Determinação quantitativa de putrescina por cromatografia em papel de filtro

The method described herein involves the quantitative determination of the amine putrescine by paper chromatography followed by spectrophotometry of the eluted spot. From the data some conclusions can be drawn: 1. Satisfactory recovery of putrescine added to plant extracts can be achieved with that method (c.a. 80-85%); 2. The absorption spectra of the reaction products of putrescine and ninhydrin shows a maximum peak at 575 mu; 3. In the assay on the effect of the lenght of heating on the color yield of the reaction product it was observed that the color development reached a maximum within 20 minutes, at 65ºC, and did not decline within the next 10 minutes: 4. It was found that the eluted ninhydrin color was stable for at least 3 hours following elution; 5. The absorbance at 575 mu of the putrescine-ninhydrin reaction product as a function of the amount of putrescine in the reaction mixture as well as applied to the chromatograms yielded a straight line.O presente trabalho descreve o desenvolvimento de um método de determinação quantitativa da amina putrescina por cromatografia em papel de filtro seguida de espectrofotometria. 80-85% de putrescina adicionada a extratos de plantas pode ser recuperada. O espectro de absorção do produto de reação entre putrescina e ninhidrina tem um pico máximo a 575 mu. O desenvolvimento da côr do produto de reação atinge um máximo em 20 minutos, a 65ºC e se mantém estável durante os 10 minutos seguintes. O produto colorido eluido do cromatograma é estável durante 3 horas

Técnica de réplica de carbono para o estudo da superfície de fôlhas de plantas ao microscópio eletrônico

A technique is described for the production of carbon negative replicas for electron microscopy, which has revealed the same type of ultraestructure observed by other authors, on leaf surfaces of the Brassica oleracea. The procedure follows: 1) deposition of a carbon film over the surface of the leaf to be studied; 2) the carbon film is then backed with Zapon Acquanite "A" lacquer as intermediate replica, whichmis applied full strenght over the specimen surface and dried before a heat lamp; 3) the carbon-zapon composite film can be stripped from the leaf with no dificulty whatsoever, and is them metal shadowed; 4) the composite film is placed, carbon side down, on a specimen screen and this placed upon a course wiremesh back in a petri-dish. Amyl acetate as solvent for the zapon is added until it just wets the support screen and the dish is covered. Thus the zapon is dissolved by the condensed amyl acetate vapors. The method has, also, allowed to observe that in the Coffea arabica leaf surfaces the characteristics ultrastructure does not present the microprojections found on the Brassica oleracea.O presente trabalho apresenta um método de réplica de superfície para o estudo da estrutura das fôlhas de vegetais ao microscípio eletrônico. O método permitiu a observação do mesmo tipo de estrutura observada por outros autores na superfície das fôlhas de couve (Brassica oleracea). O método permitiu observar que nas superfícies das fôlhas de café (Coffea arabica) a ultraestrutura característica e pràticamente desprovida do tipo de ornamentação encontrado nas fôlhas de couve

Pulverização foliar em cafeeiro (Coffea arabica L.) II: aplicação de adubos potássicos

The uptake of potassium fertilizers, namely, KC1, K2S04 and KN03, by beans and coffee leaves was studied in the experiment described herein. The fertilizers were applied as leaf sprays at the rates of 2,25, 4,50 and 9,00 grams, of K20/tree split in 3 applications which were made every week; the proper amount of salts were dissolved in 1 liter of water with wetting agent. Fifteen days after the last application both beans and leaves were sampled for analysis. No leaf injury resulted from the potassium sprays. Leaf -K and bean -K was significantly raised as consequence of the foliar applications of the K- bearing salts

Efeitos do biureto no sorgo saccarino (Sorghum Bicolor L.) (Moench) avaliados pelos conteúdos de alguns compostos nitrogenados e de açúcares

