Selection of arabica coffee progenies tolerant to heat stress

Due to high temperatures, practically all coffee farms in the state of Rondonia are of the C. canephora species. Thus, importing arabica coffee from other states becomes necessary for composition of blends, as well as for the specialty or gourmet coffee market. The purpose of this study was to select arabica coffee genotypes that exhibit satisfactory agronomic performance under high temperature conditions. The experiment was conducted in Ouro Preto do Oeste, RO, Brazil, with mean annual temperature of 25.8 degrees C and mean annual rainfall of 2300mm year(-1). The experiment was composed of 114 arabica coffee genotypes, with 103 progenies and eleven control cultivars, provided by EPAMIG. A randomized block experimental design was used with three replications, spacing of 3.0x1.0 meters and five plants per plot. All the crop seasons showed significant difference for the green coffee yield trait. In joint analysis, significant differences were detected among progenies and control cultivars. In the average of the four harvests, green coffee yield was 32.38 bags ha(-1). The cultivars 'Catuai Vermelho IAC 15', 'Obata IAC 1669-20' and 'Catucai Amarelo 2SLCAK' stood out, achieving yields greater than 40 bags ha(-1). The gain obtained from selection was 14.33 bags ha(-1), which is equivalent to an increase of 44.04% in production of green coffee. The progeny H514-7-10-6-2-3-9 stood out with an average yield of 51.20 bags ha(-1). In regard to maturation cycle, 56% of the progenies were classified as early maturity and 44% as medium maturity. Late maturity genotypes were not observed.