The peach is one of the most valuable cultivated fruit species that stands out for its early fruiting, high production potential, superior fruit quality. The trees begin to bear fruit economically from the third year after planting, the establishment of the first commercial peach plantations in Romania until now, the assortment has been subjected to a continuous process of improvement, as a result of the appearance of new more valuable varieties, the increase in demands for the quality of the fruits , of the diversification of the forms of capitalization, of the expansion of the culture areas. The adaptability of Romanian peach varieties is determined by the resistance of the fruit buds to the frosts during the winter. The data show that there is a strong negative correlation between the percentage of frosted fruit buds and fruit production. A percentage of over 55% frozen flower buds already calls into question the realization of the production plan. The verification of the adaptability of the new varieties was done through comparative cultures, organized simultaneously in several centers, with trees of the same age and on the same rootstock. Gum leaks are found in almost all stone trees, but in the case of an attack with this fungus, the leaks are abundant, leading to the rapid exhaustion of the trees. For observations or analyzed for each tree 300 leaves, 50 shoots (50 x 3 trees) 100 fruits, in three repetitions. The interpretation of the results was done by calculating the analysis of the variant, being also analyzed the expression of the character of resistance obtained by correlating the frequency with the intensity of the attack. The disease is caused by Stigmina carpohyla (syn. Coryneum beijerinckii Oud.) In the subepidermal tissues, the fungus develops its mycelium, where the fruiting bodies appear, which come to the surface by breaking the epidermis. They spread the pathogen during the vegetation period, being able to germinate at temperatures of 2-24°C. The fruits are deformed and fall before ripening. The flesh of the fruit becomes felty and has a bland taste. On the young shoots, around the buds, the bark turns brown, cracks and ulcers appear, leading to the drying of the buds. Young branches can be deformed, swellings, ulcerations, open cankers appear, which produce abundant gum leakage. The attack on the shoots is very dangerous because it leads to the drying of the trees. In almost all stone trees, gum leaks are found, but in the case of an attack with this fungus, the leaks are abundant, leading to the rapid exhaustion of the trees. The attack with this fungus is strong in the springs following winters with moderate temperatures, because the conidia retain their viability. Infections are favored by lesions in the bark of the branches caused by hail or caused by the attack of some insects.

peach varieties, disease, leaf spoting, resistance, intensity attack.

agronomy

Presentation: poster