Phosphorus is vital for the growth processes of cocoa trees but only a small quantity is required. In most soils, incorporation of phosphate in planting holes gives a significant improvement in early growth.
One reference suggests that cocoa growing soils must have certain anionic and cationic balances, including:
'The optimum total nitrogen/total phosphorus ratio should be close to 1.5, with the assimilable phosphorus content being at least equal to 180ppm of P or 0,229 per thousand of P2O5.'
Another reference estimates the phosphorus requirements of cocoa plants (based on 1,075 trees per hectare) as follows:
[TABLE NEEDS ADDING]
Stage of plant development Range of age of plants (months) Average P requirement in kg per hectare
Seedling 5-12 0.6
Immature 28 14
First year production 39 23
Mature 50-87 48
Phosphorus deficient plants show signs of stunted growth. The mature leaves are paler at the tips and margins which is followed by tip and marginal scorch. Young leaves are reduced in size, often showing interveinal pallor, and are at an acute angle with the stem.
K.C. Willson. Coffee, Cocoa and Tea. Crop Production Science in Horticulture No 8. CABI Publishing, 1999
G. Mossu. Cocoa. The Tropical Agriculturist. Macmillan press, 1992
G.A.R. Wood and R.A. Lass. Cocoa. 4th edition. Longman, 1985
International Cocoa Organization
1-19 New Oxford Street
London WC1A 1NU
Tel: +44 (0)20 7400 5050
Fax: +44 (0)20 7421 5500
The ICCO International Cocoa Agreement is available to download in Acrobat PDF format.
The procedures for becoming a member of the International Cocoa Organization are provided in Articles 52 to 57 of the International Cocoa Agreement, 2010.