Desempenho de clones de copa e painel de seringueira no sudoeste do Estado do Mato Grosso

Abstract

Resumo -O objetivo deste trabalho foi avaliar o desempenho de 12 combinações de três clones de painel (PB 311, PB 314 e RRIM 600) com quatro clones de copa (F 4512, MDF 180, IAN 6158 e IAN 6543) de seringueira cultivados no sudoeste do Estado do Mato Grosso. Utilizou-se o delineamento experimental de blocos ao acaso, com quatro repetições. Foram avaliados: produção de borracha seca, percentagem de plantas aptas à sangria, secamento de painel, estado nutricional, teor de borracha seca, plasticidade Wallace (P 0 e P 30 ), índice de retenção de plasticidade e viscosidade Mooney. As combinações das copas IAN 6543 e MDF 180 com os painéis PB 311, RRIM 600 e PB 314 apresentaram estado nutricional adequado, com produtividade de borracha seca acima de 1,41 Mg ha -1 por ano. O clone de copa IAN 6158 propiciou, em oito anos, as maiores quantidades de plantas aptas à sangria. As combinações painel/copa apresentaram baixa incidência de secamento de painel, exceto PB 311 x IAN 6158. As borrachas das 12 combinações painel/copa apresentam boa resistência à degradação térmica e alta retenção de plasticidade.Termos para indexação: Hevea, estado nutricional, plasticidade, produção de borracha seca, secamento de painel, viscosidade. Performance of rubber tree crown and panel clones in the southwest of the state of Mato Grosso, BrazilAbstract -The objective of this work was to evaluate the performance of 12 combinations of three rubber tree panel clones (PB 311, PB 314, and RRIM 600) and four crown clones (F 4512, MDF 180, IAN 6158, and IAN 6543) grown in the southwest of the state of Mato Grosso, Brazil. A randomized complete block design was used, with four replicates. The following were evaluated: dry rubber yield, percentage of tappable trees, tapping panel dryness, nutritional status, dry rubber content, Wallace plasticity (P 0 and P 30 ), plasticity retention index, and Mooney viscosity. The combinations of the crowns IAN 6543 and MDF 180 with the panels PB 311, RRIM 600, and PB 314 showed adequate nutritional status, with dry rubber yield greater than 1.41 Mg ha -1 per year. The crown clone IAN 6158 provided, over eight years, the highest number of plants suitable for tapping. The panel/crown combinations showed low incidence of tapping panel dryness, except PB 311 x IAN 6158. The rubber of the 12 panel/crown combinations shows good resistance to thermal degradation and high plasticity retention.

Avaliação de clones de seringueira para a região noroeste do Estado de São Paulo

“…Os coeficientes de variação apresentam níveis entre baixo e médio, segundo a classificação de Gomes (2009), com os valores mínimos e máximos variando entre 9,2 e 18,7%, respectivamente. Estes valores, para esta variável, nesta cultura, estão dentro dos limites observados em outros trabalhos, como os de Costa et al (2008), Gonçalves et al (2011) e Moraes et al (2013).…”

Does a graft located in the canopy of a rubber tree affect the morphologies of cells in the adjacent wood?

“…The proliferation of the fungus causing the "South American leaf blight" (Microcyclus ulei (P. Henn) v. Arx) in the areas of naturally occurring rubber trees motivated the double-grafting development, that is, formed by three distinct genetic materials, by means of the double-grafting technique (Moraes et al 2013). The doublegrafting technique consists of initially performing a basal grafting using a high productivity latex clone (panel clone), from which bleeding panels (for latex extraction) will be established, and a material of broad genetic base, originating from seeds, as rootstock.…”

“…Thus, it was sought to gather in the same material, high productivity aspects of latex and the resistance/tolerance to the South American leaf blight. The research with double-grafted rubber trees were directed to the performance evaluation of these trees in terms of vigor, growth, and the grafting success, aiming to select clones compatible among themselves (Miranda 2000;Moraes 2000;Moraes and Moraes 2004;Moraes et al 2011Moraes et al , 2013. However, the effect of canopy grafting on the anatomical structure of the panel clone has not been addressed in the literature, justifying the relevance of this study.…”