THE EFFECT OF SEEDBED PREPARATION, INTERCROPPING AND WEED CONTROL TREATMENTS ON SUNFLOWER PRODUCTIVITY AND ASSOCIATED WEEDS

Two field experiments were carried out at Sids Agricultural Research Station, Agricultural Research Center, Egypt during 2004 and 2005 summer seasons to study the effect of three possible integration between  seedbed preparation by mechanical tillage i.e. mouldboard plow + rotary plow, chisel plow three passes + rotary plow, chisel plow two passes ( farmer treatment), intercropping sunflower with soybean, sole sunflower and weed control treatments (pendimethalin at 875 g/fed., fluazifop  butyl at 62.5 g/fed., hand-hoeing twice and unweeded check) on fresh weight of weeds, yield and its components of primary crop (sunflower) and second crop soybean which intercropped with sunflower in natural infested soil by weeds.
In both seasons, the main findings mentioned seedbed preparation by mouldboard plow + rotary plow and chisel plow + rotary; sunflower and soybean intercropping and weed control treatments  (Pendimethalin hand-hoeing twice and fluazifop  butyl) reduced weed biomass ranged from (17 -  52), (34 -  76) and (20 – 96%), respectively. The previous three factors increased seed yield ranged from (2 – 18), (6 – 8) and (29 – 63%), as well as, they  gave the highest profitability  ranged from (16 – 56), (36 – 60) and (25 – 76%), respectively.
Different possible interactions between the three studied factors referred that the use of two or three combination of them increased the potential of reducing weed biomass and increasing sunflower productivity and consequently increased the profitability as compared with any single. Thus tillage systems, intercropping and weed control treatments can be used as compatible tactics for weed management with improving sunflower production.