Effect of population density and nitrogen fertilizer levels on growth, yield components, yield, and fiber properties of Egyptian cotton (Giza 95)

Two field experiments were carried out at the Farm of Sids Research Station, BaniSwef Governorate, Agricultural Research Center, Egypt, during the two successive seasons of 2016 and 2017. The aim of this study was to investigate the effect of three population density through five plant distribution, i.e. 64615 plants/fed from 10 cm between hills with leaving single plant/hill (A), 64615 plants/fed from 20 cm between hills with leaving double plants/hill (B), 43076 plants/fed from 15 cm between hills with leaving single plant/hill (c), 43076 plants/fed from 30 cm between hills with leaving double plants/hill (D) and 51692 plants/fed from 25 cm between hills with leaving double plants/hill (E) under four nitrogen fertilizer levels, i.e. (30, 45, 60 and 75 Kg N/fed) on growth, flowering, yield components and yield as well as fiber quality properties for the Egyptian cotton (Gossypium barbadense, L.), variety Giza 95.
Significant differences were detected for allmost growth, flowers, yield components and yield as well as fiber properties of cotton among the three plant densities through five plant distributions or four nitrogen fertilizer levels during 2016 and 2017 seasons. Planting pattern of D significantly surpassed the other plant densities and distributions and gave the greatest values in No. of sympodia/plant, No. of fruiting sites/plant, No. of open bolls/plant, boll weight, seed index, seed cotton yield/plant, upper half mean length and uniformity index % as well as significantly gave the shortest period from planting to first flower appearance and lowest values of plant losses % at harvest. Meanwhile, planting pattern of E significantly gave the highest values of seed and lint cotton yields/fed. On the other hand, the greatest values of plant height, No. of days to first flower appearance, lint % and plant losses % were obtained from planting pattern of A. While, planting pattern of B gave the lowest values of micronaire reading. While, the maximum values of strength (g/tex) was recorded from planting pattern of C. plant height, No. of sympodia/plant, No. of days to first flower appearance, No. of fruiting sites/plant, No. of open bolls/plant, boll weight, seed index, seed cotton yield/plant, seed cotton yield/fed, lint cotton yield/fed and uniformity index % showed significantly increased by increasing nitrogen fertilizer levels from 30 up to 75 kg N/fad, except lint % and micronaire reading were significantly decreased in the both seasons. Results revealed that planting pattern of D under soil fertilized by 75 kg N/fed gave the maximum values of No. of sympodia/plant, No. of fruiting sites/plant, No. of open bolls/plant, boll weight and seed cotton yield/plant. While, planting pattern of E with the same level of nitrogen produced the maximum values of seed and lint cotton yields/fed. Meanwhile, the greatest values of plant height and the longest period from planting to first flower appearance were obtained from planting pattern of A when received 75 kg N/fed during both growing seasons. It could be summarized that planting cotton plants (Giza 95) under planting patterns of D or E with soil fertilized by 75 kg N/fad to maximized quantity and quality of cotton yield characters.