Contribuição ao estudo do «vermelhão» do algodoeiro (Gossipium herbaceum)

Coury, T.; Malavolta, E.; Ranzani, G.; Brasil Sobrinho, M. O. C. do

doi:10.1590/S0071-12761954000100001

Resumo

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. pot experiments in which soil of one of the affected regions was used ("terra roxa", a red-brownish soil derived from basalt); 2. pot-soil experiments varying the moisture supplied; 3. sand culture experiments omitting certain elements from the nutrient solutions; 4. field plot experiments, conducted on a sandy soil; three different varieties were employed: Texas, Express, and I.A. 817; magnesium was applied either as sulfate or dolomitic limestone. All the experiments were completed with suitable chemical analyses. The results can be summarized as follows: 1. in the first trial, the not properly manured pots (minus Mg), symptoms were registered which were similar to the symptoms observed in the field; it was possible to establish some differences among three different types of reddening: due to lack of K in the mixed fertilizers used, the characteristic cotton rust made its appearance, the red color in the leaves of the minus Mg plants was all alike that described in the current literature as a symptom of Mg-deficiency; in all the treatments ocurred a yellow-reddish color in the leaves associated with the latest stages of maturity; 2. in the second experiment it was verified that when the plants in the pots with soil were kept 75 per cent of the water holding capacity, no symptom of deficiency showed up; was true even for the plants not receiving neither K nor Mg; however, plants supplied with only 25 per cent of the water holding capacity showed, respectively, cotton rust in the minus K treatment and the red purplish color in the minus Mg series; 3. the sand culture experiment confirmed lack of Mg as the cause of "vermelhão", being potash deficiency the responsible for cotton rust; 4. in the field experiment, variety LA. 817 revealed to be the most sensitive to "vermelhão" when Mg was omitted from the fertilizers; symptoms of K deficiency appeared when no K was supplied; both magnesium sulfate and dolomitic limestone proved to be equally effective in the control of "vermelhão"; 5. the analyses of material collected both in the field as well in the pots revealed that leaf petiole in the most reliable part to indicate the K and Mg status of the plant; the variation in Mg content suffered by the plants showing different stages of "vermelhão was, quantitatively, at least as large as that in K content, however when one deals with K deficient plants, that is, plants showing the typical rust, no variation occurred in the Mg content, whereas K in the dry mater dropped from more than 1 per cent to less than half per cent. Then, the following general conclusions can be drawn: 1. Mg deficiency is the cause of "vermelhão" of cotton crops; 2. K deficiency also occurred, but in a lesser degree; 3. the climate conditions - especially the lack of rain influenced the soil dynamic of K, and especially Mg, bringing a severe reduction in their assimilability; 4. the "vermelhão" disease can be easily controlled upon additions either of magnesium sulfate or dolomitic limestone.

Contribuição ao estudo do «vermelhão» do algodoeiro (Gossipium herbaceum)^* * 2.o congresso panamericano de agronomia E. S. A. "LUIZ DE QUEIROZ", U. S. P. Piracicaba, Março-abril de 1954 DEDICATÓRIA - Êste trabalho é dedicado à memória do Prof. R. AVERNA-SACCÁ

T. Coury; E. Malavolta; G.Ranzani; M. O. C. do Brasil Sobrinho

Seção Técnica de Química Agrícola, E. S. A. "Luiz de Queiroz", U. S. P. Piracicaba, S. Paulo, Brasil

SUMMARY

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. pot experiments in which soil of one of the affected regions was used ("terra roxa", a red-brownish soil derived from basalt);

2. pot-soil experiments varying the moisture supplied;

3. sand culture experiments omitting certain elements from the nutrient solutions;

4. field plot experiments, conducted on a sandy soil; three different varieties were employed: Texas, Express, and I.A. 817; magnesium was applied either as sulfate or dolomitic limestone.

All the experiments were completed with suitable chemical analyses.

