Evaluation of vegetative development of peanut (Arachis hypogea L.) crop under different solar radiation incidence

Abstract

The availability of solar radiation in terms of amount and quality inside the canopy can affect crop physiologic processes, because the increase in peanut yield is directly related with increase of the chlorophyll concentration in leaves. Therefore, based in effect of climatic elements on the crop vegetative development, was aimed to evaluate the effect of radiant flow density in peanut crop, determining the parameter chlorophyll, under different plastic coverings (thickness of 75.10-6 and 150.10-6 meters) and with no shelter. The research was carried out using twelve lysimeters with three plant rows. In each row two soil solution extractors were installed, differentiated by depths from 0.15 and 0.25 m. The values of radiant flow density were obtained by luminosity meter. The collected data were obtained daily in each environment, observing inside and outside of experimental environments. It was also obtained total chlorophyll data. Three measurements were accomplished in the last three weeks of the vegetative crop cycle, at the 85, 94 and 101 Days After Sowing (DAS), which were obtained two measurements by plant line, being one for each depth, therefore, six measurements by each lysimeter. It was concluded that peanut harvest can be accomplished with success in extreme period of the vegetative crop cycle, of 120 to 130 DAS. It was also verified a larger solar incidence in environment without plastic covering, providing an efficient development of the peanut crop outside the protected environment. In all evaluations, smallest chlorophyll index occurred in environment with larger plastic film thickness, promoting reduction in photosynthesis process. The factor extractor’s depth did not present significant differences, considering the environment with no shelter as others one with plastic covering.