Abstract :
A comparative study was designed to investigate various weed management strategies for wheat crop during 2005-06 at Agricultural Research Institute, Dera Ismail Khan. Water exudates of sorghum (Sorghum vulgare), brassica (Brassica napus), sunflower (Helianthus annuus) and rice (Oryza sativa) were used as a natural weed control approach, along with their combinations and herbicide application. Experiment comprised of twelve treatments, including control, water exudates of sorg1hum, sunflower, rice, brassica alone and their combinations. Buctril + Puma Super application was also included as treatment for comparison. Water exudates, their combinations and herbicides were applied 15, 25 and 45 days after sowing. All the treatments significantly affected number of tillers m-2, number of grains spike-1, spike weight (g), 1000 grain weight (g) and grain yield (t ha-1). However plant height and biological yield remained non-significant in all treatments. In case of grain yield (5.70 t ha-1) sunflower exudates application surpassed all treatments yet numerically lower and statistically at par values were recorded in Buctril + Puma super (5.55 t ha-1) combination treatment. The increased grain yield in sunflower exudate application treatment was due to increased in spike weight (2.98 g) and 1000 grain weight (45.13 g). Relatively better performance in number of tillers and grains spike-1 favored additionally concentrated sunflower exudates to out class all sole exudates, combination treatments and herbicide application. Maximum gypsum (1.26 t. acre-1) requirement was recorded in untreated soil followed by brassica (1.22 t acre-1) exudates treated samples. The minimum gypsum requirement of 0.344 t acre-1 were reported in sorghum treated soil. The decrease in gypsum requirement in sorghum exudates treated sample may be due to the acidifying effect of this exudate which may have leached/washed down the sodium ions. Economic analysis of the treatments confirmed that use of exudates were more economical than herbicide application.
