Resumo em Português:

Uma nova variedade de Coffea arabica L., provavelmente originária de Manhumirim, Estado de Minas Gerais, e cultivada em pequena escala no Estado do Espírito Santo, foi recebida, pelo Instituto Agronômico de Campinas, em 1937. Trata-se da variedade caturra. Carateriza-se por apresentar porte menor do que o da variedade bourbon, da qual provàvelmente se originou. Os internódios são bem curtos, tanto no caule como nos ramos, sendo intensa a ramificação secundária e de ordem inferior. As fôlhas são de um verde bem escuro, maiores e proporcionalmente mais largas do que as do Bourbon. As flores são pouco menores e os frutos e sementes um pouco maiores do que as dessa variedade. No presente trabalho apresentam-se os resultados das pesquisas taxonômicas relativas a essa nova variedade de C. arabica e alguns dados preliminares referentes à sua constituição cromosômica e genética. Verificou-se ser de 2n = 44 o número de cromosômios somáticos e, dos cruzamentos com as variedades typica e bourbon, conclui-se que os seus principais caracteres são devidos à ação de um só par de fatôres genéticos dominantes principais (Ct Ct). As observações preliminares relativas à produtividade indicam que se trata de uma variedade de elevada capacidade produtiva, merecendo, por conseguinte, a atenção que se vem dando aos trabalhos ora em realização nas principais zonas cafeeiras. A forma xanthocarpa parece diferir do Caturra Vermelho apenas na coloração amarela dos frutos, que é devida ao mesmo fator (xc xc) que carateriza a forma xanthocarpa da variedade typica (2).

Resumo em Inglês:

A new variety of Coffea arabica L., which is believed to have originated in the region of Manhumirim, in the State of Minas Gerais and which is cultivated on a small scale in the State of Espirito Santo, was sent to the Instituto Agronômico in Campinas, in 1937. The new variety is called caturra and is characterized as being somewhat smaller than the bourbon variety from which it probably originated. The internodes, both on the main stem and branches, are very short and secondary branches are abundant. It has very dark green leaves that are larger and proportionally longer than those of the bourbon variety. Also in comparison with this variety, its flowers are a little smaller but its fruits and seeds are slightly larger. The results of a taxonomic study together with preliminary information on the genetic constitution of the caturra variety, are presented in this paper. It was found to have2n=44 somatic chromosomes and from crosses made between this variety and the varieties typica and bourbon, it was determined that its principal morphological characters were due largely to the action of a single pair of dominant genetic factors (Ct Ct). Preliminary data indicate that the caturra variety has a high yielding capacity and that it may be particularly well adapted to cultivation under shade. There is a yellow fruited (xanthocarpa) form of caturra that is the same as the red fruited form except for the color difference. The yellow fruit color of caturra is probably determined by the same genetic factor (xc xc) that characterizes the xanthocarpa form of the variety typica.

Resumo em Inglês:

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.

Resumo em Português:

A determinação do potássio no solo exige processos químicos sensíveis e precisos, dado o baixo teor em que, no geral, se encontra êsse íon. A dosagem dêsse elemento, bem como a do sódio, pelos processos comuns, são bastante morosas. Por êsse motivo, resolveu-se estudar a aplicação, para os nossos solos, do método rápido da Fotometria de Chama, já em uso em outros países de clima e solos diferentes, na dosagem do potássio e sódio "trocáveis". As determinações foram, a princípio, realizadas com o Fotômetro de Chama Perkin-Elmer, modêlo 18, e, posteriormente, com o modelo 52-A. Os dados obtidos permitiram formular indicações de caráter geral para a dosagem do potássio "trocável" nos solos do Estado de São Paulo. Em linhas gerais, o método adotado nas determinações do potássio consiste no seguinte : Após a extração dos cations com uma solução 0,05 N de HNO3, a solução do solo é neutralizada com NH4OH. A seguir é levada ao fotômetro, para a dosagem do potássio, pelo processo da leitura direta da intensidade das radiações emitidas pelo elemento em análise. Como fonte de energia foi usado o ultragás (propano), misturado com ar, à pressão de 6 a 7 libras por polegada quadrada. Com relação ao potássio, o aparelho permite dosá-lo em soluções desde 0,00001 N em K+ (0,39 ppm de K) até 0,001 N (39 ppm de K). Nesses limites, as leituras são proporcionais às concentrações, e são representadas por uma reta. Foram também estudadas as interferências dos elementos Ca++, Mg++, Al+++ e Fe+++ nas determinações do potássio. Verificou-se que esses íons, nas concentrações em que usualmente se encontram nas soluções de solo, não interferem na dosagem do potássio. Para verificar a precisão das determinações de potássio pelo Fotômetro de Chama, foram elas aferidas pelo método do cobalti-hexanitrito. De um modo geral, os resultados obtidos em ambos os métodos foram bastante concordantes, confirmando a precisão e a sensibilidade da Fotometria de Chama. Conseguiu-se, por êsse método, realizar cinquenta a sessenta determinações diárias do potássio, ao passo que, pelo método do cobalti-hexanitrito, não se consegue realizar mais do que oito dessas determinações por dia, o que mostra a eficiência do Fotômetro de Chama.

