Optimization of Irrigation Strategies for Higher Biomass and Fruit Production in Kinnow Mandarin of Lower Himalaya

The experiment on Kinnow mandarin was laid out in split-plot design with four replications. The treatments comprised of four frequencies of irrigation based on net CPE (CPE-RF) i.e. at l = 1 80 mm, I = 2 120 mm, I = 3 160 mm and I = 4 240 mm in the main plots and two types of organic mulches viz. M = 1 Sal (Shorea robusta) and M = 2 Lantana (Lantana camara) leaves in addition to control (without mulch) in the sub-plots. The tree volume, biomass production, carbon sequestration, fruit yield and physico-chemical properties of Kinnow mandarin were improved significantly with irrigation treatments in order of I > I > I > I 1 2 3 4 and mulch did not influenced significantly. The tree volume of Kinnow was recorded maximum (78.94 m3) with I1 treatment as 67.5, 26.71 and 12.56 per cent more over I4 , I3 and I2 treatments of irrigation, respectively, which was positively correlated with carbon storage, carbon sequestration and fruit yield in the tree. The highest carbon stock of Kinnow (30.0 Mg/ha) followed by 28.7, 27.4 and 25.2 Mg/ha under different irrigation frequencies, respectively. Maximum fruit yield was recorded (83.30 kg/tree) with I1 treatment was 76.56, 27.62 and 11.95 per cent more over I4, I3 and I2 treatments, respectively. Kinnow fruit plants raised with M1 treatment produced 4.94 and 16.02 per cent more fruits than M2 and M3 treatment, respectively besides improving the microclimate. The study indicates that irrigation and mulching have positive response on Kinnow mandarin in Doon Valley. Therefore, 75 m3 water per plant with mulch is optimum is recommended for carbon dioxide mitigation and fruit production in Kinnow mandarin in sandy loam soils.