Effect of drip irrigation regime and mulching on growth and yield parameters of tomato (Solanum lycopersicum L.) varieties

Abstract

Agricultural water scarcity poses a serious threat to food and nutrition security in sub-Saharan African countries. Therefore, this study sought to investigate the effect of deficit irrigation and mulching on agronomic traits of two tomato (Solanum lycopersicum) varieties. The experimental design was split-split plot. Treatments consisted of two varieties assigned as main plot factor (Mongal F1 and Pectomech), deficit irrigation as subplot factor at three levels: 100, 75 and 50% crop water requirement (ET_c) and rice straw mulch as sub-subplot factor at three levels: 6, 3 and 0 t ha^-1. The results showed significant effect of treatments on measured traits. Mild irrigated Mongal F1 mulched with 3 t ha^-1 rice straw recorded significantly higher leaf chlorophyll concentration of 69.35 μmol/m². Mulching with 3 t ha^-1 rice straw resulted in higher mean leaf chlorophyll than with 6 or 0 t ha^-1. Leaf stomatal conductance was significantly higher (74.10 mmol/m²s) for plants under full irrigation combined with mulch at 6 t ha^-1 than with medium or no-mulch. Mongal F1 out-yielded Pectomech by a margin greater than 100%, especially when irrigated with higher volumes of water. Full irrigation did not significantly differ from mild deficit irrigation in fruit yield. Mongal F1 mulched at 6 t ha^-1 gave significantly higher fruit yield of 11.93 t ha^-1 than un-mulched Pectomech. The mulch effect resulted in significantly higher irrigation water-use efficiency for Mongal F1 that ranged from 2.82 – 3.10 kg m^-3 compared to un-mulched Pectomech. In addition, 50% deficit irrigated Mongal F1 recorded significantly higher irrigation water-use efficiency of 3.88 kg m^-3 than full irrigated Pectomech. The integration of mulched Mongal F1 with mild deficit irrigation can improve crop and water productivity of tomatoes under water limiting environments.