Foram realizados experimentos em ambiente controlado, em câmaras de crescimento, com duas cultivares de feijoeiro (Phaseolus vulgaris), Rosinha e Carioca, para a quantificação de componentes monocíclicos da mancha angular. Os componentes monocíclicos avaliados foram: período de incubação, severidade da doença e taxa de crescimento das lesões, sob as temperaturas de 6, 10, 14, 17, 21, 25, 29 e 33 ºC. Nenhum sintoma da mancha angular ocorreu em 6 e 33 ºC. A severidade da mancha angular foi elevada na faixa de temperatura entre 20 e 25 ºC e o período de incubação foi favorecido pela temperatura de 25 ºC, para as duas cultivares testadas. Esta temperatura também proporcionou a maior taxa de crescimento das lesões e estes dados foram ajustados, em função da temperatura por uma equação do primeiro grau. O efeito do período de molhamento foliar (5, 6, 12, 18, 24, 30, 36, 42, 48 e 54 h) na severidade da doença também foi avaliado. A severidade da mancha angular do feijoeiro aumentou com o aumento da duração do molhamento foliar até o máximo de 54 h. As variações de severidade da mancha angular do feijoeiro, em relação ao número de horas de molhamento foliar, foram explicadas pelo modelo de Richards. A função Beta-Richards explicou o efeito combinado da temperatura e da duração do molhamento foliar na severidade da mancha angular do feijoeiro para ambas as cultivares.

Monocyclic components of angular leaf spot, were quantified on two bean (Phaseolus vulgaris) cultivars Rosinha and Carioca in growth chambers. Incubation period, disease severity and lesion growth rate were assessed, at temperatures of 6, 10, 14, 17, 21, 25, 29 and 33 ºC. No angular leaf spot symptoms occurred at 6 and 29 ºC. Severity for angular leaf spot was high between temperatures of 20 and 25 ºC, and the incubation period for both varieties tested was favoured at a temperature of 25 ºC. This temperature also provided the greatest lesion growth rate and these data were adjusted by a first grade equation in function of the temperature. The effect of the leaf wetness duration (5, 6, 12, 18, 24, 30, 36, 42, 48 and 54 h) in the severity of disease symptoms was studied as well. Severity for the angular leaf spot increased with the wetness duration period to the maximum of 54 h tested. The variations of angular leaf spot in relation to the number of hours of leaf wetness were explained by the Richards model. The Beta-Richards function explained the combined effects of the temperature and leaf wetness duration in the severity of angular leaf spot, for both varieties.

Foram realizados experimentos em ambiente controlado, em câmaras de crescimento, para a antracnose do feijoeiro (Phaseolus vulgaris) causada por Colletotrichum lindemuthianum, em duas cultivares, Rosinha e Carioca, para a quantificação de componentes monocíclicos. Os componentes monocíclicos avaliados foram período de incubação e severidade da doença, sob as temperaturas de 6, 10, 14, 17, 21, 25, 29 e 33 ºC. A antracnose não se desenvolveu nas temperaturas de 6 e 33 ºC. A severidade foi mais elevada a 17 ºC e o menor período de incubação ocorreu a 29 ºC, para a cv. Rosinha, e 25 ºC para a cv. Carioca. A função beta generalizada mostrou bom ajuste aos dados de temperatura. O efeito do período de molhamento foliar (5, 6, 12, 18, 24, 30, 36, 42, 48 e 54 h) na severidade da doença também foi avaliado. Não houve incremento na severidade da antracnose do feijoeiro para períodos de molhamento superiores a 24 h. As variações de severidade da antracnose do feijoeiro, em relação ao número de horas de molhamento foliar, foram explicadas pelo modelo de Richards. A função Beta-Richards explicou o efeito combinado da temperatura e duração do molhamento foliar na severidade da antracnose do feijoeiro para ambas as cultivares.

