Control of coffee leaf rust in Kenya colony :
Results of twenty-seven trials sited at altitudes between 5000 and 6200 ft. in districts both east and west of the Rift Valley were all similar. The conclusions which can be drawn are: (a) maximum control of Hemileia vastatrix is obtained by treatments applied before commencement and during the early period of the rains; (2) timing of treatments is critical; (3) the efficiency of copper in controlling the disease diminishes with the increase of time between application and the first rains. It is considered that copper may operate first by drastically reducing the amount of residual inoculum, followed by a short period of protection; when timing has been correct, a considerable period elapses before the pathogen attains the numerical threshold necessary for invasion. Enhanced disease incidence results eventually from all control measures when these are discontinued: fungicidal sprays delay leaf-fall with the result that more leaves, both healthy and infected, which would normally be shed, are carried over through the dry season into the rains. Thus more inoculum is present, with a greater number of targets for spore-laden droplets to reach
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Format: | biblioteca |
Language: | eng |
Published: |
1962
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Subjects: | COFFEA, HEMILEIA, ROYA, ENFERMEDADES FUNGOSAS, CONTROL DE HONGOS, KENIA, CONTROL QUIMICO, HEMILEIA VASTATRIX, |
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