Effects of Controlled Environment Agriculture and Nutrient Sources on the Production of Eggplants (Solanum melongena var. esculenta L.)

Production of eggplant (Solanum melongena var. esculenta L.) was systemically evaluated under various controlled environments and nutrient supplies to produce novel information on factors affecting eggplant growth and productivity traits. Treatments of three environmental conditions (fully controlled, semicontrolled, and uncontrolled) and four nutrient sources [i.e., eggplants grown in pots with peatmoss and 100% inorganic fertilizer supply, 100% compost, 50% mix of the two, and control (e.g., peatmoss without any nutrient supply)] were replicated four times under a split-plot design. Smart agricultural tools were used for system automation and data collection. Higher light intensity in the conventional greenhouse (30 mmol/m²/day), variations in its air temperature (25 to 30^◦C), and active pollination led to its higher fruit yield (20.2 mg·ha²¹), which was significantly (P ≤ 0.05) greater and statistically different from the fruit yield of the fully controlled smart greenhouse (11.2 mg·ha²¹) and uncontrolled open field cultivation (14.1 mg·ha²¹). However, the smart greenhouse showed the best water use efficiency (33 L·kg²¹) among the other environmental treatments because of lower irrigation water requirements. This study’s significance lies in its systematic evaluation of eggplant production under various controlled environment agriculture settings to produce Qatar-specific data for the first time in the literature. The study findings suggested that conventional greenhouse cultivation could be an economically feasible (based on the benefit-to-cost ratio), energy efficient, and environmentally friendly method of producing eggplants in arid regions and agricultural conditions resembling those used in this study provided that precision agriculture practices are adopted.