Scielo RSS <![CDATA[Bragantia]]> http://www.scielo.br/rss.php?pid=0006-870519510001&lang=en vol. 11 num. 1-3 lang. en <![CDATA[SciELO Logo]]> http://www.scielo.br/img/en/fbpelogp.gif http://www.scielo.br <![CDATA[<B>Dosagem dos nitratos do solo pelo método do ácido fenoldissulfônico</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100001&lng=en&nrm=iso&tlng=en This work deals with the nitrates determination bj r the phenoldisulfonic acid method in the soils of São Paulo State. Several modifications were introduced which led to outline an analytical procedure. The nitrates are extracted by percolation, with a solution of H2SO4 0,01 N which is efficient in obtaining clear filtrates without clay and it is a saving time procedure. The ratio employed to remove soil nitrates is one weight of soil for three volumes of the extractor. The H2SO4 solution was the best extractor found because it dissolves less organic matter from the soil than other methods. Also, with the method described, the operation of removing chlorides is easy and it is possible to use a blank determination. Losses of nitrates are significant when chlorides are present in concentration as high as 11 e.μg (3.9 p.p.m.). The efficient removal of chlorides by using silver sulfate, can be performed only in acid extracts, if losses of nitrates are to be avoided. The solution free from chlorides must be neutralized with NaOH 1 N because acid reaction causes loss in nitrates which are liberated as HNO3 (gas). The residual organic matter is destructed with hydrogen peroxide after drying the solution. The hydrogen peroxide always has nitrates and the quantity of them must be determined. The residual salts from the above treatments are attacked with phenoldisulfonic acid and this solution dilutes to a convenient volume and neutralized with ammonium hidroxide (1 + 1). The color intensity developed in this reaction is read in an AC model Fisher Electrophotometer with B-425 filter calibrated for nitrates. The best readings are between 3-45 or 0,25-16,5 e.μg of NO-3. <![CDATA[<B>Combate aos nematóides pela aplicação de fumigantes no solo</B>: <B> efeito do d-d e dowfume w-40 no combate aos nematóides formadores de galhas, em tubérculos de batatinha</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100002&lng=en&nrm=iso&tlng=en No presente trabalho relatamos os resultados a que pudemos chegar com o emprêgo dos fumigantes "D-D" (Dicloropropeno-Dicloropropano), e "Dowfume W-40", na base de dibrometo de etileno, no combate aos nematóides formadores de galhas, em tubérculos de batatinha. As experiências foram efetuadas em Campinas, em terreno do tipo "Glacial", e divididas em duas fases distintas. Na primeira, tratamos o terreno com os fumigantes 18 dias antes do plantio e adubamos alguns lotes, ena segunda fase, que foi realizada no mesmo terreno, não adubamos e nem tratamos o terreno, com o fim de verificar o efeito residual dos produtos, empregando, além disso, duas variedades ao invés de uma, como na fase inicial. Os resultados apresentados vieram indicar que : a) tanto o "D-D" como o "Dowfume W-40" não prejudicaram a brotação dos tubérculos ; b) entre produções, houve, na primeira fase da experiência, uma ligeira superioridade dos lotes com fumigantes e adubados sobre o "sem tratamento com fumigante mas com adubação", e dêste, por sua vez, sôbre o "sem fumigante- e sem adubação". Na segunda fase quase não houve diferenças entre tratados e adubados ; c) tanto o "D-D" como o "Dowfume W-40" foram eficientes na redução dos nematóides formadores das galhas nos tubérculos, pois enquanto na primeira fase os canteiros "sem tratamento e sem adubação" produziram, em média, 49,5% de galhas, a maioria de caráter grave, e os "adubados mas sem fumigante" deram 20%, já nos tratados e adubados, houve apenas uma leve incidência de 1,5% para o "D-D" e 0% para o "W-40". No segundo plantio, no mesmo terreno, observamos que, além de uma reinfestação do solo, os restos da adubação não impediram a formação das galhas como na primeira fase. Para confirmação dêstes resultados, novas experiências serão executadas com fumigantes no solo.