If at all needed, the demand of shaded cocoa for fertilizer applications is consider-ably lower than that of unshaded cocoa. Hence, in organic agriculture which does not permit the application of synthetic fer-tilizers the cultivation of cocoa under shade is essential. By promoting the turnover of organic ma-terial within the plantation soil fertility can generally be maintained for successful
organic cocoa production. Regular pru-ning of trees and maintenance of a multi-tiered, diverse and densely populated agroecosystem is generally sufficient for profitable cocoa production. In addition to this and as mentioned above, it is essen-tial to return the (composted) cocoa pods to the plantation after removing the beans.
Through mycorrhiza-symbiosis many palm varieties are in a position to actively break down phosphor and other nutrients. In addition mycorrhiza fungi are capable of binding heavy metals in soil, so that their uptake through cocoa is reduced. In order to maintain and enhance soil ferti-lity it is indispensable to achieve as high an energy turnover in the soil as possible.
Ground covers and other often recom-mended mulching methods are not suffi-cient or too labour intensive. The lignin composition in the organic material app- lied is also of major importance. The deci-sive factor is a balanced ratio of old wood to younger branches, each of which con-tain different lignin components in their structure. Apart from supplying the requi- red energy to the soil rganisms the lignin is primarily a substratum for soil-borne fungi (especially basidiomycetes) which are of elementary importance to the faunal food chain.
Most infestations with pests and diseases have the following causes:
• Ignoring the succession sequences of forest systems. Having originated in the primary forest, cocoa can well en-dure old primary forest tree species as shade trees but not old secondary trees.
• Cultivation of cocoa monocultures with a small number of shade trees and species (in conventional cocoa produc- tion only 25 to 40 trees per hectare of mostly the same species are recom-mended).
Unsuitable locations (waterlogged, too dry, insufficient root layer).
• Degenerated and poor soils, lacking organic matter.
• Too dense spacings of plant species that belong to the same guild in the system.
• Unsuitable shade management.
• Deficiencies in hygiene: diseased pods, branches and leaves must be remo-ved.
• Unsuitable harvest practices: harve-sting must be carried out every 15 days.
Avoiding the above constraints means preventing pests and diseases.
Lack of air, excess moisture as well as physical disorders of the cocoa plant (in-adequate nutrition) often cause fungal di-seases. In many cases effective and su-stainable control can only be achieved
through improvement of the entire planta-tion system, especially shade manage-ment. Possibilities for this are either to drastically cut back the trees and to bring in suitable companion plant species or to coppice the trees to about 40 cm and a subsequent new formation in association with selected shade trees, food crops and cover crops.