Ecophysiological factors underpinning productivity of Hevea brasiliensis

Abstract

High land productivity is a must for any commercial cultivation including Hevea brasiliensis (rubber). Also, the high demand for natural rubber has placed great pressure on expanding rubber cultivation to new and non-traditional areas. Understanding the ecophysiological principles behind the measures of productivity improvements is vital for wide application of these measures and to assess their sustainability. This review discusses the ecophysiological principles and tools used, along with the measures taken, to address productivity needs in terms of: genotype selection, determination of optimum planting density, and establishment of intercropping systems. Breeding for high yields and selection of suitable genotypes for different growing conditions are a top priority throughout the research history of rubber, however, early selection tools are necessary to reduce the time required for this process. As for any crop, photosynthesis drives the productivity of the rubber crop and, therefore, factors that govern and/or parameters that indicate the efficiency of photosynthetic productivity under field conditions could be used as tools in the selection of Hevea genotypes. Particularly for the early selection of genotypes in breeding programmes, mature crop characteristics which determine crop photosynthesis and productivity, should be linked to juvenile plant characteristics. The spatial and temporal efficiency by which plants acquire growth resources determines the overall productivity of the rubber crop, hence the optimum planting density and suitable crop combinations in intercropping systems. Changes in crop microclimate influence the efficiency of resource capture and thereby can be important for determining planting density and intercrops. Research needs regarding all the above aspects are also discussed.

Profitability analysis for natural rubber (Hevea brasiliensis Muell. Arg.) production in Oaxaca, Mexico

“…The foregoing can be demonstrated with the benefit/ cost relation; in the case of OXHL2.5, its benefit/cost relation is 0.80, in OXHL5 it is 1.01 and in OXH16 it is 0.94. Therefore, it can be said that there is a high probability that the activity becomes less profitable with time and becomes non-viable economically for the natural rubber producers of that region, which would imply their exit from the market, coinciding with the assumptions of Rodrigo (2007) and Aguilar et al (2012).…”

Intercambio gaseoso de plantas jóvenes de Hevea brasiliensis (Will. ex A. Juss.) Müll. Arg. (Euphorbiaceae) en Antioquia, Colombia

“…Sin embargo, debido a que el caucho natural es una especie que tiene un aprovechamiento tardío (entre cinco y siete años), el registro del rendimiento como característica de interés agronómico y económico hace que los procesos se prolonguen, como los programas de mejoramiento genético (Rodrigo, 2007) y la explicación del desempeño de H. brasiliensis en condiciones ambientales adversas o favorables (estabilidad fenotípica e interacción genotipo por ambiente).…”

“…Algunas variables ecofisiológicas como fotosíntesis neta (A), conductividad estomática (g s ) y tasa transpiratoria (E) han sido ampliamente estudiadas, debido a su aplicabilidad en la explicación de los fenómenos de adaptación del caucho natural a las condiciones ambientales (Lambers, Pons, & Chapin, 2008;Nataraja & Jacob, 1999;Nugawela, Long, & Aluthhewage, 1995;Rodrigo, 2007), y otros autores mencionan incluso asociaciones positivas entre estas variables y la producción de biomasa (Nataraja y Jacob, 1999;Samsuddin, 1986;Sobhana, Sethuraj, & Vijayakumar, 1995) y el caucho seco (Samsuddin, Tan, & Yoon, 1987).…”

Redução na produção de látex da seringueira provocada pela infestação de ácaros

“…A biossíntese de látex e, consequentemente, a produção de borracha, é o resultado de uma complexa cadeia de eventos biofísicos, nutricionais e metabólicos, que estão relacionados com fatores diversos, entre eles, a produção e o transporte de fotoassimilados (Cairo, 2007). Como em qualquer cultura, a fotossíntese é fundamental para a produção da seringueira (Rodrigo, 2007) e de forma geral, os pesquisadores têm encontrado uma correlação positiva entre a fotossíntese e o potencial para a produtividade de borracha natural (Oliveira et al, 2008). Assim, é provável que a diminuição da capacidade fotossintética devido à infestação dos ácaros possa resultar em diminuição da produção.…”