Resumo em Inglês:

The determination of small amounts of potassium ions in soils requires sensitive and precise chemical methods. Measurements of potassium and sodium by the chemical methods are time consuming. The flame photometer method of measuring these ions is more rapid and has proved reliable for soils under temperate environmental conditions. It was the purpose of this study to determine whether the rapid flame photometer method of measurement of exchangeable potassium and sodium could be used effectively and with .accuracy on soils in São Paulo. The first results, in the experiments undertaken, were obtained using the Perkin-Elmer flame photometer Model 18 ; subsequently the newer model 52-A was employed. The data obtained from the tests have; been found to give a general indication for determining exchangeable potassium in the soils of the State of São Paulo. The following method of treatment of soil samples was found to give the most reliable results. After extraction of the cations with a solution of HNO3 0.05 N, the soil solution was neutralized with NH4OH. This solution was then placed in the photometer in order to measure the amount of potassium by means of reading directly the intensity of radiations emitted by this element. Ultragas (propane) mixed with air and at a preassure of 6 to 7 pounds per square inch was used as a source of energy. The apparatus used in these tests permitted determination of potassium in solution from 0.00001 N of K+ (0.39 ppm of K) to 0.001 N (39 ppm of K). Within these limites the readings were proportional to the concentrations and can be represented by a straight line. A study was also made of the interference of the elements Ca ++, Mg++, Al +++ and Fe +++ and it was found that these ions, in the concentration in which they usually exist in the soil solutions, did not interfere with the determination of potassium. In order to verify the accuracy of the determinations of potassium by the flame photometer, the method of cobalti-hexanitrite was employed using comparable soil samples. In general the results obtained by both methods were? the same, thus confirming the accuracy and sensitivity of the flame photometer. This latter method has a great advantage in that it is possible to make 50 to 00 determinations of potassium in one day whereas the cobalti-hexanitrite method is more laborious and allows analyses of only about 8 samples per day.

Resumo em Português:

O conhecimento das caraterísticas químicas dos solos tropicais e subtropicais assume, dia a dia, maior importância, à medida que se desenvolve a nossa agricultura. No presente trabalho foram examinadas amostras representativas de quatro dos principais tipos de solo do Estado de São Paulo, a saber : Massapé-salmourão, Glacial, Terra-roxa legítima e Arenito Bauru. Procurou-se determinar se os elementos potássio, cálcio e magnésio se acham na forma "trocável" e "não trocável", e em que proporções. Primeiramente são apresentadas as propriedades físico-químicas e mecânicas das amostras dos solos, a fim de melhor caraterizá-las. A seguir, são dados os resultados obtidos sobre os teores "trocáveis" de potássio, cálcio e magnésio, extraídos do solo por dois processos químicos diferentes, isto é, com solução normal de acetato de amônio e com a solução 0,05 X de ácido nítrico. Os resultados obtidos por êsses dois processos foram bastante concordantes. As mesmas amostras usadas para as dosagens da forma "trocável" desses elementos, por meio da solução 0,05 N de HN0(3), foram depois tratadas com solução de HCl 5 N, a fim de se verificar se ainda encerravam os cations K+, Ca++ e Mg++, na forma "não trocável". Observou-se que o teor de cálcio extraído por essa solução (HCl 5 N) é muito baixo, ao passo que os teores de potássio e magnésio foram elevados. Isto indica que o cálcio se encontra quase que sòmente na forma "trocável" (na parte mais externa dos colóides), ao passo que o potássio e o magnésio, além de se acharem na forma "trocável", também se encontram na forma "não trocável" (na parte mais interna dos colóides).

Resumo em Inglês:

A knowledge of the chemical characteristics of tropical and subtropical soils, is essential for the development of our agriculture. In the present study examinations were made on samples of the four principal soil types of the State of São Paulo. These types are ; Massapé-salmourão, Glacial, Terra-roxa legítima and Arenito Bauru. Determinations were made of the proportional amounts of the mineral elements potassium, calcium and magnesium, that were in exchangeable and nonexchangeable forms. A description is given of the physical-chemical and mechanical properties of the soils samples and data are presented on the amounts of "exchangeable" potassium, calcium and magnesium, obtained from the samples by two different chemical methods. In one method of extraction normal solution of amonium acetate was used and in the other a 0.05 N solution of nitric acid was employed and the results obtained from both methods of extraction were very similar. The same samples that were treated with the 0.05 N nitric acid for determination of the "exchangeable" elements, were subsequently treated with 5N HCl solution in order to determine if there was still present K, Ca and Mg cations in a "fixed form". It was found that the amount of calcium extracted by the 5N HCl solution was very small but that the amounts of potassium and magnesium were high. This indicates that the calcium was present almost entirely in an exchangeable form, in the samples tested, whereas the potassium and magnesium were present not only in an exchangeable form but also in a fixed form.

