Cocoa: Shade Management Systems

The subject of shade management systems is a rather complex issue. A multitude of shade trees and combinations are possible. Usually a combination of permanent and temporary shade trees are planted to provide shade for cocoa. Common choices are:-

Temporary shade

Existing shade		Planted shade
Coconuts		Gliricidia maculata
Rubber		Cajanus cajan
Oil Palms		Leucaena glauca
Jungle		Crotalaria anagyroides
Belukar		Moghania macrophylla
		Albizzia falcate
		Teprosia vogelli
		Sesbania punctata
Permanent shade
Coconuts
Oil palms
Gliricidia maculata
Parkia speciosa
Albizzia falcate
Fruit trees

Currently the preferred shade trees are coconut, Gliricidia, Leucaena and Cajanus.

The choice of a suitable shade system basically depends on the climatic factors (rainfall and soil moisture principally), soil fertility, adequacy of time for shade preparation, presence or absence of existing shade, sufficiency and efficiency of management inputs and objectives of the planting.

Shade management system and practices followed should be designed to :-

• to attain the shade levels required quickly and easily.
• adjust the shade levels to that required easily.
• maintain shade levels as long as required easily.
• not obstruct or hinder other management work in the area.
• allow for shade requirements of cocoa at maturity.

The key elements involved in choice of a shade management system are therefore:-

• time available.
• shade requirement of cocoa planting.
• shade requirement of cocoa at maturity.
• shade material availability.
• labour and management skills available.
• maintenance and management requirements of the shade.
• objectives of the planting i.e. cocoa mono-culture, cocoa/coconuts, etc..

Clean cleared systems

For a clean cleared system where fast growing shade trees have to be planted to provide shade for cocoa, it is usually necessary to plant the shade trees about a year ahead of cocoa. A combination of Gliricidia and Cajanus can provide adequate shade in 6-7 months (Wills, 1980). For the novices, however, it is prudent to plant the shade trees about a year ahead of cocoa to cater for adverse weather conditions and also for other unforeseen problems such as planting failures, pest and disease attach etc.

A shade management system for a cocoa-coconut intercropping system using Gliricidia as temporary shade and MAWA as minimum permanent shade is briefly outlined below as an example:-
Cocoa-coconut intercropping using Gliricidia as temporary shade and MAWA as minimum permanent shade

Planting schedule/pattern

Plant MAWA at 12m x 12m (69 palms/ha) and Gliricidia maculata at 1.5 m x 3.0 m (1800 trees/ha) about a year ahead of cocoa. Gliricidia should not be planted within 3 m from the coconuts. Cocoa at 3m x 3m (1042 trees/ha). The layout of the planting system is illustrated in Figure 2. Should Gliricidia grow poorly, supplementary shade trees such as Cajanus cajan should be planted in pockets at 1.5 m apart along the Gliricidia rows as a stop gap measure.

Gliricidia shade thinning

The above thinning schedule must be considered together with the shade levels suggested for cocoa in Table 4. Thinning should preferably be carried out during the early part of the wet season when the Gliricidia has refoliated.

Fig. 2 Cocoa/Coconut intercropping MAWA as minimum economic shade

Scale :_ 1cm : 3m

Note:- MAWA and Gliricidia planted one year ahead of cocoa

Under existing shade systems

Another category of planting system is to retain some of the existing shade trees as temporary shades such as planting cocoa under thinned jungle, old oil palm and old rubber trees. The retained temporary shade trees to be removed completely in stages as the cocoa matures and as the planted shade trees (usually a combination of MAWA, Gliricidia and Leucaena) could provide shade for cocoa.

Such system usually entails the adjustment of the existing shade to a suitable level prior to planting cocoa. Usually, as much big trees as possible are removed and the desired intermediate and permanent shade trees are planted prior to planting cocoa.

The main advantage of this system is that it obviates the need to establish temporary shade and hence saves time and probably initial expenditure. However, there is a major drawback in the system. The falling timber from the retained oil palm, jungle/rubber trees when they are poisoned can cause considerable damage to the under planted cocoa if too many big trees are retained. The amount of work and costs incurred in rehabilitating the damage cocoa and clearing/staking the fallen timber can be considerable. This is particularly true for planting under thinned jungle and old rubber.

An example of under thinned jungle system using Gliricidia/Leucaena as intermediate shade and MAWA as permanent shade is outlined below and overleaf in chronological order:-

Planting cocoa under thinned jungle using Gliricidia/Leucaena as intermediate shade and MAWA as final permanent shade

1. under-brushing
2. fell all jungle trees with diameter bigger than 15-20 cm
3. clean clear 120 cm wide rentices for planting cocoa and shade trees. Distance between rentices i.e. between cocoa rows at 3.5 m apart.
4. Selectively fell the bigger of the remaining jungle trees in areas where the jungle tree shade is still too dense.
5. Blanket spray the area
6. Plant a mixture of Gliricidia and Leucaena alternately at 3.5 m x 5.0 m (571 trees/ha)
7. Plant MAWA coconuts at 14m x 10m (71 palms/ha)
8. Plant cocoa at 3.5 m x 2.5 m (1142 bushes/ha)
9. Poison all the remaining jungle trees in stages within one year after the cocoa has been planted.
10. Poison all the intermediate shade gradually as the cocoa matures and when MAWA is able to provide shade for cocoa.

As for the other systems, shade thinning must be considered together with the shade requirements of cocoa outlined in Table 4.

Reference 
Ooi L.H. and Chew P.S. 1985. Some important agronomic and agricultural practices in cocoa estates. TDMB Plantation Management Seminar, Kuala Trengganu

Note: The full list of references quoted in this article is available from the above paper.