Elucidating the Yield and Quality Response of Lime and Lemon under Different Spacings in Sub-tropical Conditions

Increased tree density has been implemented as a strategic tool to enhance agricultural yield in a sustainable way and hence net returns. It is advantageous especially in fruits such as lime and lemon, where the tree canopy progressively expands over time and land remains unutilized owing to conventional spacings. As a result, a field investigation was undertaken to evaluate the effect of planting density on the production of lime and lemon cultivars, viz., 'Kagzi lime' (Citrus aurantifolia [Christ.] Swingle), 'Limequat' (C. aurantifolia x Fortunella japonica) and 'Baramasi lemon' (C. limon [L.] Osbeck) budded on 'Rough lemon' (C. jambhiri Lush.) rootstock at the Punjab Agricultural University, Ludhiana, India. The experimental grove was comprised of six plant spacings, i.e., 6 m x 6 m, 6 m x 5 m, 6 m x 4 m, 5 m x 5 m, 5 m x 4 m and 4 m x 4 m in a randomized block design (RBD) in triplicate with three trees per replication. Fruit yield, fruit weight, juice content, total soluble solids (TSS), ascorbic acid, as well as phenolic and flavonoid content were recorded to be highest in 'Baramasi lemon'. Regardless of the cultivars, lime and lemon trees spaced at the widest spacing were found to be superior in terms of fruit yield and quality than the rest of the spacings. Fruit yield was reported to be positively correlated with number of fruits, fruit weight, juice content, TSS, vitamin C, peel thickness, as well as phenolic and flavonoid content; however, it was negatively correlated with titratable acidity. Overall, the findings of this study revealed that the cultivar 'Baramasi lemon' outperformed the other cultivars under sub-tropical conditions of northern India.