Assessment of Interference of Growing Period of Amarant (Amaranthus retroflexus L.) and Lambs Quarter (Chenopodium album) on Yield and its Components of Rapeseed

In order to evaluate interference of different growth period weeds such as Amarant (Amaranthus roflexus L.)and Lambs Quarter (Chanopodium album) on cultivars of oilseed rape, a factorial based on randomized complete block design with three replication was conducted in Agricultural Experiments at station the Islamic Azad University, Tabriz Branch in 2008. The factors were three oilseed rape fall cultivars (SLM046, Opera, Okapi) and six controlling methods at different growth period (complete weed control, controlling weeds at 3-5 leaves, at 5-8 leaves, at the beginning flowering, at 50% flowering, and competition of weeds in all of the time). Analysis of data revealed that effect of interference weeds on height, number of pod, oil yield was significant at 1% level of probability and on number of grains per pod, 1000-grains weight and grain at 5% probability levels. The effect of oilseed rape cultivars on height, number of grains per pod, oil yield was significant at 1% probability levels and number of pod and weight of 1000-grain in 5% probability levels. The highest grain yield and oil yield were found to be 54% and 55%, respectively as compared with those of control. Also, grain yield was correlated with number of pod(r=0.886), weight of 1000-grain(r=0.513), number of grain in pod(r=0.783) significantly at 1% probability levels. In order to increase grain yield, control with SLM046, recommend to farmers.