و چند گونه علف هرز در شرايط رقابت GLYCINE MAXL ارزيابي شاخص هاي رشد سويا

Evaluation of soybean (Glycine max L.) and some weed species growth indices under competition condition

In order to evaluate soybean growth indicies in competition with some weed species, an experiment was conducted in Karaj during 1999-2000. The experimentaldesign was randomized complete block with four replications and five treatments including control (soybean without weed), redroot pigweed (Amaranthus retroflexus), velvetleaf (Ahutilon theophrasli), bbarnyardgrass (Echinochloa curs-galli) and conunon lambsquarlers (Chenopodium album). Evaluation of growth indices indicated that between four weed species, velvetleaf with the highest crop growth rate (CGR), relative growth rate (RGR) and total dry matter (TDM) was the most competitive weed on reducing soyabean total dry matter (TDM), crop growth rate (CGR), relative growth rate (RGR) and leaf area index (LAI). Redroot pigweed, barnyardgrass and common lambsquarters were in lower ranks of affectivenes. Noticeably, the high value of weed criterions CGR, RGR, TDM and IAI influenced the more on soyabean yield and growth indices under comptition condition.