Rubber tree exploitation systems utilized in Asian clones Prang Besar, in the West of São Paulo, Brazil

O objetivo deste trabalho foi avaliar o desempenho produtivo e os aspectos fisiológicos e econômicos de quatro clones asiáticos Prang Besar de seringueira [Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg.], sob diferentes sistemas de sangria. O experimento foi instalado na Fazenda Santa Gilda, Município de Guararapes, SP, em delineamento de blocos ao acaso, com parcelas subdivididas no tempo. Os tratamentos principais foram os clones PB 260, PB 235, PB 330 e PB 217, submetidos a nove sistemas de sangria: ½S d/3.ET 2,5% 8/y; ½S d/3.ET 5% 8/y; ½S d/4.ET 2,5% 8/y; ½S d/4.ET 5% 8/y; ½S d/5.ET 2,5% 8/y; ½S d/5.ET 5% 8/y; ½S d/7.ET 2,5% 8/y; ½S d/7.ET 5% 8/y e ½S d/2 (testemunha). As variáveis avaliadas foram: perímetro do caule, produção de borracha seca, secamento do painel; foi avaliada, também, a viabilidade econômica. Os resultados mostram a superioridade econômica dos sistemas ½S d/5.ET 2,5% 8/y e ½S d/7.ET 5% 8/y, para o clone PB 260; ½S d/7.ET 2,5% 8/y para o clone PB 235; e ½S d/3.ET 2,5% 8/y e ½S d/3.ET 5% 8/y, para os clones PB 330 e PB 217, comparados com a testemunha. A menor incidência de secamento do painel foi observada no sistema ½S d/7.ET 5% 8/y, exceto para o clone PB 235.The objective of this work was to evaluate the yield performance, and economic and physiologic aspects of four Asian clones Prang Besar of rubber tree [Hevea brasiliensis (Willd. ex A. Juss.) Muell. Arg.], in different tapping systems. The trial was placed at Santa Gilda farm, City of Guararapes, São Paulo State, Brazil, in a randomized block design with split-plot in time. The main treatments were PB 260, PB 235, PB 330 and PB 217 clones submitted to nine systems of tapping: ½S d/3.ET 2.5% 8/y; ½S d/3.ET 5% 8/y; ½S d/4.ET 2.5% 8/y; ½S d/4.ET 5% 8/y; ½S d/5.ET 2.5% 8/y; ½S d/5.ET 5% 8/y; ½S d/7.ET 2.5% 8/y; ½S d/7.ET 5% 8/y and ½S d/2 (check). The variables evaluated were: girth increment, dry rubber production, brown bast; it was also evaluated the economic viability. Results indicated the economical superiority of the ½S d/5.ET 2.5% 8/y and ½S d/7.ET 5% 8/y systems in PB 260 clone; ½S d/7.ET 2.5% 8/y system in PB 235 clone; and ½S d/3.ET 2.5% 8/y and ½S d/3.ET 5% 8/y in PB 330 and PB 217 clones, compared with the check. The smallest incidence of panel desiccation was observed in ½S d/7.ET 5% 8/y system, except for PB 235 clone