Scientific Analysis of Reference Evapotranspiration, Soil Properties and Pulp Nutrients in Jamun Grown under Subtropics

Field experiment of ICAR project “Genetic resource management and improvement in Jamun” was conducted in subtropical climatic zone of Lucknow, UP, India. Scientific analysis showed differential reference evapotranspiration during critical stages of Jamun. It was found that the weekly average reference evapotranspiration during first and second fruiting season was between 1.15 to 5.90 and 1.30 to 5.76 mm day^-1. Scanty rainfall amount of 4.09 and 15.86 mm during critical growth and reproductive stages was received. Recent data indicated variability in soil temperatures in Jamun orchards under the influence of subtropical climate. It was inferred from analysis of average of 630 observations at 10 and 20 cm depths that in morning and afternoon hours, soil temperature of 14.94 to 15.22°C and 19.79 to 19.84 °C, respectively. A range of 0.23 to 0.43% soil organic carbon and 0.28 to 1.12 mg kg^-1 Zinc recommended the urgent needs for improvement in soil health condition. Water holding capacity of 20.21 to 20.52 and 19.18 to 19.72%; porosity of 36.06 to 41.18 and 40.07 to 41.82% was estimated in irrigated and non-irrigated plots respectively. Soil moisture content varied from 8.1 to 12.5 per cent in irrigated trees and lower (< 8 per cent) in non-irrigated tress. Systematic analysis of soil properties indicated need for nutrient management at critical fruit developmental stages. Recent data of Jamun fruit pulp nutrients was noted as 0.129 to 0.145% P and 0.026 to 0.031% K respectively. The highest pulp Zn, Cu, Mn and Fe was noted as 22.50, 34.17, 53.33 and 1576.60 mg kg^-1 respectively. Irrigation improved the orchard condition and yield performance in Jamun (52.34 to 96.74 kg tree^-1). The current experiment suggested for sincere scientific efforts needed for enhancing resource use efficiency vis-a-vis Jamun productivity under subtropics.