Data_Sheet_1_Supplemental LED Lighting Effectively Enhances the Yield and Quality of Greenhouse Truss Tomato Production: Results of a Meta-Analysis.xlsx

Intensive growing systems used for greenhouse tomato production, together with light interception by cladding materials or other devices, may induce intracanopy mutual shading and create suboptimal environmental conditions for plant growth. There are a large number of published peer-reviewed studies assessing the effects of supplemental light-emitting diode (LED) lighting on improving light distribution in plant canopies, increasing crop yields and producing qualitative traits. However, the research results are often contradictory, as the lighting parameters (e.g., photoperiod, intensity, and quality) and environmental conditions vary among conducted experiments. This research presents a global overview of supplemental LED lighting applications for greenhouse tomato production deepened by a meta-analysis aimed at answering the following research question: does supplemental LED lighting enhance the yield and qualitative traits of greenhouse truss tomato production? The meta-analysis was based on the differences among independent groups by comparing a control value (featuring either background solar light or solar + HPS light) with a treatment value (solar + supplemental LED light or solar + HPS + supplemental LED light, respectively) and included 31 published papers and 100 total observations. The meta-analysis results revealed the statistically significant positive effects (p-value < 0.001) of supplemental LED lighting on enhancing the yield (+40%), soluble solid (+6%) and ascorbic acid (+11%) contents, leaf chlorophyll content (+31%), photosynthetic capacity (+50%), and leaf area (+9%) compared to the control conditions. In contrast, supplemental LED lighting did not show a statistically significant effect on the leaf stomatal conductance (p-value = 0.171). In conclusion, in addition to some partial inconsistencies among the considered studies, the present research enables us to assert that supplemental LED lighting ameliorates the quantitative and qualitative aspects of greenhouse tomato production.

用于温室番茄生产的集约化栽培系统，搭配覆盖材料或其他装置对光照的截留作用，可能引发冠层内部相互遮荫，为植株生长创造次优环境条件。目前已有大量经同行评议的发表研究，探讨了补充发光二极管（LED）光照对改善植株冠层光照分布、提升作物产量及优化品质性状的作用。然而，由于不同实验中的光照参数（如光周期、光照强度与光质）及环境条件存在差异，相关研究结果往往存在矛盾。本研究针对温室番茄生产中的补充LED光照应用开展全球性综述，并通过荟萃分析进一步解答以下研究问题：补充LED光照是否能够提升温室串番茄生产的产量与品质性状？本荟萃分析通过对比对照组（仅自然光照，或自然光照+高压钠灯（High-pressure sodium, HPS）光照）与处理组（自然光照+补充LED光照，或自然光照+HPS光照+补充LED光照）的独立组间差异，共纳入31篇已发表论文与总计100组观测数据。荟萃分析结果显示，与对照组相比，补充LED光照对产量提升40%、可溶性固形物含量提升6%、抗坏血酸含量提升11%、叶片叶绿素含量提升31%、光合能力提升50%以及叶面积提升9%均具有统计学意义上的显著正向影响（p值<0.001）。与之相反，补充LED光照对叶片气孔导度未表现出统计学意义上的显著影响（p值=0.171）。综上，尽管纳入的研究中存在部分不一致之处，但本研究可证实，补充LED光照能够改善温室番茄生产的产量与品质表现。