M.A. Thesis:

Examine the interaction frequency and dose of herbicide on the yield Asrt

In order to investigate the effect of application time in reducing the dose of Imazometabenz methyl (Aceret) herbicide, a factorial experiment was conducted based on randomized complete block design with 3 replications . The factors were: application time (Tillering and Tillering+stem elongation) and reduced amount of Aceret herbicide at five levels (0, 25, 50, 75 and 100% of recommended dose) (0, 0.18, 0.35, 0.56 and 0.75 g .ha-1 active ingredient). The results showed that application time had significant effect on number of grain per spike, 1000 seed weight, grain yield and weed dry weight, and did not affect plant height, number of fertile tillers and biological yield. The use of herbicide at tillering + stem elongation was better than herbicide application at tillering. The use of the recommended dose of herbicide produced the highest number of tillers, number of fertile tillers, number of seeds per spike, grain yield, biological yield, 1000-grain weight, harvest index and lowest dry weight of weeds. The use of herbicide at tillering + stem elongation produced the highest economic yield with the recommended dose of herbicide, which did not have a significant difference with the use of 75% of the recommended dose. 75% reduction in the recommended dose of herbicide failed to produce a satisfactory economic yield. In general, it is possible to reduce the use of herbicide by 25% during tillering + stem without significant reduction of yield.

Keywords: Low herbicide dose, Competition, Dual‐Response herbicide, Wheat