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Bragantia, Volume: 8, Número: 1-12, Publicado: 1948
  • As ferramentas e máquinas agrícolas nacionais: constituição química dos materiais empregados na sua fabricação e análise de suas propriedades mecânicas. Parte I - As enxadas calçadas

    Roston, P. J.

    Resumo em Inglês:

    A comparison has been made between faced hoes manufactured in Brazil and those manufactured in Great Britain. The Brazilian hoes lack uniformity in the raw materials employed in subsequent heat treatments and in the finishing processes. The British hoes were used as a standard for all comparison. Differences between Brazilian and British hoes were due in part to the differences in raw material employed and in part to the different methods of fabrication. In the author's opinion, the Brazilian hoes are of poorer quality because the raw material are very heterogeneous. They come from several sources and there is no process for selection of raw materials. In this regard it is suggested in this paper that the Brazilian factories should buy the raw material at the same source and that this material should be more carefully selected. The British hoes are more uniform and it is assumed that they are made by more modern mechanical processes and that the operations are controlled more rigorously than in Brazil. The author gives tentavite specifications for selection of raw material for the manufacture of faced hoes in Brazil. These specifications cover the chemical composition of the raw material to be employed and the width and height of the facing as well as the heat treatment to which the hoes should be submitted.
  • A salinidade do solo em canteiros de estufa

    Franco, C. M.

    Resumo em Inglês:

    It has been noticed in the greenhouse of the "Instituto Agronômico de Campinas" that many species of plants developed poorly when planted in seed beds that have been repeatedly used without change of soil. In many cases even the seeds would not germinate in such seed beds. Experiments have showed that the; lack of normal plant development in these beds is the result of the increase in soil salinity. This salinity may be due to additions of fertilizers or to salts introduced in the ordinary applications of water. It was found that the soil solution had an osmotic pressure of 13.5 athmospheres at the wilting point. The tests showed that common bean (Phaseolus vulgaris L.) plants were more susceptible to the soil salinity than were the soybean and the corn plants. Floading of those seed beds several times resulted in the leaching of salts and the restoring of conditions favorable for normal plant growth.
  • Variedades de batatinhas (Solanum tuberosum L.) procedentes da Holanda: Parte I - Resultados experimentais da primeira plantação, no país, com tubérculos importados em 1947

    Boock, O. J.

    Resumo em Inglês:

    The author reports the results of six experiments with eight yellow fleshed potato varieties from Holland, conducted at six different locations in the State of São Paulo. Time of planting was February-March, less favorable than August-September, because of climatic conditions during the growth period (somewhat dry weather). For this reason, yields were not good. Observations were made on development; resistance, precocity and production of varieties, as well as specific gravety of tubers. Under the conditions of the experiments the varieties Voran and Alpha were the least susceptible to Phytpphthora while Eersteling, and Saskia were the most susceptible. The Doré, Eersteling, Saskia and Geelblon were found to be early maturing varieties while Alpha, Voran and Libertas were late maturing varieties. The varieties Eigenheimer and Bintje revealed themselves the better yielders, with about 7.3 metric tons of tubers per hectare. Yields of next experiments, conducted at September-October, are expected to be better.
  • Variedades de batatinha (Solanum tuberosum L.) procedentes da Holanda: parte II - resultados experimentais da segunda plantação, no país, com tubérculos importados em 1947

    Boock, O. J.

    Resumo em Inglês:

    This paper presents the results obtained from six replicated experimental plantings of Irish potatoes in the State of São Paulo, Brazil. The potatoes tubers employed as seed in these test plantings were selected from the crop produced from the original tubers introduced from Holland in 1947. The results obtained from plantings in February 1947 made of the original seed pieces were the subject of a previous publication. The current tests reported herein were carried out in the same areas as those previously reported. The date of the second planting was, September 1947 and the second crop was harvested in February and March of 1948. The results obtained from the second plantings were similar to those secured from the original tests. Phytopthora infection was prevailent and caused considerable damage to the Eersteling and Saskia varieties while the Alpha and Voran varieties appeared to have appreciably more resistance. Under the conditions tested, the Eersteling, Saskia, Doré, and Geelblon were found to be early maturing varieties, while Alpha, Voran, and Libertas, were late maturing varieties. The highest average yields per hectar were 16 tons with the variety Eigenheimer and 12.4 tons with the variety Bintje. The yields obtained from the second plantings were greater than those obtained from the first plantings. This difference in yield has been attributed to the more favorable distribution of rain in the second growing season.
  • Himenomicetos brasileiros - IV: Polyporaceae - 1