<hr/>Results are reported on the application of the soil fumigants "D-D" (dichloropropene-dichloropropane) and "Dowfume W-40" (ethylene dibromide) for the control of the root-knot nematode on potatoes. The experiments were done at Campinas (State of São Paulo, Brazil) in soil of the "Glacial" type. The tests cover two distinct phases. In the first the soil of certain plots was fumigated 18 days prior to planting. There were four treatments : fumigation and fertilizer, fumigation without fertilizer, fertilizer alone, and without fumigation or fertilizer. In the second phase, performed a year later on the same land, no fertilizer was used and no fumigant applied in order to determine the residual effect of the chemicals. In the second phase two potato varieties were used instead of only one as in the first. The results show that : a) Neither "D-D" nor "Dowfume W-40" harmed the production of tubers. b) In the first phase of the experiment the production of the plots with fumigants and fertilizers was slightly better than that of the plots with fertilizer only and in turn the latter was better than that of the plots without fumigants and without fertilizer. In the second phase there was almost no difference between plots with chemical treatments and plots with fertilizer. c) "D-D" as well as "Dowfume W-40" efficiently reduced root-knot nematodes on the tubers. This is shown in the 1st phase of the experiment by the plots without fumigation and without fertilizer, where 49.5% of the tubers were galled, mostly seriously ; on the plots that received only fertilizer, 20% were galled while those fertilized and fumigated with "D-D" were 1.5% galled and with "Dowfume W-40" 0% In the 2nd planting on the same site the residual fertilizer however did not reduce the formation of galls. Further experiments are planned. <![CDATA[<B>Efeito da frequência e severidade de corte das fôlhas sobre a duração de vida do sisal</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100003&lng=en&nrm=iso&tlng=en The present paper deals with the influence of four different leaf-cutting cycles combined with three levels of severity of cutting upon the life cycle of sisal plant (Agave sisalana Perrine). According to the results obtained, it may be concluded that less frequent cutting induces the plant to pole earlier, and greater severity of cutting prolongs its life eyele. <![CDATA[<B>Identificação microquímica de minerais primários de potássio no solo</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100004&lng=en&nrm=iso&tlng=en This paper reports a study, from a chemical arid microcheniical point of view, of the soil potassium in the type of soil originating from the Arenito Bauru. A mechanical separation of the soil was carried out in order to study the potassium distribution in the soil. The fractions 0.250 to 0.105 mm, 0.105 to 0.053 mm, 0.053 to 0.020 mm, 0.020 to 0.010 mm and 0.010 to 0.002 mm were isolated. The chemical data, i. e., the exchangeable and the total potassium content pointed out the occurrence of primary minerals of potassium in the fractions, 0.250 to Ò.105 mm, 0.105 to 0.053 mm and 0.053 to 0.020 mm. A simple microchemical technique was performed by which it was possible to differentiate the potassium bearing mineral from quartz, ilmenite, magnetite and other minerals. Primary minerals of potassium were found in those fractions and this fact indicated that the total potassium content in the samples studied was due to the presence of those minerals. <![CDATA[<B>Ensaio de variedades de cafeeiros III</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100005&lng=en&nrm=iso&tlng=en O ensaio de variedades de cafeeiros foi iniciado na Estação Experimental Central de Campinas, em 1931. A primeira colheita foi realizada em 1935. Em 1939, foi feita a publicação dos resultados referentes ao período 1935-38. Em 1949, nova publicação reuniu os dados do período 1935-46. No presente trabalho vêm relatados os acontecimentos relativos aos anos que decorreram de 1947 a 1950, ano por ano, e feito o exame dos resultados no período todo, desde o início da produção (1935-1950). O ensaio teve prosseguimento normal nos anos de 1947 a 1950. Foram feitas as adubações adequadas, as capinas se realizaram em ordem, as colheitas se processaram regularmente bem. A produção média foi examinada ano por ano, verificando-se que, nesse período, o Bourbon amarelo sempre se colocou no primeiro lugar. Todas as demais variedades tiveram alterações de colocação na competição de produção. No período em exame (1947-1950), a variedade mais produtiva foi o Bourbon amarelo, seguida pelo Bourbon vermelho, Sumatra, Maragogipe, Nacional e Amarelo de Botucatu. Com relação ao amadurecimento dos frutos, a variedade mais precoce foi o Amarelo de Botucatu, seguido pelo Sumatra, Nacional, Bourbon vermelho, Bourbon amarelo e, finalmente, o Maragogipe, que foi o mais