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Abstract
A major factor limiting yield and quality of maize (Zea mays L.) is the spread of weeds in maize fields. Thus, two field experiments were conducted at Sids Agricultural Research Station, Agricultural Research Centre (A.R.C.), during 2013/2014 and 2014/2015 seasons to study the efficiency of four pre-emergence herbicides at different rates: [acetochlor 84% EC (Harnss) at 840, 1260 and 1680 g a.i. fed.-1 (feddan= 4200 m2), sulcotrione 15% SL (Prestige) at 150, 225 and 300 g a.i. fed.-1, metribuzin 70% WG (Marin El-Nasr) at 210, 315 and 420 g a.i. fed.-1 and pendimethalin 45.5%CS (Stomp Extra) 682.5, 1023.8 and 1365g a.i. fed.-1] as well as hand hoeing (twice) and unweeded control on yield, yield components and quality characters of maize. Also, study the residual effect of these herbicides on the following winter crops (wheat and faba bean). The results revealed that the herbicides used at different rates and hand-hoeing gave better and wide weed control spectrum of total annual weeds (both grassy and broad leaved) than the unweeded control. Dry weight of total annual weeds was generally correlated with herbicide rates, whereas metribuzin at the highest rate (420 g a.i. fed-1) gave controlling effect (85.7, 82.2%), while metribuzin at the lowest rate of (210 g a.i. fed-1) gave controlling effect (65.3, 73.1%), at first survey in both seasons. The yields in all herbicidal treatments were significantly greater than the untreated control and there were no adverse effects on the growth and development of plants and grain yield and its quality (carbohydrate% and protein %). Metribuzin at 420 g a.i. fed- 1 gave the highest grain yield (29.3 and 28.4 ardab fed-1) (ardab = 140 kg), while pendimethalin at 682.5 g a.i. fed-1gave the lowest grain yield (18.8 and 19.4 ardab fed-1) in both seasons, respectively