Ganho de seleção em genótipos de aveia para cobertura do solo e forragem utilizando índice de seleção

Abstract

The crops of white oats and black oats are diversification alternatives in the winter period, being used for the production of vegetal cover and forage. However, the cultivars recommended for production in the South of Brazil present low performances in floodplain soils. The objective of this work was to estimate the genetic gain in segregating populations of oats for soil and forage cover. The design used was that of increased blocks, intercalated two cultivars with intercalary controls. For the analysis of forage oats, the following variables were measured: number of tillers per plant, sowing days at first cut, dry matter yield, leaf: stem ratio. For soil cover the following variables were performed: Day of the last cut at the first cut, plant height, number of final tillers and total dry matter. Statistical analyzes were performed using the Genes program. For the genetic gain estimation, the classic Smith and Hazel index was used, using five economic weights: DPg, CVg, Mean 1: 1 and random (30,30,500,1500). The data in relation to DPg, CVg and Means, were obtained through Analysis of Variance (ANOVA). However, the 1: 1 weight was assigned to maintain a uniformity among the variables, assigning the same value to all variables. The random weight was attributed seeking greater gain for variables of higher value in relation to forage and for soil cover, in this case assigning a higher value in relation to forage for leaf: stem (1500) and dry matter (500) and for only for the variables total dry matter (1500) and number of final tines (500). The AGROPLANALTO / IPR CABOCLA and FAPA2 / IPR126 black oat crosses present positive gains both in relation to the 1: 1 and CVg weights.