Periódicos

URI permanente desta comunidadehttps://thoth.dti.ufv.br/handle/123456789/3352

Navegar

Filtros

1941 - 194927

Configurações

Data inicial: 1941Data final: 1949

Resultados da Pesquisa

Agora exibindo 1 - 10 de 27
  • Imagem de Miniatura
    Item
    Variedades de cafeeiros
    (Universidade de São Paulo, Escola Superior de Agricultura, 1948-07-15) Mendes, Carlos Teixeira
    No estudo das variedades de cafeeiros que povoam o Estado de São Paulo, além de mil outros detalhes correlacionados com sua cultura e sua genética (produtividade, rusticddade etc.) podemos levar em consideração outros dois pontos de vista : o da "bebida" e o do "tipo". Em relação à primeira, não será preciso perder muito tempo para demonstrar que as variedades predominantes em nossas culturas não constituem a causa das bebidas finas ou das menos boas. Ao meio em que vivem é que se deve imputar, mais que a tudo, a razão do fato. As duas variedades que englobam de modo quase absoluto, nossas culturas, são a "Nacional" e a "Burbon", as, mesmas que, de Campinas para o Norte do Estado produzem afamados cafés e que, na Sorocabana te no vale do Paraiba só contribuem com produtos indiscutivelmente inferiores aos daquela zona.
  • Imagem de Miniatura
    Item
    A broca do café (Hipothenemus Hampei, Ferrari, 1867)
    (Universidade de São Paulo, Escola Superior de Agricultura, 1946) Godoy Júnior, Carivaldo
    A finalidade deste trabalho é a de verificar a procedência ou não das afirmações de vários observadores sobre a infestação da broca, com referência às partes altas e baixas de um cafezal e com referência aos pontos cardeais; finalmente, aproveitámos a oportunidade para estudar, sob o mesmo aspeto, uma parte abandonada.
  • Imagem de Miniatura
    Item
    Observações citológicas em Coffea. VII - A macrosporogênese na variedade "monosperma"
    (Instituto Agronômico (IAC), 1941) Bacchi, Oswaldo
    This article deals with the observations made in the ovule and development of the macrogametophyte in Coffea arabica L. var. monosperma. The young ovule is normally constituted by a rudimentary nucellus surrounded by a single and well developed integument. No irregularities are found until the beginning of the first meiotic division in the ma-crosporocyte which is situated inside the nucellus. The two meiotic divisions are very abnormal and during this process, 44,4 % of the otherwise normal macrospores degenerate. Only. a few normal macrospores are formed. The functional macrospore is not always the chalazal one as in the normal coffee varieties. Irregularities occur also in the subseguent divisions in the formation of the embryo sac. Degeneration then increased from 44,4 to 82,0%. Only one complete embryo sac has been found among the 87 examined ovules. During the formation of the embryo sac, even when complete degeneration occurs, the ovule increases in volume due to the multiplication of the integument cells. From the moment in which the embryo sac should be formed (two days after the flower opening) this increase in volume stops. A total desorganization of the ovule occurs around 105 days after the opening of the flower.
  • Imagem de Miniatura
    Item
    Genética de Coffea. X - Hereditariedade da ocorrência de sépalas desenvolvidas nas flores de Coffea arabica L. Var. goiaba Taschdjian
    (Instituto Agronômico (IAC), 1946) Krug, C. A.; Carvalho, Alcides
    No presente trabalho, os autores, após a apresentação de alguns dados sôbre a natureza do cálice na triho Ixorex (Rubiacex), descrevem os caraterísticos dêste órgão em Coffea, detalhando, a seguir, uma variação encontrada em Coffea arabica L., isto é, na var. goiaba. Esta variedade se carateriza por apresentar sépalas bem desenvolvidas e persistentes, o que dá ao fruto certa semelhança com o da goiabeira (Psidium guajava L.), daí provindo o seu nome. Supõe-se que a presença de um cálice desenvolvido constitui um caráter primitivo, sendo o cálice rudimentar encontrado nos demais representantes do gênero, consequência da supressão quase completa das sépalas, por mutação. A seguir relatam-se os resultados da análise genética, concluindo-se que o desenvolvimento das sépalas é condicionado por um só par de fatôres genéticos principais, sd sd (abreviação de "sépala desenvolvida")- Em F1— Normal x goiaba — (Sd Sd x sd sd) — nota-se uma dominância incompleta, apresentando os híbridos um cálice de tamanho intermediário. A variabilidade da forma e do tamanho do cálice constatada, principalmente entre as plantas híbridas, é atribuída a fatôres genéticos modificadores que afetam a ação do par de fatôres principais ; a variabilidade deste caráter dentro da mesma planta é atribuída a fatôres fisiológicos.
  • Imagem de Miniatura
