Two field experiments were performed at the Research andExperiment center, Faculty of Agriculture al Moshtohor during 1991 and 1992
seasons to study the effect of nitrogen levels (0, 30, 60 and 90 kg N/fed) and
number of plants per hill (L 2 and 3 plants/hill,) on yield and yield components of
cotton Giza 75 cultivar. The experimental design was split plot with four
replications. The results indicated that:
Plant height, number of sympodia/plant, boll weight, se’ed cotton yield per
plaiiي and seed co/lou yield per feddan were significantly increased by increasing
N level up lo 90 kg N/fed., whereas there was no signijى cant dfference between 60
and 90 kg N/fed. On the other hand, nitrogen rates had no significantly effect on
number of open boll,c/plant and number of plants at harWst/fed.
Number of plants/hill significantly affectedyiëld and yield components
except plant height. One plant per hill produced the highest number of
sympodia/plant, tiumber of open boils/plant, boll weight and seed Cottoii
yieia/plauzt, while the highest number of plants at harvest/fed, and seed (‘011011
yieldifrd. were obtained by 3 plants per hi/i.
Siginficant luiteractions occurred between number of plants/hi/I (i/Id N
/eve) on all characters under study. The highest seed cotton yieldperfeddwi ,.Ia,s’

obtained from 3 plants/hi/i with 60 kg N/feddan.