Evaluation of shallow subsurface drip irrigation for the production of acorn squash

Abstract

Subsurface drip irrigation (SDI) has been increasingly used for the production of numerous agronomic crops and a limited number of vegetable crops. To determine the impact of SDI compared with surface drip irrigation (SUR), a study was conducted in 2011 and 2012 with ‘Table Queen’ acorn squash (Cucurbita pepo var. turbinata) with irrigation initiated at 75% and 50% plant available water (PAW). The study was arranged as a factorial randomized complete block design and plants were grown with two irrigation types (SUR or SDI) and two tensiometer-controlled irrigation regimes. Results from 2011 suggested that SDI used less water compared with SUR at each irrigation set point. However, in 2012, significantly more water was used in all treatments due to warmer temperatures and less rainfall. In 2012, SDI used more water than SUR treatments at the same irrigation set point. In 2012, yield was affected by irrigation treatment. Plants grown using SUR irrigating at 75% PAW had greater numbers of fruit compared with other treatments. Furthermore, the highest yielding treatment had more than twice the number of irrigation events than the other treatments though the average lengths of irrigation events were shorter. Although overall yields were greater in 2012, irrigation water use efficiency (iWUE) was lower than in 2011 due to increased water use. These results suggest that while SDI may have some advantages over traditional SUR, environmental factors during growth can significantly impact the efficiency and productivity of each system.