    Item
    Genética de Coffea. IX - Observações preliminares sôbre quimeras genéticas em Coffea arabica L.
    (Instituto Agronômico (IAC), 1946-06) Carvalho, A.; Krug, C. A.
    Após uma discussão geral sôbre a natureza das quimeras vegetais, esclareceu-se a ação dos alelos Na na em Coffea arabica L., chamando a atenção para diversos casos de mutações somáticas ocorridas com êstes fatôres, o que demonstra a sua instabilidade em determinados ambientes genéticos. A seguir, apresentam-se os resultados de diversas análises, com o fim de esclarecer a natureza genética de quatro dessas mutações somáticas. No primeiro caso (planta 605), o ramo murta (Na na) produzido numa planta nana (na na) revelou ser inteiramente da constituição Na na ou possuir, pelo menos, duas camadas de células geradoras mutadas, entre as quais a segunda, responsável pela origem dos gâmetas. Em duas outras plantas examinadas (RP 101-91 e RP 103-17), de constituição Na na (murta) e que produziram ramos com folhagem típica de bourbon (Na Na) a mutação, entretanto, não atingiu a segunda camada geradora, constituindo os ramos mutados prováveis quimeras genéticas periclinais. Não se conhece a estrutura exata dessas quimeras, porquanto não se sabe ainda quantas camadas geradoras existem em Coffea arabica L., e qual ou quais delas influenciam a forma das fôlhas. Apenas se conclui que a segunda camada geradora, aparentemente, não é a principal responsável por êsse caraterístico.
  • Imagem de Miniatura
    Item
  • Imagem de Miniatura
    Item
    Determinação do potencial biótico da "broca do café" - Hypothenemus Hampei (Ferr.) - E considerações sôbre o crescimento de sua população. III - Curva termometabólica da "broca do café" e sua aplicação no estudo do crescimento de sua população
    (Instituto Agronômico (IAC), 1949) Mendes, Luiz O. T.
    Lançando mão de dados publicados por outro autor, (1) sôbre o comportamento da "Broca do Café", quando criada a várias temperaturas, em laboratório, o autor, aceitando em princípio que uma hipérbole equilátera traduz o termometabolismo da espécie, calcula a constante térmica da espécie (K = 339,26) e determina a sua temperatura mínima efetiva (T0 =15,12 °C). É deduzida a equação termometabólica para êsse inseto, dada por D = 339,26 / (T-15,12). Considerando que, num cafèzal, a temperatura do ar não é constante, variando de acôrdo com a estação do ano, o autor pondera que a curva de crescimento de uma população de "Broca do Café" será melhor representada em gráfico onde seja levada em conta a influência da temperatura no desenvolvimento do ciclo biológico do inseto. Dessa maneira, apreciando exemplos numéricos apresentados em trabalho anterior, e construindo novo gráfico, em vez de colocar os valores de "t" no eixo das abscissas, a intervalos regulares, coloca-os a intervalos previamente calculados pela aplicação da equação termometabólica do inseto, de acordo com a temperatura média do mês. Os exemplos são analisados em função das temperaturas normais de Campinas para um período de 58 anos (1890-1947). A análise dos gráficos apresentados mostra até onde a temperatura do ambiente pode influir no desenvolvimento de uma população de "Broca do Café", em condições de campo.
  • Imagem de Miniatura
    Item
    Sintomas de deficiências minerais no cafeeiro
    (Instituto Agronômico (IAC), 1949) Franco, C. M.; Mendes, H. C.
    Coffee plants (Coffea arabica L.) were grown in nutrient solutions for the purpose of studying deficiency symptoms of the following elements : nitrogen, phosphorus, potassium, magnesium, calcium, sulphur and iron. The methods employed in the growing of coffee plants in the nutrient solutions are described. After preliminary tests with several nutrient solutions Hoagland's formula was selected as most suitable for the present tests. However, the quantity of phosphate employed in the basic nutrient solution was reduced to one third of that given in Hoagland's formula. This reduction in phosphate was made because of the previous results obtained by Jacob which seemed to indicate that the coffee plant requires only very small amounts of phosphorus. In the present tests phosphorus deficiency symptoms were obtained and these results suggest that Jacob's failure to obtain phosphorus deficiency symptoms may be ascribed to use of Shive's solution, which has a very high phosphate content. While growing in this complete nutrient solution his plants may have stored enough phosphorus to supply their needs later when they were transferred to the solution lacking this element. In the course of the present investigation it was found that in the nutrient solutions containing KH2PO4 and having a pH higher than 5.5, the coffee plant