Growth analysis of corn and beans under different shade conditions

Abstract

The environmental effects are based on prevalent factors in plant development, since it determines the conditions for maintenance of the life. Therefore,  the aim of this study was to evaluate the growth characteristics at the initial stage of corn and beans in different environments of cultivation: protected environment (with screen shades transparency of 50%) and the external environment. The experiment was carried out during September to November, 2008, with a duration of sixty days, in an area of the meteorological station of the Federal University of Ceará, using a randomized design in a factorial 2x2 (two cultures and two treatments) with four replications. Planting of seeds were carried out in pots with a capacity of 10 kg containing sieved soil and applied fertilizer. The variables evaluated in both treatments (protected environment and external environment were: leaf area, leaf dry weight, dry stem, root dry mass, total dry matter, leaf area ratio, leaf weight ratio and specific leaf area. The results were submitted to variance analysis and the means  were compared by the Tukey test in both experiments. It was concluded that the values obtained in beans and corn crops, for the production of dry matter, were higher in plants grown in the external environment in relation to the protected environment. Morphologic changes in plants were observed in order to adapt the plants to adverse conditions. The growth of maize, a C₄ plant, had better results than growth of beans, a C₃ plant, in both protected environment and external environments.