Integrated Fertilizer, Irrigation and Variety Management Strategies for Sustainable Greenhouse Tomato Production in Tropical Climates

Abstract

Optimizing nutrient supply, irrigation and varietal selection is critical for maximizing greenhouse tomato productivity in tropical climates. This study assessed the combined effects of fertilizer levels, irrigation water requirements, and variety on greenhouse tomato growth characteristics, rootzone EC and pH, yield, and potassium use efficiency under contrasting micro-climates. A split-split plot design compared three (3) levels of fertilizer (F1: 100 %, F2: 80 %, F3: 60 %), three levels of irrigation water requirement (I1: 100 %, I2: 80 %, I3: 60 %) and two tomato varieties (V1: Jalila F1, V2: Yetty F1) across contrasting micro-climates. Variations in irrigation levels notably affected EC and pH, with micro-climate 2 exhibiting more pronounced responses. Optimal irrigation and fertilization generally improved plant height, stem girth, chlorophyll content, and biomass (leaf, stem and side-shoot), in Jalila F1 and Yetty F1. Yield and potassium use efficiency were maximized under the combination of 100 % fertilizer and 100 % irrigation, with notable variations observed across micro-climates. In micro-climate 1, Jalila F1, treated with 100 % fertilizer level and 100 % irrigation requirement, had the highest yield (101.6 t/ha), and Yetty F1, treated with 100 % fertilizer level and 100 % irrigation water requirement, had the highest yield in micro-climate 2 (91.7 t/ha). The findings show that integrating moderate fertilization, full irrigation, appropriate variety selection and micro-climate can simultaneously improve yield and quality and optimize potassium use efficiency. Such strategies are essential for sustainable intensification of greenhouse tomato production in water-limited tropical environments.