Effect of foliar application of Zn2+ fertilizer on growth, yield and fiber characteristics of cotton varieties (Gossypium hirsutum L.)

A field experiment was conducted to evaluate the effect of foliar application of Zn2+ solution on growth, yield and fibre characteristics of different cotton varieties (NIAB-78 and Sohni). The treatments of 0.1% Zn2+ solution at early stage, 0.5% Zn2+ solution at early and flowering stages, while 0.33% Zn2+ solution at three (early, flowering and boll formation) stages. The Zn2+ solutions were applied is the form of ZnSO4. The recommended doses of NPK viz. 120-50-50 kg per ha were applied in all treatments. The observations recorded were, number of shedded flowers per plant, number of productive bolls per plant, number of closed bolls per plant, number of rotten bolls per plant, number of bolls per plant and seed cotton yield per plant or per ha. The fiber characteristics viz. staple length, micronaire value seed index and G.O.T% were also recorded. The soil was non-saline, clay loam, medium alkaline, poor in organic matter and high in CaCO3 content, generally deficient in; P and Zn2+ but adequate in K+, Cu2+, Mn2+ and Fe+ content. Generally significant results were recorded at T3 sprayed at early and flowering stages and T4 sprayed at early, flowering and boll formation stages. It is evident that plants prayed with Zn2+ solution had more productive bolls, less number of closed and rotten bolls, higher Seed cotton and straw yield, with no problem of flower shedding. Foliar application of Zn2+ spray generally had no marked effect on fibre characteristics. Variety NIAB-78 remained more efficient than Sohni in almost all recorded parameters. Generally significant effects of Zn2+ were observed at T3 sprayed at early and flowering stages and T4 sprayed at early, flowering and boll formation stages. The significant effects of foliar application of Zn2+ on plants were generally associated with higher contents of P, K and micronutrients (Cu2+, Fe2+, Mn2+ and Zn2+). It is concluded that 0.1% ZnSO4 applied on cotton into three splits at three different stages i.e. early, early and flowering, and early, flowering and boll formation, gives higher yield. Foliar application of ZnSO4 is more economical than soil application.