Optimum number and time of hand weeding compared with chemical control effects on productivity of wheat (triticum aesatlvum L.) and its associated weeds in newly reclaimed land [electronic resource].

Includes reference.

A field experiment was conducted at Ismailia Agricultural Research Station, Agricultural Research Center during the two successive seasons 2006/2007 and 2007/2008 to study the optimum number and time of hand weeding as compared with chemical weed control and their effects on the fresh weight of total annual weeds and grain yield of wheat (Triticum aesativum L.) in new reclaimed lands. Results pointed out that, hand weeding once, twice, thrice at all times and chemical weed control significantly reduced the fresh weight of total annual weeds and increased wheat grain yield as compared with unweeded check. Hand weeding once at different times in the first and second surveys was not effective against the total annual weeds in both seasons as compared with hand weeding twice and chemical control treatments. Delay hand weeding once to 60 days after sowing (DAS) in both seasons was more effective on reducing total annual weeds than hand weeding once at 30 or 45 DAS in both seasons. Concerning wheat grain yield, hand weeding once at different times in both seasons gave less wheat yield as compared with all hand weeding twice or chemical weed control treatments. Hand weeding twice and thrice gave the best weed control against total annual weeds and increased wheat grain yield in both seasons. Bromoxynil at the rate of 576 9 (a.i) /ha. or tribenuron-methyl at the rate of 14.4 9 (a.i)/ha. followed by clodinafop- propargyl at the rate of 50.4 9 (a.i) /ha~. gave the highest values of reduction percentage in fresh weight of total annual weeds at 75 DAS in both seasons (95% and 95.4%, respectively) and gave the highest value of wheat grain yield (ton/ha.), Le 2.8 t/ha in the first season, 3.3 in the second season as compared with unweeded check.

Summary in Arabic.

1