الفهرس 
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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).