Monocyclic components of anthracnose caused by Colletotrichum lindemuthianum were quantified on two bean (Phaseolus vulgaris) cultivars Rosinha and Carioca, in growth chambers. Incubation period and disease severity were assessed, at temperatures of 6, 10, 14, 17, 21, 25, 29 and 33 ºC. Anthracnose did not develop at temperatures of 6 and 33 ºC. The severity was highest at 17 ºC and the shortest incubation periods occurred at 29 ºC for the cv. Rosinha and 25 ºC for the cv. Carioca. Beta function was fitted to data of disease severity at different temperatures. The effect of the leaf wetness duration (5, 6, 12, 18, 24, 30, 36, 42, 48 and 54 h) in disease severity was assessed as well. There was no increment in anthracnose severity of the bean for periods of wetness superior to 24 h. The variations of anthracnose in relation to the number of hours of leaf wetness were explained by the Richards model. The Beta-Richards function explained the combined effect of the temperature and leaf wetness duration in the severity of anthracnose, for both varieties.

Sintomas de deficiências de macro e micronutrientes foram induzidos nas variedades de Vigna sinensis "pitiúba" e "dorminhoco* cultivando-as em solução nutritiva com omissão de um elemento de cada vez. Embora os sintomas, de modo geral, concordem com os descritos na literatura para outros feijões, observou-se diferença varietal na susceptibilidade às carências.

This paper deals with the results of an experiment designed to induce symptoms of deficiency of macro and micronutrients in two varieties of "cowpea" extensively grown in the Northeast of Brazil, "dorminhoco" and "pitiúba". As a rule, the results show that visual abnormalities found in the test plants agree with those described in the literature for other beans. It seems, however, that both varieties are less sensitive to the omission of S, Cu, and Mo from the substrate.

É apresentada uma chave para identificação visual das deficiências de macro e de micronutrientes em Vigna sinensis.

Symptoms of deficiency of macro and micronutrients were induced in Vigna sinensis by growing two cultivars in nutrient solution under the necessary treatments. Results there of were used to prepare a key which could be used in the visual diagnosis of mineral deficiencies. As a rule, the information obtained is in agreement with result found in the literature for other legumes. It is noteworthy, however, that symptoms of Mo and Zn first showed up in older leaves.

Duas cultivares de Vigna sinensis, "dorminhoco" e "pitiúba" foram cultivadas em solução nutritiva completa ate o fim do ciclo. Nas diferentes partes, vegetativas e reprodutivas, foram determinados os macro e micronutrientes. Os dados obtidos permitiram estimar as exigências de uma população no campo e as quantidades de elementos exportados como produto colhido.

Two varieties of Vigna sinensis, "dorminhoco" and "pitiuba", were grown in nutrient solution till the end of the life cycle and then analysed in order to gain information about their needs for macro and micronutrients. The following has been found: (1) both varieties have the same needs; (2) production of 1 ton of beans requires the following quantities of macro (kg) and micronutrients (g): N - 76, P - 4, K - 85, Ca - 50, Mg - 13, S - 6. B - 320, Cu - 20, Fe - 1855, Mn-162, Mo - 7 and Zn - 89. (3) a comparison with data in the literature has shown that Vigna presents a higher demand for B and Fe than soybean.

Foram induzidas deficiências de macronutrientes em duas cultivares de Vigna sinensis cultivadas em solução nutritiva. A determinação da matéria seca das diferentes partes permitiu verificar o efeito da falta de um nutriente no crescimento e na produção. As análises minerais forneceram indicações que ajudam na avaliação do estudo nutricional.

Vigna sinensis, varieties "Dorminhoco" and "Pitiúba", was grown in nutrient solution in the presence and absence of macronutrients; leaves (upper and lower) were collected for analysis at the and of the life cyle or when symptoms of deficiency were marked. Variations found in leaf composition agree, as a rule, with what is contained in the literature with regards to other species under the same type of experimental conditions: reduction in concentration in the tissue when the element was absent from the substrate; interionic, counter ion, and dilution effects. The following levels of macronutrients were associated with maximun growth: N=1.97 ± 0.16; P=0.14 ±0.03; K= 3.20 ± 0.36; Ca=5.38 ± 0.41; Mg=0.66 ± 0.14; S=0.15 ± 0.04. As indication of deficiency, on the other hand, the corresponding leaf contents would be: N =1.28 ± 0.13; P = 0.02 ± 0.01; K=0.64 ± 0.10; Ca=1.79 ± 0.24; Mg=0.14 ± 0.05; S=0.05 ± 0.01. Due to the large differences found between foliar composition in the control and the deficient plants it is very likely that under field conditions deficiencis may occur when the level of a given element in the leaves is higher than those presented herein. Dry matter was affected in the following decreasing ords: Complete, -S, -Mg, -P, -K, -Ca, -N; therefore, the lowest yield was obtained in the treatment lacking nitrogen.

