Controle da ferrugem do cafeeiro com aplicacao da mistura triadimenol + dissulfoton em solo submetido a tres níveis de umidade :
An experiment was conducted under field conditions during 1993 and 1994, in Vicosa, State of Minas Gerais, Brazil, aimed at determining the effectivity of triadimenol + disulfoton applications in controling coffee leaf rust caused by Hemileia vastatrix Berk. & Br., under different soil moisture conditions. The treatments consisted of the application of 0.18 g of triadimenol + 0.90 g of disulfoton per coffee plant. The first treatment was irrigated weekly with 20 l of water per plant, whereas the second one was irrigated weekly with 10 l; the third one was not watered and was subjected to the local climatic conditions; and the fourth one was the control left without fungicide + insecticide applications and receiving no irrigation. At 15 and 45 days after fungicide application (15 a.f.a. and 45 a.f.a.), two pairs of leaves (in 1993) or one pair (in 1994) in four plagiotropic branches located on the medium part of the plant were inoculated with uredioniospores. Evaluations were made 40 days after each inoculation to determine disease severity. There were differences in the rusted foliar area between the treatments with and without irrigation. Irrigated treatments had a larger proportion of rusted foliar areas. The results obtained in the two consecutive years for the 45 a.f.a. indicated that a 55-days period or longer, after fungicide application on the soil, is necessary to allow the fungicide to translocate to the above-ground plant parts, the consequence being the significant reduction observed in disease severity after such a period. Soil moisture conditions under which the experiment was carried out, were no detrimental to the efficiency of the chemicals even during the year of 1993 when rainfall levels were lower.
| Main Authors: | , , , |
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| Format: | biblioteca |
| Language: | eng |
| Published: |
Jun
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| Subjects: | COFFEA ARABICA, HEMILEIA VASTATRIX, ROYA, ENFERMEDADES FUNGOSAS, CONTROL QUIMICO, TRIADIMENOL, DISULFOTON, CONTENIDO DE AGUA EN EL SUELO, BRASIL, |
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