RCAAP Repository

Com base nos parâmetros Vm e Km obtidos de ensaios de cinética de absorção, verificou-se a influencia do Al e do Mn e do grau de tolerância de cultivares de trigo a cada um desses elementos sobre a absorção de P. Utilizaram-se raízes destacadas de plantas com 7 dias de idade de 3 cultivares com tolerância diferencial ao Al (Sonora 63C - suscetível; Yecora - intermediária e IAS 63 - tolerante) e de 3 cultivares com tolerância diferencial ao Mn (CNTl -suscetível; Sonora 63C - intermediária e IAS 55 - tolerante). Foram empregadas 10 soluções experimentais cujas concentrações de KH2PO4 variaram de 10-6M até 10-4M, marcadas com 32P. Nos ensaios efetuados na presença de Al ou Mn, usaram-se concentrações de 10-4M de AlCl3 ou MnCl2. Concluiu-se que: a) a absorção de P se realiza através de um único mecanismo; b) na ausência ou presença de Al ou de Mn existem diferenças genéticas na absorção do P nao relacionadas com o grau de tolerância aos 2 elementos; 2) o Al e o Mn, mais aquele do que este, estimulam a absorção do P.

Seven tropical grass species were cultivated in nutrient solutions added the following amounts of phosphorus in mg./ 1.: 0.12, 0.48, 1.94, 7.75, 31.00. 75 days later, the plants were harvested and divided into: leaves, stems, scheaths and roots. The material was dried at 1789F, wheighed analysed for phosphorus by the conventional colometric method. The data were submited to statistical treatement and interpretation. The authors concluded: 1. Differential phosphorus responses among the grasses, were observed. B. humidicola and H. rufa showed the lowest external phosphorus requirements, followed by B. decumbens, M. minutiflora, P. maximum, P. purpureum, and D. decumbens. 2. Differential phosphorus contents were observed among the species. The highest internal phosphorus requirement was observed for D. decumbens (0.38%) followed by B. decumbens (0.32%), B. humidicola (0.26%), M. minutiflora (0.24%), P. maximum (0.24%), P. purpureum (0.20%). 3. The best absorption capacity and utilization of phosphorus was observed for B. humidicola followed by P. purpureum, P. maximum. D. decumbens, B. decumbens, and M. minutiflora.

The experiment was carried out in greenhouse from 17/ 8/1978 to 17/11/1978, on a Dark Red Latossol (LVe), medium texture. The potassic sources were: potassium chloride, a water soluble salt and four (4) samples of a insoluble potash mineral proceeding from the Plateau of Poços de Caldas, State of Minas Gerais, which were submitted previously to an hydrothermal treatment in order to alter its crystalline structure. Two levels of K(2)0 were applied, 100 kg K(2)0/ha and 200 kg K(2)0/ ha. The results showed no strong differences among the potassic materials regarding the quantity of potassium absorbed by the rice plant and the efficiency in the utilization of the potassium from those materials.

The experiment consisted of 15 treatments (3x5), that is, three levels of ammonium sulphate CO, 100 and 200 ppm) and 5 levels of N-Serve (0, 1, 2, 4 and 8 pptn) , with three replicates. Samples of an alfisol were mixed with their corresponding treatments, placed in PVC tubes, and incubated during 160 days at a temperature between 269C-309C. After each leaching period with water, in a total of five leachings, the nitrate contents were determined. The data showed the nitrate contents in the treatments with N-Serve were lower than those without N-Serve. Better efficiency was obtained with the higher level, of nitrapyrin. The persistence of 2-chloro-6(trichloromethyl) pyridine in the soil increased with increasing levels of this inhibitor. After incubation period of 80 days, the effectiveness of N-Serve was completely reduced.

Young tomato plants (Lycopersicum esculentum Mill.) cv. Santa Cruz, lineages Kada and Samano, were cultivated in solutions with different calcium concentrations (0 ppm, 50 ppm, 100 ppm, 200 ppm and 400 ppm Ca) with the following purposes: a) to study the effects of calcium on yhe growth of the plant; b) to correlate calcium supply and blossom-end rot; c) to correlate calcium supply and the nutrient concentrations in the tomato plant; d) to reveal nutritional differences between the lineages. Ninety days adter starting the different treatments, plants were collected and separeted into old leaves, new leaves, lower part of the stem, superior part of the stem and fruits. The plant material was dried and analysed for macro-nutrients. The main conclusions were: - the greates dried matter production was obtained with the supply of 388 ppm of calcium in the culture solution for the Kada lineage and of 400 ppm for Samano lineage; - for the lineage Samano a concentration of calcium in the solution (200 ppm) higher than for the lineage Kada (100 ppm) was necessary in order to prevent appearance of blossom-end rot; - the calcium concentration in fruits was not affected by the calcium concentration in the nutrient culture; - calcium added to the culture solution decreased the nitrogen concentration and increased the calcium concentratio in both lineage parts; - the concentration of the other nutrients presented differences in the lineage and in the analysed parts; - concentration of calcium in the culture solution brings an increased improvement in the magnesium concentration in leaves and in the superior part of the stem of the lineage Samano, while in parts of lineage Kada a decrease of magnesium concentration was observed.