The results can be summarized as follows:

1. in the first trial, the not properly manured pots (minus Mg), symptoms were registered which were similar to the symptoms observed in the field; it was possible to establish some differences among three different types of reddening: due to lack of K in the mixed fertilizers used, the characteristic cotton rust made its appearance, the red color in the leaves of the minus Mg plants was all alike that described in the current literature as a symptom of Mg-deficiency; in all the treatments ocurred a yellow-reddish color in the leaves associated with the latest stages of maturity;

2. in the second experiment it was verified that when the plants in the pots with soil were kept 75 per cent of the water holding capacity, no symptom of deficiency showed up; was true even for the plants not receiving neither K nor Mg; however, plants supplied with only 25 per cent of the water holding capacity showed, respectively, cotton rust in the minus K treatment and the red purplish color in the minus Mg series;

3. the sand culture experiment confirmed lack of Mg as the cause of "vermelhão", being potash deficiency the responsible for cotton rust;

4. in the field experiment, variety LA. 817 revealed to be the most sensitive to "vermelhão" when Mg was omitted from the fertilizers; symptoms of K deficiency appeared when no K was supplied; both magnesium sulfate and dolomitic limestone proved to be equally effective in the control of "vermelhão";

5. the analyses of material collected both in the field as well in the pots revealed that leaf petiole in the most reliable part to indicate the K and Mg status of the plant; the variation in Mg content suffered by the plants showing different stages of "vermelhão was, quantitatively, at least as large as that in K content, however when one deals with K deficient plants, that is, plants showing the typical rust, no variation occurred in the Mg content, whereas K in the dry mater dropped from more than 1 per cent to less than half per cent.

Then, the following general conclusions can be drawn:

1. Mg deficiency is the cause of "vermelhão" of cotton crops;

2. K deficiency also occurred, but in a lesser degree;

3. the climate conditions - especially the lack of rain influenced the soil dynamic of K, and especially Mg, bringing a severe reduction in their assimilability;

4. the "vermelhão" disease can be easily controlled upon additions either of magnesium sulfate or dolomitic limestone.

Texto completo disponível apenas em PDF.

Full text available only in PDF format.

LITERATURA CITADA

ABRAHAO, J., A. C ANDRADE e A. A. BITANCOURT. 1952 O "vermelhão" ou "fome de potássio" do algodoeiro, um desequilíbrio fisiológico entre a folhagem e a frutificação, 2a. Reunião Sulamericana de Fitogeneticistas e Fitoparasitologistas (Piracicaba, Abril). Mimeogr.

A. O. A. C. 1948 Em "Official and tentative methods of analy sis", sixth edit. publ. by the Assoc. Offic. Agric. Chem., Washington, D. C.

ARNON, D. I. and D. R. HOAGLAND. 1943 Composition of the tomato plant as influenced by nutrient supply, in relation to fruiting. Bot. Gaz. 104: 576-590.

AVERNA-SACCÁ, R. 1912 Chlorosis of orange and other plants on ferruginous soils. Bol. Agr. (S. Paulo), 13, ser. 1912, n. 2:129-150. (B.L.M.E., vol. 1, p. 1076, 1948).

BARNES, W. C. 1943 Effect of soil acidity and some minor elements on the growth of Irish potatoes. S. C. Agr. Expt. Sta. Ann. Retp.: 127-132.

BEMELMANS, J. 1952 A fome de potássio. Bol. Sup. Serv. Tec. Café 304: 500-504.

CIFERRI, R. Sem data Em "Fisiologia Vegetale", Edizione Agricole - Bologna.

COOIL, B. J. 1948 Potassium deficiency and excess in guayule. II. Cation-anion balance in the leaves. Plant Physiol. 23:403-424.

COOIL, B. J. and M. C. SLATTERY. 1948 Effects of potassium deficiency and excess upon certain carbohydrate ond nitrogenous constituents in guayule. Plant Physiol. 22: 425-442.

COOPER, H. P. and R. W. WALLACE. 1937 Results from an experiment upon the use with cotton of various sources of potash salts with and without lime and magnesium. S. Carolina Agr. Expt. Sta. 50th Ann. Rept: 129-130.

