Non-destructive measurement of leaf area and leaf pigments in feijoa trees

Método não-destrutivo para estimar área foliar e pigmentos foliares em feijoa

ABSTRACT

Leaf area (cm² per leaf) and leaf pigment content are important traits that can be used to better understand a plants physiology. In this study, empirical non-destructive models for leaf area and leaf pigment based on the leaf dimensions, length (L) and width (W) in centimeters, and chlorophyll meter readings were developed for feijoa (Acca sellowiana). The experiment was carried out during January 2016 using five-year-old trees of 60 genotypes, grown under field conditions in the state of Paraná, Brazil. The proposed leaf area (LA) model was $$LA=0.0022L^3+0.1482W^2+0.6159LW+0.1076$$ (R² = 0.99). Three current leaf area models found in the literature were also assessed. All of the already created models were less accurate than the model proposed in this article. The proposed leaf pigment models were based on the Falker Chlorophyll Index for Chlorophyll a (A) and b (B), these were $$Ch{l}_a=2.564A+13.098B-42.605$$ (R² = 0.94), $$Ch{l}_b=1.538A+3.287B+8.847$$ (R² = 0.86) and $$Carotenoids=0.947B+8.943$$ (R² = 0.88) expressed as µmol m^-2 of leaf blade. In conclusion, the proposed models in this study were shown to be a reliable non-destructivel way of estimating A. sellowiana leaf area and leaf pigment.

Key words:
indirect estimates; pineapple guava; Acca sellowiana