Análise de crescimento e valor protéico de cultivares de sorgo

Abstract

A widely used method to understand the dynamics of crop production is the growth analysis, which details the morphological and physiological changes as a function of time through the accumulation of dry matter. Studies on growth analysis in forage plants help to understand the effects of management strategies employed under various medium conditions. In this sense, the objective of this work was to evaluate the morphophysiological components through growth analysis and crude protein content of four sorghum cultivars (BRS 800, BRS 802, BRS 810 and Qualimax). The research was conducted in a greenhouse at the Campus of the Federal University of Amazonas (UFAM) from March to August 2016. The experimental design Project was completely randomized in a factorial scheme 4x7, consisting of 4 sorghum cultivars and 7 evaluation periods Which corresponded to 14, 28, 42, 56, 70, 84 and 98 days after the emergency (AED). In this study, plant height, leaf area, shoot dry matter weight, leaf area index, leaf area ratio, specific leaf area, leaf weight ratio, net assimilation rate, relative growth rate, and Protein value of the cultivars. BRS 810 and Qualimax obtained the highest leaf aerial index with maximum values at 63 DAE. BRS 810 and Qualimax stood out from the other cultivars regarding leaf area index, leaf area ratio, specific leaf area and relative growth rate, being a good forage option. BRS 800 presented the highest net assimilation rate, which gives it the best photosensitive efficiency. All cultivars presented crude protein contents between 11% and 15%, which meets the nutritional requirements of the animals. Sorghum cultivars should be used in growth stages close to 50 days, in order to obtain higher forage production.