tardio. A variedade que apresentou sementes de maior tamanho foi o Maragogipe ; o Nacional, o Amarelo de Botucatu e o Sumatra produziram sementes de tamanho intermediário e o Bourbon vermelho e o Bourbon amarelo as de menor tamanho. A análise dos dados referentes ao período todo do ensaio (1935-1950), isto é, dezesseis colheitas, demonstraram o seguinte : a) existe diferença significativa entre a produção do Bourbon amarelo e a do Bourbon vermelho ; sendo o Bourbon amarelo mais produtivo ; b) existe diferença significativa entre a produção do Bourbon vermelho e a do Sumatra ; c) existe diferença significativa entre a produção do Sumatra e a do Maragogipe, Nacional e Amarelo de Botucatu ; d) não existe diferença significativa entre a produção do Maragogipe, Nacional e Amarelo de Botucatu ; e) o aumento médio de colheita, por ano, da variedade Bourbon amarelo, é maior do que o do Bourbon vermelho ; f) o aumento médio de colheita, por ano, do Maragogipe, é maior que o do Nacional e o do Amarelo de Botucatu.<hr/>The coffee varietal trial was initiated at the Campinas Experimental Station in 1931. The first harvest was gathered in 1935. The results for the period 1935-38 were published in 1939 and the united results for 1935-46, in 1949. The present paper describes the individual observations for the years 1947 to 1950 and examines the results for the whole period from the beginning (1935-1950). The trial proceeded normally in the years 1947-50. Adequate fertilizers were applied, the ground was cleaned regularly and the process of harvesting was satisfactory. The mean yield was studied year by year. During the period, Bourbon amarelo always attained first place while the other varieties varied in placing. The order of the varieties, in respect of the total yield for 1947-50, was : Bourbon amarelo (yellow Bourbon), Bourbon vermelho (red Bourbon), Sumatra, Maragogipe, Nacional and Amarelo de Botucatu. The variety which was the earliest to produce mature fruits was Amarelo de Botucatu, followed by Sumatra, Nacional, Bourbon vermelho, Bourbon amarelo and finally Maragogipe. The variety producing the largest seeds was Maragogipe : Nacional, Amarelo de Botucatu and Sumatra produced seeds of intermediate size, while the smallest were those of Bourbon vermelho and Bourbon amarelo. The analysis of the data for the whole period of the trial, i. e., for sixteen harvests, shows the following : a) the yield of Bourbon amarelo is significantly higher than that of Bourbon vermelho. b) the yield of Bourbon vermelho is significantly higher than that of Sumatra. c) the yield of Sumatra is significantly higher than those of Maragogipe, Nacional and Amarelo de Botucatu. d) the yields of the last three do not differ significantly among themselves. e) the rate of improvement of yield of Bourbon amarelo is greater than that of Bourbon vermelho. f) the rate of improvement of yield of Maragogipe is greater than those of Nacional and Amarelo de Botucatu. <![CDATA[<B>Analise estatística do ensaio de variedades de café</B>: <B>parte II</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100006&lng=en&nrm=iso&tlng=en This paper continues the statistical analysis of a coffee varietal trial at Campinas (1, 2, 3), utilising the data of a further period of 4 years. Variety D (Yellow Bourbon) has now drawn significantly ahead of C (Bourbon) as is shown by fig. 1 compared with fig. 2b of reference (3). This possibility was foreseen at the time of the earlier analysis (3), from a consideration of the annual rates of increase of yield. This is of interest to the general problem of selection of perennial plants, because it shows that not only average yield but also rate of increase of yield is a useful criterion for selection. <![CDATA[<B>Uma nova espécie de <I>Mononchus (Nematoda, Mononchidae)</i></B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100007&lng=en&nrm=iso&tlng=en This communication describes a new species of Mononchus which was found at the Experimental Station of Monte Alegre (Ibiti), State of São Paulo. Species of Mononchus are of interest because they are believed to be predators of other nematoids. The predatory habit of the new species was observed in the laboratory. Assuming that its behaviour is the same in the field, we may consider the species as an ally of man in controlling populations of nematoids in the soil. M. ibitiensis differs from its nearest related species M. muscorum by its smaller pharynx ; by smaller dortooth, opposited by four ribs, each of