الفهرس 
Effect of weed control on weed infestationOnly 14 pages are availabe for public view
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Abstract
Two field trials were conducted in Sakha Research Station in two successive
seasons of 1991/92 and 1992/93 to find out the effect of weed control treatments on
weed control and growth criteria, yield, yield components and juice quality of sugar
beet (Beta vulgaris L.).
The important results could be summarized as follow:
1- Comparing with unweeded treatment, Pyradur, metamitron and chloridazon
herbicidal treatments decreased number of sugar beet total weeds after I 0
weeks by 30.7, 20.4 and 12_9% and after 18 weeks by 30.9, 27.8 and 13.4 %,
respectively. Such poorly weed control levels of single herbicides proved the
necessary needed for effective weed control programs in beet field.
2- The additional of one or two hoeings improved drastically the efficiency of all the
applied herbicidal treatments.
3- Mechanical weed control of beet weeds with four hand weedings or hoeings existed the highest
reduction in numbers of broad-leaved, grassy and total weeds. Previous mechanical weed control
treatments decreased number of total beet weeds after 10 weeks by 96.2 and 96.9% and after 18
weeks by 90.7 and
92.8 %, respectively than the control.
4- No detectable differences in fresh weight of broad-leaved weeds, grasses and total weeds
were obtained after I 0 weeks from sowing between herbicide + one hoeing; herbicide + two hoeings
and mechanical weed control treatments.
5- Integrated weed control treatments exerted a drastic increase in root yield of sugar beet.
The highest value for root yield in this investigation was recorded from conventional four hoeings
treatment.
6- Hand hoeing 4-time treatment was the highest sugar yielder followed with herbicide + 2 hoeings
and handweedings treatments and in third order with herbicide + one hoeing treatments, whereas
single herbicides were the lowest.
7- The economic benefits for integration weed control programs in sugar beet were
increased as the number of hoeings increased. Additional two hoeings raised the net
incomes of the pre-mentioned herbicidal treatments (chloridazon, Pyradur and
metamitron) to be 772, 840 and 848 L.E/fed., respectively.