Effect of Irrigation Intervals, Wheat Straw Mulch, and Aluminum Silicate Anti-transpirant Spray on Eggplant Yield and Some Water Relationships under Low Plastic Tunnels in El- Arish Region

Abstract

This research was carried out at the Experimental Farm of the Faculty of Environmental Agricultural Sciences, Arish University, North Sinai, Egypt, positioned at 31° 7ꞌ 38ꞌꞌ north and 33° 49ꞌ 34ꞌꞌ east, with an average elevation of 20 m above sea level, throughout the winter growing periods of 2020-21 and 2021-22. The primary objective was to assess the impact of varying irrigation frequencies (daily, every two days, and every three days), the use of crushed wheat straw as organic mulch (with or without), and the application of aluminum silicate as an anti-transpirant (with or without) on water consumption, water use efficiency, yield reductions, water conservation, and fruit yield of eggplant (Solanum melongena L.), cv. Betra in sandy loam soil conditions. Seedlings were transplanted on October 20th and were watered using a drip irrigation system. Each experimental plot covered an area of 10.5 m² (7 m in length and 1.5 m in width), with plant spacing set at 50 cm within rows, resulting in a planting density of 1.33 plants/m². The study followed a split-split plot design within completely randomized blocks with three replicates. The main plots were assigned irrigation frequencies, mulch treatments were randomized in sub-plots, and the anti-transpirant aluminum silicate spray treatments were randomly allocated in sub-sub plots. Notably, in the study, control treatment (daily watering without organic mulch or aluminum silicate anti-transpirant) showed the highest water consumption, reaching nearly 2580 m³/fed in both seasons. In contrast, the lowest water consumption, approximately 1200 m³/fed, was achieved with irrigation every three days combined with organic mulch and aluminum silicate application. Watering every two days with organic mulch and aluminum silicate anti-transpirant significantly improved total fruit yield, reaching approximately 33 ton/fed, this represented an increase of 27 % in the first season and 31 % in the second season. Additionally, water use efficiency was notably enhanced to around 21 kg/m³ in both seasons. Similarly, watering every three days with organic mulch and aluminum silicate spray effectively conserves water, achieving a 53 % reduction in water usage across both seasons. It could be concluded that using combined wheat straw as an organic mulch and aluminum silicate as foliar an anti-transpirant under lack irrigation (every two days) of eggplant plants can improve fruit yield productivity and save water under the current water shortage conditions in the world.