Crescimento, produtividade e balanço hídrico de gramíneas forrageiras, nos tabuleiros costeiros de Alagoas

Abstract

Livestock farming is generally characterized by the extensive exploitation of pastures with low quality and low productivity, with the aim of evaluating the growth and production of six grass genotypes for pasture, adjusting empirical models to growth variables and identifying the best genotype (s). The experiment was conducted at the Agricultural Sciences Center (CECA) in the Alagoas Coastal Trails Region, with a randomized complete block design with thirty plots. The treatments were composed of grass genotypes: Capim Elefante cv. BRS Kurumi, Brachiaria decumbens cv. Basilisk, Brachiaria hybrid cv. Mulato II, Panicum maximum cv. Massai and Panicum maximum cv. Mombasa and Brachiaria brizantha cv. Xaraés. The evaluation period was from 04/17/2018 to 08/12/2018. The variables analyzed in this experiment were leaf area index (LAI), light interception index (I.L.), mean plant height (I.D.) and fresh biomass (M.F.) and dry biomass (M.S.). The 3-parameter Sigmoidal model was adjusted to the mean plant height and the linear model was adjusted to the LAI. The significant qualitative variables were submitted to the Tukey test at the 5% level of error probability. In the evaluation period there was no water and thermal restriction. The values estimated by the sigmoidal and linear model were adjusted to the observed data. According to the F test there was no significant difference between the treatments at the 5% probability level for the LAI and light trap (IL) variables, but there was a significant difference at the 1% probability level of the canopy height error ( AD), days between cuts (PEC) and fresh mass (MF). For the dry mass (DM) there was a significant difference in the level of 5% of probability between treatments. With this, it was concluded that the empirical models fit well the analyzed variables and that the Panicum máximum cv. Mombasa, Panicum máximum cv. Massai and Capim elefante cv. Kurumi, are the most suitable genotypes for the coastal board region.