CRESCIMENTO, SEVERIDADE DE REQUEIMA E PRODUTIVIDADE DE CULTIVARES DE BATATA SOB ADUBAÇÃO ORGÂNICA E MINERAL

Abstract

The choice of organic fertilizer and cultivars to grow potato crops in organic cultivation is determinant for success in this cropping systems. The objective of this study was to quantify the growth, late blight severity (Phytophthora infestans) and yield in potato cultivars managed with organics and minerals fertilizers. It was evaluated the growth of two potato cultivars, IPR Cris and IAC Vitoria, and the severity of late blight and yield parameters, including a third cultivar, Catucha, with four management of fertilization, cattle manure (EB), chicken manure (EA), NPK fertilizer (NPK) and without fertilization (SA). The seeds were planted with 0.80 m between rows and 0.25 m between plants in a randomized block design with three replications in a factorial scheme 2 or 3 x 4 (cultivar x fertilizer). Growth assessments were performed at 15, 30 and 45 days after emergence. Late blight severity evaluations started from the first symptoms in the experiment and followed until all the plots had no leaf area. The final yield evaluation was done after the plant maturation. There was no significant interaction between cultivars and fertilization managements for the growth parameters. The cultivar IAC Vitoria showed higher initial growth, but its development was impaired due to the early loss of leaf area. The management of fertilization with EA and NPK resulted in plants with higher growth than SA management, mainly in relation to leaf area index. The cultivar Catucha showed lower progress of late blight than the other cultivars, allowing the plants of this cultivar to remain for a longer period in the field. The management with EA resulted in plants more resistant to the development of the late blight than the plants managed SA in cultivar IPR Cris. The management with EA resulted in higher total and commercial yield in cultivar Catucha. Cultivar Catucha with EA is the best option for the organic cropping systems of potato in the region.