Bragantia

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List of Papers (Total 271)

Coeficiente de variação e índice de variança

The object of the present paper is a study of the usefulness of two relative measures of variation, the well known coefficient oj variation and a new term proposed in this paper and called the index of variance. These terms are defined by the equations : coefficient of variation : σ% = s /v/v. 100 index of variance :σ/ √. 1.  It is shown that, for theoretical reasons, only the...

Estudos sôbre a inflorescência de milho com referência especial aos problemas filogenéticos

1) The present paper deals with variations in the structure of the inflorescences of the Maydeae Americanae, especially of the ear of Zea Mays, which came under observation during our genetical studies during the last 10 years. Care was tauken to include only such structures which were observed frequently and had in general an aspect which could not be described as a pathological...

Genética de Coffea: X - Hereditariedade da ocorrência de sépalas desenvolvidas nas flores de Coffea arabica L. Var. goiaba Taschdjian

In" this paper the authors discuss the nature of the calyx in the Ixorex (Rubiacex), calling special attention to this character in Coffea. The calyx of the goiaba variety of Coffea arabica L. differs from the normal type being well developed, foliaceous and persistent, the fruit being similar in appearance to the guava (Psidium guajava L.). It is supposed that the presence of a...

Chuvas e umidade relativa do ar em Campinas de 1890 a 1945

In order to investigate if the Citrus disease Tristeza could be caused by a change in the rainfall, its distribution or in air humidity a study of these factors was made based on data obtained from 1890 to 1945 at Campinas, São Paulo, Brazil. A large variation in the data was found but no tendency could be noticed as to increase or decrease of any of factors analysed. This does...

Estudo agrícola-tecnológico de diversas variedades de Phormium tenax Forster

In spite of the polymorphism of Phormium has long been known, no systematic attempt has been made until now to study comparatively the agricultural value and fiber quality of the varieties. This paper is concerned with preliminary results about leaf yield, fiber-content, und general growth of six varieties, of Phormium tenax Forster including a detailed fiber analysis. It is...

Poliembrionia em citrus

The studies on polyembryony in Citrus reported in this paper show that there is a great variability in the degree of polyembryony among the seeds, fruits and trees of a same form or variety of Citrus. Seeds from different crops of the same plant also show considerable variation in the degree of polyembryony. In order to obtain reliable data on the degree of polyembryony in Citrus...

Determinação do potencial biótico da "broca do café": Hypothenemus Hampei (Ferr.) - E considerações sôbre o crescimento de sua população. II - A importância da diminuição do índice inicial de infestação no grau final de frutos de café atacados pela praga

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...

Taxonomia de Coffea arabica L.: II - Coffea Arabica L. Var. Caturra e sua forma Xanthocarpa

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...

Um enrolamento das fôlhas do fumo de causa genética

A type of leaf-roll has been noticed for many years in commercial tobacco plantings in the State of S. Paulo. Leaf-roll plants were supposed to be affected by a virus disease, but repeated attempts to transmit it by grafting, juice inoculation and by insect vectors failed consistently. Later studies showed that the leaf-roll condition is due to genetic factors and that probably...

Quantidade de água transpirada pelo cafeeiro cultivado ao sol

In determinations made with a porometer it was verified that the stomatal opening of coffee leaves increases in size immediately after the leaves are detached from the plant (fig. 1). This fact indicates that the method of rapid weighings of detached leaves is not suitable for studies on the transpiration of the coffee plant. The transpiration of coffee plants has been determined...

Vermelhão do algodoeiro

A disease associated with the infestation of cotton plants by the cotton or melon aphid, Aphis gossypii Glov. is described under the name of "vermelhão" or anthocyanosis. Symptoms of the disease resemble those resulting from magnesium deficiency. Aphids collected from diseased plants reproduced the disease when fed on cotton seedlings for 48 hours. Symptoms usually appeared from...

Látices retangulares

This paper presents the analysis of a simple rectangular lattice with two replications of the basic group X and Y. It is recalled that the rectangular lattices permit the comparison of k(k+1) progenies in breeding programs and help to complete the series of numbers of progenies that can be compared through lattices and incomplete block designs.

Fermentação alcoólica do caldo da cana de açúcar var: Co.290. II. Influência da estirpe de fermento utilizada sôbre o rendimento alcoólico

About 80 per cent of sugar cane acreage in the State of São Paulo is planted with Co.290. Various strains of alcoholic yeast were compared in their ability to ferment the juice of this variety. Four strains out of eleven (F-29, F-34, F-1, and F-2) gave yields that were significantly higher than that of the others. The utilization of selected yeast strains contributed to a better...

