Department of Soils, Haryana Agricultural University, Hissar (Haryana)
Investigations were carried out on the variations in the endogenous nitrogen content in relation to abscission of flower buds/flower/bolls and the effect of application of urea (0.0, 0.2 and 0.4%), singly and in combination with zinc sulphate (0, 0.2, and 0.4%) on the abscission of flower buds, flowers and bolls of cotton (Gossypium hirsutum Linn) cultivar J-34. Endogenous nitrogen content was high in the retained, low in the yellowed and the lowest in the abscising flower buds as well as flowers and bolls of the same age. Urea application enhanced flower bud abscission but increased weight of the individual boll and the yield per plant. Zinc sulphate increased the weight of the individual boll and thus increased the yield. The interaction between urea and zinc sulphate was found to be significant in respect to almost all the parameters studied. An inverse relation between the number of bolls retained per plant and the weight of the individual boll was observed. The data suggest that urea and zinc sulphate may be used in balanced proportions for maximum benefit in yield.
