Effect of boron, lime and their residue on yield of cauliflower, leaf composition and soil properties

Abstract

Cauliflower grown on acid sandy loams of Chotanagpur region, Bihar suffers from a severe B-deficiency (brown rot) causing heavy loss. To correct this problem, a field experiment was conducted during three successive seasons: rabi (winter, October-March), 1985; kharif (rainy, June-September) 1986; and rabi 1986 with two lime levels (0 and 3.4mT/ha) and six B levels (0-3.75 kg/ha). Boron increased the curd yield by 59–90% over control and reduced curd rot from 52% (control) to 7% (1.5 kg/ha). Increasing B rates enhanced hot water soluble (HWS) B in soil (0.1 to 0.9 μg/g), and leaf B (7.6 to 29.2 μg/g), leaf Ca (1.3 to 1.7%), leaf Mg (0.24 to 0.32%) and depressed Ca/B ratio (2951 to 1195) and K (4.0 to 3.8%) in leaf. Lime increased curd yield by 23% and reduced curd rot from 20% (no-lime) to 10%. Calcium, Ca/B ratio, K in leaf, pH, exchangeable Ca and effective CEC in soil improved while B in leaf, HWS B, exchangeable Mg and K, 1 M KCl- and BaCl₂-TEA-extractable acidity were depressed by lime. Due to successive cropping, B and K in leaf, HWS B and exchangeable K in soil decreased while Ca and Ca/B ratio in leaf and exchangeable Ca in soil increased. During the kharif season of 1986 maximum response to lime was observed and resulted in 116% higher curd yield and increased pH and lowered extractable acidity in soil. Significant leaching losses occurred during the kharif season of 1986 as shown by reduced B in leaf, HWS B, exchangeable Ca and Mg and effective CEC in soil. Application of 1.5 kg B ha⁻¹ in conjunction with lime produced high curd yield and corrected B-deficiency for three successive crops.