Compensated Root Water Uptake for Drip Irrigated Chile.

Partial root drying (PRD) experiments were conducted in greenhouse to evaluate water saving, productivity and compensated root water uptake patterns for chile (NuMex Joe Parker; Capsicum annuum). Three treatments used include: (i) fully irrigated (control), (2) PRD for vertical split-root system, and (3) PRD for lateral split-root system. Soil water content was measured using TDR sensors and plant parameters using LI-6400XT. Meteorological data recorded were net radiation, soil and air temperature, and relative humidity. To account for changes in evaporative demand inside the greenhouse, atmospheric vapor pressure deficit values were calculated using Murray’s equations (1967) using the hourly average air temperature and relative humidity data Water stress was applied to the top 37% of the root zone in the vertical split system whereas alternate wetting and drying was imposed on each compartment in the lateral split-root system. The experiments for second year are in progress and we hope that two year experiments will show that chile plants under both PRD treatments could compensate for water stress by taking up more water from the water available portion of the root-soil system without affecting transpiration or photosynthetic rates to meet peak water demand.