AN INDEX OF COMPETITION FOR ESTIMATING CROP LOSS DUE TO WEEDS

Abstract

An "index of competition" is derived that can be used to estimate crop loss due to weeds when weed and crop species, density of weed stand, and expected weed-free yield are known. Experimental data are used to derive this index for wild oats (Avena fatua L.) in barley, wheat, and flax, respectively. Loss in grams per square meter equals ab1x, where a equals expected weed-free yield (g/m2), x equals number of weeds per square meter, and b1 equals "index of competition." This index is 0.0230, 0.0339, and 0.0601 for wild oats in barley, wheat, and flax, respectively.