Management of water resources and biomass accumulation characteristics in flue-cured tobacco with micro irrigation
Flue-cured tobacco is grown in West Godavari District of Andhra Pradesh in 20,000 hectares during Rabi Season i.e, between October to March under irrigated conditions. Check Basin System of surface irrigation method is followed for irrigating the crop using ground water resources through Tube Wells. Numerous problems arise while surface irrigating tobacco such as, considerable seepage, conveyance and evaporation losses, high energy costs, greater wastage of fertilizers and nutrients, higher weed population, uncontrolled, unmeasured and uneven water supply creating a mismatch between need of the crop and availability. The objective of the current study was to evaluate the efficacy of Drip Irrigation system under different plant geometry and irrigation methods to enhance the Water Use Efficiency (WUE). 16 mm UV stabilized inline drip lines were used for the study with inline drippers located 40 cm apart discharging 2 litres per hour. The trial was conducted in 2004 and 2005 crop seasons. Broad Bed and Furrow (BBF) method of planting pattern with drip irrigation resulted in achieving 10% higher cured leaf yield (2745 kg/ha) compared to the conventional method of plantation with surface irrigation (2487 kg/ha). The BBF method with drip irrigation also resulted in enhancing the ripeness characteristics of the cured leaf. Leaf chloride levels were lower at 0.4% in BBF and Paired Row method with drip irrigation, compared to 0.8% in conventional method of plantation with surface irrigation. The water use efficiency was higher at 9.15 kg/mm under drip irrigation with BBF method compared to 4.9 kg/mm under conventional system of irrigation. The implementation of micro irrigation system in flue-cured tobacco cultivation, in West Godavari District of Andhra Pradesh, will assume importance in sustaining the tobacco production by rationalizing the use of water and power, with a potential to save 40 million cu.m. of water resources each year.