COOPER, H. P., W. B. ROGERS and R. W. WALLACE. 1943 Experiments with potash fertilizer for cotton. S. Carolina Agr. Expt. Sta. 47th Ann. Rept.: 16-18.

COWIE, G. A. 1951 Em "Potash", Edward Arnold and Co., London.

DIXON, M. 1949 Em "Multienzyme Systems", Cambridge Univ. Press, Cambridge.

DROSDOFF, M. and D. C. NEARPASS. 1948 Quantitative microdetermination of magnesium in plant tissue and soil extracts. Anal. Chem. 20: 673-674.

ECKSTEIN, O., A. BRUNO, J. W. TURRENTINE. 1937 Em "Kenzeichen des Kalimangels", Verlagsgesellschaft fur Ackerbau, Berlin.

HACKEMANN, F. 1952 Fome de potássio. Sind. Ind Ad. Colas Est. S. Paulo Circ. 58-52. HEWITT, E. J. 1951 The role of the mineral elements in plant nutrition. Ann. Rev. Plant Physiol. 2: 25-52.

HOAGLAND, D. R. and D. I. ARNON. 1950 The water culture method for growing plants without soil. Calif. Agr. Expt. Sta. Circ. 347.

JAVILLIER, M. et S, GOUDSCHAUX. 1940 The magnesium of chlorophyll. Ann. Agron. 10: 9-14.

JENNY, H. 1951 Em "Mineral nutrition of plants", ed. E. Troug, The University of Wisconsin Press.

JOHNSON, C. M. and E. EPSTEIN. 1949 Em "Methods of chemical analysis. Soil Science 113 University of California". Mimeogr.

JONES, E. W. and E. J. HEWITT. 1950 Cit. em MALAVOLTA, 1953.

LEHR, J, J. 1949-50 Exploratory pot experiments on sensitiveness of different crops to sodium: A. Spinach. Plant and Soil 2: 37-48.

LOEW, O. 1903 The physiological role of mineral nutrients in plants. U. S. D. A. Bur. Plant Ind. Bul. 45.

MALAVOLTA, E. 1953 Em "Apontamentos de Química Agrícola. II, Química Vegetal", Piracicaba, Mimeogr.

MAMELI, E. 1912 Sulla influenza del magnesio sopra la formazicnc delia chlorofilla. Inst. Bot. Univ. Pavia (Ser. 2) 15: 151-205.

MC MURTREY, J. E. 1948 Em "Diagnostic techniques for soils and crops", publ. by the American Potash Institute, Washington, D. C.

MITSCHERLICH, E. A. 1930 Em "Die Bestimmung des Dungerbedurfnisses des Bodens", 3a. ed., Paul Parey, Berlin.

MULDER, E. G. 1949 Investigations on the nitrogen nutrition of agricultural crops. I. Experiments with ammonium nitrate limestone en grassland. Verlag. Landbouwk. Onderzoek. N. 55.7: 1-95. (C. A. 44 (3): 5508. 1950).

MULDER, E. G. 1950 Mineral nutrition of plants. Ann. Rev. Plant Physiol. 1: 1-24.

MULLISON, W. R. and E. MULLISON. 1942 Growth responses of barley seedlings in relation to K and Na nutrition. Plant. Physiol. 17: 632-644.

OLSEN, C. 1948-a Absorptively bound potassium in beech leaf cells. Physiol. Plantarum 1: 136-141.

OLSEN, C. 1948-b The mineral, nitrogen, and sugar contens of beach leaves and beech-leaf sap at various times. Compt. rend. trav. lab. Carlsb. sér. chim. 26: 197-230.

PAIVA NETTO, J. DE, R. A. CATANI, M. S. QUEIROZ e A KUPPER. 1950 Em "Anais da Primeira Reunião Brasileira de Ciência do Solo", publ. pela Sec. Bras, de Ciência do Solo, Rio de Janeiro.

PEECH, M. 1948 Em "Diagnostic techniques for soils and crops", Publ. by the American Potash Institute, Washington, D. C.

