Effect of Management Practices on Grain Yield, Test Weight, and Lodging of Soft Red Winter Wheat 1

Little yield improvement of soft red winter wheat ( Triticum aestivum L. em Thell.) has occurred in Pennsylvania and other northeastern states during the past 30 years while wheat yields have nearly doubled in several European countries. In England and Wales, about 40% of this increase is attributed to improved management. Our objective was to determine the potential yield increases under Pennsylvania conditions from near optimum combinations of seeding rate, row spacing, seeding depth, and N fertilization in the spring. Field experiments were conducted at a total of 15 locations during 1981 and 1982 on either Typic or Ultic Hapludalf soils. The cv. Roland was used, and treatments were seeding rates of 100,168, or 235 kg ha −1 , 19 or 38 mm seeding depths, 127 or 178 mm row spacing, and 0, 34, 67, or 100 kg ha −1 of N fertilizer topdressed in March at growth stage 3 (Feekes scale). Grain yields ranged from 2642 to 5342 kg ha −1 and averaged 4134 kg ha −1 . Yields increased in 14 of 15 environments when row spacing was decreased to 127 mm. The average yield increase from using narrow row spacing was about 7.5%. The effect of spring N fertilization was variable but grain yields and test weights were decreased at N levels above 34 kg ha −1 . Seeding rate responses also were variable, but averaged over all environments, yields were not increased by using more seed than 168 kg ha −1 . The greatest response to seeding rate occurred following late planting. At five of six locations where seeding depth effect was significant, yields were greatest from deep seeding. The best combination of treatments was 168 kg ha −1 of seed, 38 mm seeding depth, 127 mm row spacing, and 34 kg ha −1 of N. The average yield for this combination was 4630 kg ha −1 which is more than double the state average yield.