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Abstract Because of weeds constituted a major problem in crops production, losses in crop yield caused by weeds exceeded the losses come from any other categories of agricultural pests. The weeds 1 have been controlled by several ways, e.g. hand weeded, chemical ..•• etc. Chemical weed control is an important cultural practice for raising the yield and quality as well as reducing the cost of production (Uzenbove and Sandybaeva, 1977). In general, herbicides are toxicants, but the sensitivity of plants to most herbicides varies considerably from one species to another. These chemicals are used to control undesirable species growing in association with a desirable plant, however, most of these chemicals might remain active in the soil for a week or a year or even more such as atrazine (1-12) months, ametryne (6-10) months (Birk and Roadhouse, 1964; Fink and Doty 1969; Lebaron, 1970; ElSherbeni and Abd El-Baki, 1985). Therefore, the subsequent crops cultivated in the area previously treated by such herbicides are negatively affected. This adverse side effect depends upon kind of the persistance of the herbicide used and the species of growing crops (Frank, 1966). |