absorbs insufficient iron. This difficulty of iron absorption by the coffee plants grown in nutrient solution was overcome by a technique previously described that is, when iron deficiency symptoms appeared on plants being tested for other deficiencies the nutrient solution was changed and the new solution used contained no phosphate. The plants were allowed to grow in this solution for two to four days and then the phosphate was added. In this way the plants absorbed sufficient iron for their requirements. The present paper describes and the color plates illustrate the symptoms on coffee plants that were associated, in the present studies, with nutrient solutions deficient in the various elements listed.
  • Imagem de Miniatura
    Item
    Análise estatística do ensaio de variedades de café
    (Instituto Agronômico (IAC), 1949) Stevens, W. L.
    This paper describes the statistical analysis of a varietal trial with two unusual characteristics : (i) The plant (coffee) is one of those which show strong maxima and minima of production in alternate years. This phenomenon must be prevented from masking or biasing the other varietal comparisons in which we are interested. (ii) The design of the experiment is systematic. It was laid down in Campinas, Brazil, in 1933 at a time when the principles of randomisation were not so widely known as they are today. THE EXPERIMENT AND DATA. Six varieties are compared, denoted by A B C D E and F (see page 104). They are planted in thirty rows, each with 50 plants, according to the systematic design : A B C D E F A B C D E F A B C D E F A B C D E F A B C D E F Data for twelve years are available in quadro 1 but those of the small and irregular yields in the first two years were discarded. The mean yields of the remaining ten years (1935-1946) appear by figure 1 to be fairly regular and consistent in their behaviour. Most of the plants, but by no means all, showed their maxima in the even years. STATISTICAL ANALYSIS. The quantity of primary interest is the mean yield over the whole period. It is essential that these means should be based (as here) on an even number of years in order to eliminate, from their comparisons, the effect of the alternations of maxima and minima. The magnitude of the oscillation is conveniently measured by total of even years minus total of odd years. Finally we need a linear function of the annual yields for measuring secular trend in order to discriminate varieties which are slowly gaining on the others. The usual linear orthogonal polynomial (with coefficients —9, —7, —5, etc.) is unsuitable because it is not independent of the component of oscillation. A suitable function is obtained instead by using the coefficients —2 —2 —1 —1 0 0 +1 +1 +2 +2. The coefficients of the three linear functions thus defined are set out in quadro 2 (page 107), where it will be verified that they are mutually orthogonal. The effect of the heterogeneity of the soil is as far as possible eliminated (separately for the three functions) by an analysis of covariance, using the number of the row (1-30) as the concommitant observation. A simple linear regression formula is however inadequate. The regressions were taken to the fifth degree by means of orthogonal polynomials. Since the "between varieties" contribution must be removed from the sums of squares and products, the regression coefficients are no longer independently obtainable. It is found however that the normal equations fall into two sets, one yielding the regression coefficients of odd degree and the other those of even degree. Consequently the use of orthogonal polinomiais still effects a considerable saving of work. The computations are set out in full in quadro 3 and in abbreviated form in quadro 4 and 5 for the total, the oscillation and the trend respectively. (Note that the comma indicates the decimal point.) We find that a quadratic regression is adequate for the first and cubic regressions for the others. For the sake of uniformity, a cubic regression was used in every case. The residuals found by subtracting the varietal means from the rows are plotted in figures 2a, 3 and 4a. respectively, together with the regression curves and the 2.5% control limits. These control charts suggest that it is not unreasonable to suppose that the remaining variation is random. Next we use the regression formulae to correct the varietal means. The approximate 80% fiducial intervals of the mean annual yields (kg per row) and the rate of increase of yield (kg per row per year per year) are shown in figures 2b and 4b respectively. In the case of the component of oscillation, the analysis of covariance failed to show the slightest suggestion of differences