Impacts of Weed Interference on Some Growth Indices and Grain Yield of Corn

The aim of this study was investigated the effect of weed interference on some growth indices and grain yield of corn (Zea mays L.), an experiment was carried out in a randomized complete block design with four replications during 2019 growing seasons at the Moghan region.

The experiment was included fourteen treatments; seven weed-infested and seven weed free treatments were applied at regular intervals (0, 10, 20, 30, 40, 50 and 60 days) after corn emergence in which weeds were allowed to grow until harvest and weeds were removed, respectively. Total dry weight of weeds, total dry matter (TDM), leaf area index (LAI), crop growth rate (CGR) and yield of corn were measured.

The results showed that all measured traits were affected by weed interference duration and weedcontrol period. Weed interference duration increased total dry weight of weeds and weed-free duration reduced total dry weight of weeds. Also, increase in weeds interference duration significantly reduced TDM, LAI, and CGR and grain yield of corn. On the other hand, TDM, LAI CGR and grain of corn increased by rising weed-free duration.

Considering of 10% yield loss, the critical period of weed control was 3 and 52 days after corn emergence, respectively. The weed interference duration had a significant effect on grain yield of corn and weed interference at the whole season. Weed interference reduced grain yield of corn.