Melhoramento do cafeeiro: XVIII- O efeito do alelo Xanthocarpa na produção

Abstract

Previous experimental data have inrlicaled that yellow pericarp coffee types showed a tendency to produce higher yields than the corresponding red fruited ones. In order to study the possible effects of the xanthocarpa allele on yield, the production of 193 plants of a progeny derived from a heterozygous (Xcxc) bourbon plant was determined individually in 1958 and 1959. The progeny segregated as follows: 46 red, 87 heterozygous and 60 yellow fruited plants. The red, heterozygous and yellow fruited classes yielded respectively, 8.1, 8.2 and 7.6 kg of ripe fruits per plant, showing that the xanthocarpa allele does not influence the yield of the bourbon variety. Observations on time i>f fruit ripening in these three classes of plants in 1959 have indicated that the yellow fruited coffee is earlier than the red one, while the heterozygous class is intermediate (table 2). As great efforts are now being made in Brazil to increase the quantity of high grade coffees, prepared by the wet method (through pulping), which requires, exclusively, the harvest of mature fruits, the differential behaviour in maturity of red and yellow types is also of considerable practical importance. Farmers are now being advised to establish, at least, part of their coffee groves with yellow pericarp varieties in order to extend, as much as possible, the total period of coffee harvest.