Climate change impact on phenological stages of sweet and sour cherry trees in a continental climate environment

Abstract

This study presents the impact of climate change on the first four phenological stages: bud swelling (code 51 BBCH Monograph), budburst (code 53), beginning of flowering (code 61), and end of flowering (code 69) of sweet cherry (Prunus avium L., Germersdorfer cultivar) and sour cherry (Prunus cerasus L., Crisana cultivar) trees, grafted on seedling, in a temperate-continental climate. We tested the hypothesis that the time to the onset of the phenological stages (TOPS) occurred earlier due to climate change and analyzed the consequences for farmers. Weather and phenological data from 1970 to 2018 were statistically processed. There was a rise in air temperature (T) during January through May, with a significant increase in March and April. Inverse linear relationships were found between TOPS and time, as well as between TOPS and some climate variables: maximum, mean and minimum T, and sunshine hours. There is an advance in the first three phenological stages, with stage 51 as the earliest. The impact is important in relation to insect pollination, pesticide application, and occurrence of climate accidents due to late frost. Insect pollination does not always occur simultaneously with the flowering of trees in spring. Rain and cold temperatures can interfere with pollination. Application of pesticides in orchards should be adjusted according to the weather course. Farmers should consider additional pesticide treatments to hamper development of specific pests and diseases. They should adjust irrigation scheduling and perhaps harvesting time. These results might be useful for farmers in other countries with similar environments.