PFEIFFER, T. 1918 Em "Der Vegetatationversuch", Verlagsbuchhandlung Paul Parey, Berlin.

PRINCE, A. L., M. ZIMMERMAN and F. E. BEAR. 1947 The magnesium supplying powers of 20 New Jersey soils. Soil Sci. 63: 69-78.

RABINOWITCH, E. I. 1945 Em "Photosynthesis and related processes", vol. 1, Interscience Publ., Inc., New York.

RAUMER, E. VON. 1883 Kalk und Magnesia in der Pflanze. Landw. Vers. Sta. 19: 253-208.

SAUER, H. 1950 O avermelhamento das folhas do algodoeiro seria uma consequência de ataque do pulgão. "Fôlha da Manhã" (S. Paulo) 12 jan. 1950: 11

STOUT, P. R., R. OVERSTREET, L. JACOBSON and A ULRICH. 1947 The use of radioactive tracers in plant nutrition studies. Soil Sci. Soc. Amer. Proc. 12: 91-97.

TRUOG, E, R. J. GOATES, G. C. GERLOFF and K. C. BERGER. 1947 Magnesium-phosphorus relationships in plant nutrition. Soil Sci. 63: 19-25.

VOLK, N. J. 1934 The fixation of potash in difficultly available forms in soils. Soil Sci. 37: 267-287.

WALLACE, T. 1944 Em "The diagnosis of mineral deficiencies in plants by visual symptoms", His Majesty's Stationery Office, London.

WALLACE, T. and E. J. HEWITT. 1946 Studies in iron deficiency of crops I. Problems of iron deficiency and the interrelationships of mineral elements in iron nutrition. The Jour. Pomol. Hort. Sci. 22: (3-4): 153-161.

WALSH, T. and E. J. CLARK. 1945 Chlorosis of tomatoes with particular reference to potassium-magnesium relations. Proc. Roy. Irish Acad. 50B: 245-263.

WALSH, T. and T. F. O'DONOHOE. 1945 Magnesium deficiency in some crops plants in relation to the level of potassium nutrition. Jour. Agr. Sci. 35: 254-263.

WILLSTATTER, R. und A. STOLL. 1913 Em "Untersuchungen uber chlorophyll. Methoden und Ergebnisse", Berlin.

ZIMMERMAN, M. 1947 Magnesium in plants. Soil Sci. 63: 1-12.

