RCAAP Repository

Cocoa seedlings were grown in nutrient solution in order to find out the effects of the levels of N, P, K in the substrate on growth, symptoms and chemical composition of the leaves. A 3x3x3 factorial design was used. The following conclusions can be drawn. 5.1. Among the three elements under study, only nitrogen had a positive, significant effect on growth as measured by height and dry weight. 5.2. The level of a given elements in the leaves did increase when its level in the nutrient solution was raised. On the other hand the N content was positively affected by the concentration of P in the substrate. 5.3. A decrease in the N/P and K/P rations in the leaves was observed when the nutrient solutions had, res-respectively, absence of K and N and high level both of K and N. The N/K ratio increased with the level of P in the substrate. 5.4 A highly significant positive correlation was found between N content in the leaves and dry weight. This was not the case however, insofar P and K are considered - no correlation whatsoever was observed.

In this paper the authors describe the results obtained from the determination of molybdenum in sugar cane plant, grown in soils and climate prevailing in Piracicaba, State of São Paulo, Brazil. The molybdenum was determined in samples cut monthly from the 8th to 14th month, from an experiment consisting of 6 plots, 3 fertilized and 3 unfertilized. The fertilized treatment received 40 kg N (ammonium sulfate) 100 kg P2O3, (superphosphate) and 40 kg K2O (potassium chloride) per hectare, just before planting. Molybdenum was determined by thiocyanate-stannous chloride method, using carbon tetrachloride-butyl alcohol misture, for extrating the colored complex. The results obtained show a parallelism in the absorption of molybdenum by the plants of both treatments. The concentration of molybdenum in the stalks have a tendency to decrease, where as it kept more or less constant in leaves, with a exception in the 14° month when it rised probable because of a migration of molybdenum of the stalks to the leaves. The total amount molybdenum taken up was higher with the fertilized plot due its greater mass prodution.

Eight root-knot nematode forms are known to occur in Brazil, namely Meloidogyne exigua, M. incognita, M. j. javanica, M. j. bauruensis, M. inornata, M. hapla, M. arenaria arenaria and M. coffeicola. After presenting a historical resume of the root-knot disease, as well as observations on symptoms, distribution and spread, and life history of the nematodes, a study of the morphological characters used in identification of species is made, a key for separating the forms referred to above being also prepared. As no information on host plants of the coffee root-knot nematode (M. exigua) was available, a few tests were performed, as an attempt to infect several plant species. Pepper (Capsicum annuun) was the only plant attacked by M. exigua, having failed all attempts to infect nine other plants, including tomato var. Rutgers. M. exigua incited formation of galls on roots of cucumber, but no adult female was found in the tissue. In a final chapter dealing with control, a review of all methods available is presented.

This paper describes the determination of exchangeable calcium and magnesium in soil by using ethylenediamine tetracetic acid, after the separation of the principals interferents (iron, aluminum, manganese and phosphate) by using both ammonium hidroxide and ammonium sulfide in only one operation. In order to compare the chelometric and the permanganometric methods for determining exchangeable calcium, five replications of nine soils were analysed by both methods. The accuracy of the determination of exchangeable magnesium in soil was evalueted by means of the recovered magnesium, when the proposed method was applied. The data obtained in both studies allowed to conclude that the technique proposed is good and the accuracy is satisfactory.

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Os autores fizeram levantamento do grau de resistência em variedades de caqui à Cercosporiose, e concluiram que há variação da resistência entre as principais variedades cultivadas no Estado de São Paulo. Em ensaios com pulverização fungicidas, Maneb (Dithne M-22) mostrou ser mais eficiente que a calda bordalêsa no contrôle da doença.

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In this paper we present the results of pollen analysis of twelve sample of honey and twelve sample of pollen, colected by Apis mellifera L., during march to October of 1960 at Piracicaba, SP Brazil. Eleven species of nectariferous plants were identified by pollen analysis in honey and thirteen species of poliniferous plants were identified by pollen analysis of pollen collected by the bees. In this work I could evaluate the flowering period of honey plants around this area, using pollen analysis as a indirect method. We also compared this indirect evaluation with direct observation of flowering period of honey plants in São Paulo State, according to KERR and Amaral. Doing that we could point out that pollen analysis is a good method to use in our future studies of phenology of honey plants.

Working, by WINKLER method for determination of D. O. of fresh water, collected at and next to Escola Superior de Agricultura "Luiz de Queiroz", of Universidade de S. Paulo, the A. has found that of the 17 determinations, which were made, 6 showed numbers lower than limits established by Sanitary Code of Estado de São Paulo, Brazil, respecting dissolved oxygen (D. O.). This shows that tested waters are unsafe by use as potable. RIDEAL-STEWART modification was also used for the same samples, with results again more disfavorables for fresh water. Biochemical oxygen demand (B. O. D.) moreover was determinated in same samples.

