Estimativa do índice de área foliar e determinação do coeficiente de extinção luminosa da abóbora Cucurbita moschata var. Japonesa

Abstract

The indirect methods for the determination of leaf area index (LAI), which are characterized in total that measures radiation penetrate inside the cover, are currently the most used, because they are more practical. The study was to measure and estimate the leaf area index, adjust an equation through product (length x width x leaf area) and determine the light extinction coefficient in pumpkin Cucurbita moschata var. japanese. To develop a model, twenty sheets were measured by calculating the length and width and to the estimation of leaf area index were used five repetitions of 1 m2, being made three measures inside the leaves and a measure at the top of the plants. Later, its leaves were collected for leaf are a measurements in the laboratory. For obtaining the light extinction coefficient (k) were measured fifteen points of culture, in conditions of sun and shade. The LAI was measured and estimated 2.624 and 1.145, showing a mathematical model with linear growth and yields a straight and the extinction coefficient was 0.59. This work was important to determine the values of LAI measured, estimated and the extinction coefficient for the cultivation of pumpkin.