ABRAHAO, J., A. C ANDRADE e A. A. BITANCOURT. 1952 O "vermelhão" ou "fome de potássio" do algodoeiro, um desequilíbrio fisiológico entre a folhagem e a frutificação, 2a. Reunião Sulamericana de Fitogeneticistas e Fitoparasitologistas (Piracicaba, Abril). Mimeogr.
A. O. A. C. 1948 Em "Official and tentative methods of analy sis", sixth edit. publ. by the Assoc. Offic. Agric. Chem., Washington, D. C.
ARNON, D. I. and D. R. HOAGLAND. 1943 Composition of the tomato plant as influenced by nutrient supply, in relation to fruiting. Bot. Gaz. 104: 576-590.
AVERNA-SACCÁ, R. 1912 Chlorosis of orange and other plants on ferruginous soils. Bol. Agr. (S. Paulo), 13, ser. 1912, n. 2:129-150. (B.L.M.E., vol. 1, p. 1076, 1948).
BARNES, W. C. 1943 Effect of soil acidity and some minor elements on the growth of Irish potatoes. S. C. Agr. Expt. Sta. Ann. Retp.: 127-132.
BEMELMANS, J. 1952 A fome de potássio. Bol. Sup. Serv. Tec. Café 304: 500-504.
CIFERRI, R. Sem data Em "Fisiologia Vegetale", Edizione Agricole - Bologna.
COOIL, B. J. 1948 Potassium deficiency and excess in guayule. II. Cation-anion balance in the leaves. Plant Physiol. 23:403-424.
COOIL, B. J. and M. C. SLATTERY. 1948 Effects of potassium deficiency and excess upon certain carbohydrate ond nitrogenous constituents in guayule. Plant Physiol. 22: 425-442.
COOPER, H. P. and R. W. WALLACE. 1937 Results from an experiment upon the use with cotton of various sources of potash salts with and without lime and magnesium. S. Carolina Agr. Expt. Sta. 50th Ann. Rept: 129-130.
COOPER, H. P., W. B. ROGERS and R. W. WALLACE. 1943 Experiments with potash fertilizer for cotton. S. Carolina Agr. Expt. Sta. 47th Ann. Rept.: 16-18.
COWIE, G. A. 1951 Em "Potash", Edward Arnold and Co., London.
DIXON, M. 1949 Em "Multienzyme Systems", Cambridge Univ. Press, Cambridge.
DROSDOFF, M. and D. C. NEARPASS. 1948 Quantitative microdetermination of magnesium in plant tissue and soil extracts. Anal. Chem. 20: 673-674.
ECKSTEIN, O., A. BRUNO, J. W. TURRENTINE. 1937 Em "Kenzeichen des Kalimangels", Verlagsgesellschaft fur Ackerbau, Berlin.
HACKEMANN, F. 1952 Fome de potássio. Sind. Ind Ad. Colas Est. S. Paulo Circ. 58-52.
HEWITT, E. J. 1951 The role of the mineral elements in plant nutrition. Ann. Rev. Plant Physiol. 2: 25-52.
HOAGLAND, D. R. and D. I. ARNON. 1950 The water culture method for growing plants without soil. Calif. Agr. Expt. Sta. Circ. 347.
JAVILLIER, M. et S, GOUDSCHAUX. 1940 The magnesium of chlorophyll. Ann. Agron. 10: 9-14.
JENNY, H. 1951 Em "Mineral nutrition of plants", ed. E. Troug, The University of Wisconsin Press.
JOHNSON, C. M. and E. EPSTEIN. 1949 Em "Methods of chemical analysis. Soil Science 113 University of California". Mimeogr.
JONES, E. W. and E. J. HEWITT. 1950 Cit. em MALAVOLTA, 1953.
LEHR, J, J. 1949-50 Exploratory pot experiments on sensitiveness of different crops to sodium: A. Spinach. Plant and Soil 2: 37-48.
LOEW, O. 1903 The physiological role of mineral nutrients in plants. U. S. D. A. Bur. Plant Ind. Bul. 45.
MALAVOLTA, E. 1953 Em "Apontamentos de Química Agrícola. II, Química Vegetal", Piracicaba, Mimeogr.
