The Role of Corn Variety and Population in Meeting Target Yield Level for Phase III Bond Release

Abstract

Two experiments were conducted in western Kentucky to evaluate the effects of varietal selection, plant population, and soil ripping on productivity of corn (Zea mays L.) growing on recentlyreconstructed prime farmland. In Experiment 1, 3 corn hybrids with known maturities (full-season--125 days, mid-season--120 days, early-season--115 days) were planted at populations of 14,900; 19,000; 20,600; and 24,200 kernels per acre to form a 3 by 3 factorial treatment set. All treatment combinations were further split into ripped and nonripped variables. Four replications were used, and the experiment was conducted 3 consecutive years. The full-season hybrid was more productive than the mid-season hybrid, which was more productive than the early-season hybrid. The effect of population was somewhat variable, depending upon available soil moisture and/or precipitation. The highest overall average corn yield was attained at the highest population (24,200 kernels per acre). Soil ripping increased corn yield for each hybrid x population treatment each year. In a separate experiment, the productivity of 42 commercial corn hybrids available in western Kentucky was evaluated. This experiment indicated that yield of corn will vary considerably depending upon the hybrid used. Yields ranged from·104.3 to 64.4 bu/a, with 14 of the 42 hybrids exceeding the yield needed for Phase III bond release. There was a relationship between maturity date and yield in that early-season varieties generally produced higher yields than later-maturing varieties.