04719naa a2200205 a 450000100080000000500110000800800410001910000200006024501330008026000090021352040250022265000170424765000190426465000400428365000150432370000200433870000200435870000230437877301120440111318582022-03-11       2021    bl uuuu     u00u1 u    #d1 aROCHA, D. J. A.  aStability and mega-environment identification of forage oats production in the southern region of Brazil.h[electronic resource]  c2021  aIn the southern region of Brazil, forage oats are the most used species for sowing to provide quality forage for feeding ruminants during the winter period. Forage oats have become increasingly important in an integrated grain and livestock system, as a forage crop in succession with summer crops such as soybeans and corn. Several lines and cultivars of forage oats have been evaluated in the National Forage Oats Trial (ENAF) in Brazil. Such trials are a valuable source of information for inference about the adaptability and stability of forage production. The differential response of genotypes in different environments is known as genotype-by-environment interaction (G ?? E) and it interferes with the selection and recommendation of cultivars. The GGE biplot is a method that allows the graphical visualization of genotype effects and G x E interaction of multi-environment trials. This study aimed to evaluate the stability of production and to identify mega-environments for forage oats in the southern region of Brazil. The data of the trials were gathered from the Meetings of the Brazilian Oat Research Commission. The ENAF aims to evaluate genotypes of oats from different research institutions in different environments. The trials were conducted during four years (2016 to 2019) and at eight locations: Itaqui, Passo Fundo and Tr??s de Maio in the state of Rio Grande do Sul; Lages and Papanduva, in Santa Catarina; Londrina and Santa Teresa do Oeste in Paran??; and Cap??o Bonito in the state of S??o Paulo. Nine genotypes were evaluated, three of black oat (Avena strigosa Schreb.) and five of white oat (Avena sativa L.). The sowing was carried out with a density of 350 viable seeds/m?? for all trials. The plots consisted of five rows of four meters long and 0.20 m between the rows (4.0 m??). The experimental design was a randomized complete block design, with four replicates. The fertilization used was based on the table of fertilizer and liming recommendation for the states of Rio Grande do Sul and Santa Catarina. For the evaluation of forage yield, the three central rows were cut (2.4m??), and herbage dry matter yield was determined at all locations. The data were subjected to analysis of variance. Once the presence of G x E was observed, the interaction and stability of production were analyzed using the GGE blipot graphical visualization method. The present study revealed that the interaction of cultivar and environment was significant, which means that the evaluated cultivars behaved differently over the years at different locations. The variation was explained for the most part by the environmental variance. The cultivar UPFA 137 showed high productivity associated with production stability during the four years at eight environments, being considered as the ideal genotype. The mega-environments are defined by different winning cultivars (YEN et al., 2000), and the present study suggests the existence of two mega-environment for forage oats production in the southern region of Brazil. The first mega-environment contains the locations of Santa Tereza do Oeste, Londrina, and Tr??s de Maio, and have the cultivar IPR Suprema as the winner (corner genotype). The others locations constitute the second mega-environment with the cultivar UPFA 137 being the winner. Despite IPR Suprema winning just at three locations, this cultivar gave a higher average yield across the locations. The cultivars IPR Esmeralda, FAPA2, Fundacepfapa 43, and Iapar 61 performed intermediately between IPR Suprema and UPFA 137 at all locations. The other corner cultivars, IPR Cabocla, Moreninha, and IPR 126 were the lowest-yielding cultivars. The GGE biplot model proved to be suitable for the analysis of multi-environment experiments of the National Forage Oat Trial and mega-environments identification for forage oats production in Brazil. This information is valuable in adopting the best management for individual cultivars and the recommendation of cultivars for each environment.  aAvena sativa  aAvena strigosa  agenotype by environment interaction  aGGE biplot1 aFLARESSO, J. A.1 aC??RDOVA, U. A.1 aSTRADIOTO NETO, J.  tIn: CONGRESSO BRASILEIRO DE MELHORAMENTO DE PLANTAS, 11., 2021, Online. Resumos... Pelotas, RS: SBMP, 2021.