which has six denticles and by the presence of three caudal glands connected with a pore without valve. <![CDATA[<B>Adubação da batata doce em São Paulo</B>: <B>Parte I - Efeito da adubação mineral</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100008&lng=en&nrm=iso&tlng=en Visando estudar a influência da adubação na cultura da batata doce para as condições do Estado de São Paulo, foram efetuadas várias séries de ensaios abrangendo diversos aspectos do problema. Neste trabalho, são apresentados apenas os resultados de 31 ensaios planejados para estudar o efeito dos elementos N, P e K, sôbre o desenvolvimento das ramas, produção, número de batatas por plantio e pêso médio das batatas, nos principais tipos de solo do Estado. Os resultados dos demais ensaios dêste plano serão objeto de outros artigos. Vários planos e delineamentos experimentais foram adotados. Como fonte de elementos minerais foram utilizados os seguintes adubos comerciais : salitre do Chile, sulfato de amônio, superfosfato de cálcio, farinha de ossos degelatinados, cloreto de potássio e sulfato de potássio. As fórmulas correspondentes a cada canteiro foram preparadas previamente, e as misturas assim obtidas aplicadas a lanço sôbre o solo antes do preparo dos camalhões. A fertilidade natural do solo e outros fatôres de ordem agrícola mostraram ter muito maior influência na produção da batata doce que a adubação. Geralmente, apenas se obtiveram aumentos substanciais de produção, determinados pela adubação, nos ensaios plantados em terras de fertilidade muito baixa. Nesses casos, apesar de se mostrarem bastante elevados os aumentos percentuais de produção, as diferenças ou aumentos absolutos foram muito pequenos, muitas vêzes, abaixo de 3 t/ha. Desta forma, os aumentos de produção não compensaram os gastos com adubos. Nos ensaios de produção normal (acima de 10 t/ha), foi verificado um único caso de efeito de nitrogênio na produção, que se deu em Mococa, em solo do arqueano. Efeitos de fósforo ou de potássio foram observados unicamente em solos de origem glacial, de Sorocaba. Um único caso de interação de nitrogênio e fósforo foi obtido em solo do arenito de Bauru, em Pindorama. Com relação ao desenvolvimento das ramas, sempre que houve influência significativa de algum elemento, êste foi o nitrogênio. Isto geralmente se verificou nos ensaios instalados nos solos de origem glacial. É de se ressaltar que não se verificou correlação alguma entre o desenvolvimento das ramas e a produção. Sôbre outros dados, como percentagem de falhas, número de batatas por planta, pêso médio das batatas, etc, foram insignificantes ou mesmo nulos os efeitos das adubações ou elementos estudados. Um fator que demonstrou grande influência na produção e desenvolvimento da batata doce foi a falta de rotação de cultura. Verificou-se que, nos ensaios onde se fêz o cultivo seguido dessa planta por mais de um ano no mesmo terreno, a produção caiu enormemente nos anos seguintes, muitas vezes para a terça ou quarta parte. Para as condições do Estado de São Paulo, os resultados obtidos indicaram que a adubação mineral direta para a batata doce não constitui, em geral, uma prática economicamente recomendável. Esta planta deve ser cultivada em rotação com outras culturas mais exigentes, que, necessitando de adubações pesadas, permitam à batata doce, no ano seguinte, aproveitar de modo mais vantajoso os restos dos adubos que ficaram retidos no solo.<hr/>In order to study the effects of fertilizers on sweet potato, in the conditions of the State of São Paulo, a series of experiments was undertaken to cover the different aspects of the problem. In this paper, results are presented only for 31 experiments planned to study the effects of N, P and K on root development, yield, number of potatoes and mean weight, in the principal types of soil in the State. The results of the other experiments will be considered in further papers. Various plans and experimental designs were used. As a source of mineral elements, the following commercial fertilisers were employed : Chile saltpetre, sulphate of ammonia, superphosphate, degelatinised bone meal, potassium chloride and potasssium sulphate. The formulas for each plot were made up in advance and the mixtures broadcast over the soil before trenching. It appeared that the natural fertility of the soil and other agricultural factors had much more influence on the production of sweet potato than had the application of fertilizers. Substancial responses to fertilizer were