Identification of Optimal Environments for Cotton Cultivars in the Brazilian Cerrado

Core Ideas There are genotype × environment interaction for cotton in Brazil Genotype + genotype × environment interaction identified essential environments in Cerrado. Brazilian Cerrado is divided in two mega‐environments. In Brazil, cotton cultivars are tested annually in different environments at the final stages of breeding programs. Thus, identifying groups of environments with similar edaphoclimatic characteristics is crucial to determine the environments with higher discriminating ability of genotypes, known as essential environments. This work aimed to divide the Brazilian Cerrado environments into mega‐environments in relation to fiber yield of cotton genotypes and identify essential environments for the conduction of trials in each mega‐environment. Fiber yield was evaluated in 19 competition trials of cotton cultivars in the 2013–2014 and 2014–2015 seasons. The experimental design was a randomized block with 12 treatments and four replications. After verifying significant genotype × environment (G×E) interaction, mega‐environments and essential environments were identified using the genotype + G×E (GGE) biplot method. Two mega‐environments were detected. Mega‐environment 1 was formed by Santa Helena do Goias–Goiás State (GO), Primavera do Leste–Mato Grosso State (MT), and São Desidério–Bahia State (BA). Mega‐environment 2 was formed by: Trindade–Minas Gerais (MG), Campo Verde–MT, Pedra Preta–MT, Luiz Eduardo Magalhães–BA, Magalhães de Almeida–Maranhão State (MA), Teresina–Piauí State (PI), and Chapadão do Sul–Mato Grosso do Sul State (MS). Primavera do Leste in mega‐environment 1 and Pedra Preta in mega‐environment 2 are the optimal sites to conduct trials with cotton genotypes because due to high yield discriminating ability and more representative. This information is useful for breeders to plan the next steps for trials in the Brazilian Cerrado, minimizing resources, such as labor and trial time.