Two field experiments were carried out in the Agriculltural Research and F.xperimental Station, Faculty of Agriculture Moshtohor kalubia, during 1993 and 1994 seasons, lo study the effect of different tillage managements, weed control and phosphorus fertilizer on growth, yield, yield components and associated weeds of sunflower as well as some soil properties
The results indicated that mold board and chisel operation reduced the bulk density and salinity values of soil but the soil porosity increased Soil pH tended to decrease with depth in no-tillage and chisel, but it slightly increased with moldboard. Moldboard was more effective than other treatments in reducing weed biomasses. Hand hoeing as well as topogard were the best treatments in depressing total fresh and dry weight of weeds (g/m²). Weed control was improved with application of phosphorus. Seed yield/ fed increased significantly by moldboard. Controlling weeds improved considerably all characters studied of sunflower over the unweeded check Phosphorus had a significant effect on all characters studied of sunflower. The interaction of tillage and weed control treatments was significant on seed yield/ fed and dryweight of weed/ m² at 75 days from sowing. The highest seed yield/fed. was recorded by moldboard treatments receiving topogard at 1.5 kg/ fed and phosphorus fertilizer (24 kg P2O5 / fed)