Two field experiments were carried out at the Research and Experimental Station at floshtohor during 1990 and 1991 seasons. The aim of this investigation was to study the effect of weed control treatments and plant spacing on growth. seed yield, yield components oil percentage and associated annual weeds of the sunflower plant variety Hayak. The results indicated clearly that handwriting treatment gave the best effect on the total dry weight of weed, at the different stages. However, codal was the most effective herbicide against total dry weight of weeds compared with other herbicides. )(andweediflq treatm.nt gave the highest values of number of leaves, leaf area indec, 100— seed weight, seed yield /plant, and oil yield/fad. Application of Codal pro duced the highest averages of plant height, head diameter, weight of head, oil percintago and oil yield/fad. Whereas, the Yurore gave the highest value of stem diameter. High plant population (10 cm between hills) caused a reduction in total dry weight of weeds at the different periods of growth. Number of leaves, stem diameter. head diameter weight of head/plant. 100-seed weight, seed yield/plant and oil percentage significantly increased with the increase in distance between hills (40cm) while, plant height, LAI, seed and oil yield/fad, were significantly decreased. The, effect of the interaction between weed control treatments and plant spacing was insignificant on all the characters studied except seed yield/fad. in both seasons. The highest seed yield of sunflower could b. achieved by hand weeding twice and plant spacing 10 cm between hills. |