MAMELI, E. 1912 Sulla influenza del magnesio sopra la formazicnc delia chlorofilla. Inst. Bot. Univ. Pavia (Ser. 2) 15: 151-205.
MC MURTREY, J. E. 1948 Em "Diagnostic techniques for soils and crops", publ. by the American Potash Institute, Washington, D. C.
MITSCHERLICH, E. A. 1930 Em "Die Bestimmung des Dungerbedurfnisses des Bodens", 3a. ed., Paul Parey, Berlin.
MULDER, E. G. 1949 Investigations on the nitrogen nutrition of agricultural crops. I. Experiments with ammonium nitrate limestone en grassland. Verlag. Landbouwk. Onderzoek. N. 55.7: 1-95. (C. A. 44 (3): 5508. 1950).
MULDER, E. G. 1950 Mineral nutrition of plants. Ann. Rev. Plant Physiol. 1: 1-24.
MULLISON, W. R. and E. MULLISON. 1942 Growth responses of barley seedlings in relation to K and Na nutrition. Plant. Physiol. 17: 632-644.
OLSEN, C. 1948-a Absorptively bound potassium in beech leaf cells. Physiol. Plantarum 1: 136-141.
OLSEN, C. 1948-b The mineral, nitrogen, and sugar contens of beach leaves and beech-leaf sap at various times. Compt. rend. trav. lab. Carlsb. sér. chim. 26: 197-230.
PAIVA NETTO, J. DE, R. A. CATANI, M. S. QUEIROZ e A KUPPER. 1950 Em "Anais da Primeira Reunião Brasileira de Ciência do Solo", publ. pela Sec. Bras, de Ciência do Solo, Rio de Janeiro.
PEECH, M. 1948 Em "Diagnostic techniques for soils and crops", Publ. by the American Potash Institute, Washington, D. C.
PFEIFFER, T. 1918 Em "Der Vegetatationversuch", Verlagsbuchhandlung Paul Parey, Berlin.
PRINCE, A. L., M. ZIMMERMAN and F. E. BEAR. 1947 The magnesium supplying powers of 20 New Jersey soils. Soil Sci. 63: 69-78.
RABINOWITCH, E. I. 1945 Em "Photosynthesis and related processes", vol. 1, Interscience Publ., Inc., New York.
RAUMER, E. VON. 1883 Kalk und Magnesia in der Pflanze. Landw. Vers. Sta. 19: 253-208.
SAUER, H. 1950 O avermelhamento das folhas do algodoeiro seria uma consequência de ataque do pulgão. "Fôlha da Manhã" (S. Paulo) 12 jan. 1950: 11
STOUT, P. R., R. OVERSTREET, L. JACOBSON and A ULRICH. 1947 The use of radioactive tracers in plant nutrition studies. Soil Sci. Soc. Amer. Proc. 12: 91-97.
TRUOG, E, R. J. GOATES, G. C. GERLOFF and K. C. BERGER. 1947 Magnesium-phosphorus relationships in plant nutrition. Soil Sci. 63: 19-25.
VOLK, N. J. 1934 The fixation of potash in difficultly available forms in soils. Soil Sci. 37: 267-287.
WALLACE, T. 1944 Em "The diagnosis of mineral deficiencies in plants by visual symptoms", His Majesty's Stationery Office, London.
WALLACE, T. and E. J. HEWITT. 1946 Studies in iron deficiency of crops I. Problems of iron deficiency and the interrelationships of mineral elements in iron nutrition. The Jour. Pomol. Hort. Sci. 22: (3-4): 153-161.
WALSH, T. and E. J. CLARK. 1945 Chlorosis of tomatoes with particular reference to potassium-magnesium relations. Proc. Roy. Irish Acad. 50B: 245-263.
WALSH, T. and T. F. O'DONOHOE. 1945 Magnesium deficiency in some crops plants in relation to the level of potassium nutrition. Jour. Agr. Sci. 35: 254-263.
WILLSTATTER, R. und A. STOLL. 1913 Em "Untersuchungen uber chlorophyll. Methoden und Ergebnisse", Berlin.
ZIMMERMAN, M. 1947 Magnesium in plants. Soil Sci. 63: 1-12.

