EVALUATION OF SOME CHEMICAL AND MECHANICAL WEED CONTROL METHODS ON ASSOCIATED WEEDS, GROWTH, YIELD AND QUALITY OF SUGAR BEET UNDER NEWLY RECLAIMED SANDY SOIL AT NUBARIYA

Two field trials were carried out during 1998/99 and 1999/2000 seasons to
evaluate the effect of some chemical and mechanical weed control methods on
growth, yield and juice quality as well as associated weeds of sugar beet (Beta
vulgaris, L.) grown in newly reclaimed sandy soil at Nubariya. The most important
results obtained could be summarized as follows:
        -     All weed control treatments reduced significantly fresh weight of sugar beet
weeds as compared to the unweeded treatment.
        -     Metamitron was the most effective herbicide on controlling weeds followed by
chloridazon and hand hoeing 3 times, respectively.
        -     Addition of one hand hoeing improved drastically the efficiency of the two applied
herbicides with two concentrations in controlling sugar beet weeds when
compared with other treatments.
        -     The results showed that Metamitron at rate of 2 kg/fed plus one hand hoeing
resulted in good control of total weeds after 20 and 24 weeks from sowing.
        -     Data indicated that the photosynthetic pigments chl.a, chl.b and carotenoids
significantly decreased due to all herbicidal treated plots than the plots of hoeing
treatment. Hand hoeing treatment raised significantly photosynthetic pigments as
compared with the untreated control plants after 18 weeks from sowing.
        -     All growth criteria i.e., plant height (ern), LAI, leaves number/plant, root/top ratio
and root characters responded significantly to 2 kgs Metamitron/fed + one hoeing
followed by Chloridazon 2 kg/fed + one hoeing and hand hoeing 3-times,
respectively, as compared with the untreated control treatment.
        -     Concerning the effect of weed control treatments on yield components of sugar
beet plants, corresponding data cleared that 2 kgs Metamitron/fed + one hand
hoeing gave the highest values of tops, roots, biological and sugar yields.
        -     Application of 2 kgs Metamitron/fed + one hand hoeing caused significant
increases in values of juice quality parameters I.e., T.S.S., sucrose and purity %
as compared with the untreated control treatment.
        -     Generally, it can be concluded that addition of one hand hoeing to 2 kgs
Metamitron/fed or 2 kgs Chloridazon/fed were the recommended treatments for
obtaining the highest growth, yield and juice quality of sugar beet plants as well
as significant reduction in total weeds under newly reclaimed sandy soil at
Nubariya.