BOTANICAL STUDIES ON GROWTH IN FLOWER ABORTION IN COTTON

Abstract

Growth or cot ton plants Gi za 85 obviousl y affected with fol iar appl ication 5 times wi th 15 days intervals starting at 60 days of p l a n t age wi th N at 50 and 250 ppm , P or K at 25 and 50 ppm and paclobutrazol ( PPm ) at 5 and I 0 ppm as well as combinations of PPm at 5 ppm wi th the l ow l evel of each of N, P and K. ln this res pect. i t v;;as o f in terest that si gnificant increase exi sted in n u mbers of bo th vegetati ve branches and the formed leaves/plant as well as t heir d ry wei g hts and total l eaf area with PP333 at 5 or I 0 ppm and K at 25 ppm . 1\ l so. a natomi call y, ma n y featurt:s or l eaf structures clearl y were modi-fied with most of the applied treatments. Here, all ap plied treatmen ts si gnificant ly increased thickness of each of midvein, xyl em a nd phloem ti ssues. lamina u pper and l ower e p idermis anc! pali sade a nd spongy ti ssues as well. In add ition, dimensions and the xy l em vessel rows number · of the main vascular bundle were also signi fica ntl y increased with all a pplied treatments. Moreover, anatomical alterations in l eaf anatom y ex i sted \·Vi th a pplied treatments ensure the essentiality of increasing the cross secti onal area of phloem for improving both growth and producti vity or cotton pl a n ts. Furthermo re, most appli ed treatments obviously increased the determined b i oconst ituents m leaves, I.e. crude protein and car bohydra te contents. As for yield and i ts components; different applied treatments si gni fican tly i ncreased seed cotton yield as well as lint weight with most of the a ppli ed treatments. Also, seeds number pe r boll was i ncreased wi th most of the a pplied treatments. Here, seeds we ight was nearl y beh aved as the same as seeds number. In addition, different a p pl i ed treatments increased oil percentages in seeds to reach its max imum with P P333 at I 0 ppm.