Devido a numerosas discrepâncias nos resultados de estudos experimentais relativos à interação flúor-manganês, propusemo-nos a verificar se a adição de manganês 5 água fluoretada (1 ppm), em diferentes proporções fluor-manganês, levaria a uma diferente fixaçao do halogênio. Para tanto, 24 ratos Wistar, recém-desmamados, foram mantidos em dieta padrão de caseína a 27%, recebendo na sua água de consumo: 1) H2O destilada (controle); 2) 1,0 ppm de flúor: 3) 1,0 ppm de flúor + 0,5 ppm de manganês (F:Mn = 2,0); 4) 1,0 ppm de flúor +1,0 ppm de manganês (F: Mn = 1,0). Foram anotados o peso ganho e o consumo de alimento e água, durante os 60 dias de experimento, após o qual as patas traseiras, dos animais sacrificados, foram autoclavadas e desossadas, e os femures retirados. Posteriormente, foram estes submetidos à secagem, extração da gordura, pulverização e analise do flúor fixado. Também foram efetuadas analises da composição centesimal da ração e de flúor e manganês nesta e nas diferentes águas de consumo. Os resultados de percentagem do flúor ingerido fixado nos femures, foram analisados estatisticamente pelo teste não-paramétrico de Kruskal-Wallis (níveis de 1% e 5%) mostrando que, para as proporções consideradas, o flúor na taxa de 1 ppm, o manganês, quando administrado após o desmame, parece não afetar a fixaçao do flúor. Contudo, faz-se necessário dar continuidade aos estudos com novas proporções e taxas mais elevadas de flúor e manganês.

Young tomato plants (Lycopersicon esculentum Hill.) 'Santa Cruz', lineages Kada and Samano, were cultivated in solutions with different calcium concentrations (0 ppm, 50 ppm, 100 ppm, 200 ppm and 400 ppm Ca) with the following purposes: (a) to correlate calcium supply and the nutrient concentrations in the tomato plant, and (b) to reveal nutritional differences between the lineages. Ninety days after started the different treatments, plant were collected and separated into old leaves, new leaves, lower part of the stem, superior part of the stem and fruits. The plant material was dried and analysed for micro-nutrients, excepting for chlorine and molybdenum. The main conclusions were as follows: - the concentration of calcium in the culture solutions increased the magnesium concentration in the leaves and in the superior part of the stem of the lineage Samano, while in the parts of lineage Kada a decrease of magnesium concentration was observed; - the concentration of the other micronutrients presented differences in the lineage and in the analysed parts.

The experiment herein described was carried on a podzolic soil, in the State of São Paulo, Brazil with the double hybrid corn HD-6999B. The following conclusions were drawn: 1 - In respect of placement and times of application of superphosphate-32P and ammonium sulfate-15N the data showed that: a) greater yield and fair quantity of protein were obtained when the nitrogen and phosphorus were mixed and applied in banding at seeding time; b) lower yield and lower quantity of protein were obtained when phosphorus and applied in banding and nitrogen applied at side-dressing, 83 days after seeding; c) phosphorus application in banding and nitrogen application in side-dressing, 63 days afeter seeding, gave a fair yield and a higher quantity of protein and a higher efficiency of nitrogen of the fertilizer in its conversion into protein. 2 - In respect of % FPPF, it seemed there was an effect of NHΪ on phosphorus uptake, but this effect disapeared at 63 days after seeding. Regarding the % NPPF, there was also an effect of phosphorus on nitrogen uptake, but of short duration. 3 - The corn plants still continue to take up the nitrogen of the fertilizer even at 73 and 83 days after seeding, not to increase yield, but to increase the contents and quantity of protein. 4 - The maize leaf +2 can be taken for analisys at 73 days after seeding as an indicator of the nutritional status of maize plant in nitrogen and phosphorus. In the case of potassium, the leaf will be taken for analisys at 117 days after seeding. 5 - The superphosphate at the level applied constituted a limiting factor for better yield.

