EFFECT OF SEEDING RATE ON GRAIN YIELD, STRAW YIELD AND HARVEST INDEX OF EIGHT SPRING WHEAT CULTIVARS

Abstract

Eight cultivars of spring wheat, Triticum aestivum L., were evaluated at seeding rates of 110, 270 and 430 seeds/m2 in a total of nine experiments spanning three locations, two dates of seeding and 2 yr. Grain yield exhibited a significant cultivar × experiment × linear response to seeding rate interaction. Grain yield of Pitic 62 showed a significant decrease with increased seeding rate in one experiment while giving the greatest increase in another. Over all experiments, the highest seeding rate gave the highest grain yield. For straw yield, Chester showed the greatest response to seed rate, Canuck the least. With the exception of Canuck, which showed a significant increase in harvest index with increased seeding rate, harvest index tended to be greater at the intermediate seeding rate.