Estudo da adsorção do feromônio rincoforol: aplicação de carvões do tronco do coqueiro e do endocarpo do coco de dendê como dispositivos de liberação prolongada

Abstract

The coconut crop (Cocos nucifera L.) is very developed in Brazil, but this crop suffers from numerous pests, which cause irreparable damage to the coconut tree. Among the main pests, the beetle Rhyncoforus palmarum is the exponent that transmits the nematode responsible for the red ring disease. As a control tool for this pest, currently, the use of pheromones associated with food traps has been shown to be quite efficient in capturing the insect pest. The pheromone used is called Rincophorol and is available in plastic eppendorf. Studies aimed at reducing the consumption of plastic in the handling of pheromones are under development, whose application of the capture agent would be carried out in solid matrices, such as coal. In this context, the present study aimed to evaluate the adsorptive and desorption capacity of activated carbon from the endocarp of palm coconut and coconut tree trunk (not activated) in the incorporation of Rincophorol, carrying out daily mass measurements, being also analyzed the influence of the use of stabilizer together with the pheromone, the charcoal granulometry and the number of holes in the sachet in the release process. To carry out the adsorption of pheromone on charcoal, a complete experimental design 23 was developed in order to investigate the aforementioned parameters, varying the number of holes (5 or 15), granulometry (0.5 mm < Ø < 0.64 mm and Ø > 0.64 mm) and the presence of the stabilizer, resulting in mass loss. In plastic sachets, measuring approximately 6.0 cm in length and 4.0 cm in height, 1.0 g of the studied charcoals were inserted, moistened with 700μL of Rincophorol, which were placed in a handmade support, 3 .0 cm from each other to promote the release of the semiochemical. The system (support + sachets) were kept in a greenhouse to simulate the condition of pheromone release from the field. The characterization of activated carbon from the endocarp of palm coconut was carried out and an analysis of the mass decay was carried out in the first 30 days, since it is in the first month that the greatest release of the pheromone occurs; afterwards, the experiment continued until completing 140 days. After this time, a statistical treatment of the data was carried out, for both coals, in order to identify the favorable condition to promote a controlled release, in addition to analyzing the behavior of mass transfer through mathematical drying models (Lewis and Page). Finally, the feasibility of prolonged dispersion of the pheromone in charcoal, in comparison with eppendorf, was investigated.