Resumo em Inglês:

The known species of Coffea can be grouped into two categories according to the color of their endosperm which is either green or yellow. The commercially cultivated varieties of Coffea arabica L. and Coffea canephora Pierre ex Froehner are well known for the green color of their seed while the less known varieties of Coffea liberica Hiern and Coffea Dewevrei De Wild, et Th. Dur. have yellow Feed. In 1935, however, a yellow seeded type of C. arabica, was found in Brazil and has been described as Coffea arabica L. var. cera K.M.C. ; it is believed to have originated by mutation from Coffea arabica L. var. typica Cramer. In this paper the authors present the results of a genetic study of the yellow seeded mutant known as "cera". It has been found that in C. arabica, yellow endosperm is controlled by one pair of recessive factors cece. Hybrid seeds containing a Cece embryo were green (xenia), their endosperm being either Cecece or CeCece. Cera is a tetraploid variety and when it was crossed with diploid Coffea species having yellow endosperm, it was found to produce only yellow hybrid seeds. The cera, which is a yellow seeded mutant has been useful not only for definitely showing that the bulk of the coffee seed is true endosperm, but it has also proved useful is study of the biology of the coffee flower.

Resumo em Português:

Em trabalho apresentado à Academia Brasileira de Ciências, o autor, estudando o que se conhece a respeito do comportamento da "Broca do Café", deduziu uma equação teórica que traduz o crescimento de uma população dêsse inseto, nos cafèzais, considerando-a do tipo fechado, à vista da limitação dos seus meios de subsistência. A infestação porcentual de frutos de café pode ser achada a qualquer momento "t" pela aplicação da fórmula Pt(4)0 = 100/1+(m/iq - 1) e -2,303 log (m/iq - 1)- log (m/iqp2 - 1)]t Continuando seus estudos, e aproveitando-se dos dados biológicos já publicados por outro pesquisador (1), o autor determina que, podendo uma única fêmea do inseto atacar sucessivamente até quatro frutos, a equação atrás se transforma em Pt(4)0 = 100/1+ (20,02/iq - 1) e - 2,303 [log (20,02 - iq)/(1-iq)]t que pode ser aplicada no curso de uma safra, uma vez que o espaço de tempo correspondente ao desenvolvimento das quatro gerações (4 t), se ajusta aproximadamente ao período de desenvolvimento e maturação dos frutos, até a época de colheita. O ponto de inflexão da curva é achado quando t= log (20,02/ iq - 1) / log (20,02 - iq)/ (1 - iq) São dados alguns exemplos pelos quais é demonstrada a grande importância do índice inicial de infestação, no grau final de ataque pela praga, uma vez que, quanto maior o valor numérico do índice "iq", tanto menor será o valor de "t" em relação ao ponto de inflexão, isto é, quanto maior o grau inicial de infestação, tanto mais cedo atingirá êle o nível de 50% de frutos atacados.

Resumo em Inglês:

The author presents a new equation that is believed to indicate more accurately the population growth of the coffee berry borer - Hypothenemus hampei (Ferr.) - under ideal environmental conditions. This new equation is based on previously published data by the author (2) and takes into account results of other biological studies (1) concerning this insect. It is now possible to calculate the percentage of attacked coffee fruits at any given time "t", between the limits 0 and 4, by the formula Pt0(4)- 100 / 1 + (20.02/iq - 1) e - 2.303 [log (20.02 - iq) / (1 - iq)] t where i = initial infestation factor q = average number of active females, per coffee fruit, in the moment when "i" is determined. The derived equation is chiefly based on the following biological data : a) the normal sex ratio is 1 male to 9.75 females ; b) only the females attack the fruits; c) an active female may, during the season of fruit development, attack as many as four fruits in the field, and in each fruit can deposit an average of 20.97 eggs. In this paper three theoretical examples are given of the application of the new equation, and the results obtained show the importance of the initial infestation factor in the final percentage of attacked coffee fruits.

Resumo em Português:

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.

Resumo em Inglês:

Based on published data (1) concerning the effect of temperature on the life-cycle of the coffee berry borer, and on the assumption that an equilateral hyperbole expresses the lengths of an insect life-cycle stage at various constant temperatures, the author has calculated the representative thermometabolic equation for the insect to be : D = 339.3 /(T-15.12) In the equation, "D" represents the lengths (in days) of the insect life-cycle stage, "T" the temperature in degress centigrade, and the value 15.12 °C is the calculated minimum effective temperature, or the threshold of development for the insect. The thermometabolic curve and its reciprocal (velocity curve) are presented graphically in figure 1. In a previous paper the author presented three curves representing the growth of the population of infested coffee fruits, under constant temperature conditions, and where the time "t" was plotted at regular intervals. Considering, however, that the development of the insect life-cycle stage is a function of temperature and by consequence that the time "t" can be calculated from the thermometabolic equation for the insect, and knowing the normal monthly temperature of Campinas (calculated mean for 58 years - from 1890 to 1947), it is now possible to present a graph (see figure 2) where the calculated time "t" is plotted according to the mean temperature of the month. The curves in the graph indicate the importance of the influence of temperature on the growth of the population of infested coffee fruits, under field conditions.