Non-destructive and accurate method for predicting cowpea leaflet area

Abstract

Leaf area (LA) is one of the most important measures for evaluating plant growth, as it directly influences photosynthetic activities, transpiration, and is closely correlated with dry matter accumulation. Destructive and non-destructive methods can be used to evaluate this. In this context, this work aimed to formulate and fit allometric equations to estimate leaflet area in cowpea accessions as a function of leaflet linear dimensions. This study was carried out at the Federal Rural University of the Semi-Arid Region, Mossoró, RN, Brazil. A total of two thousand leaflets from ten cowpea accessions were evaluated. Length (L), width (W), and area of leaflets were measured, and the derived variables L × W, L², and W² were subsequently calculated. Descriptive analysis was used to calculate the maximum, mean, and minimum values of the data. The criteria for choosing the best equations to estimate the leaflet area in individual and pooled analysis of cowpea accessions were: coefficient of determination, Akaike’s information criterion, Willmott’s agreement index, and root mean square error. In addition, principal component analysis was also performed. The leaflet area of cowpea can be estimated using a non-destructive method based on biometric measurements from images. Using the product L × W, the leaflet area of cowpea accessions can be estimated by the equation ŷ = 0.6685×LW.