Blackberry cultivars, nitrogen and potassium fertilization under drastic summer pruning in a subtropical area

The expansion of blackberry cropping in subtropical regions is recent, requiring adaptability studies and the development new cultivars, as well suitable plant management. Aiming to study agronomic performance (Rubus spp.) under drastic summer pruning a region, response four cultivars (‘BRS Tupy’, ‘Guarani’, ‘Brazos’ ‘Choctaw’) N K fertilization was evaluated during two growing seasons Jundiaí (Brazil). experiment used split-plots randomized complete block design with replicates. plots consisted combinations three rates (75, 150 300 kg·ha–1·year–1) (50, 100 200 kg·ha–1·year–1 K2O) factorial arrangement an additional control treatment without fertilizer application. In subplots, were studied. Considering fruit yield, accumulation phytomass mineral elements, nutrient efficiency use, that showed greater adaptation cultivation area management are ‘Brazos’, ‘BRS Tupy’ ‘Choctaw’, order. An annual application 120 67 kg·ha–1 K2O, respectively, expected be sufficient achieve maximum economic yield.