    Teixeira, A. R.
  • Absorção de fósforo e ferro, de soluções nutritivas

    Franco, C. M.; Loomis, W. E.

    Resumo em Inglês:

    Moderate amounts of KH2PO4 (0.5 to 0.7 millimols) caused iron chlorosis of seedlings in solutions less acid than pH 5.5-6.0. The trouble could be avoided by omitting the phosphorus entirely and adding it separately after 2-4 days. Even with this modification the Knop type of solution (Hoagland, 2) caused persistent chlorosis in soybeans and broccoli. In the commonly used Shive solution (R5-C2) a large excess of KH2PO4 holds the pH of the solution between 4.5 and 5.0 and chlorosis is moderate to slight. The Shive solution contains 36 times as much phosphorus as the Hoagland and 6-week-old plants growing in it absorbed 15 times as much to make a slightly poorer growth. The addition of as little as 0.125 g per liter of NH4NO3 resulted in decidedly acid solutions in every experiment with nine plant species representing seven families. Initial pH's of 5.25 in an unbuffered solution fell to minimums of 3.9 to 2.9 and then rose, to pH 5.0 or 6.0 with large plants. The low pH's were shown to be due to a preferential absorption of NH+4 ion and the later rise to the slower absorption of the NO-3 ion. The use of NH4NO3 prevented iron chlorosis with some plants, notably soybeans, but resulted in acidities which were injurious to young corn and to cotton. In work done in this series but not described above, the "X" solution containing NH4NO3 gave exceptional growth of young coffee (Coffea arabica), but was toxic to older plants. It is probable that iron chlorosis has more effect on solution culture results than any other single factor, and frequently than all other factors. Iron absorption from cultures is reduced by phosphorus, probably by H2PO-4 ions especially, at pH's of about 6.0 or higher. The use of Ca3(PO4)2 reduces the trouble as does the use of enough KH2PO4 to maintain a pH below 5.5. In tank culture H2SO4 may be used more cheaply to accomplish the same result. In miscellaneous work with the Knop type of solution chlorosis can be reduced or prevented by omitting phosphorus from the solution and adding it separately 2-4 days later after iron has been absorbed.
  • A experimentação do sisal: parte I - experiências de espaçamento

    Medina, J. C.

    Resumo em Inglês:

