EFFECT OF PHOSPHATE FERTILIZATION AND ZINC FOLIAR APPLICATION ON GROWTH AND YIELD OF COTTON

Abstract

To investigate the response of cotton (Gossypium hirsutum L. cv Lashata) to three levels of phosphorus (50 , 75 , and 100) kg P.ha-1 and four zinc concentrations (0 , 40 , 80 and 120 mg Zn.l -1) . A field experiment was conducted on the Expermental Farm, Department of Field Crop Sciences, College of Agriculture / University of Baghdad . A randomized complete block design with four replications was used . The results showed an increase in number of sympodia in both season 7.23 and 7.76, dry weight 105.5 and 107.9 g.plant-1, number of open bolls 8.55 and 9.28 per plant, boll weight 4.21 and 4.34g at application 100 kg P.h-1 that reflected increasing seed cotton yield 2179 and 2462 kg.ha-1 and lint cotton yield 816.5 and 908.8 kg.ha-1, increasing strength lint 9.78 and 19.36g.tex-1 respectively, while application of phosphorus non-significant effect in length and fineness. Foliar application of zinc concentration from 0 to 120 mg Zn. l -1 to increase number of sympodia in both season 7.15 and 7.65, dry matter weight 104.9 and 107.6 g.plant-1, number of open bolls 8.67 and 9.40, boll weight 4.26 and 4.41g that result increase seed cotton yield 2220 and 2497 kg.ha-1 and lint cotton yield 834.2 and 944.1 kg.ha-1 increasing strength lint 20.01 and 19.52g.tex-1 respectively, did not foliar application of zinc affeceted on length, fineness. Interaction between phosphorus and zinc was significant effect on number of sympodia 8.06 and 8.74, dry weight 109.8 and 111.6 g.plant-1, number of open bolls 9.24 and 9.97, boll weight 4.49 and 4.68, seed cotton yield 2475 and 2799 kg.ha-1, lint cotton yield 973.1 and 1071.2 kg.ha-1 was achieved at application 100 kg p.ha-1 with 120 mg Zn. l -1, interaction between phosphorus and zinc non-significant effect on length, fineness, strength lint during 2010 and 2011 season.Conclusion on this study foliar of zinc necessary at being problem in soil and interaction with phosphorus and that it may be recommended application 100kg P.ha-1 with 120 mg Zn. l -1 (192 g Zn.ha-1) of cotton.