Growth and Yield of Spring Wheat as Influenced by Shelter and Soil Water1

Abstract In the Northern Great Plains, windbreaks have historically been used to protect crops and soils from winds, but data on the effects of windbreaks on growth and yield of small grains is limited. ‘Waldron’ wheat (Triticum aestivum L.) was grown on Parshall fine sandy loam (Pachic Haploboroll) with and without shelter (slat‐fence enclosures), both with and without irrigation, to determine the effects of soil water and shelter on wheat growth and yield. In 1973 and 1974, plant height, tiller production, leaf area index (LAI), specific leaf weight (SLW), and dry matter were measured at tillering, heading, and grain‐filling growth stages. Also, grain yield, kernel weight, number of heads, straw yield, and plant height were measured at crop maturity. The combination of shelter and irrigation resulted in greater dry matter production, higher LAI, lower SLW, more tillers per plant and taller plants than irrigation alone. Shelter for dryland (nonirrigated) wheat did not increase vegetative growth, other than plant height early in the growing season. With irrigation, sheltered wheat yields increased 6.4 q/ha or 21.8% over the exposed wheat. Dryland sheltered wheat yield was 3.8 q/ha or 19.4% less than that for the exposed crop. Number of heads and straw production for each treatment responded the same to soil water and shelter as did grain yield. Results of this study show that growth and yield of spring wheat in the Northern Great Plains is increased significantly when grown under sheltered vs. exposed conditions provided soil water supply is adequate.