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The purpose of the experiments described in this paper was to study the possibilities of eradicating hills of Atta sexdens rubropilosa Forel, 1908, which is the most important "saúva" ant (parasol ant) in the State of São Paulo, Brazil. The experiments were performed at Piracicaba, during the years 1960-1964. The following products were used in several projects: a) Nemagon (emulsifiable concentrate); b) aldrin (emulsifiable concentrate); c) "MM 33" (carbon bisulphide + methyl bromide); d) methyl bromide; e) carbon bisulphide; f) carbon bisulphide + phosphorus; g) aerosol of carbon bisulphide + heptachlor + chlordane; h) chlordane (emulsifiable concentrate); i) aldrin + fungicide (dust); j) dusts of heptachlor, chlordane, and aldrin, each plus a fungicide; and k) chlordane (dusts). The results obtained are seen in tables 1 to 13.

This paper deals with Cerosipha forbesi (Weed, 1889) (= Aphis forbesi) the strawberry root aphid, one of the noxious insects to the strawberry plant in the State of São Paulo, Brazil.

São descritos, em minúcias, os afídeos Idiopterus brasiliensis Moreira, 1925 e Phorodon menthae (Buckton, 1876), da família Aphididae.

O presente trabalho relata os dados obtidos sobre a determinação da capacidade de troca de cátions do solo, através da determinação do cálcio por fotometria de chama. A amostra de solo (2g) foi prèviamente saturada com íons cálcio, o excesso do reagente foi lavado e o cálcio deslocado do solo, mediante extração com solução normal de acetato de amônio pH 7. A determinação do cálcio, contido no extrato, foi feita mediante o emprêgo do fotômetro de chama Coleman modêlo 21. Os dados obtidos, demonstraram que a técnica adotada, além de sua simplicidade e rapidez, fornece resultados cuja precisão é satisfatória.

This paper deals with the determination of potassium in fertilizers by the flame photometric method. A preliminary study was performed in order to know the relationship between potassium concentration and readings in the Coleman flame photometer, model 21. It was verified a linear relation when the concentration of potassium was in the range of 0 and 30 ppm. The presence of some ions like calcium, magnesium, iron, sodium, phosphate, sulfate and ammonium were studied and showed that calcium and magnesium cause no interference in the method. Ammonium caused a slight interference when 550 ppm of NH4+ and 10 ppm of potassium were present. With 20 ppm of potassium the influence of ammonium was observed only with 995 ppm. Sulfate caused a moderate influence and phosphate interfered, giving lower results. The determination of potassium, with five replications, in three fertilizer mixtures, were performed in solutions that underwent a previous separation of phosphate and sulfate by an anion exchange resin and in solutions not purified by ion adsorption. The results showed good agreement indicating it is not necessary the separation of phosphate and sulfate when there is a several fold dilution of the solution. The method for determining potassium in fertilizers by flame photometry is very rapid and afford a good precision.

O presente trabalho descreve a determinação da capacidade de troca de cátions (CTC) do solo e de argilas, através da troca isotópica com cálcio radioativo, 20Ca45. Foi determinada a CTC de oito amostras de solo e de quatro de argilas, tendo sido feitas 5 pesagens de cada amostra de cada um dos materiais, a fim de se avaliar a precisão do método. O cálculo da CTC foi feito mediante a expressão: X = a1/a2 c - c a1 = atividade específica do cálcio da solução de equilíbrio antes de entrar em contato com o solo. a2 = atividade específica do cálcio da solução de equilíbrio após o contato com o solo. c = número de e.mg de cálcio da solução de equilíbrio e calculado para 100g de solo. X = capacidade de troca de cations em e.mg por 100g de solo.

This paper presents a infiltration rates study on cultivated soil, determined by sprinkling and by means of water impoundment in cilinder infiltrometer. Infiltration rates obtained with cylinder infiltrometers were compared with infiltration rates under sprinkler irrigation. We obtained high degree of correlation, between dates of two methods. We believe this correlation must be kept for diferents soil types. In any way, we can say, should be possible to estimate infiltration rates for sprinkler irrigation, from cilinder infiltrometer measurements if enough replications are made. The cylinder infiltrometer, that we have used was according to Muntz, and some improvement was necessary on the apparatus, in order of obtaining a better reading and constant hydraulic head.

Four antibiotics have been tested (penicillin, streptomycin, chloranphenicol and aureomycin), with relation to induction of mutations in a strain of S. typhimurium triptophanelles and in a strain of X. campestris also deficient for tryptophan. No mutagenic action was detected in any case analysed.

The present paper deals with study of the resistance against five antibiotics in a phytopathogenic bacterium Xanthomonas campestris (Pammel) Dowson. When the antibiotics were added to the solid medium in which the bacteria were grown, the colonies resistant to the streptomycin and erythromycin appeared even in the highest concentration used; as to the penicillin, aureomycin and cloranfenicol when in concentrations higher than 200 mcg/ml, 0,3 mcg/ml and 128 mcg/ml respectively, resistant colonies did not appear. So, the results show that the penicillin was the least efficient antibiotic and aureomycin the most effetive to Xanthomonas campestris.

This paper describes the data concerning the weight of the trunk branches and leaves of the coffee tree at the age of ten years and growing in a latosol of Piracicaba, State of São Paulo, Brasil (Table 1).