Jamshid Abbassi Sh - MSc student of identification and control of weeds.
Bijan Yaaghoubi - scientific member of Iranian Rice Research Institute
Mohammad Ali Baghestani - scientific member of Iranian Research Institute of Plant Protection

On direction weed management of rice (Oryza sativa) in frequently flooded irrigation conditions with herbicide general herbicides with emphasis on rice significant weeds includeBarnyardgrass (Echinochloa crusgalli), Sedges (Jancus) and Broadleaves, one study was carried out in randomaized complete block design with 14 treatment and 4 replications during 2010.Treatment were: Butachlor 60%EC, Pertilachlor 50%EC, Oxadiargy l30%EC, Pendimethalin33%EC, Molinate 72%EC, Thiobencarb 50%EC at 4, 2, 3.4, 4, 6, 6 Lit/ha respectivly and Cinosulfuron 20%WG at 150 g/ha. The results indicated that Pertilachlor +Pertilachlor treatment with 3471 kg/ha grain yield had the best output in comparison other treatments. However Thiobencarb + mixed of Bentazone and Propanil treatment had the best efficiency in reduction of weed biomass in comparison other treatments. But seems severrelationship of Thiobencarb to elements: temprature, light, water presur of soil matrix, organic carbon, soil prophyl, and oxidative&reductive flooded in soil application stage led to obtaine second step with 3454 kg/ha yield. This is meanwhile that Oxadiargyl + mixed of Bentazone and Propanil and Butachlor + mixed of Bentazone and Propanil treatments with 3390 and 3349 kg/ha yield respectively had had acceptable yield in comparison three time handweeding check treatment with 3044 kg/ha yield.

Barnyardgrass, Pendimethalin, frequently irrigation,Oryza sativa