Optimal Wheat Seeding Rates for Conventional and Narrow Rows for Cheat-Free and Cheat-Infested Fields

Abstract

Serious cheat (Bromus secalinus L.) infestations often result after several years of conservation tillage in continuously cropped winter wheat (Triticum aestivum L.) fields in the U.S. Southern Great Plains. This study was conducted to determine profit maximizing seeding rates for conventional and narrow row production systems for both cheat-free and cheat-infested fields. Maximum likelihood methods were used to estimate wheat response functions. The profit maximizing seeding rate was relatively insensitive to the price of seed and the price of wheat. However, optimal seeding rates were found to be greater in cheat-infested plots. Reducing row spacing from conventional (9 in.) to narrow (3 in.) rows, with the seeding rate held constant, resulted in increased yields in both cheat-free and cheat-infested plots. It is appropriate to recommend that seeding rate be increased in fields that are heavily infested with cheat. However, the cheat problem can not be solved by changing either row spacing or seeding rate.