No summary/description provided

An experiment was carried out to study the effects of the following population densities cauliflowers (plants per ha): 20,833 (0.60 m x 0.80 m), 25,641 (0.60 m x 0.65 m), ....37.037 (0.60 m x 0.45 m) , 55.555 (.0.60 m x 0.30 m), and 111,111 (0,60 m x 0,15 m) ; variety Snow ball. It was concluded that the effects of plant population density are greater on curd quality (weight and size) than on production per ha. The best plant population density to produce cauliflowers curd for Brazil market is from 20,000 to 25,000 plants/ha while for mini-curd is above 55,000 plants/ha.

This research, deals with the effects of exogenous growth regulators on infection by microorganisms on soybean (Glycine max cv. Davis) seeds. To study the influence of the chemicals, soybean plants were sprayed with gibberellic acid (GA) 100 ppm, (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm, succinic acid-2,2-dimethy1hydrazide (SADH) 4,000 ppm, indolylacetic acid (IAA) 100 ppm, 2,3,5-triiodobenzoic acid (TIBA) 20 ppm (three applications), and Agrostemin (1g/10 ml/ 3 1). Application of growth regulators did not affect infect ion by microorganisms on soybean seeds. The prominent fungus isolated was Phomopsis sojae. Alternaria and Fusarium spp. were isolated from seeds. The presence of a bacterium on the seeds was observed. The delay in harvest and high humidity increased the number of seeds from which Phomopsis was recovered.

A trial was carried out on an eight old coffee plantation with visible zinc problems. The plantation was situated nearly the city of Jaú (22º30'S, 48º30'W). State of São Paulo, Brazil. The soil is classified as medium texture Oxisol of low base saturation (Latossol Vermelho Amarelo - fase arenosa). The pulverization program started in november 1977, followed in march and July 1978 (heavy harvest) and ended in march and July 1979 (light harvest). Is should be mentioned that a well reconized characteristic of arábica coffe is its habit of biennial bearing, a very heavy harvest is most often followed by a light load the next year. The following treatments and amounts of chemicals per cova hole (4 trees) were tested in accordance with a random block design: 1. 1 g of zinc (zinc sulphate, 0.5%) 2. 3 g of nitrogen (urea, 1.3%) 3. 1 g of zinc + 3 g of nitrogen (zinc sulphate 0.5% + urea 1.3%) 4. 0.25 g, 0.50 g, 1.00 g, 2.00 g of zinc plus 0.75 g, 1.50 g, 3.00 g and 6.00 of nitrogen (correspondent to NZN* 15-0-0-5 as 0.75%, 1-5%, 3.0% and 6.0% by v/v). Foliar absorption data were obtained by collecting the 3rd and 4th pairs of the coffee leaves and analysed them for N, P, K, Ca, Mg, S, B, Cu, Fe, Mn, and Zn. The main results may be summarized as follows: 1. The maximum calculated yields of clean coffee were obtained by the applications of 5.84 1 of NZN (1.13%) per hectare. 2. The applications of zinc sulphate (0.5%) and urea (1.3%) together or separate did not affected the coffee bean production. 3. The applications of 15.0 1 of NZN per hectare reduced the coffee yields. 4. Leaf damages and burning symptoms were observed by the applications of urea (1.3%) plus zinc sulphate (0.5%) and larger doses than 7.5 1 of NZN per hectare. 5. Leaf tissue analysis show that the concentrations of the elements were affecred by the age of the leaves and by the yields of the coffee trees. 6. The applications of increasing doses of NZN causes an increase in the concentration of zinc, manganese and boron in the leaves and decreased the concentration in calcium and potassium the leaves. 7. The concentration of zinc in the leaves associated with the heavy harvest, in July, was 70.0 ppm.

O presente trabalho refere-se à uma pesquisa realizada no Departamento de Agricultura e Horticultura da ESALQ, em Piracicaba , S.P. (Latitude 22º42' sul, Longitude 47º38' W.G. e altitude 546 m). Procurou-se por intermédio de semeadura em diferentes épocas e com utilização de cobertura artificial avaliar o comportamento do cultivar IAC 17 de algodão (Gossypium hirsututm L.) com referência à produção e a qualidade das fibras em relação à radiação solar incidente. A radiação solar incidente, medida e registrada, assim como a insolação, durante o período do ensaio foram tabuladas e confrontadas com os valores de produção e caracteres agronômicos. O tratamento sob cobertura apresentou nível médio de radiação solar incidente equivalente a menos de 20% daquele a céu aberto, o que causou redução tanto na produção quanto nos caracteres agronômicos e tecnológicos das fibras do algodão.

