L. C. Monaco

Melhoramento do cafeeiro: XL-estudos de progênies e híbridos de café catuaí

Progenies of the cultivars Catuai Vermelho and Catuai Amarelo of Coffea arabica and populations derived from crosses between selected trees of these and plants of other cultivars, were evaluated in relation to plant characteristics and average yield of ripe fruits. After analysis of 64 Catuai progenies, only two revealed to be heterozygous for the Caturra allele (Ctct); among these, 19 were homozygous for red exocarp (XcXc),. 42 for yellow exocarp (xcxc) and three heterozygous (Xcxc) for this characteristic. Concerning the occurrence of empty locules, 17 progenies were heterozygous and 47 homozygous, without this abnormality. Catuai plants reached an average tree height of 190 cm and an average tree diameter of 189 cm after nine years in the field, while the Mundo Novo cultivar reached an average height and diameter of 238 and 211 cm, respectively. The Catuai Vermelho (progenies H 2077-2-5-46, and H 2077-2-28), and the Catuai Amarelo (progenies H 2077-2-5-32, H 2077-2-5-5, H 2077-2-12-64, H 2077-2-5-66, and H 2077-2-5-39) were the most productive and revealed homozygous for the caturra alleles. In four of the backcross populations of Catuai x Mundo Novo and in two F2 populations of hybrids between these cultivars, promising coffee trees were selected to be further used in the breeding program. A few promising plants were also detected in the F2 of the hybrid Mundo Novo x Sao Bernardo. These latter selections nave also a small height and it is expected to be used at higher field densities.

Melhoramento do cafeeiro: XXXVII - Observações sobre a resistência do cafeeiro ao bicho-mineiro

A survey on the level of resistance of coffee species and cultivars to the leaf miner (Perileucoptera coffeella) was carried out under field conditions. It was observed that the diploid coffee species namely C. eugenioides, C. dewevrei, C. racemosa, C. liberica, and C. kapakata present a high level of resistance, while C. stenophylla is almost immune to the insect. C. canephora and C. congensis are susceptible. Within the species C. arabica only the mokka variety showed some degree of resistance. No relation was noticed between resistance to the leaf miner and the leaf blade thickness, in the diploid, tetraploid and octoploid forms of C. arabica and diploid and tetraploid C. canephora. The leaf blade size also does not influence the leaf miner attack. Observations on the attacked leaves of some interespecific F1 hybrids between diploid coffee species indicated the dominant nature of the resistance. Suggestions are presented for the transfer of the resistance alleles to the economic susceptible C. canephora and C. arabica species.

Café Icatu como fonte de resistência a colletotrichum coffeanum

Linhagens e progenies do cultivar icatu, selecionadas em Campinas, foram testadas na Coffee Research Station, Ruiru, Quenia, a fim de avaliar o grau de resistencia ao ataque de Colletotrichum coffeanum, agente responsavel pela molestia mais conhecida por CBD. Os dados de infeccao obtidos para 11 linhagens e sete progenies foram comparados com os dos cultivares testemunhas Rume Sudan, resistente, e SL 28, suscetivel. Considerando apenas a frequencia de resistentes, com grau 1 de infeccao, destacaram-se a progenie H 4782-10 M e a linhagem LCH 3851-4 T. As populacoes com graus de 1 a 4 de resistencia ocorreram em menor escala do que no Rume Sudan, porem salientou-se a progenie H 4782-10 M, com elevada resistencia. As maiores porcentagens de plantas suscetiveis foram verificadas nas linhagens LCH 3849-7 M e LCH 4782-13 T, as quais se aproximam da linhagem suscetivel SL 28. Os dados preliminares indicam que o germoplasma icatu, como o hibrido de timor, oferece perspectivas de constituir razoavel fonte de resistencia genetica ao agente da CBD.

