STIMULATION OF LATEX PRODUCTION IN SERINGUEIRA (HEVEA BRASILIENSIS L.) WITH ETRHEL DOSES

ABSTRACT The use of the Ethrel® stimulant on rubber cultivation has become essential to ensure greater rubber production. When applied on the cut of the tree, this stimulant releases the ethylene gas that causes an increase of the exudation period of the latex flow. Dilutions and applications should be performed correctly so that they do not cause tapping panel dryness, which would leave the plant unproductive for a long time. Thus, the objective of this study was to evaluate the effects of increasing doses of ethrel on tapping panel dryness and rubber production of rubber tree clones. Three experiments were conducted using a randomized block design with four treatments (ethrel doses) and three replicates. The clones used were RRIM600, PR255 and PB217 submitted to doses of the stimulant Ethrel 0%, 2.5%, 3.3% and 5% with an interval of application of 30 days. The d/7 bleeding system was used. The productive performance was evaluated monthly and the total of plants with tapping panel dryness at the end of the work. All clones presented a linear positive response to increasing doses. The dose of ethrel 5% favors higher rubber yields in the three evaluated clones, but is associated with high percentage of drying. Thus, it was concluded that the production of rubber is affected positively with the increase of ethrel doses, but this increase causes a higher incidence of panel drying. Thus, it is recommended to use the ethrel 2.5% dose so the production is guaranteed without causing the tapping panel dryness. RESUMO O emprego do estimulante Ethrel® na cultura da seringueira tornou-se essencial para garantir maiores produções de borracha. Ao ser aplicado no local do corte da árvore, esse estimulante libera o gás etileno que provoca o aumento do período de exsudação do fluxo do látex. As diluições e aplicações devem ser realizadas de forma correta para que não provoquem secamento nos painéis, o que deixaria a planta improdutiva por longo tempo. Dessa forma, objetivou-se avaliar os efeitos de doses crescentes de ethrel no secamento de painel e na produção de borracha de clones de seringueira. Conduziu-se três experimentos utilizando-se o delineamento em blocos casualizados com quatro tratamentos (doses de ethrel) e três repetições. Os clones utilizados foram RRIM600, PR255 e PB217 submetidos às doses do estimulante Ethrel 0%, 2,5%, 3,3% e 5% com intervalo de aplicação de 30 dias. Utilizou-se o sistema de sangria d/7. Foram avaliados o desempenho produtivo mensalment