*

2.o congresso panamericano de agronomia

E. S. A. "LUIZ DE QUEIROZ", U. S. P. Piracicaba, Março-abril de 1954

DEDICATÓRIA - Êste trabalho é dedicado à memória do Prof. R. AVERNA-SACCÁ

Datas de Publicação

Publicação nesta coleção
02 Out 2012
Data do Fascículo
1954

This work is licensed under a Creative Commons Attribution-NonCommercial 4.0 International License.

[1] ABRAHAO, J., A. C ANDRADE e A. A. BITANCOURT. 1952 O "vermelhão" ou "fome de potássio" do algodoeiro, um desequilíbrio fisiológico entre a folhagem e a frutificação, 2a. Reunião Sulamericana de Fitogeneticistas e Fitoparasitologistas (Piracicaba, Abril). Mimeogr.

[2] A. O. A. C. 1948 Em "Official and tentative methods of analy sis", sixth edit. publ. by the Assoc. Offic. Agric. Chem., Washington, D. C.

[3] ARNON, D. I. and D. R. HOAGLAND. 1943 Composition of the tomato plant as influenced by nutrient supply, in relation to fruiting. Bot. Gaz. 104: 576-590.

[4] AVERNA-SACCÁ, R. 1912 Chlorosis of orange and other plants on ferruginous soils. Bol. Agr. (S. Paulo), 13, ser. 1912, n. 2:129-150. (B.L.M.E., vol. 1, p. 1076, 1948).

[5] BARNES, W. C. 1943 Effect of soil acidity and some minor elements on the growth of Irish potatoes. S. C. Agr. Expt. Sta. Ann. Retp.: 127-132.

[6] BEMELMANS, J. 1952 A fome de potássio. Bol. Sup. Serv. Tec. Café 304: 500-504.

[7] CIFERRI, R. Sem data Em "Fisiologia Vegetale", Edizione Agricole - Bologna.

[8] COOIL, B. J. 1948 Potassium deficiency and excess in guayule. II. Cation-anion balance in the leaves. Plant Physiol. 23:403-424.

[9] COOIL, B. J. and M. C. SLATTERY. 1948 Effects of potassium deficiency and excess upon certain carbohydrate ond nitrogenous constituents in guayule. Plant Physiol. 22: 425-442.

[10] COOPER, H. P. and R. W. WALLACE. 1937 Results from an experiment upon the use with cotton of various sources of potash salts with and without lime and magnesium. S. Carolina Agr. Expt. Sta. 50th Ann. Rept: 129-130.

[11] COOPER, H. P., W. B. ROGERS and R. W. WALLACE. 1943 Experiments with potash fertilizer for cotton. S. Carolina Agr. Expt. Sta. 47th Ann. Rept.: 16-18.

[12] COWIE, G. A. 1951 Em "Potash", Edward Arnold and Co., London.

[13] DIXON, M. 1949 Em "Multienzyme Systems", Cambridge Univ. Press, Cambridge.

[14] DROSDOFF, M. and D. C. NEARPASS. 1948 Quantitative microdetermination of magnesium in plant tissue and soil extracts. Anal. Chem. 20: 673-674.

[15] ECKSTEIN, O., A. BRUNO, J. W. TURRENTINE. 1937 Em "Kenzeichen des Kalimangels", Verlagsgesellschaft fur Ackerbau, Berlin.

[16] HACKEMANN, F. 1952 Fome de potássio. Sind. Ind Ad. Colas Est. S. Paulo Circ. 58-52.

[17] HEWITT, E. J. 1951 The role of the mineral elements in plant nutrition. Ann. Rev. Plant Physiol. 2: 25-52.

[18] HOAGLAND, D. R. and D. I. ARNON. 1950 The water culture method for growing plants without soil. Calif. Agr. Expt. Sta. Circ. 347.

[19] JAVILLIER, M. et S, GOUDSCHAUX. 1940 The magnesium of chlorophyll. Ann. Agron. 10: 9-14.

[20] JENNY, H. 1951 Em "Mineral nutrition of plants", ed. E. Troug, The University of Wisconsin Press.

[21] JOHNSON, C. M. and E. EPSTEIN. 1949 Em "Methods of chemical analysis. Soil Science 113 University of California". Mimeogr.

[22] JONES, E. W. and E. J. HEWITT. 1950 Cit. em MALAVOLTA, 1953.

[23] LEHR, J, J. 1949-50 Exploratory pot experiments on sensitiveness of different crops to sodium: A. Spinach. Plant and Soil 2: 37-48.

[24] LOEW, O. 1903 The physiological role of mineral nutrients in plants. U. S. D. A. Bur. Plant Ind. Bul. 45.

[25] MALAVOLTA, E. 1953 Em "Apontamentos de Química Agrícola. II, Química Vegetal", Piracicaba, Mimeogr.

[26] MAMELI, E. 1912 Sulla influenza del magnesio sopra la formazicnc delia chlorofilla. Inst. Bot. Univ. Pavia (Ser. 2) 15: 151-205.

[27] MC MURTREY, J. E. 1948 Em "Diagnostic techniques for soils and crops", publ. by the American Potash Institute, Washington, D. C.

