Optimum Seeding Rate And Stand Assessment Of Soft Red Winter Wheat

Cultivar selection and seeding rate influence soft red winter wheat (Triticum aestivum L) grain yield. Re-evaluating optimum seeding rate for crops is necessary as modern cultivars may show a greater yield advantage when planted at a higher plant population compared with older cultivars. Furthermore, the relationship between wheat stem population density and yield needs to be understood to help producers make informed estimates of yield potential. The objectives of this research were to determine: (a) the agronomic and economic optimum seeding rate (AOSR and EOSR, respectively) of soft red winter wheat, and (b) the relationship of wheat stem population density and grain yield. Trials were established during two growing seasons at two locations in Ohio with four wheat cultivars and four seeding rates ranging from 1.85 to 6.18 million seeds ha(-1). Among the four cultivars, the quadratic plateau model resulted in an average AOSR of 4.20 million seeds ha(-1) and an average EOSR of 3.13 million seeds ha(-1). The AOSR was 10-33% greater than the previous recommendation of 2.96 to 3.95 million seeds ha(-1). This increase may be due to modern wheat cultivars having a higher tolerance to increased plant density as the previous recommendation, which is over 30-yr old. Wheat stem number was linearly related to grain yield and explained 31% of the variability in yield. Planting the optimum number of wheat seeds followed by wheat stand evaluation in the spring should result in maximum economic return and informed decisions regarding wheat yield potential.