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Coury,T.; Malavolta,E.; Ranzani,G.; Brasil Sobrinho,M. O. C. do. |
During the years 1948, 1949 and 1951 a disease occurred in the cotton crops of the state of S. Paulo Brazil (S. Am.), which caused a severe drop in yields. The abnormality was characterized by a typical reddish - purple color of the leaves, being by this reason, called "vermelhão", that is, reddening of the cotton plant. The disease was associated with a dry season. Among the several hypotheses raised to explain the causes of the disease were: insect attack, potassium deficiency - where from the name "potash hunger" was also given -, and magnesium deficiency: In order to study the problem the Department of Agricultural Chemistry of the College of Agriculture of the University of São Paulo, at Piracicaba, carried out a series of experiments as follows: 1.... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1954 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761954000100001 |
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Espironelo,A.; Brasil Sobrinho,M. O. C. do; Moraes,R. S. de. |
Em ensaios em vasos foram estudados os efeitos do boro na cana-de-açúcar var. CB 41-14 (cana-planta e cana-soca), através da administração de doses crescentes do elemento à cana-planta cultivada em solo da série Ibitiruna, do Município de Piracicaba, com teor muito baixo de boro solúvel em água quente. Ao solo dos vasos (80 litros de capacidade) foram administradas as doses de 0, 0,5, 1, 2, 3, 4 e 8 ppm B, sob a forma de ácido bórico. Foram obtidos dados de produção de cana (planta e soca) e do teor de boro em folhas de três posições na planta (+3, +1 e -1), em amostragens feitas aos cinco e oito meses de idade da cana-planta, e calcularam-se dados de açúcar-provável (cana-planta e soca). O boro aplicado ao solo não proporcionou aumentos nas produções de... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1976 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051976000200003 |
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Coury,T.; Ranzani,G.; Malavolta,E.; Brasil Sobrinho,M. O. C. do. |
In several cotton crops areas of the State of S. Paulo it was observed, during the years of 1948, 1949, and 1951, the appearance of a purple color of the leaves; the color appears in the opening of the bolls and was correlated with a decrease of production. The opinions concerning the cause of such abnormality were very different and sometimes contradictory; certain investigators attributed the disease to insect attack, others to bad climatic conditions whereas others to a potassium deficiency now called "fome de potássio" (potash hunger); our ideas on the subject is another one. We think that the disease is caused by lack of a suitable supply of magnesium. This opinion is largely based on the syntomatology found in the literature. To study the problem,... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1953 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761953000100006 |
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Malavolta,E.; Coury,T.; Arzolla,J. D. P.; Haag,H. P.; Brasil Sobrinho,M. O. C. do. |
The rate of nitrification of several nitrogenous fertilizers (ammonium sulfate, nitre-chalk, ureia, and cottonseed meal) was studied in three soils, namely, "terra roxa legítima", a red soil derived from basalt, "terra roxa misturada", a soil also derived from basalt but with a higher proportion of sand, and "areito Corumbataí", a sandy soil. The effects of the following treatments on nitrification were considered: addition of limestone of micronutrients (Fe, Cu, Zn, Mn, and Mo), and inoculation with a suspension of spores of Aspergillus wentii, a heterotrophic nitrifier. The results showed that: in "terra roxa legítima" limestone had no influence on the nitrification rate, whereas the micronutrients estimulated the oxidation of nitre-chalk, cottonseed... |
Tipo: Info:eu-repo/semantics/article |
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Ano: 1958 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761958000100005 |
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