The proposed project aims to address the problems associated with the lack of income produced after replanting of rubber on smallholdings. Plantation tree crops, such as rubber, play an important role in income generation for smallholder farmers in the humid and sub-humid tropics. No return on investment is produced, however, during the first five to six years after replanting, when trees are too young to be tapped. This poses significant financial problems since, given the limited land available, smallholders are unable to adopt a replanting cycle as is traditionally practised on estate lands. Intercropping provides the most practicable means available to smallholders for improving income generation on immature plantations.

The needs of both the land-poor and landless could be met from the adoption of intercropping on immature rubber lands through several means; (1) intercropping could replace the income lost from rubber during the first 5-6 years after planting, (2) intercropping would increase land use efficiency in situations where limited land availability is a key factor generating poverty and (3) intercropping could raise the living standards of the land-poor through improved access to land on a contractual basis and greater opportunities for wage labour.

Physiological relationship between plant growth/development and environmental variables (CO2, light, wind, temperature and water) understood in target crops and improve cropping strategies developed and promoted.

• An analysis of the agronomic and socio-cultural factors influencing farming practice on smallholder rubber lands.
• Key biological processes determining intercrop performance on-farm understood.
• Strategies for working with farmers and extension staff to improve cropping practice on immature rubber lands developed.
• Recommendations for intercropping that best meet the needs of smallholder rubber growers produced.