Weather conditions during the blossoming period and their effect on the yield of three cultivars of blackcurrant (Ribes nigrum L.)

This study presents the influence of major weather factors during the blackcurrant blossoming period on the yields of the ‘Ojebyn’, ‘Titania’ and ‘Roodknop’ cultivars, cultivated in Warmia (Olsztyn). The study was conducted for five years (2003-2007). Among the factors analysed were the currant yield, the duration of the blossoming period, average daily air temperature, the number of days with frost at the height of 2 m and at the ground level, total rainfall during the blossoming period and the number of days with rainfall during the blossoming period.

The statistical analysis of particular weather factors has shown that the number of days with frost contributed significantly to the yield of the fruit. A linear correlation analysis has shown that the yield of the three examined cultivars of blackcurrant depended on variable weather conditions during the blossoming period. The yield of the ‘Ojebyn’ cultivar was significantly correlated with the duration of the blossoming period, the number of days with frost and the number of days with rainfall. A significant correlation in the ‘Titania’ cultivar was found with the number of days with frost and with the total amount of rainfall during the blossoming period. The fruit yield from the ‘Roodknop’ cultivar in the five-year period under study depended only on one variable: the duration of the blossoming period. The highest yield was obtained from the ‘Titania’ cultivar.