Estimativa da área foliar do girassol por método não destrutivo

Abstract

Simple, rapid, and non-destructive methods that help to estimate leaf area accurately are very important to assess plant growth under field conditions. The objective of this study was to adjust equations to estimate the area of a single sunflower leaf and also the area of total leaves per plant as a function of linear measurements of them. It was also verified the possibility of using common models for the sunflower cultivars BR-122 and M-734. Six plants of each cultivar in the early stage of flowering and full flowering were harvested. The area of each leaf was determined by the direct method. The length along the midrib and the width perpendicular to leaf insertion in the petiole were determined. Linear, quadratic, cubic, exponential, and potential models were adjusted. The potential models Ŷ i = 1.6329X i1,7164 and Ŷ i = 0.5405X i1,0212 using the width measurements and width x length, respectively, were the most adequate to estimate the leaf area. The model Ŷ i = 5.1014X i2,4383 allowed to precisely estimate the total leaf area according to the number of leaves per plant. The accuracy of the adjusted equations to estimate each leaf are and total leaves area was not reduced when common models were adjusted to the two cultivars used.