Interferência de plantas daninhas em diferentes densidades nos aspectos fisiológicos do grão-de-bico

Abstract

The objective of this work was to evaluate the effect of Euphorbia heterophylla, Commelina benghalensis and Glycine max on the physiological characteristics of chickpeas. The randomized block design was used, with 4 replications, in a 3 x 4 factorial scheme, composed of 3 weed species (G. max, E. heterophylla and C. benghalensis) and 4 densities (0, 1, 2 and 4 plants.pots^-1 which is equivalent to 0, 14, 28 and 56 plants m^-2). The variables analyzed were: Variable Fluorescence/ Maximum Fluorescence ratio (Fv/Fm), stomatal conductance, internal carbon concentration, transpiration and liquid photosynthesis rate. The Fv / Fm ratio indicated the presence of stress in the chickpeas when living with all the weeds studied, in which G. max was the weed that caused the lowest density of stress (6.67 plants m^-2). With the present work it was possible to conclude that the chickpea suffers strong interference from G. max in its physiological performance, even in lower densities. When in competition with C. benghalensis and E. heterophylla, the chickpeas proved to be more competitive, requiring a higher density of these weeds to cause physiological damage.