Retracted: Canopy management improves better orchard light penetration, optimum tree growth, and fruit quality of apple (Malus domestica Borkh.) trees grown in mild winter tropical condition

Abstract

Abstract This paper has been retracted. VIEW RETRACTIONManagement of tree canopy involves optimizing tree framework for early flowering in late winter, improved fruit quality, and rehabilitation of mature trees. This study evaluates the effects of pruning severity on light penetration, tree growth, and fruit quality in mature Anna (Malus domestica Borkh.)/MM-106 apple trees grown under mild winter tropical conditions. Pruning treatments at four severity levels (un-pruned control, light, moderate, and severe pruning) were applied to 15-year-old trees over two growing seasons (2017 and 2018). Changes in leaf area, light interception, leaf and canopy net carbon exchange rate (NCER), and transpiration were recorded. Results show that pruning reduced leaf area and canopy photosynthetic activity but improved water use efficiency by enhancing water retention through reduced transpiration and NCER. Pruning affected fruit size and fresh weight but had no significant effect on fruit colour, soluble solids content, starch, or firmness. The study suggests that moderate pruning enhances light penetration and tree architecture, which may contribute to better physiological crop load and fruit quality under mild tropical conditions. Significance of this Study What is already known on this subject? Canopy management is a well-established practice in fruit tree cultivation, aimed at improving light distribution within the tree canopy. In temperate climates, techniques such as pruning, thinning, and training have been shown to enhance tree growth, fruit development, and quality. However, the impact of these practices on apple trees (Malus domestica) grown in tropical regions with mild winters, where growing conditions differ significantly from temperate zones, has been less well-explored. What are the new findings? This study provides new insights into the effectiveness of canopy management techniques for apple trees in mild winter tropical conditions. The research demonstrates that proper canopy management significantly improves light penetration, resulting in better tree growth and enhanced fruit quality. It also highlights that optimizing canopy structure can alleviate common challenges in tropical climates, such as insufficient light exposure and uneven fruit ripening, leading to more uniform and higher-quality fruit production. What are the expected impacts on horticulture? The findings are expected to impact apple production in tropical regions by offering a viable strategy for enhancing orchard productivity and fruit quality. By adapting canopy management practices to tropical conditions, growers can achieve more consistent yields and better-quality fruit, potentially expanding apple cultivation into new regions with previously unsuitable growing conditions. This could have economic benefits for tropical apple farmers, contributing to increased sustainability and profitability in apple production

Keywords

• Malus domestica
• canopy light interception
• tree growth
• fruit quality
• water use efficiency
• pruning severity