Ocurrencia de Cercospora coffeicola y Hemileia vastatrix en progenies de Big Coffee VL (Coffea arabica)

Abstract

The study was carried out in an area of the Agriculture Department (21º14'43 "S and 44 ° 59'59" W, 919 meters above sea level, at the Federal University of Lavras (UFLA). progenies were evaluated of the Big Coffee VL variety (Coffea arabica L.), from Piumhí-Minas Gerais-Brazil, (2019, 2020). The progenies are classified by grain size (Large, Medium and Small). The Idea of Cercospora coffeicola and Hemileia vastatrix, from the Big Coffee VL progenies, were evaluated. The statistical model was the Randomized Blocks (DBC) with split-plots on time, with assessments over time. The main plot was the 108 plants and the subplots the six genotypes per progeny. The analysis of variance was performed for the Idea of, Hemileia vastatrix and Cercospora coffeicola, with data transformation: root (x + 1). The genotypes had a significant variation for the F test. This means that, depending on climatic conditions (temperatures and rainfall), the genotypes behaved differently, which is interesting in a breeding program. The variation coefficients are good. In general, when they are below 30 %, it is an acceptable range. For Hemileia vastatrix, the Scot-Knott mean test (<0.05) grouped the Idea results into groups: group “a” (genotype 9) has the highest value, group “b” (genotypes 4.6 , 7,8,12,16, 17 and 18), presented intermediate values while group “c” (genotypes 1, 2, 3, 5, 10, 11, 13,14 and 15) show lower Idea values of Hemileia vastatrix. “P” progenies tend to have higher mean values for Hemileia vastatrix. For Cercospora coffeicola, group “a”, (1, 2, 4, 8, 10, 12 and 16), and group “b”; (3, 5, 6, 7, 11, 13, 14, 15, 17 and 18), presented intermediate values. The groups were formed by genotypes followed by the same letter, so that each group is the same, but different from the others. From the evaluated progenies it is possible to select Hemileia vastatrix and Cercospora coffeicola tolerant plants. Genotype 5 (M-20) was found among the best for Hemileia vastatrix and Cercospora coffeicola resistance. Genotypes 5 (M-20) and 7 (G-12) showed lower Idea of Cercospora coffeicola and can be considered a good material for genetic improvement. These materials may be interesting in the search for multiple tolerances to Hemileia vastatrix and Cercospora coffeicola.