Nutrição do coqueiro e controle biológico no manejo do ácaro Aceria guerreronis Keifer (Acari: Eriophyidae)

Abstract

Brazil has about 280 thousand ha cultivated with coconut trees (Cocos nucifera L.), in the whole national territory, with production of about two billion fruits. There are several factors that limit the productivity of the coconut, such as arthropod-pests, especially the Aceria guerreronis Keifer necrosis mite (Acari: Eriophyidae). In this context, the susceptibility of crops to pests can be affected by the type of fertilization used "Theory of Trophibiosis". Thus, the objective of this work was to study the effect of different types of manure compared to the fertilization in relation to the attack of the A. guerreronis mite and its biological control by Proctolaelaps bickleyi Bram. The study was conducted in commercial coconut plantation, dwarf green variety in the period of 15 months. The treatments applied were: formulated chemical fertilizer, recommended chemical fertilization + laying hen, recommended chemical fertilization + bovine manure, recommended chemical fertilization + goat manure, laying hen, cattle manure, goat manure, chemical manure + Goat, chicken manure + bovine manure + goat manure. The means of mites present according to the treatment were compared by the Tukey test (<0.05). In a second moment, P. bickleyi was released in 0, 50, 75 and 90 individuals per plant, where a regression analysis was performed to observe the mean of the pest mite. It was observed in the results that for leaf 14 the chemical fertilizer + goat had the lowest mean of necrotic mites, in the control the highest average mites were found, for leaf 18 the lowest average was Chicken + Bovine + Goat and the highest in the control. The necrotic mite population as well as the productivity of the coconut crop varied according to the fertilizers that were applied. In the predation tests for the fruits of leaves 14 and 15 there was a decrease in the necrotic mite population, mainly for the larger numbers of released predators. Coconut fertilization decreases the necrotic mite population in coconut. The P. bickleyi mite decreases the necrotic mite population in the fruits of leaves 14 and 15.