model 707), and the silage from each treatment row was collected and weighed in a weigh wagon.