Dry root yield, nutrient uptake and economics of Ashwagandha (Withania somnifera L. Dunal) as influenced by planting layouts, spacings and nutrient management under drip irrigation

Abstract

A field experiment was conducted during rabi season for two years to study the response of Ashwagandha [Withania somnifera (L.) Dunal] to planting layouts, spacings and nutrient management levels under drip irrigation at Rahuri (Maharashtra). There were twenty four treatment combinations consisting of three planting layouts (broad bed furrow, ridges and furrow, flat bed) along with two treatments of spacings (30 cm x 20 cm, 45 cm x 20 cm) were embedded in main plots. Four levels of nutrient management (75 : 37.5 : 37.5 kg N,P2O5, K2O + 5 t FYM/ha, 50 : 25 : 25 kg N, P2O5, K2O + 5 t FYM/ha,25 : 12.5 : 12.5 kg N, P2O5, K2O + 5 t FYM/ha and control) were taken in sub plots. Broad bed furrow planting layout recorded significantly higher values of yield attributes viz., number of roots, root length, root diameter, dry root weight, number of berries and seed yield per plant and consequently recorded higher dry root (790 kg/ha) and seed yield (11.46 q/ha), nutrient uptake and harvest index (18.86%) as compared to ridges furrow and flat bed. The closer spacing of 30 cm x 20 cm registered significantly high dry root yield, seed yield, nutrient uptake and harvest index than wider spacing of 45 cm x 20 cm. At 30 cm x 20 cm spacing, the increase in dry root yield and seed yield was 19.89 and 15.20% over 45 cm x 20 cm, respectively. Significant increase in dry root yield, seed yield and nutrient uptake was noticed with increase in fertilizer levels from control to 75 : 37.5 : 37.5 kg N, P2O5, K2O + 5 t FYM/ha. Application of 75 : 37.5 : 37.5 kg N, P2O5, K2O + 5 t FYM/ha recorded significantly higher yield attributes as well as dry root yield (837 kg/ha), seed yield (13.29 q/ha), N (130.34 kg/ha), P (30.07 kg/ha) and K (159.49 kg/ha) uptake and harvest index (21.33%) than rest of fertilizer levels. Economic evaluation indicated that broad bed furrow planting method produced higher gross returns (‘ 2,20,379/ ha), net returns (‘ 1,60,796/ha) and B:C ratio (3.67) followed by ridges furrow and flat bed. The spacing of 30 cm x 20 cm and fertilized with 75:37.5:37.5 kg N, P2O5, K2O + 5 t FYM/ha obtained maximum gross returns (‘ 2,56,946/ha), net returns (‘ 1,92,496/ha), and B:C ratio than others.