Ciência Rural
URI permanente para esta coleçãohttps://thoth.dti.ufv.br/handle/123456789/10366
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Resultados da Pesquisa
Item Parasitism of Meloidogyne exigua races 1 and 2 in coffee plants derived from Timor Hybrid(Universidade Federal de Santa Maria, 2021) Pereira, Antonio Alves; Caixeta, Larissa de Brito; Fatobene, Bárbhara Joana dos Reis; Oliveira, Claudio Marcelo Gonçalves; Gonçalves, Wallace; Guerreiro Filho, OliveiroTo investigate the degree of parasitism of two populations of Meloidogyne exigua, the gall index (GI) and the reproduction factor (RF) of M. exigua races 1 (Est E2) and 2 (Est E1) were analyzed in 47 progenies on F3:4 or F4:5 generation derived from the crossing between Coffea arabica cv. Catuaí Amarelo and Timor Hybrid. C. canephora cv. Apoatã IAC 2258 and C. arabica cv. Catuaí Vermelho IAC 144 were used as resistance and susceptibility checks, respectively. The genotypes that were classified as resistant or susceptible by RF were similarly classified by GI, showing a close relationship between both methodologies. The data also indicated no differences in virulence between the nematode populations, since the progenies showed similar resistance reactions to the M. exigua races 1 and 2. According to GI from the 47 mother plants evaluated, 27 progenies (57.4%) were classified as resistant to M. exigua races 1 and 2, with GI ranging from 0.0 to 1.4 and 20 progenies (42.6%) were susceptible with GI from 2.6 to 4.4. These results showed that most of the evaluated germplasm was very promising in relation to the development of new Arabica coffee cultivars with resistance to M. exigua.Item Selection of arabica coffee progenies tolerant to heat stress(Universidade Federal de Santa Maria, 2015-07) Teixeira, Alexsandro Lara; Souza, Flávio de França; Pereira, Antonio Alves; Oliveira, Antonio Carlos Baião de; Rocha, Rodrigo BarrosDue 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°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 ‘Catuaí Vermelho IAC 15’, ‘Obatã IAC 1669-20’ and ‘Catucaí 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.