Plant Population Density and Maturity Effects on Profitability of Short‐Season Maize Production in the Midsouthern USA

Abstract

Maize (Zea mays L.) production in the Midsouthern USA has increased dramatically in recent years, primarily as a function of growing nematode pressure in cotton (Gossypium hirsutum L.) and soybean [Glycine max (L.) Merr.] fields as well as the increasing yield potential of maize hybrids. Traditionally, 112‐ to 120‐d maturity hybrids (full season) have been grown using 76‐cm row spacing at population densities of ≈6 to 8 plants m−2. These hybrids, however, reach the reproductive phase of development during the period of a typical midseason drought. Shorter‐season (<110‐d maturity) hybrids, by contrast, avoid a large portion of this drought and require substantially less irrigation. The yield potentials of short‐season hybrids are similar to those of full‐season hybrids, but they require substantially narrower rows (50 cm) and increased populations (10 to 12 plants m−2). In this report, economic trade‐offs among irrigation, seeding rates, yield potential, and seasonal market price trends for production of short‐season hybrids are evaluated. Shorter‐season hybrids were comparable to longer‐season hybrids in terms of yield potential and partial returns. In general, profit‐maximizing seeding rates were higher for shorter‐season hybrids, and higher seasonal prices were insufficient to offset higher seeding costs and thereby change optimal hybrid choice. While irrigation use was curtailed with shorter‐season hybrids, irrigation savings, at current irrigation costs, were insufficient to offset higher seeding costs. Finally, using a simple decision rule of picking maize hybrid by selecting top‐yielding hybrids is challenged in this study as lower‐yielding hybrids with lower seeding requirements exhibited higher comparative returns than the highest‐yielding hybrids at one of the locations.