Adubação do cafeeiro com nitrato de potássio via solo e folha, no outono-inverno e primavera-verão: efeitos na atividade da redutase do nitrato, no crescimento das plantas e na produção

Abstract

The objective of this work was to verify the effect of the fertilization of 100g N/year/plant, in three periods (autumn-winter, spring-summer and autumn-winter/spring-summer) and three types of application (leaf, soil and leaf/soil) on the development, production and nitrate reductase activity (NR) on four years old Rubi-MG cultivar. The analysis of type and time of application showed no alteration on NR activity being higher on roots in cold weather and higher on leaves in warmer weather. The same was observed with growth pattern, fast in hot/rain season and slow in dry/cold period. During autumn-winter, applications may be performed on leaf or leaf-soil. These types of fertilization were the most efficient during growth recovering. When the fertilization occurred in both periods, any type may be used. Although, several pulverizations are nonviable, one or more pulverization with KNO3 can efficiently replace soil fertilization.