ISHS Acta Horticulturae 309: XV International Symposium on Fruit Tree Diseases
STUDY OF THE ECOLOGICAL FACTORS INFLUENCING ATTACKS BY PLUM POX VIRUS |
| Authors: | G. Vanek, J. Kotuc, M. Kölber, M. Németh, L. Szõke |
| Abstract:
By investigating the rapid spread, pathogenicity, large hostrange and epidemic damages caused by plum pox virus, it was found that any changes in the environmental factors of the hostplants may also induce modification in the agressivity of the virus. These changes have two significant sources with great influence on plant ecology. The first is the continuous application of fertilizers having cumulative impact on long-term, thus, contributing to the disequilibra of the soil. The other factor is industry /heat power station, etc./ with the cumulative effect of pollution imissioned into the air. During the investigations the authors try to describe these impacts, with their tendencies and extent, as well as they determine their effect on the pathogenicity /agressivity/ of virus and on plant quantity and quality. Based on results of hydroponic experiments it was found that the virus concentration within the plant and the infection level are increased partly by the calcium deficiency, partly by the potassium deficiency and the nitrogen excess. It was found on soils damaged with pollutants of industrial origin /acid, magnesite imission/ and treated with only fertilizers that the soil EUF-Ca content and the pH decrease with the improvement of the damages caused by the virus. These two impacts together increase the PPV agressivity. Minimal damages were found only for environmental factors if plum was grown on uncultivated areas without fertilization and imission. Ca imission caused by cement factories decreased also the virus agressivity, compensating the negative effect of fertilizers. The environmental damages can be well determined with EUF soil analyses and leaf analyses and a relation was found with the agressivity of the virus. It is thought that virus agressivity can be decreased by reestablishing the soil equilibrium. Investigations on this subject are continuously made. | |
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