| dc.description.abstract | Chapter I: Cheat, feral rye, Italian ryegrass, jointed goatgrass, and wild oats are common and troublesome weeds of hard red winter wheat in Oklahoma. Field experiments were conducted to quantify the wheat grain yield losses caused by interference of those weeds with wheat. Data collected were weed density and wheat grain yield. Chapter II: In addition to reducing wheat grain yield, the five above mentioned weeds affect wheat grain quality. The field experiments were also conducted to quantify the wheat grain quality reductions and price discounts that occur as a result of weed interference. Data collected were wheat grain moisture content, test weight, foreign material, shrunken and broken kernels, dockage, grade, and price discount. Chapter I: All five weeds included in these experiments are capable of significantly reducing wheat grain yield. The weeds and their density plus the amount of rainfall a location receives within 10 days after planting significantly affected the severity of the yield losses caused by weeds. Observed yield losses caused by cheat, feral rye, Italian ryegrass, jointed goatgrass, and wild oats were as high as 39.7, 94.6, 77.3, 36.6, and 52.2%, respectively. Chapter II: These five weeds are also capable of causing significant wheat grain quality reductions and price discounts. As was the case with yield loss, wheat grain quality was significantly affected by the weed and density of weeds present, as well as the amount of rainfall a location receives within 10 days after planting. Price discounts caused by cheat, feral rye, Italian ryegrass, jointed goatgrass, and wild oats were as high as 84, 560, 395, 96, and 125 cents hectoliter-1. | |