Foram induzidas deficiências de micronutrientes em duas cultivares de Vigna sinensis, "Dorminhoco" e "Pitiúba" cultivadas em solução nutritiva. A determinação de matéria seca das diferentes partes permitiu verificar o efeito de falta de cada elemento no crescimento e na produção. As análises minerais das folhas deram dados que servem para a avaliação do estado nutricional.

Vigna sinensis, varieties "Dorminhoco" and "Pitiúba" were grown in nutrient solution both in the presence and in the absence of micronutrients dry matter production was measured either at the end of life cycle or whenever symptoms of deficiency were sufficiently acute to warrant an early harvesting; leaves were then analysed for mineral composition. Dry matter production obeyed the following decreasing order: Complete > - Mn = - Mo = - Cu > - Zn > - B; pods were formed and filled in all treatments except the last two; yield, however, was much lower than in the full strength solution which gave an average equivalent to 1.5 ton per hectare of dry beans. Leaf analyses showed consistently that lack of a nutrient in the substrate leads to a decrease in its contents in the tissue. Other variations were induced in leaf composition by the different treatments being all of them in agreement with common cases of dilution and interionic effects on uptake and in translocation. The inverse relationship between Fe and Mn, however was not substantiated. Tentatively the following leaf levels (in ppm) could be considered as satisfactory: B = 203 ± 31; Cu = 6±0.79; Fe = 817 ± 103; Mn = 148 ± 21; Mo = 0.24 ± 0.05; Zn = 43 ±9; deficient levels could be considered: B = 44 ± 25;Cu=5±1.2; Fe = 337 ± 31; Mn = 24 ± 6; Mo = 0.20 ± 0.08; Zn = 24 ± 5.

Neste trabalho é apresentado um estudo sobre a determinação do cálcio trocável do solo, através do método colorimétrico do glioxal bis (2-hidroxianil). São apresentados os dados referentes às curvas de absorção e a estabilidade do glioxal e do composto cálcio glioxal, a relação entre as leituras e a concentração de cálcio em soluções padrões e a interferência de diversos íons. Com base nos resultados encontrados, é proposta uma técnica para a determinação do elemento, em extratos de solo, obtidos com solução de cloreto de potássio 1 normal» sendo os interferentes mascarados com cianeto de potássio e trietanolamina. Os resultados obtidos na determinação do cálcio em oito amostras de solo do Estado de São Paulo, são comparados com aquêles encontrados através do método quelatométrico do EDTA.

The method for the colorimetric determination of exchangeable calcium in soils, based on the reaction with glyoxal is proposed. The interference of some ions which are normaly found in soil extracts, (magnesium, copper, manganese, aluminum, iron and sulfate) as well as its elimination with KCN and trietanolamine, were studied. The new method was compared with the one using EDTA titration, the results showing the same precision for both.

O presente trabalho relata os dados obtidos sôbre a concentração e a quantidade de macronutritntes, N, P, K, Ca, Mg e S no tronco, ramos, fôlhas e frutos do cafeeiro, Coffea arabica, L, variedade mundo novo [(B. Rodr.) Choussy], aos dez anos de idade e crescendo em solo latossólico da Escola Superior de Agricultura "Luiz de Queiroz", em Piracicaba. São apresentados também os dados obtidos nas mesmas condições, sôbre o pêso de diversas partes (tronco, ramos, fôlhas e frutos) do cafeeiro.

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).

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.

O presente trabalho relata os dados obtidos na separação do estrôncio do cálcio, pelo uso de uma solução de NH4- EDTA, com pH entre os valores 4,8 e 5,3, passando através de uma coluna de resina trocadora de cátions. Assim, 200 ml de uma solução a 2,5% de NH4- EDTA com pH = 4,8 e contendo 0,36 mg de estrôncio e 199,2 mg de cálcio (o que dá uma relação de 1 de Sr para 553 de Ca) foram passados através de uma coluna de 25 a 28 ml de resina trocadora de cátions Amberlite IR - 120 (H+) prèviamente preparada. O estrôncio ficou retido na coluna e o cálcio continuou na solução que passou. Depois de passar solução de NH4- EDTA com pH 5,3 e solução de HCl de 0,25 a 0,75 N, o estrôncio foi eluido com solução 3N de HCl. Como empregou-se estrôncio radioativo Sr-89, esse ion foi determinado por radiometria, para se conhecer a eficiência da separação. O cálcio foi determinado pelo método permanganométrico em solução de NH4- EDTA após a eliminação do agente quelante. Os dados obtidos mostraram que houve uma separação muito eficiente, indicada pela porcentagem de recuperação do estrôncio qu efoi de 97,7, 97,0 e 98,6% ao passo que a recuperação do cálcio foi de 100,0, 99,9 e 99,7%.

