SUBSTITUIÇÃO SUSTENTÁVEL DE ERITRINA POR SERINGUEIRA EM SAF DE CACAUEIRO

Abstract

Excessive shading provided by Erythrina species to cacao (Theobroma cacao), still observed in south of Bahia, Brazil is among the main factors of the low yield of productive and resistant to witches' broom (Moniliophthora perniciosa) by clones used in the renovation of crops formed with the cacao-Erythrina system. Baseb on this perception and to modernize the farming system of this important cocoa producing region, it is proposed to replace Erythrina trees for rubber trees (Hevea brasiliensis). This specie is considered a component suitable for use in multifunctional agroforestry systems (AFS), and has high economic value, adapted to the local growing conditions, efficient as CO2 saquestration besides provides the cacao trees with quality shading, because the easy handling of the canopy architecture. It is a new regional planting scheme, which provides sustainability to the cacao and rubber agribusinesses and recovers the productivity of large areas of cacao trees attacked by witches' broom while significantly expanding the area planted with rubber trees. All at a lower cost without the need to clear primary forests of the Atlantic Forest and also without causing changes to the soil characteristics of the previous system of land use (cacao-Erythrina), maintaining the natural mechanisms of nutrient recycling. Thereby, it expected higher productivity of these rubber tree plantations due to the use of productive clones, resistant and with crown characteristics suitable for planting in AFS, besides being planted in fertile soils and with better management practices. Therefore, the actual process of introducing rubber requires minor adjustments regarding the arrangement, spacing, density and planting orientation, seeking better spatial distribution among plants. Well structured, this system decreases the effects of competition between the associated crops for water, nutrients, space and, mainly, light. Furthermore, favors the natural weed control, the nutrient recycling and the residual share of exogenous fertilizers. However, to minimize the operating cost of deploying and succeed in the replacement, it should be prioritized productive cacao crops, established in deep soils, without physical handicaps and flat or gently undulating topography. The results of initial studies are promising and show that the annual growth rates of rubber trees were not affected by the competition, even when implanted in severely restrict light conditions, beginning the entry into tapping with just over six years old. Further, indicates that the proposed system is viable not only from an ecological point of view but also social and economic, due to fixation of rural labor and creation of employment and income. Therefore, it is of great strategic potential for sustainable rural development in the cacao producing regions of Bahia.