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| Franco,C. M.. |
| It has been noticed in the greenhouse of the "Instituto Agronômico de Campinas" that many species of plants developed poorly when planted in seed beds that have been repeatedly used without change of soil. In many cases even the seeds would not germinate in such seed beds. Experiments have showed that the; lack of normal plant development in these beds is the result of the increase in soil salinity. This salinity may be due to additions of fertilizers or to salts introduced in the ordinary applications of water. It was found that the soil solution had an osmotic pressure of 13.5 athmospheres at the wilting point. The tests showed that common bean (Phaseolus vulgaris L.) plants were more susceptible to the soil salinity than were the soybean and the corn... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1948 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051948000100002 |
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| Franco,C. M.; Loomis,W. E.. |
| Moderate amounts of KH2PO4 (0.5 to 0.7 millimols) caused iron chlorosis of seedlings in solutions less acid than pH 5.5-6.0. The trouble could be avoided by omitting the phosphorus entirely and adding it separately after 2-4 days. Even with this modification the Knop type of solution (Hoagland, 2) caused persistent chlorosis in soybeans and broccoli. In the commonly used Shive solution (R5-C2) a large excess of KH2PO4 holds the pH of the solution between 4.5 and 5.0 and chlorosis is moderate to slight. The Shive solution contains 36 times as much phosphorus as the Hoagland and 6-week-old plants growing in it absorbed 15 times as much to make a slightly poorer growth. The addition of as little as 0.125 g per liter of NH4NO3 resulted in decidedly acid... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1948 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051948000100006 |
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| Furlani,A. M. C.; Catani,R. A.; Moraes,F. R. P. de; Franco,C. M.. |
| No presente trabalho foram estudadas as variações nos teores dos nutrientes nas folhas de mudas de cafeeiro (Coffea arabica L. cv. catuai) em função das quantidades de cloreto e de sulfato de potássio aplicadas, acompanhadas de observações sobre os sintomas de toxicidade e sobre o desenvolvimento das plantas. O ensaio foi instalado em vasos, em casa de vegetação, constando de 12 tratamentos com cinco repetições, e o solo utilizado procedeu do grande grupo Latos-solo Vermelho-amarelo, Orto. Foram determinados nas folhas, os teores de macro e micronutrientes. Altos teores de Cl foram relacionados com sintomas de redução no crescimento, necrose e desfolhação. Foi estabelecido um limite de toxicidade para o cultivar estudado. Em função dos tratamentos, houve... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1976 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051976000200009 |
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| Franco,C. M.; Mendes,H. C.. |
| Coffee plants (Coffea arabica L.) were grown in nutrient solutions for the purpose of studying deficiency symptoms of the following elements : nitrogen, phosphorus, potassium, magnesium, calcium, sulphur and iron. The methods employed in the growing of coffee plants in the nutrient solutions are described. After preliminary tests with several nutrient solutions Hoagland's formula was selected as most suitable for the present tests. However, the quantity of phosphate employed in the basic nutrient solution was reduced to one third of that given in Hoagland's formula. This reduction in phosphate was made because of the previous results obtained by Jacob which seemed to indicate that the coffee plant requires only very small amounts of phosphorus. In the... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1949 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051949000300002 |
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