Most often yields of cauliflower remain low due to inadequate supply of micronutrients particularly of boron. Studies were therefore undertaken to optimize rate of B fertilization and evaluate efficiency of various sources for correcting its deficiency more economically in different agro-ecological zones of India. To correct B deficiency, eight field studies were conducted to evaluate the relative efficiency of B sources and optimize rates of B application needed for cauliflower crop grown in soils in different agro-ecological zones (AEZ) of India. Granular borax penta hydrate has been commercially made available for correcting B deficiencies in agricultural crops. Treatments comprising of borax at the rate of 75, 100 and 125% and Granubor II at 75, 100 and 125% of the recommended rate 1.00 kg B ha-1 were imposed along with one B control (NPK alone).
The study covers major soils types like hill and mountainous (Alfisols) of the Himalayas, red sandy loam and lateritic soils (Alfisols) of central and eastern India and alluvial soils of Gujarat (Ustochrepts) and calcareous (Calciorthent) soils representing various agro-ecological zones of the India. Deficiency of boron ranged from 2-84% in certain soils and agro-ecological zones. Application of B significantly increased the biomass yield as well as economic benefits of cauliflower in different soils, crops and zones. Response of crops to 0.75 kg B ha-1 gave a significantly low yield. Increasing rates of boron added at 100 to 125% of the recommended dose gave significantly higher yields in different soils. Both the sources like Granubor II and borax significantly increased the yield over the control. Granubor II outperformed the crystalline borax in most of the soils in correcting B deficiency in cauliflower and gave higher benefit cost ratio. Thus preferential use of Granubor II at the rate of 1.25 kg B ha-1 was found to be beneficial to correct B deficiency in cauliflower over borax in different soils of India.