    Sisal (Agave sisalana Perrine) accounts for about one half of the world's production of hard fibers. In spite os its economic importance pratically no research work has been carried out on this plant. Very little is known about the agronomic problems of its cultivation, while the physiological and genetic problems are nearly unknown. This is perhaps due to the fact that A. sisalana is a perennial plant with a life cycle of 5-8 years and the carrying out of field research work requires a great deal of time and is very expensive. This paper, the first of a series to be published on the agronomic problems of sisal cultivation, presents the data obtained from field trials on distance of planting and its relation to weight and number of leaves produced. The experiments were carried out at the Ribeirão Preto and Pindorama Experiment Stations of the Instituto Agronômico de Campinas. Sisal bulbils about one year old were planted in the latter part of 1939 in 4 randomized blocks of 9 plots each where different distances between and within the rows were used. Production data were obtained by cutting the leaves at one year intervals begining 2 ½ years from date of planting in the field. Only those leaves that were attached to the plant at an angle greater than 45.° in relation to the main axis of the plant were cut each year. Only in the trial at Ribeirão Preto the leaves were counted and weighted by plants. In the poling plants all leaves than existing were taken off, even the youngest ones adjacent to the pole (flower stalk). Descorticator machine for fiber extraction was not available, so that reliable data on fiber yield could not be obtained. A "probable" fiber yield was obtained by using 3% of leaf w r eight as a basis for calculations. This percentage is recognised as an average fiber content usually obtained from sisal leaves. From the data obtained from the spacing trials described in this paper the following conclusions can be drawn : 1. The life cycle from date of field planting to poling stage of most of the sisal plants in these trials varied from 5 to 8 years. A very small number of plants however had not poled even after 8 years when the present experiments were ended. 2. The life cycle of the sisal plants showed a close relationship to planting distances. At the greater planting distances the plants tended to pole much earlier than at closer planting distances. 3. It was observed that there was a marked seasonal incidente of poling. The flower stalk of almost all plants have appeared during the period of January to March. 4. A marked effect to the distance os planting on plot yields, as measured by total leaf weight, was observed. The greater the density of plants per unit area the greater the leaf production. 5. Under present leaf cutting practice, e. g., to cut yearly only the leaves at an angle greater than 45.° in relation to the main axis of the plant, the shorter distances between the rows are not recommended. The narrow spacing between rows not only restricts the passage of workers, but also hinders adequate cultivation (weeding and sucker growth control). 6. The planting distances of 2 x 2 meters (2500 plants per hectare) was the worst spacing tried. Besides giving a low plant density per unit area it prevents ingress to the planting from any direction. 7. To increase plant density per unit area the closing up of plants within rows is more indicated than closing up the distance between rows. 8. The advantages of the distances of planting between rows of 2.40 or 3.00 meters and 1.20 meters within rows, under present leaf cutting practice, are many. It facilitates weeding, control of suckers growth, and leaf cutting operations.
  • Algumas determinações físicas e químicas da fibra de rami

    Castro, G. Paiva; Correia, F. A.

    Resumo em Inglês:

    Tests were made on samples of ramie fibers (Boehmeria nivea Hook., var. locally known as Murakami), obtained from three month old plants grown at Campinas, State of São Paulo. The harvested material was processed and the fibers were degummed and bleached by the methods described. The physical and chemical tests made on six samples of the fibers gave the following average results : PHYSICAL TESTS Length maximum.................................. 360 mm average .................................. 200 mm minimum .................................. 90 mm Width maximum ................................. 63 mm average................................... 32 mm minimum .................................. 16 mm Tensile Strength maximum ................................. 70 g average .................................. 32 g minimum .................................. 11 g Fineness .................................. 5.80 Higroscopicity ........................... 7.36% Reabsorption.............................. 7.94% Relation Y................................. 6198 Relation Z ................................. 5.68 CHEMICAL TESTS Hydyolvsis alpha...................................... 1.30% beta....................................... 2.56% Acid purifibation ....................... 2.30% Ash........................................ 1.20% Celulose.................................. 96.63%
  • Adubação para viveiro de fumo: Experiência preliminar em vasos

    Santos, S. Ribeiro dos; Fraga Jr., C. G.

    Resumo em Inglês:

    This paper describes an experiment with factorial design and two levels of treatment, used in testing fertilizer applications for tobacco seed beds. The fertilizers employed were : Chilean nitrate, superphosphate, potassium chloride, and cotton seed meal. Tobacco plants were grown in ten liter clay pots containing a steam sterilized soil composed of equal parts* of thoroughly mixed sub-soil and surface washed sand. Each of the sixteen treatments tested was applied to six pots and these were divided into three replications of two pote each. Measurements of height and weight of the plants were taken about two months after the seed germinated. An analysis of the data obtained is presented and shows that under the conditions of the test, all fertilizer applications which contained phosphate had a significant influence on plant growth. The NPK treatment was found to be the most advantageous. It was further determined that nitrogen and potash had a significant effect on plant growth in a group of eight treatments analyzed.
  • Ilustração de publicações técnicas preparo e apresentação de quadros, figuras e estampas

    Camargo, A. Pais de
Instituto Agronômico de Campinas Avenida Barão de Itapura, 1481, 13020-902, Tel.: +55 19 2137-0653, Fax: +55 19 2137-0666 - Campinas - SP - Brazil
E-mail: bragantia@iac.sp.gov.br