between varieties. DISCUSSION. An examination of the regressions on number of row reveals the interesting fact that the more fertile portions of the field produce lower yields in the odd years than the less fertile portions. The reason is presumably that the heavier yields in the even years, by exhausting the plant, depress the yields in the following years. The major differences between varietal means over the ten years were sufficiently clear even before the analysis though some of the adjustments are appreciable. A striking fact is that, although there are big general differences between varieties, there are no significant differences between them in respect of the amplitude of oscillation. In other words, the increment of yield in the better varieties is obtained equally in odd and even years. In spite of the large component of oscillation, it is possible to discriminate varieties in respect of their rate of increase of yield (figure 4b). CONCLUSIONS. (i) The extra difficulty introduced by the strong alternations of yield from year to year can be solved b y the choice of suitable orthogonal functions of yearly yields. (ii) Once again a systematic design is found wanting — it fails to eliminate the effect of soil heterogeneity from varietal comparisons. This defect can however be removed, for practical purposes, by an adequate analysis of covariance on row number.
  • Imagem de Miniatura
    Item
    Ensaio de variedades de cafeeiros II
    (Instituto Agronômico (IAC), 1949-05) Mendes, J. E. Teixeira
    An experiment was started in 1931 for the purpose of making a comparative study of the productivity of following varieties of Coffea arabica L, : Nacional (Coffea arabica L. var. typica Cramer) Amarelo de Botucatu (Coffea arabica L. var. typica Cramer forma xanthocarpa (Caminhoá) Krug) Bourbon (Coffea arabica L. var. bourbon (B. Rodr.) Choussy) Bourbon amarelo (Coffea arabica L. var. bourbon (B. Rodr.) Choussy forma xanthocarpa Krug) Sumatra (Coffea arabica L. var. typica Cramer) Maragogipe (Coffea arabica L. var. maragogipe Hort. ex Froehner) The results obtained from this experiment for the period 1935-1938 have been the subject of a previous publication. The present paper concerns results obtained from the same experiment for the period 1939-1946. The data obtained have been analysed by varieties and years in relation to : date of ripening of coffee berries, average size of coffee beans and total production. The results of this analysis showed that there were definite annual variations in production by varieties. With respect to ripening of fruits (cherries) on the varieties tested, it was found that the Amarelo de Botucatu variety had the earliest date of ripening in every year. The Nacional and Sumatra varieties varied by years but they were always later than the Amarelo de Botucatu in date of maturity of the cherries. The fruits of Bourbon and Boubon Amarelo were slightly later than all of of the above mentioned varieties and the Maragogipe matured fruit later than all other varieties studied. The data on the average size of coffee beans showed that the Maragogipe variety produced the largest bean. The Bourbon Amarelo and Bourbon produced beans of the smallest size. The Nacional, Sumatra and Amarelo de Botucatu produced beans that were intermediate in size between the Maragogipe and Bourbon. The analysis of production showed that for each year for the first four years (1935-1938) there was a definite yearly increase in production for each variety tested. The data obtained for subsequent years (1939-1946) show that, for all except the Maragogipe variety, each year with a high yield was followed by a year with lower coffee production (see figure 1). On the basis of the total production for the entire period studied (1935-1946) it was found that Bourbon Amarelo variety was the most productive followed closely by the variety Bourbon. The Sumatra variety was intermediate in total production and appreciably less than the Bourbon types. The lowest yielding varieties in this experiment were Nacional, Amarelo de Botucatu and Maragogipe. The production data have also been studied by four year periods and as a result certain interesting minor variations in relation to varieties have been noted. A more detailed statistical analysis of the production data from this experiment has been carried out by Prof. W. L. Stevens (see following article in this issue). He has showed that the coffee varieties studied can be placed in three statistically different classes. The varieties, by classes, according to their decreasing capacity of production, are as follows : a ) Bourbon Amarelo and Bourbon ; b) Sumatra ; c) Nacional, Amarelo de Botucatu and Maragogipe.