Growth and Yield Response of Broccoli (Brassica oleracea var. italica) to Application of Calcium, Boron and Zinc in Alkaline Soils of Indo-Gangetic Plains of India

The field experiment was conducted during winter (rabi) season of 2022-23 and 2023-24 at Shri Guru Granth Sahib World University, Fatehgarh Sahib, Punjab (India) to evaluate the effect of soil application of calcium (gypsum) and soil or foliar application of boron (B) and zinc (Zn) on growth and yield of broccoli on alkaline soils under sub-tropical conditions of central Punjab. Soil application of boron (1.5 kg B/ha) or zinc (5 kg Zn/ha) as well as foliar application of B (0.3% borax) or Zn (0.5% zinc sulphate), alone or in combination, increased the growth (plant height, number of leaves plant-1, leaf length, leaf width and plant spread), yield attributing characters (number of secondary heads plant-1, weight of main head plant-1, weight of secondary heads plant-1 and total weight of heads plant-1) and total marketable head yield (t ha-1) of broccoli significantly over their no application (control) during both the years. Foliar application of both B and Zn was better than their soil application in increasing the crop growth and productivity. Combined application of B and Zn was better than their sole application, irrespective of their mode of application. The highest value of growth parameters, yield attributes and marketable head yield was obtained with combined foliar application of B and Zn. Foliar application of B or Zn alone were at par with each other in terms of growth, yield attributes and the yield, proving significantly better than soil application of B or Zn alone or combined while their combined application in soil was significantly better than their sole application in soil. However, soil application of Zn alone performed better than soil application of B alone. Application of calcium (100 kg ha-1), however, could not increase the growth and yield of the crop over its no application. The combined application of B and Zn, preferably through foliar spray (B as 0.3% borax and Zn as 0.5% zinc sulphate), may be suggested for obtaining higher marketable yield of broccoli in micronutrient (B and Zn) deficient alkaline soils of central Punjab.