Multivariate analysis of morphological and biochemical traits of lemon under different irrigation intervals

Lemon is an economically and nutritionally important fruit crop in Bangladesh, yet its productivity is often constrained by water scarcity and suboptimal irrigation practices. This study evaluated the morphological, physiological, yield, and biochemical responses of lemon to different irrigation intervals under field conditions using multivariate analysis. The experiment was conducted at the Bangladesh Agricultural University Germplasm Centre using a randomized complete block design (RCBD) with five irrigation treatments: no irrigation (T0), regular irrigation (T1), irrigation every 15 days (T2), 30 days (T3), and 45 days (T4), each with three replications. Significant treatment effects were observed for fruit weight, juice content, vitamin C, total sugar, reducing sugar, titratable acidity, chlorophyll content, and relative water content (RWC). Regular irrigation (T1) and irrigation at 15-day intervals (T2) produced the highest fruit weight, juice content, and yield, whereas the no-irrigation treatment (T0) recorded the highest vitamin C, total soluble solids, reducing sugar, and total sugar, indicating stress-induced biochemical responses associated with osmotic adjustment. Principal Component Analysis (PCA) and correlation analysis identified fruit weight, juice content, yield, and sugar-related traits as the major contributors to variability among irrigation treatments. Regression analysis indicated generally weak linear relationships, suggesting that irrigation interval alone explained only a small proportion of trait variation. Cluster analysis grouped T1 and T2 as the most favorable irrigation regimes for maintaining superior growth, yield, and overall fruit quality. These findings demonstrate a clear yield–quality trade-off under water stress and provide practical guidance for optimizing irrigation management to improve water-use efficiency and sustainable lemon production in water-limited environments.