Ecofisiologia do desenvolvimento e a estimativa por uso de modelos matemáticos em Poaceas e Fabaceas

Abstract

The increase in agricultural productivity is related to the management and positioning of genetics adapted to the most varied environmental conditions, therefore, determining plant growth is essential to obtain high yields. Thus, the present study aimed to evaluate the development of corn, sorghum, soybean and bean plants using different methods. In Chapter I, the ecophysiology of the growth of corn hybrids in the second crop was evaluated, at regular intervals of 14 days after sowing (DAS) by the simple logistic method, for six commercial hybrids. In Chapter II, the ecophysiology of sorghum growth under the effect of nitrogen management was evaluated, at regular intervals of 14 DAS by the simple logistic method, for nitrogen doses, being: T1: 0 N; T2: 10 kg of N at sowing + 55 kg in topdressing; T3: 20 kg of N at sowing + 55 kg in topdressing and T4: 30 kg of N at sowing + 55 kg in topdressing. In Chapter III, a morphophysiological analysis was evaluated: a non-destructive technique to evaluate the growth of beans and soybeans. Data were collected at regular DAS intervals by the destructive method in order to determine non-destructive growth models for soybeans under the effect of soil flooding and beans under the application of growth regulator. In Chapter IV, a non-destructive technique to evaluate the growth of maize and sorghum plants was evaluated: morphophysiological growth analysis. Data were collected at regular DAS intervals by the destructive method in order to determine non-destructive growth models for maize hybrids and nitrogen doses in sorghum. The results demonstrated that plants of different corn hybrids presented a variation of 1239.08 to 1681.36 g m-2 in dry mass accumulation. Different doses of nitrogen topdressing in sorghum plants presented variations of T1 16.65% and T4 51.11% in dry mass accumulation. The correction factors for beans were 0.104 and 0.0006 for (Af) and (Wf), respectively. For soybeans, the factors were 0.14 (Af) and 0.301 (Wf). The results obtained in these studies also demonstrated that the correction factors for Af were 10.35 and for Wf were 0.072 for corn. For sorghum, the correction factor for Af was 8.75 and for Wf was 0.038. The efficiency of corn and sorghum in transforming sunlight into biomass is limited by environmental variations, affecting productivity. Models that calculate leaf area and biomass help to improve production. Soybeans and beans react differently to flooding, with soybeans adjusting at 60 days and beans reaching their peak at 38 days after sowing. It is concluded that these data are fundamental to improve agricultural management in variable conditions, and may affect the accumulation of nutritional reserves, leading to significant implications on the final yield of crops.