چكيده لاتين :
In order to investigate effect of different periodical weed interference on yield and yield component
in winter canola (Brassica napus VaT. Okapy) a field study was conducted in Tarbiat Modarres University on
2004. A randomized complete block design with 3 replication was used to study two sets of treatments. In first
set of treatments, the crop was kept weed-free until 2, 4, 6 and 8 leaves, initiation of flowering, 50% pod set and
harvest stages. In second set of treatments weeds were allowed to grow with crop until above stages. Results
showed that periodical weed interference had no influence on seed thousand weight and seed number on pods
on lateral branches but caused to significantly reduction on pod number on main and lateral branches and seed
number on pod on main shoot with increasing weed interference duration. Seed yield significantly affected and
decreased by weed interference duration exceeding.
