THE PROPER IRRIGATION INTERVALS FOR VEGETATIVE AND FRUITING STAGES OF COTTON CULTIVAR GIZA 83

Three field experiments were conducted at Mallawi Agric. Res. Station, Minia Governorate during 1993-95 seasons to study the effect of irrigation intervals during vegetative and fruiting stages on growth, earliness, yield and its components of Giza 83 cotton cultivar. Four irri­gation treatments after the second irrigation were used: (1) every 15 days during both vegetative and fruiting stages, (2) every 25 days dur­ing both vegetative and fruiting stages, (3) every 15 days during veget­ative growth stage and every 25 days during fruiting stage and (4) eve­ry 25 days during vegetative growth stage and every 15 days during fruiting stage. The results indicated that the irrigation intervals of 15 days during vegetative and fruiting stages increased number of fruiting branches/plant, open bolls/plant, boll weight, seed cotton yield/plant and per feddan and decreased yield earliness. Lint percentage and seed index were slightly affected by irrigation treatments.