| Autor: |
Pak, H. A., Beever, R. E., Laracy, E. P. |
| Předmět: |
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| Zdroj: |
Plant Pathology; Sep90, Vol. 39 Issue 3, p501-509, 9p |
| Abstrakt: |
Changes in the proportion of dicarboximide-resistant strains of Botrytis cinerea were monitored in two vineyard trials conducted during the period from October 1985 to November 1987. Dicarboximide resistance frequency in samples taken prior to flowering from wood (dead cane-ends, dead tendrils, old bunch remains) was high (66%) in the first trial, and low (12%) in the second trial. In treatments where resistance frequency was high on wood in spring, it decreased during the phase of disease establishment in new bunches irrespective of whether or not dicarboximide fungicides were applied. In the absence of dicarboximide applications, resistance frequency showed little change during the phase of disease development in bunches. The resistance frequency increased, however, if dicarboximide fungicides were applied, the extent of increase depending on the number and timing of applications and on disease severity at the time of application. Where resistance frequency was high on the wood at harvest, it decreased over the following winter but increased again in spring even though no dicarboximides had been applied. The best disease control in both trials was obtained with a programme in which dicarboximide fungicides were only applied during the period from veraison until harvest. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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