The present paper discusses a greenhouse experiment carried out at the Departamento de Solos, Geologia e Fertilizantes da Escola Superior de Agricultura "Luiz de Queiroz" da Universidade de São Paulo, Brazil, to observe the phytotoxic affects on sweet sorghum (Sorghum bicolor L. (Moench) of different doses of biuret added to urea and applied both to soil and leaves. Two types of soils were used - Sandy Quartz and Clayish - Terra Roxa, and the following treatments applied: 1 - 1.15 g N/pot in soil 2- 1.15 g N/pot + 1% biuret in soil 3- 1.15 g N/pot + 2% biuret in soil 4- 1.15 g N/pot + 3% biuret in soil 5- 1.15 g N/pot foliar application 6- 1.15 g N/pot + 1% biuret foliar application 7- 1.15 g N/pot + 2% biuret foliar application 8- 1.15 g N/pot + 3% biuret foliar application The amount of urea applied was 2.5g/pot. The results showed that both soil and foliar biuret applications did not affect the metabolism of the nitrogenous compounds (proteins and aminoacids) although there was variation in sugar content.Este trabalho foi desenvolvido no Departamento de Solos, Geologia e Fertilizantes da Escola Superior de Agricultura "Luiz de Queiroz", USP, com a finalidade de estudar os efeitos fitotóxicos do biureto, adicionado à uréia, ao sorgo sacarino (Sorghum bicolor L.) (Moench), tanto aplicado no solo como em pulverização foliar. Trata-se de um ensaio em vaso, conduzido em casa de vegetação e em dois tipos de solo: um arenoso-Areia Quartzosa e outro argilo-Terra Roxa. Os tratamentos foram: 1- 1,15 g N/vaso no solo 2- 1,15 g N/vaso + 1% de biureto no solo 3_ 1,15 g N/vaso + 2% de biureto no solo 4- 1,15 g N/vaso + 3% de biureto no solo 5- 1,15 g N/vaso via foliar 6- 1,15 g N/vaso + 1% de biureto via foliar 7- 1,15 g N/vaso + 2% de biureto via foliar 8- 1,15 g N/vaso + 3% de biureto via foliar Os resultados mostraram que os compostos nitrogenados (proteínas e aminoácidos) do sorgo apresentaram metabolismo aparentemente não alterado em presença de biureto, em qualquer dos dois tipos de aplicação enquanto que ocorreram variações nos teores de açúcares redutores e açúcares totais

Effects of biuret on sweet sorghum (Sorghum Bicolor L.) (Moench) evaluated by the development of plant

This paper relates an experiment carried out at the Departamento de Solos, Geologia e Fertilizantes of the Escola Superior de Agricultura "Luiz de Queiroz" from the Universidade de São Paulo, Brazil, to observe the phytotoxic effects on sweet sorghum (Sorghum bicolor L.) of different doses of biuret added to urea and applied both to soil and leaves. Two types of soils were used-Sands Quartz and Terra Roxa, a clayish soil from the municipality of Piracicaba. The treatments were as fallows: 1. 1.15 g/N pot in soil 2. 1.15 g/N pot + 1% biuret in soil 3. 1.15 g/N pot + 2% biuret in soil 4. 1.15 g/N pot + 3% biuret in soil 5. 1.15 g/N pot, foliar application 6. 1.15 g/N pot + 1% biuret, foliar application 7. 1.15 g/N pot + 2% biuret, foliar application 8. 1.15 g/N pot + 3% biuret, foliar application The amount of urea applied was 2,5 g/pot The results showed that both soil and foliar biuret applications did not affect the plant development, which was evaluated by plant height and leaves and stem dry matter.O presente trabalho foi realizado no Departamento de Solos, Geologia e Fertilizantes da Escola Superior de Agricultura "Luiz de Queiroz", USP , com a finalidade de estudar os efeitos fitotóxicos do biureto adicionado à uréia, aplicado no solo ou via foliar, em sorgo sacarino (Sorghum bicolor L.) (Moench). Foram usados dois tipos de solos: um arenoso-Areia Quartzosa e um argiloso-Terra Roxa. Os tratamentos foram: 1. 1,15 g N/vaso no solo 2. 1,15 g N/vaso + 1% de biureto no solo. 3. 1,15 g N/vaso + 2% de biureto no solo. 4. 1,15 g N/vaso + 3% de biureto no solo. 5. 1,15 g N/vaso, via foliar. 6. 1,15 g N/vaso + 1% de biureto via foliar. 7. 1,15 g N/vaso + 2% de biureto via foliar. 8. 1,15 g N/vaso + 3% de biureto via foliar. A quantidade de uréia aplicada foi de 2,5 g/vaso. Os resultados obtidos indicaram que o biureto aplicado no solo ou nas folhas não afetou o desenvolvimento das plantas avaliado pela altura e massa de matéria seca de folhas e de caules