Effects of Organic Calcium Sources and Calcium Nutrition on Growth, Yield, and Quality of Okra (Abelmoschus esculentus L Moench)

Abstract

The field experiments were conducted at the College of Agriculture, Padannakkad and RARS, Pilicode Kerala Agricultural University. The first investigation was performed in a completely randomized design with three treatments - by dissolving egg shells, bone pieces and powdered lime shell in coconut water vinegar replicated five times. The objective was to develop an organic calcium source for foliar spray by studying the physico- chemical characteristics and shelf life. The second experiment aimed to identify the best source and method of calcium nutrition, thereby assessing its impact on the growth, productivity, and profitability of okra [Abelmoschus esculentus (L.) Moench].  This experiment was carried out in a randomized block design (RBD) with nine treatments replicated three times. The solution prepared from egg shells can be used as an organic calcium source for foliar sprays.  The highest fruit weight was exhibited by T6(KAU POP + foliar spray of 0.5 percent calcium chloride), which was statistically on par with T5(KAU POP + foliar spray of one percent calcium nitrate) and T7 (KAU POP + foliar spray of 0.5 percent calcium acetate). The total fruit yield (24.93 t ha-1) was significantly superior in all treatments where calcium is applied externally. Foliar application of calcium chloride and calcium nitrate along with KAU POP significantly increased fruit and plant dry matter production. The results demonstrate the significant role of calcium nutrition in enhancing yield, quality and economic returns in okra. The application of the recommended dose of nutrients as per KAU POP coupled with foliar spray of either 0.5% calcium chloride or 1.0% calcium nitrate can be suggested for improving calcium nutrition and thereby productivity in Okra.