generally observed only in soils of very low fertility. In these cases, even although the percentage increases in yield were considerable, the absolute increases (often less than 1.1 tons per acre) were insufficient to pay for the application of fertilizar. Among those trials producing satisfactory yields (over 4 tons per acre), only one showed a response to nitrogen. This was in Mococa on "massapê-salmourão" soil. Responses to phosphorus or potassium were noted only on soils of "glacial" origen in the "Sorocaba" region. A single case of nitrogen-phosphorus interaction was observed on "Arenito de Bauru" in Pindorama. Whenever the development of vines showed a response, this was always due to nitrogen. This was generally found on soils of "glacial" origim. It must be pointed out however that no correlation was found between vine development and yield. Other data, such as percentage of failures, mean weight of potato, etc., failed to show significant response to manuring. One factor which showed a strong influence on yield and growth of sweet potato, was crop-rotation. It was found that, in those trials where the plant was cultivated continuously, the yield fell drastically in subsequent years, often to a third or quarter. The results obtained show that, for conditions prevailing in the State of São Paulo, the direct application of mineral fertilizers to sweet potato is not usually an economic proposition. This plant should be grown in rotation with more exhausting crops, which demarnd heavy dressings. The sweet potato can then benefit from the residual effects of these dressings in the following year. <![CDATA[<B>Aspectos da cultura do cereal "Adlay"</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100009&lng=en&nrm=iso&tlng=en A new variety of adlay (Coix lacryma-jobi L.) is being cultivated in the Slate of São Paulo, its chief characteristics being small height, oblong black seeds, and fair yield, especially in low lands, with abundant rainfall and high temperature. Some trials were conducted with this plant in four experiment stations of the Instituto Agronômico in the State of São Paulo. The yields were very variable from year to year and place to place. The following preliminary statements could be made with regard to highland conditions in this state: a) adlay should be planted in October-November ; b) spacing and rate of planting is not very important within the limits of 60-120 cm between rows and 8 to 33 g of seed per 10 m in the row, on account of the great tillering power of the plant ; c) in poor and acid glacial soil of Capão Bonito, a fertilizer trial gave indication that complete mineral fertilizer and limestone applied every year gave good results, while in mixed terra roxa soil, in Jau, the greater reaction was to phosphorus and nitrogen. <![CDATA[<B><I>Xiphinema brasiliense,</I> nova espécie de nematóide do Brasil, parasita de <I>Solanum tuberosum</I> L.</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100010&lng=en&nrm=iso&tlng=en Xiphinema brasiliense, a new opistodelphic species of Brazilian nematode, was found in soil around potato roots at Sapecado (State of São Paulo, Brazil). It differs from the other known opistodelphic species of the genus, by its type of tail end, which is digitate. It contrasts most strongly with X. ensiculiferum (Cobb, 1893), in which the shape of the extremity is decidedly hemispheroidal. The species most closely resembling X. brasiliense isX. chambersi Thorne, 1939, from which it is distinguished by its longer stylet and the mentioned characteristic form of the end of the tail. The X. brasiliense amphids are also very short and wide, unlike those of X. chambersi. <![CDATA[<B>A multiplicação de batatinha por meio dos brotos</B>]]> http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051951000100011&lng=en&nrm=iso&tlng=en Xiphinema brasiliense, a new opistodelphic species of Brazilian nematode, was found in soil around potato roots at Sapecado (State of São Paulo, Brazil). It differs from the other known opistodelphic species of the genus, by its type of tail end, which is digitate. It contrasts most strongly with X. ensiculiferum (Cobb, 1893), in which the shape of the extremity is decidedly hemispheroidal. The species most closely resembling X. brasiliense isX. chambersi Thorne, 1939, from which it is distinguished by its longer stylet and the mentioned characteristic form of the end of the tail. The X. brasiliense amphids are also very short and wide, unlike those of X. chambersi.