Abstract

Sulfur (S) has been recognized as an important plant macronutrient, associated with high yield and quality, particularly in crops of the Brassica genera. Polyhalite is a natural mineral which occurs in sedimentary marine evaporates, consisting of a hydrated sulfate of potassium (K), calcium (Ca) and magnesium (Mg). The objective of this study was to test the bioefficacy of polyhalite on the performance of two major Brassica oleracea cole crops in India, cauliflower and cabbage. Sulfur application gave rise to significantly increased yield and quality of the two crops. Potassium enhanced S uptake, while in turn, S appeared to promote phosphorus (P) and Ca uptake. The highest yields of cabbage and cauliflower, 32.8 and 39.5% more than the control, respectively, were obtained with 100% and 75% of the recommended N-P-K and S doses, respectively, delivered through polyhalite. Possible reasons for the failure of a 100% S dose, either through polyhalite or gypsum, to further increase yield attributes are discussed. More research is required to adjust nitrogen (N) and K fertilization practices where S administration takes place.