Yield, water requirement, nutrient uptake and fruit quality of zucchini squash grown in soil and closed soilless culture

TLDR

The study compared zucchini grown in soil versus closed soilless systems (cocofibre, perlite, pumice) in a greenhouse, evaluating precocity, yield, water use, nutrient uptake, and fruit quality. Soilless cultivation produced higher yield, harvest index, and water‑use efficiency, with pumice requiring the least water, cocofibre giving earlier yield, greater nutrient uptake, increased carbohydrate content, and lower fruit nitrate, demonstrating that switching from soil to closed soilless culture can improve water and nutrient control, yield, and fruit quality.

Abstract

SummaryThe effects of soil and closed soilless systems (cocofibre, perlite and pumice culture) on precocity, productivity, water use, plant mineral composition and fruit quality were studied on zucchini plants (Cucurbita pepo L. 'Afrodite' grown in a greenhouse at Viterbo, central Italy. The plants grown in a soilless system exhibited higher yield (total, marketable and fruit number), harvest index, and water-use efficiency compared with those grown in soil. Among soilless treatments, pumice had the lowest water requirement and hence the highest water use efficiency. Use of cocofibre led to the earliest yield compared with the other substrates due probably to the higher minimal temperatures recorded on the organic substrate. Plants grown in soilless culture had a higher uptake of N, Mg, Na, Fe, Cu, Mn, Zn than those grown in soil. After 73 d of solution recycling in soilless treatments, N-NO3, K, P, Fe and Mn were depleted by 26, 16, 40, 92, and 25% respectively, while Ca, Mg, Na, Cu and Zn increased by 6, 69, 113, 360, and 981 % respectively. Carbohydrate concentration (glucose, fructose, sucrose and starch) increased in soilless over soil culture. No significant differences were observed in dry matter or total protein content. Nitrate concentration of fruits was lower in soil than in soilless treatments. The results demonstrated that the growers may improve water and nutrient control, yield and fruit quality by switching from soil to closed soilless culture.