EFFECT OF SOIL APPLIED HERBICIDES ON WEEDS, QUALITY CHARACTERISTICS AND SUGAR YIELD OF SUGARCANE SACCHARUM OF FICINARUM L.

To investigate the effect of soil applied herbicides and their concentrations on weed control, quality characteristics and sugar yield in sugarcane, two experiments were conducted at the field of the General Company of Sugarcane/Missan during 2001. The first experiment was on plant cane crop, and the second on the Ratoon-1 crop. Each experiment included 14 treatments of soil applied herbicides in RCBD with three replications. Results showed that application of Q.06 kg a.i/ba isoxaflutole in plant-one crop caused significant reduction in weed dry weight (173.21 g/m(2)) which represented 79.64% reduction as compared to 851.00 g/m(2) from control. In ratoon-1 cane crop, application of 3.2 kg a.i/ha atrazine significantly reduced weed dry weight to 1.24 g/m(2) which represented 96.94% reduction as compared to 40.52g/m(2) from control. Results also showed that different soil applied herbicides caused no significant effects on cane juice quality characteristics either in plant-cane or ratoon-1 crop such as sucrose, brix, or purity%. However, application of 0.06 kg a.i/ha atrazine or 0.115 kg a.i/ha clomazone on plant cane crop produced greater auger yield 4.45, 4.54 and 4.63 t/ha, respectively as compared to 3.24 t/ha in the control. in Ratoon-1 cane crop, greater sugar yield (7.89 t/ha) was obtained from the application of 0.12 kg a.i/ha isoxaflutole as compared to 6.62 riha in the control. The conclusion drawn from these results that although different herbicide treatments showed differences in their effect on weed growth and dry weight, greater increment percentage of sugar yield 41.6% and 19.2% from plant-cane and ratoon-1 crop, respectively where achieved by isoxaflutole.