Enhancement of productivity, water- and nutrient use efficiency and economics through drip fertigation and tray seedlings in FCV tobacco (Nicotiana tabacum) under irrigated Alfisols of Andhra Pradesh

Abstract

A field experiment was conducted for two consecutive seasons (2014–16) and a bulk trial for one year (2016– 17) at ICAR-Central Tobacco Research Institute Research station, Jeelugumilli, West Godavari district, Andhra Pradesh under semi arid tropical climate to study the effect of different combinations of drip irrigation, furrow irrigation, tray seedlings, normal seedlings, drip ferti-gation and soil application of fertilizers at 3rd, 25–30, 40–45 days after planting or 10, 25–30, 40–45 days after planting, on green leaf yield (GLY), cured lead yield (CLY), grade index (GI), leaf nicotine and reducing sugars, water- and fertilizer use efficiency as well as economics in FCV tobacco (Nicotiana tabacum). The experiment was laid out in a RBD with five replications, nine treatment combinations and was conducted with specified treatments for the first two years and bulk plots during the following year. Two separate plots, viz. N₀ P_26.2K_99.6 (T₁₀) and N₁₂₀P_26.2K₀ (T₁₁) were grown for comparison and calculation of N and K use efficiencies during the first two years. T₄ (drip irrigation, tray seedlings, drip fertigation at 3^rd, 20–25 and 40–45 DAP) and T₂ (drip irrigation, tray seedlings, drip ferti-gation at 10, 25–30 and 40–45 DAP) recorded increased GLY by 23.87, 16.95, CLY by 16.67, 13.83 and GI by 23.43, 21.46% during first and second years, respectively and also higher leaf nicotine when compared to furrow irrigation, normal seedlings, soil application of fertilizers (T₉ ) i.e. farmers practice. N, P, K uptake and nitrogen and potassium use efficiencies under different treatments were evaluated. Bulk plots grown with tray seedlings, drip irrigation and drip fertigation accrued additional profit of `25,285, benefit: cost ratio of 1.82, WUE of 11.74 kg of cured leaf/ ha-mm of water as compared to 5.77 kg of cured leaf/ha-mm in normal seedlings, furrow irrigation and soil application of fertilizers. Only 57.2% of total quantity of furrow irrigation is required for drip irrigation and there is 203.5% increase in WUE with drip irrigation as compared to furrow irrigation.