A simple, rapid and efficient method of separation of strontion from calcium can be perfomed by using a solution of 2.5% NH4- EDTA, with pH adjusted to 4.80 to dissolve those cations. After, the solution is passed through a 25-28 ml column of the Amberlite 1R-120 (4+) cation exchange resin. Strontinum is quantitatively retained on the resin, while calcium passes through. After removal of ammonium ions with 0.25 to 0.75 normal solution of HC1, the strontium is eluted with 3 normal solution of HCl. The method was used to separate strontium and calcium from prepared strontinum-calcium mixture containing 0.36 mg of Sr with radioactive strontinum Sr-89 and 199.2 mg of Ca. The recovery of strontinum was 97.7, 97.0, and 98.6% in three replications and the recovery of calcium was 100.0, 99.9 and 99.7%. The strontinum was determined radiometrically with the "1000" Scaler, model SC-33, Tracerlab, Inc.

O presente trabalho relata os dados obtidos na determinaçao do zinco em plantas segundo uma nova técnica. Esta nova técnica consistiu em se aliar a separação do zinco de outros interferentes, através do emprego de uma coluna de resina trocadora de anions, ao método polarografico da dosagem do citado elemento. A amostra de planta (1, 000g) foi incinerada em copo de Pyrex a 450-5009C durante 90 minutos e o zinco foi extraido da cinza com solução de HC1 2N. A separação do zinco de outros elementos interferentes foi feita pela passagem da solução através da resina trocadora de anions, Amberlite, IRA-401. Após a eluiçao do zinco da coluna, a solução obtida foi levada ao polarografo registrador. (Sargent, modelo XXI) para a determinação, Trabalhando-se com um conjunto de 10 (dez) a 12 (doze) colunas de resina, pode-se executar 10 (dez) a 12 (doze) determinações num periodo de 6 (seis) horas.

This paper deals with the polarographic determination of zinc in plants after its separation with an anion exchange resin column. One gram of plant was ashed in a 20 ml beaker at 4505009C for 90-100 minutes. The solution of plant ash in 2N hydrochloric acid was passed through the column formed by a resin bed (Amerlite IRA-401) of 9 cm of length, which adsorbed zinc in the form of an anion an allowed to pass all the interfering ions. Twenty ml of 0,125 N sodium nitrate solution was used to elute the zinc and the effluent was dried in silica dish in vapour bath. Ten ml of 0, 35 N ammonium hydroxide with 0, 0125 % of gelatin, were added to the dish and the solution was stirred in order to dissolve the zinc. Three to five ml of solution were transferred to one special cell of the Sargent Visible Recording Polarograph Model XXI and the polarogram were obtained with the dropping mercury electrode and the stationary pool of mercury as the second electrode. Some of the obtained data are presented: PLANT Micrograms of zinc Micrograms %Recuperation added to the sample of zinc found (average) Coffee (leaves) 0,0 9,2 Coffee (leaves) 0,0 9,2 Coffee (leaves) 0,0 9,2 Coffee (leaves) 20,0 29,2 Coffee (leaves) 20,0 30,4 101,4 Coffee (leaves) 20,0 29,2 Sweet Clover (aerial part) 0,0 22,4 Sweet Clover (aerial part) 0,0 22,4 Sweet Clover (aerial part) 0,0 21,2 Sweet Clover (aerial part) 20,0 42,4 Sweet Clover (aerial part) 20,0 43,6 101,9 Sweet Clover (aerial part) 20,0 42,4 Sugar Cane (leaves) 0,0 12,0 Sugar Cane (leaves) 0,0 12,0 Sugar Cane (leaves) 0,0 10,8 Sugar Cane (leaves) 20,0 31,8 Sugar Cane (leaves) 20,0 31,8 100,6 Sugar Cane (leaves) 20,0 31,8 With the proposed method it is possible to analyse ten to twelve plant samples in six hours.

