Model adjustment for estimating bell pepper leaf area index and dry mass accumulation as a function of degree days

Abstract

This study was carried out at SIPA (Integrated Agroecological Production System), in Seropédica, RJ, Brazil, with the objective of generating models for characterizing variation and evolution of leaf area index (LAI) and total dry mass of Bell pepper as a function of degree days. Experimental design was of plots split in time, with three replications. The matematical models obtained by regression analysis on the basis of the significance of the coefficients, the F value in the variance analysis of regression, and higher determination coefficient (R²). Based on adjusted curves for LAI and dry mass and in their respective maximum values degree days is a viable methodology for determination of crop phenological stages. The values of LAI and biomass accumulated by the plants were not significantly different between tillage systems. Bell pepper needed a total of 1533 degree days for completing its productive cycle, with maximum dry mass accumulation occurring at 1059 and 1148 degree days for conventional and no till cropping, respectively.