In the realm of controlled environment horticulture, particularly organic tomato production, managing greenhouse pests like whiteflies, leafminers, and thrips under hot and humid conditions remains a significant challenge.
These pests, along with the inadequate stress tolerance of existing cultivars, contribute to low tomato productivity by hindering optimal fruit set and yield. While the individual effects of bioprotection and grafting strategies in conventional systems have been well-studied, their combined effects in controlled environments are less understood. This study, conducted in Qatar, investigates the combined efficacy of grafting ('Maxifort' × 'Valdeon RZ') and bioprotection strategies (yellow sticky traps, Spinosad, and Bacillus thuringiensis) in mitigating pest infestations and enhancing the yield of organically grown hydroponic tomatoes in challenging environmental conditions. The experimental design featured a strip plot with grafted and nongrafted 'Valdeon RZ' as the main treatments, and the bioprotection methods as subplots. Grafted 'Valdeon RZ' on Maxifort showed superior seedling quality, with increased stem diameter and improved root attributes. Notably, grafted plants treated with Spinosad demonstrated a 27% increase in net assimilation rate, 17% higher stomatal conductance, and a 22% reduction in transpiration loss, alongside an 18% decrease in electrolyte leakage. Furthermore, these plants flowered four days earlier than untreated, nongrafted counterparts, and exhibited a 22% improvement in fruit set and an 18% increase in pollen viability, with a 28% reduction in flower drops. In terms of yield, grafted plants treated with Spinosad produced a 26% higher marketable fruit yield compared to control plants. The fruits also showed superior postharvest quality, including better firmness, higher soluble solids content, improved acidity, and enhanced color dynamics. Among the bioprotection strategies, Spinosad was the most effective, reducing leafminer by 40%, whitefly by 28%, and thrips by 22% compared to untreated controls.
These findings suggest practical strategies that can minimize pest infestations while boosting tomato yield in organic hydroponic systems within protected environments.
Dash, Prosanta & Guo, Bing & Leskovar, Daniel. (2025). Enhancing Hydroponic Organic Tomato Resilience through Grafting and Bioprotection Strategies. HortScience. 60. 334-343. 10.21273/HORTSCI17990-24.
Source: Research Gate