Growth and Yielding of Ten Cultivars of Plums (Prunus domestica L.) Grown in Organic System

In recent years, Polish producers have been increasingly interested in organic fruit production. In this growing system, it is very important to choose cultivars that are less susceptible to diseases and pests. In a study conducted between 2016 and 2024 in central Poland, the suitability of ten plum cultivars (‘Cacanska Lepotica’, ‘Cacanska Najbolja’, ‘Kalipso’, ‘Katinka’, ‘Jubileum’, ‘Presenta’, ‘Silvia’, ‘Tophit’, ‘Tophit Plus’, and ‘Vision’) for organic cultivation was assessed. The results demonstrated that organic plum cultivation is feasible; however, it remains challenging. Based on long-term observations and experimental data, it was found that early-ripening plum cultivars such as ‘Katinka’, ‘Kalipso’ and ‘Cacanska Lepotica’ are more suitable for organic farming than others. Fruits of these cultivars were either not infested or only occasionally affected by the plum fruit moth and exhibited only sporadic symptoms of brown rot. The medium-early-ripening ‘Cacanska Najbolja’ cultivar is also worth noting, as the trees yield well in organic orchard conditions; however, the fruit is sometimes affected by rot-causing diseases and by the plum fruit moth. Fruits of late-ripening cultivars (‘Presenta’, ‘Tophit’, ‘Tophit Plus’, and ‘Vision’) were significantly more frequently infested by plum fruit moth caterpillars and exhibited a higher incidence of rot. The highest level of plum fruit moth infestation was observed in the fruit of ‘Tophit Plus’, whereas ‘Jubileum’ was the most susceptible to brown rot. These findings provide long-term evidence supporting cultivar selection as a key non-chemical strategy for improving the reliability of organic plum production under temperate climate conditions. The results may support cultivar selection strategies aimed at improving the sustainability and reliability of organic plum production in temperate climates.