Efeito de alta temperatura no desenvolvimento de Hemileia vastatrix em cafeeiro suscetível

The development of rust epidemics in tropical conditions of Brazil has been different than previously expected. Despite of high humidity the development is reduced to a minimum during the summer. High temperature was assumed to have a detrimental effect on the rust development. This paper reports the results of a study concerning the effect of high temperature on Hemileia vastatrix development. Temperature treatment of inoculated young plants at 400C for 4 hours in 4 consecutive days was sufficient to prevent rust development. The curative effect was permanent indicating that the fungus was destroyed inside the plant tissue. Practical implications of such results are considered.

Resistência do cafeeiro a nematóides: I - Testes em progênies e híbridos, para Meloidogyne exigua

Procurou-se identificar fontes de resistencia ao nematoide Meloidogyne exigua em cafeeiros derivados de hibridos interespecificos e em progenies de cafe arabica oriundas da Etiopia, em experimentos estabelecidos em duas localidades. A infestacao foi feita por dois processos usados com frequencia nesse tipo de trabalho. As avaliacoes do grau de ataque foram feitas quatro e 12 meses apos a infestacao, em Campinas e Ribeirao Preto, respectivamente, adotando-se escala variando de zero, para ausencia de galhas, a cinco pontos para grande intensidade de ataque. Verificou-se que a leitura feita aos quatro meses e tao eficiente quanto aos 12 meses, indicando a possibilidade de abreviar consideravelmente a duracao dessas avaliacoes. Notou-se, no experimento de Ribeirao Preto, uma reducao de aproximadamente 8% no crescimento das mudas infestadas e verificou-se, tambem, uma reducao de 11,5% e 12% nos pesos verde e seco das plantas, devido ao ataque do nematoide. De 1.692 plantas examinadas nos dois experimentos, selecionaram-se 106 (6,3%), caracterizadas pela ausencia de galhas. As populacoes derivadas dos hibridos entre Coffea arabica e C. canephora revelaram-se mais promissoras, contribuindo com maior numero de plantas resistentes. As plantas do experimento instalado em Campinas foram inoculadas tambem com a raca II de Hemileia vastatrix para o estudo da resistencia conjunta aos dois patogenos. Essas selecoes, em numero de 38, representam valioso material para o programa de melhoramento do cafeeiro.

Efeito de dias longos no crescimento e florescimento de cultivares de café

The initial reports indicated that coffee is a short day plant. Data later reported, however, revealed that coffee may flower under long day photoperiod. The present study was carried out in order to evaluate the effect of day length on plants of Mundo Novo, Catuai Amarelo, Burbom Vermelho, Semperflorens and Geisha cultivars grown under photoperiod of 12 and 18 hours. Vegetative growth was intensified by 18 hours of light. Flowering occurred more intensely in long day treatment. The data available indicate that induced coffee plants may keep the flowering capacity independently of day length. It is suggested that the age of the coffee branch tissues play an important role to the flowering process.

Melhoramento do cafeeiro XXXVI: produtividade do café de porte pequeno com poda dos ramos inferiores

Thirty coffee progenies homozygous or heterozygous for the genes caturra (Ct), San Ramon (Sr) or laurina (lr) were studied in Campinas to evaluate the yielding capacity of these semi-dwarf coffee types. A triple retangular 5 x 6 lattice, replicated three times with plots having two individual trees, was established in 1967. Individual tree yielding records were taken for the period 1969 to 1972. After the 1972 crop, prunning was performed in one plant of each plot, leaving the other plant as control. Individual tree records for the two following crops were taken. Catuai entries LCH 2077-2-5, H 2077-2-12-158, H 2077-2-5-47, and H 2077-2-12-183 gave the highest total yields in the four years period. The same entries after six consecutive crops have practically equal performance, confirming the feasibility of early selection in C. arabica. No prunning effect was detected on yield, on plant height, and on lateral branches development. Consequently prunning the lower lateral branches may be used to make the mechanical harvesting or spraying operation more efficient mainly for these semi-dwarf cultivars.

