Resumo
Tomato roots heavily disfigured by root-knot nematodes were throughly mixed with soil. At various time intervals, samples were taken from the mixture and treated in closed containers by each of the folio wing nematicides: D.D., E.D.B. and M.B. The efficacy of the treatment was tested by setting indicator plants in the treated soil and by examining their roots for the presence of galls two months later. In other words, the ability of the three nematicides to penetrate nematode galls after various periods of rotting, which varied from 5 to 30 days was studied. The main conclusions drawn are as follows: a) no nematicide among the three listed above showed the ability for complete destruction of the nematodes protected inside the roots, for a number of small galls developed on the root system of the indicator plant in all treatments; b) smaller and less numerous galls were present on the roots of the indicator plants grown in soil treated after a rotting period of 30 days; c) however, the control obtained seems to be quite satisfactory economically, since the check plants grew poorly and have developed a very unhealthy root system. This is in accordance with STARK & LEAR (1947), LEAR (1951) and CICCARONE's (1951) statements. The results of the present experiments show again that awaiting for the rotting of galls of the root-knot nematodes is not indispensable for an economically convenient soil fumigation. Fields in which many fleshy infected roots from previous crops have been buried can be economically fumigated immediately, without any loss of time. Notwithstanding, when thick woody roots are present in the soil, the above statements may not hold true. This should constitute a new problem calling for further experiments. Another essay dealing with methyl bromide alone, consisted in treating cotton roots heavily disfigured by Meloidogyne incognita in a container (diameter = 28cm, height = 32 cm), which remained closed for five days. After the treatment, the roots were mixed with soil, in which tomato seedlings were planted. After a growing period of two months, the roots of the tomato plants were washed in running water and examined for the presence of galls. As an early infeccion was present in the root system of all plants, the inefficacy of the treatment has been proved.
Escola Superior de Agricultura "Luiz de Queiroz" Universidade de S. Paulo - Piracicaba
SUMMARY
Tomato roots heavily disfigured by root-knot nematodes were throughly mixed with soil. At various time intervals, samples were taken from the mixture and treated in closed containers by each of the folio wing nematicides: D.D., E.D.B. and M.B. The efficacy of the treatment was tested by setting indicator plants in the treated soil and by examining their roots for the presence of galls two months later. In other words, the ability of the three nematicides to penetrate nematode galls after various periods of rotting, which varied from 5 to 30 days was studied.
The main conclusions drawn are as follows: a) no nematicide among the three listed above showed the ability for complete destruction of the nematodes protected inside the roots, for a number of small galls developed on the root system of the indicator plant in all treatments; b) smaller and less numerous galls were present on the roots of the indicator plants grown in soil treated after a rotting period of 30 days; c) however, the control obtained seems to be quite satisfactory economically, since the check plants grew poorly and have developed a very unhealthy root system. This is in accordance with STARK & LEAR (1947), LEAR (1951) and CICCARONE's (1951) statements.
The results of the present experiments show again that awaiting for the rotting of galls of the root-knot nematodes is not indispensable for an economically convenient soil fumigation. Fields in which many fleshy infected roots from previous crops have been buried can be economically fumigated immediately, without any loss of time.
Notwithstanding, when thick woody roots are present in the soil, the above statements may not hold true. This should constitute a new problem calling for further experiments.
Another essay dealing with methyl bromide alone, consisted in treating cotton roots heavily disfigured by Meloidogyne incognita in a container (diameter = 28cm, height = 32 cm), which remained closed for five days. After the treatment, the roots were mixed with soil, in which tomato seedlings were planted. After a growing period of two months, the roots of the tomato plants were washed in running water and examined for the presence of galls. As an early infeccion was present in the root system of all plants, the inefficacy of the treatment has been proved.
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LITERATURA CITADA
- BOOCK, O. J. & L. G. E. LORDELLO, 1952 - Tratamento dos tubérculos-semente de batatinha com brometo de metilo no combate aos nematóides das galhas. Bragantia 12: 363-364.
- CHRISTIE, J. R. & G. S. COBB, 1940 - The inefficacy of methyl bromide fumigation against the chrysanthemum foliar nematode. Proc. Helminth. Soc. Washington 7: 62.
- CICCARONE, A., 1950 - Resultati di fumigazione nematocida in terreno ricco di organi vegetali carnosi, vivi e presentanti galle non decadute di Heterodera marioni (Cornu) Goodey. Boll Stazione Pat. Veg. 8, série III: 181-186.
- DIETER, C. E., 1954 - Factors affecting results with soil fumigants. Plant Dis. Reptr., suppl. 227: 98-101.
- GODFREY, G. H., J. OLIVEIRA & H. M. HOSHINO, 1934 - Increased efficiency of chloropicrin for nematode control with better confinement of gas.Phytopathology 24: 1332-1346.
- LEAR, B., 1951 - Use of methyl bromide and other volatile chemicals for soil fumigation. Cornell University, Agric. Exp. Station, Memoir 303, 48 pp.
- STARK, F. L., JR. & B. LEAR, 1947 - Miscellaneous greenhouse testes with various soil fumigants for the control of fungi and nematodes. Phytopathology 37: 698-711.
- STEINER, G., 1951 - Curso de nematologia geral de plantas. Instituto Agronômico, Campinas, 20 pp. (mimeografado).
- TAYLOR, A. L., 1943 - Soil fumigation with chloropicrin for control of the root-knot nematode, Heterodera marioni. Phytopathology 33: 1166-1175.
- TAYLOR, A. L., 1951 - Chemical treatment of the soil por nematode control. Advances in Agronomy 3: 243-264.
- TAYLOR, A. L. & C. W. McBETH, 1940 - Preliminary testes of methyl bromide as a nematocide. Proc. Helminth. Soc. Washington 7: 94-96.
Experimentos com os nematicidas D. D., E. D. B. e brometo de metilo no combate aos nematódeos causadores de galhas em raízes de plantas (Meloidogyne spp.)
Datas de Publicação
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Publicação nesta coleção
28 Set 2012 -
Data do Fascículo
1956
