Title: Effect of plant density and weeding frequency on reducing competitiveness of weeds and improving peanut yield,
Abstract: In order to study on the effect of plant density and weeding time on the growth and yield of peanut, a trial conducted as factorial with 2 factors including; plant density in 3 levels (a1: 60000, a2: 80000 and a3: 100000 plant/ha) and weeding time in 4 levels (No-weeding, weeding one time at 2-4-leaf stage, weeding two times at 24 and 6-8-leaf stage, and weeding three times at 2-4 leaf, 6-8 leaf and crop canopy closure time of peanut) using randomized complete block design in 4 replications in the Kiashahr port, Guilan province. Weed dry weight, peanut cumulative dry weight, pod yield, ripen pod number on plant, weight of ripen pod, shoot yield, kernel production percentage and 100 seed weight studied as traits in the experiment. Analysis of variance showed that plant density had significant effect on the most characteristics and increasing in density caused to improving of traits. Also, results revealed that weeding time influenced the traits significantly. Based on mean comparison, 80000 and 100000 plants/ha densities were more effective than 60000 plants/ha on some traits including: peanut cumulative dry weight, pod yield, ripen pod number on plant, shoot yield, 100 seed weight. In addition, 2 and 3 weeding controlled all weeds in the peanut field better than other treatments. Based on results can explain that growth and yield of peanut can be improved under proper plant density and weeding time. The best treatment was 80000 plants/ha with 2 weeding to increase yield of peanut.