Field experiments in two crops of papaya were conducted at ICAR-Indian Institute of Horticultural Research for four years during 2016-19 to standardise spacing with optimum soil volume wetting for drip irrigation. Narrowing the plant rows drastically reduced the plant height while leaf production affected significantly due to reduction in intra row spacing. The height at first fruiting was significantly lower with a spacing of 1.8 m x 1.5 m (56.4 cm) significantly differing from both 1.5 m x 1.5 m (60.9 cm) or 1.8 m x 1.8 m (66.8 cm). Significantly higher mean fruit yield (42.2 t/ha) was recorded with the spacing of 1.5 m x 1.5m as compared to either 1.8m x 1.5m (23.4 t/ha) or 1.8m x 1.8m (22.1 t/ha). Significantly higher water use efficiency (71.3 kg/ha.mm) was recorded in papaya by following closer spacing of 1.5 m x 1.5 m. Among the interactions, higher papaya yield (48.0 t/ha) was recorded with normal drip irrigation (80% soil volume wetting) under closer spacing (1.5 m. x 1.5 m). Further, higher water use efficiency (129 kg/ha. mm) could be obtained by scheduling the irrigation at 30% soil volume wetting especially by planting at 1.5 m. x 1.5 m. spacing suggesting its suitability for water scarcity areas.
Modelling the impact of pulsing of drip irrigation on the water and salinity dynamics in soil in relation to water uptake by an almond tree