Grãos defeituosos em café colhido verde

The frequency of defective coffee beans was determined in samples of unripe fruits of the cultivar Mundo Novo (Coffea arabica).Ten samples of 1000 seeds each obtained from green fruits after sundrying and shelling were independently scored for the commercial defects by three coffee classifiers. Each one of the classifiers recorded the occurrence of green-coated, brown and black beans before and after removal of the silver skin. The data revealed that more than half of the beans had normal green color whereas 44.9 per cent were green-coated, 3.5 per cent were brown and 0.1 per cent were black beans. The removal of the silver skin affected the previous classification giving 59.7 per cent of normal green beans, 39.5 per cent of brown and 0.3 per cent of black beans. These observations indicated that the so-called green-coated beans are caused by the presence of the silver skin which retains green pigments probably chlorophyll. On the other hand the browns which have been considered as product of over-fermentation were scored in a much higher frequency whereas the percentage of black beans was little altered after the removal of the silver skin. The factors responsible for origin of the brown and black beans are discussed. Preliminary studies of the cup quality of the normal green beans selected from these samples indicated that the quality of the beverage had the poor taste characteristic of unripe coffee despite of the appearance of the beans.

Melhoramento do cafeeiro: XXXIX - produtividade e características de progênes S2 e S3 de Mundo Novo e Burbom Amarelo e de híbridos entre esses cultivares

Yield, plant and seed characteristics of S2 and S3 Mundo Novo and Burbom Amarelo coffee progenies and single and double hybrids between plants of these cultivars were recorded in a field experiment located in Campinas. Some of the single hybrids were synthesized according to a chaincross design, in order to evaluate the combining ability of the mother plants. It was verified that the Mundo Novo progenies yielded, on the average, 22 per cent more ripe fruits than those of Burbom Amarelo, and that all Mundo Novo Amarelo progenies yielded less than the best Mundo Novo progeny MP 388-6-20. No significant differences among the yields of single and double hybrids and the best Mundo Novo progenies have been noticed. Single hybrids between high yielding Mundo Novo plants have shown better yielding ability than those among lower yielding ones. It has also been observed that hybrids between Mundo Novo plants outyielded those between Mundo Novo and Burbom Amarelo plants, although no significant differences have been observed. On the other hand no evidence of heterosis for the plant characteristics studied as well as for the yielding ability has been found in the analyzed hybrids.

Melhoramento do cafeeiro XXXIV: comportamento de cafeeiros de porte pequeno, em Monte Alegre do Sul

Analisaram-se o desenvolvimento e a produtividade de progenies de cafeeiros de porte reduzido pertencentes aos cultivares san ramon, caturra e sao bernardo, na regiao montanhosa de Monte Alegre do Sul. Tomou-se como padrao a progenie n.° 662 do cultivar burbom vermelho, de porte medio. Usou-se o delineamento em blocos ao acaso, parcelas subdivididas, com quatro e uma planta por cova em cada parcela a fim de avaliar a reacao de 18 progenies nessas duas modalidades de plantio. De modo geral as progenies tiveram altura pouco maior quando plantadas a quadro mudas. Os dados de producao de cafe maduro no periodo de 15 anos indicaram que apenas algumas progenies nao mostraram diferencas de producao quando plantadas a uma ou a quatro plantas por cova, enquanto outras revelaram diferencas significativas a favor do plantio a quatro mudas. Tambem mostraram que as progenies dos cultivares de porte pequeno produziram menos do que a de burbom vermelho 662. Os valores do coeficiente de correlacao e o da interacao entre a modalidade de plantio e producao das progenies indicaram que as melhores progenies plantadas a uma muda no geral tambem o sao quando plantadas a quatro mudas por cova. Observou-se, ainda, que no plantio a quatro mudas as porcentagens de graos chatos mostraram-se pouco menores e, as de graos moca, pouco maiores, em relacao ao plantio a uma unica planta por cova.