Fermentação do caldo da cana de açúcar (Saccharum officinarum L.) var. Co. 290. Influência da adição de sais de amônio e farelo de arroz sôbre o rendimento alcoólico(*)

The sugar cane variety Co. 290 is widely distributed in the State of São Paulo. Its juice does not ferment very well because it seems to be deficient in nutrients for the yeast. Comparative tests were carried out to determine the influence of ammonium salts and rice polishings on the alcohol yield when these substances were added to the juice of this variety prior to fermentation...

Amostragem de solo para estudos de fertilidade

The following methods of collecting soil samples for fertility studies were compared : 1) thirty individual samples covering the whole area ; 2) ten composite samples, each consisting of five individual samples, covering the whole area ; 3) five composite samples, each consisting of 20 individual samples, covering the whole area. The three types of samples were collected in each...

Adubação do milho: VIII - Ensaios com estêrco e adubos minerais

In this paper are reported the results of experiments conducted during several years at three different sites of the State of São Paulo: Campinas, on terra roxa misturada soil; Ribeirão Prêto, on terra roxa legítima soil, and Engenheiro Hermilo, on glacial soil. In the Campinas experiment, beside other treatments, manure at the rate of 12.8 metric tons per hectare was compared...

Determinação do período de tempo para amonificação e nitrificação de diversos fertilizantes nitrogenados

In this paper results obtained with the phenomenon of ammonification and nitrification in several nitrogen fertilizers are presented. The objective was the determination of the intensity and evolution of these phenomena. For this purpose an experiment was set up including the following nitrogenous fertilizers: ammonium sulfate, urea, castor bean cake, blood meal, horn and hoof...

Melhoramento do cafeeiro: XII - Variabilidade em linhas puras de café

Three isogenic progenies of Red Bourbon coffee (Coffea arabica L.var. bourbon (B. Rodr.) Choussy) were investigated in relation to several characteristics in a balanced lattice experiment with 16 entries, five replications, each plot with four individual plants. Two of these isogenic progenies were obtained by artificial self-pollination of two plants which were derived from...

Ensaios de variedades de amendoim. II - Oitava e nona séries de ensaios

This paper presents the results of peanut variety trials carried out at three experiment stations of the Instituto Agronômico, viz., Campinas, Ribeirão Preto, and Pindorama, during two consecutive years (1951-52 and 1952-53). The 16 varieties compared in the tests represented the most promising ones as determined in previous experiments already reported. The best yields were...

Comportamento de variedades de cana de açúcar no arenito de Bauru

Sixteen varieties of sugar cane were tested in a sandy soil of "arenito de Bauru" type at the Usina Miranda, Presidente Alves. Three harvests were made (plant cane, 1st and 2nd stubble). Cane and sugar yields of the first harvest alone and of the three harvests together were analysed statistically and gave the following indications: 1)  Of the 16 varieties tried, Co.419, C.B.40...

Adubação do algodoeiro: V - Ensaios com azôto, fósforo e potássio, em "campos de cooperação

This paper reports the results obtained in 71 fertilizer experiments with cotton conducted from 1935-36 up to 1941-42 in private farms located on the principal soil types of the State of São Paulo's cotton belt. In this work were compared 0, 40 and 80 kilograms of P2O5, per hectare, as well as three levels of nitrogen and of potash, and three forms of phosphates. Nitrogen and...

Levantamento da fertilidade de solos da estação experimental de Pindamonhangaba

The present paper deals with fertility tests carried out with soil samples from the Pindamonhangaba Agric. Exp. Sta., one of the branch stations of the Instituto Agronômico. The samples were collected from four soil series: Pinda, Pinhão, Guatemala, and Prateada. The test plants (romaine lettuce) were grown in aluminum pots containing 1.5 kg of soil. The following fertilizer were...

Fermentação do mosto de uva: influência do sistema de vinificação sôbre a acidez volátil do vinho

Three different fermentation techniques were compared to determine their influence on the volatile acidity of the wine. They were as follows; a) natural fermentation: b) with the selected wine yeast strain I.A.-78, and c) with a mixture of yeasts. The results of these experiments, with six replications, pointed out that the fermentation with the wine yeast strain I.A.-78 gave...

Adubação da batatinha experiências com adubos minerais e farelo de cacau

This paper reports the results obtained in five experiments conducted from 1946 to 1950 and designed to study the effect of the addition of cocoa-shell meal to mineral fertilizers supplying 40-120-60 and 80-120-60 kilograms of N-P205-K2O per hectare. The mentioned meal, which is a by-product of the cocoa industry and consists essentially of the shells of the cocoa beans, was...

Novo amostrador para as terras roxas

In this paper is described a new soil sampler, specially designed for use in sampling Brazilian purple-soil series, which is known to present very peculiar physical properties. The sampler was developed as a result of the need to sample the soil frequently, for the purpose of maintaining the soil water balance in irrigation experiments, carried on field plots. This basic method...