Non-destructive Method for Estimation of Leaf Area of Clerodendrum Volubile, a West AfricanNon-conventional Vegetable

Abstract

In this study, mathematical models for calculating the area (A) of each of 486 randomly selected leaves of clerodendrum volubile were developed from the well-known general equation A = KLW where L is the length and W is the maximum width of the leaf. Each leaf was first photocopied on A4 paper of known weight per unit area, and after measuring the length (L) and maximum width (W), the leaf template was cut out from the paper to determine its weight. The true area of each leaf was determined from the weight and area of the A4 paper and the weight of the leaf template. Multiple regression analysis of data was done with SPSS 16.0 computer package program to find the relation between the leaf area and the leaf linear dimensions. The model equations obtained are stated as follows: (i) A = 0.683 LW with R2 = 0.992 and RMSE = 2.516, (i) Log(A) = 0.157 + 0.994Log(LW) with R2 = 0.976 and RMSE = 0.038, (ii) Log(A) = - 0.118 +0.884Log(L) + 1.097log(W) with R2 = 0.976 and RMSE = 0.037, (iii) Log(A) = 0.891Log(LW) with R2 = 0.999 and RMSE = 0.045, A simplified model equation for obtaining the area of the leaf of clerodendrum volubile in the field is found to be A = 0.321L2 with R2 = 0.980 and RMSE = 3.919 as W = kL (R2= 0.988, RMSE = 0.460) and LogA = - 0.450 + 1.956LogL with R2 = 0.928 and RMSE = 0.646.