[28] MITSCHERLICH, E. A. 1930 Em "Die Bestimmung des Dungerbedurfnisses des Bodens", 3a. ed., Paul Parey, Berlin.

[29] MULDER, E. G. 1949 Investigations on the nitrogen nutrition of agricultural crops. I. Experiments with ammonium nitrate limestone en grassland. Verlag. Landbouwk. Onderzoek. N. 55.7: 1-95. (C. A. 44 (3): 5508. 1950).

[30] MULDER, E. G. 1950 Mineral nutrition of plants. Ann. Rev. Plant Physiol. 1: 1-24.

[31] MULLISON, W. R. and E. MULLISON. 1942 Growth responses of barley seedlings in relation to K and Na nutrition. Plant. Physiol. 17: 632-644.

[32] OLSEN, C. 1948-a Absorptively bound potassium in beech leaf cells. Physiol. Plantarum 1: 136-141.

[33] OLSEN, C. 1948-b The mineral, nitrogen, and sugar contens of beach leaves and beech-leaf sap at various times. Compt. rend. trav. lab. Carlsb. sér. chim. 26: 197-230.

[34] PAIVA NETTO, J. DE, R. A. CATANI, M. S. QUEIROZ e A KUPPER. 1950 Em "Anais da Primeira Reunião Brasileira de Ciência do Solo", publ. pela Sec. Bras, de Ciência do Solo, Rio de Janeiro.

[35] PEECH, M. 1948 Em "Diagnostic techniques for soils and crops", Publ. by the American Potash Institute, Washington, D. C.

[36] PFEIFFER, T. 1918 Em "Der Vegetatationversuch", Verlagsbuchhandlung Paul Parey, Berlin.

[37] PRINCE, A. L., M. ZIMMERMAN and F. E. BEAR. 1947 The magnesium supplying powers of 20 New Jersey soils. Soil Sci. 63: 69-78.

[38] RABINOWITCH, E. I. 1945 Em "Photosynthesis and related processes", vol. 1, Interscience Publ., Inc., New York.

[39] RAUMER, E. VON. 1883 Kalk und Magnesia in der Pflanze. Landw. Vers. Sta. 19: 253-208.

[40] SAUER, H. 1950 O avermelhamento das folhas do algodoeiro seria uma consequência de ataque do pulgão. "Fôlha da Manhã" (S. Paulo) 12 jan. 1950: 11

[41] STOUT, P. R., R. OVERSTREET, L. JACOBSON and A ULRICH. 1947 The use of radioactive tracers in plant nutrition studies. Soil Sci. Soc. Amer. Proc. 12: 91-97.

[42] TRUOG, E, R. J. GOATES, G. C. GERLOFF and K. C. BERGER. 1947 Magnesium-phosphorus relationships in plant nutrition. Soil Sci. 63: 19-25.

[43] VOLK, N. J. 1934 The fixation of potash in difficultly available forms in soils. Soil Sci. 37: 267-287.

[44] WALLACE, T. 1944 Em "The diagnosis of mineral deficiencies in plants by visual symptoms", His Majesty's Stationery Office, London.

[45] WALLACE, T. and E. J. HEWITT. 1946 Studies in iron deficiency of crops I. Problems of iron deficiency and the interrelationships of mineral elements in iron nutrition. The Jour. Pomol. Hort. Sci. 22: (3-4): 153-161.

[46] WALSH, T. and E. J. CLARK. 1945 Chlorosis of tomatoes with particular reference to potassium-magnesium relations. Proc. Roy. Irish Acad. 50B: 245-263.

[47] WALSH, T. and T. F. O'DONOHOE. 1945 Magnesium deficiency in some crops plants in relation to the level of potassium nutrition. Jour. Agr. Sci. 35: 254-263.

[48] WILLSTATTER, R. und A. STOLL. 1913 Em "Untersuchungen uber chlorophyll. Methoden und Ergebnisse", Berlin.

[49] ZIMMERMAN, M. 1947 Magnesium in plants. Soil Sci. 63: 1-12.