|
|
|
|
|
Arzolla,J. D. P.; Haag,H. P.; Malavolta,E.. |
WATER-CULTURE EXPERIMENTS. Two water-culture experiments were carried out to study the absorption and the translocation of radiozinc in young coffee plants as influenced by two factors, namely, concentration of heavy metals (iron, man ganese, copper and molybdenum) and method of application. Inert zinc was supplied at an uniform rate of 0. 05 p. p. m.; the levels of iron supply were 0, 1.0, and 10.0 p. p.m.; manganese was supplied in three doses 0, 0.5, and 5.0 p. p.m.; copper- 0, 0. 02, and 0. 2 p. p. m.; molybdenum- 0, 0. 01, and 0. 1 p. p. m. When applied to the nutrient solution the activity os the radiozinc (as zinc chloride) was 0. 15 microcuries per plant. In the study of the leaf absorption, Zn65 was supplied at the level of 0. 10 microcuries per... |
Tipo: Info:eu-repo/semantics/article |
|
Ano: 1962 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761962000100003 |
| |
|
|
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 |
|
Ano: 1958 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761958000100005 |
| |
|
|
Malavolta,E.; Menard,L. Neptune; Arzolla,J. D. P.; Crocomo,O. J.; Haag,H. P.; Lott,W. L.. |
Due to the great importance of coffee to the Brazilian economy, a good deal of the work carried out in the "Laboratório de Isótopos", E. E. A. "Luiz de Queiroz", Piracicaba, S. Paulo, Brazil, was dedicated to the study of some problems involving that plant. The first one was designed to verify a few aspects of the control of zinc deficiency which is common in many types of soils in Brazil. An experiment conducted in nutrient solution showed that the leaf absorption of the radiozinc was eight times as high as the root uptake; the lower surface of the leaves is particularly suited for this kind of absorption. Among the heavy metal micronutrients, only iron did not affect the absorption of the radiozinc; manganese, copper, and molybdenum brought about a... |
Tipo: Info:eu-repo/semantics/article |
|
Ano: 1959 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0071-12761959000100004 |
| |
|
|
|