ISHS Acta Horticulturae 293: IX International Symposium on Apricot Culture
PHYTOPATHOLOGICAL PROBLEMS OF APRICOTS IN CZECHOSLOVAKIA |
| Author: | J. Molnár |
| Abstract:
Apart from late frosts, apricot decline is the most serious problem of apricot growing in Czechoslovakia. The annual loss of trees due to apricot decline amounts to 2 – 7 % in the average. Analyses of tumours of the trees died and dying have shown that Cytospora cincta was the most colonized pathogen. Pseudomonas syringae bacteria were represented in smaller degree. Sharka on apricot /PPV/ is showing a tendency to increase. We did not observe any resistant cultivar. Since 1980 the occurrence and harmfulness of apricot leaf scorch /Gnomonia erytrostoma/ have been rising. Ascospores are the only source of primary infections. Their maturing and releasing occur in spring in apricot postblossom time and they last about 4–8 weeks. Infections are supported by precipitation during releasing of ascospores. If hydrothermical coefficient value increases in the course of the period by 2–2,5 times compared to normal /1,6 – 2,1/, one may count with high occurrence of apricot leaf scorch. Other fungal diseases /Monilia sp., Clasterosporium carpophilum, Megacladosporium carpophilum/ are important only in years with abundant precipitation during spring months. Among animal pests, Operophtera brumata and Spilonota ocellana are of local importance. Mealy plum aphid /Hyalopterus pruni/ is more important as the vector of Sharka virus. Among lepidopterous pests, peach twig borer | |
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