Adubos de liberação controlada e foliar na produção de mudas de cajueiro-anão "BRS 226"

Abstract

Important advances were promoted in Brazilian cashew with dwarf cashew clones launching and with replacement of seedlings seminal by (grafted plants). In the current cashew seedling production system no fertilization is carried out, however, using technologies such as foliar fertilization and controlled-release fertilizers could ensure high quality seedlings. The aim of this study was to evaluate the effects of controlledrelease and foliar fertilizers application on cashew rootstock formation and on grafted seedlings. Three experiments in a completely randomized design were conducted: the first one evaluated the effect of 3.70 kg m-3 controlled-release fertilizer (CRF) 13-06-16 application at sowing and the effect of 2.5 g L-1 (recommended dose) foliar fertilization (FF) application 30 days after sowing (DAS) on 'CCP 06' rootstock. In the second experiment was tested the effect of CRF application at sowing; FF 30 DAS; CRF after grafting (AG); FF 45 days after grafting (DAG); CRF at sowing + FF 45 DAG and FF30 DAS + FF 45 DAG. In the third experiment was evaluated FF 45 DAG (50% of the recommended dose) + 60 DAG (50% of the recommended dose); FF 60 DAG(recommended dose); FF 45 DAG (recommended dose) + 60 DAG (recommended dose) and FF 80 DAG (recommended dose). Neither that the applications of CRF nor FF promoted positive effects on 'CCP 06' cashew rootstocks development when compared to the control. CRF application after grafting, CRF at sowing + FF 45 DAG; AF 30 DAS + AF 45 DAG; 45 DAG (50% of recommended dose) + 60 DAG (50% of recommended dose) and AF 80 DAG (recommended dose) promoted an increase in total dry matter mass of the grafted seedling 'BRS 226'. It was concluded that the applications of controlled-release and foliar fertilizers did not influence the formation of ‘CCP 06’ rootstock, but promote an increase in BRS 226 cashew seedlings development.