The status of zinc in sugar cane, variety Co 419, troughout its life cyle, was studid in samples cut monthly, from the 6th to 15th month, from an experiment carried on under the conditions of soil and climate prevailing in Piracicaba, State of São Paulo, Brazil. The experiment consisted of 6plots, 3 fertilized and 3 unfertilized. The fertilized ones received 40 kg of N (ammonium sulfate), 100 kg P2O5 (superphosphate) and 40 kg K2O (potassium cloride) per hectare, just before planting. The zinc content was determined by the Zincon method, after separation of zinc from other ions by means of the ion Exchange Resin III, Merck. The results obtained show that there was a tendency to decrease the zinc level in the stalks, whereas it kept more or less constant in the leaves; there was an exception in January, when the zinc level in the stalks had a sharp raise: 38-90-20 and 28-60-23 ppm for the fertilized an unfertilized treatments. There was a parallelism in the absorption of zinc by the plants from 4 hills of both treatments, through the whole - plantcycle but, the total amount taken up was higher with the fertilized plot due to its greater mass production.

In this paper the authors have studied the manganese absorption by the sugar cane plant, variety Co 419, in samples cut monthly, from the 6th to 15th month of life in the climate prevailing at Piracicaba, State of Sao Paulo, Brazil. From October to February (6 th to 10 th month of the plant life), which coincided with the rainy season, the manganese content was higher in the stalk than in the leaves, for both treatments, fertilized and unfertilized. There was a sharp decrease in manganese content in the stalks, after February, in both reatments. In the leaves there was little variation in manganese content throughout the plant tissue. The stalks from the unfertilized plots had a larger variation in manganese content, specially from the 6 th to the 10 th month. In the leaves of the sugar cane from the unfertilized plots, the manganese content varied from 116 to 220 ppm, whereas in the fertilized treatments thire was a variation from 150 to 220 ppm. From these results, althoug not being a foliar analyses, and considering the easy availability of manganese in acid soils, there must be enough of it, if we consider 40 ppm (EVANS, 1955) as a minimum for healthy plants.

O presente trabalho relata os dados relativos a análise qualitativa e quantitativa do precipitado, que se forma quando se adiciona a uma solução contendo estrôncio, dicromato de potássio, em meio amoniacal e hidroalcoólico. Em lugar de se formar cromato de estrôncio simples, SrCrO4, forma-se um cromato que além do estrôncio, contém os ions amônio e potássio. Soluções padrões contendo desde 1, 8 até 50,5 mg de estrôncio, foram tratadas com solução de dicromato de potássio 2 normal, amoníaco e solução hidroalcoólica com 95% de álcool absoluto. O precipitado foi pesado e a equação de regressão que relaciona o peso do estrôncio colocado e o peso do precipitado obtido, e a seguinte: Y = 4,58 X + 0, 84, onde: X é o pêso em miligramas, do estrôncio colocado Y é o pêso em miligramas, do precipitado A composição provável do precipitado parece ser 6 SrCrO4 (NH4)2 CrO4. 6K2CrO4

This paper describes the data obtained concerning qualitative and quantitative analyses of the precipitate formed when to a solution containing strontium ion are added potassium dichromate, ammonium hydroxide and 95 per cent alcohol. Three replications of standard solution containing 1.8, 4..4, 8.8, 13.7, 27.5, 41.2, and 50.5 mg of strontium were treated with potassium dichromate and then, with constant stirring 95 per cent of alcohol and ammonium hydroxide. The precipitate was allowed to stend for two hours and afterward was centrifuged, washed with 95 per cent alcohol dried at 80ºC for 14-16 hours and weighed. Qualitative analysis of the precipitate showed potassium and ammonium ions, besides strontium and chromate. The relationships between the weight of strontium and the weight of the precipitate obtained is given by the regression line expressed by the equation: Y = 5.48 + 0,84, where X, is the weight of strontium in milligram Y, is the weight of the precipitate in milligram The value 4, 58 for the B parameter of the regression equation and the qualitative and quantitative analysis of the precipitate, suggested that its composition must be quite different from the simple strontium chromate SrCr0(4). The data allow to admit the following probable composition: 6 SrCrO4 . (NH4)2CrO4 . 6K2CrO4