Investigation of dose and time application of Metribuzin on wheat (Triticum aestivum) cultivars yield and weeds control in Varamin

In order to survey the efficiency of metribuzin herbicide (sencor %75 wp) in weed control and its influence on wheat cultivars، a field study was conducted in Varamin region. Experiment was carried out in randomized complete block design (RCBD) with 4 replication as factorial arrangement. The experimental factors consist of: wheat cultivar in 3 levels (Shiraz، Pishtaz and M-79-6 line)، different amount of metribuzin herbicide in 4 levels (0، 0. 5، 0. 75 and 1 kg/ha as commercial substance in form of 75 percent wettable powders (wp %75) and time application of herbicide in 2 levels (Pre-emergence and Post-emergence)، together with weed infested treatment were compared and evaluated. For results explanation wheat yield (grain & biological)، weeds dry matter and their number was measured before and 30 days after herbicide treatment. Results showed that 0. 5 Kg/ha dose in pre-emergence time had the most suitable influence on reducing weeds control and least phytotoxicity on wheat cultivars. But due to high phytotoxicity، wheat cultivars and different amount of metribuzin in two time application were not showed any significant difference in wheat yield in weed infested treatments and non treatments.