Mangas, do cultivar Imperial, foram submetidas, em pós-colheita, a vários procesos de forçamento da maturação: 1) queima de serragem; 2) vaporização do álcool; 3) carbureto de cálcio (acetileno); 4) gases de etileno; e 5) imersão em ethefon. Todos os processos aceleraram a maturação, quando comparados ao controle. A maior eficiência ficou com os processos do carbureto, etileno e ethefon. A vaporização do álcool, mostrou-se também de interesse, o mesmo não ocorrendo com a queima de serragem, processo de baixa eficiência.

Mangas, do cultivar Paheri, foram colhidas no estádio de vez e submetidas à dosagens de ethefon de 0 - 250 - 500 - 1.000 e 2.000 ppm. Todas as dosagens aceleraram a maturação dos frutos, com ganho de tempo de 48 a 72 horas. A avaliação da maturação foi feita através da determinação de sólidos-solúveis, acidez total e coloração externa dos frutos.

This research deals with the effects of growth regulators on flowering and pod formation in soybean plant (Glycine max cv. Davis). Under greenhouse conditions, soybean plants were sprayed with 2,3,5-triiodobenzoic acid (TIBA) 20 ppm, Agrostemmin (1g/10 ml/3 l) gibberellic acid (GA) 100 ppm, and (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm. Application of TIBA increased number of flowers. 'Davis' soybean treated with CCC and TIBA presented a tendency to produce a lower number of pods.

Com a finalidade de verificar o efeito da adubação nitrogenada e intensidade luminosa sobre a qualidade das mudas de tomateiro cv Roma VF, foi instalado um experimento em con dições de estufa de vidro, no Setor de Horticultura da ESALQ, Piracicaba (SP). Os tratamentos consistiram em plantas sombreadas, com e sem adubação. Foram observados a altura, diâmetro do caule, e desenvolvimento do sistema radicular das mudas após 32 dias de germinação e os níveis de carboidratos e nitrato no caule. Dos resultados concluiu-se que a adubação nitrogenada na fase de muda é muito importante para se obter plantas sadias e fortes e em condições sombreadas, com adubação nitrogenada, as mudas são maiores, com alto teor de nitrato, enquanto que em condições de pleno sol e adubada, elas possuem maior diâmetro e sistema radicular mais desenvolvido.

The effects of growth retardants on infestation by Potyphagotarsonemus tatus (broad mite) on cotton (Gossypium hirsutum L. cv. IAC-17) plants was studied. Cotton plants were sprayed with (2-ch1oroethy1) trimethylammonium chloride (CCC) 250, 350 and 450 ppm, and with 1,1-dimethyl-piperidinium chloride (Pix) at concentrations of 84, 167 and 250 ppm. Growth retardants did not give effective control of Potyphagotarsone mus tatus but application of Pix 167 ppm showed a tendency to reduce mite attack.

This research deals with the effects of exogenous growth regulators on production of soybean plant (Glycine max cv.. Davis) under greenhouse conditions, At the flower anthesis, 2,3,5-triiodobenzoic acid (TIBA) 20 ppm was applied. Other two applications with TiBA, with intervals of four days, were realized. Before flowering, Agrostemin (1 g/10 ml/3 1), gibberellic acid (GA) 100 ppm, and (2-chloroethyl) trimethylammonium chloride (CCC) 2,000 ppm were applied. It was observed that CCC and TIBA reduced stem dry weight. Soybean plants treated with TIBA reduced weight of pods without seeds , seed number and seed weight.

The present work deal t wi th an experiment under field conditions and a laboratory test of soil incubation the objectives were as follows: a. to study effects on soybean grain product ion and leaf composition of increasing doses of potassium chloride applied into the soil through two methods of distribution; b. to observe chemical modifications in the soils incubated with increasing doses of potassium chloride; and, c. to correlate field effects with chemical alterations observed in the incubation test, The field experiment was carried out in a Red Latosol (Haplustox) with soybean cultivar UFV - 1. Potassium chloride was distributed through two methods: banded (5 cm below and 5 cm aside of the seed line) and broadcasted and plowed-down. Doses used were: 0; 50; 100 and 200 kg/ha of K2O. Foliar samples were taken at flowering stage. Incubation test were made in plastic bags with 2 kg of air dried fine soil, taken from the arable layer of the field experiment, with the following doses of KC1 p,a. : 0; 50; 100; 200; 400; 800; 1,600; 3.200; 6,400 and 12,800 kg/ha of K(2)0. In the conditions observed during the present work, results allowed the following conclusions: A response by soybean grain production for doses of potassium chloride, applied in both ways, banded or broadcasted, was not observed. Leaf analysis did not show treatment influence over the leaf contents for N, P, K, Ca, Mg, and CI, Potassium chloride salinity effects in both methods of distribution for all the tested closes were not observed.