Cocoa Fertilizer Applications / Manuring

Nursery Stage

The objective is to have seedling with good leaf area and encourage root development. Soil used for polybags should preferably be sandy clay loam but using other potting material such as recycled organic material is also applicable. The soil is thoroughly mixed with 10gm Ground Rock Phosphate (GRP) and 10gm Ground Magnesium Limestone (GML) for a size 15x20 cm polybags. As the size of the polybags increase, the amount also increase about 10gm of each type of fertilizer. Watering is essential to maintain the soil in a moist condition but waterlogging should be avoided by all means. Seedlings will respond to fertilizers applied at ‘little-and-often’ rate. Upon emerging of the leaves at about 2-3 weeks old, weekly spraying of foliar fertilizer is recommended switching to suitable compound fertilizer after the 3^rd month applying at forthnightly interval.

Immature Stage – 1 to 3 years old plants

Soil condition during planting is important to ensure good growth. Soil pH value preferably be about 4.5 and moist but not waterlogged. In its initial growth, cocoa plants need overhead shade of 80 – 90 % and inter-planting under tall plants such as coconut, pili, banana and mahogany is suitable to achieve this condition. But using artificial temporary shade is also being done by planters who preferred to plant cocoa in a monoculture cultivation of zero-shade condition. The purpose of routine fertilizer application in this immature stage is to ensure vigorous growth in root and canopy formation to achieve an early crop production.

Mature Stage – above 3 years old plants

Adequate quantities of fertilizer should be applied to coincide with the onset of periodic leaf flushes and the peak seasonal cropping months. Leaf growth following the initiation of a flush consumes large quantities of nutrients, lowering the nutrient status for sometime until photosynthesis by the new leaves restores the carbohydrates used for their growth. Adequate supply of nutrients is therefore essential to maintain nutrient levels of older trees. This is an important consideration for young trees whose nutrient reserves are much smaller. In the case of leaf flushing, N should be well sustained whilst following successful formation of the cherelles, K is important. The effect of flushing on cherelle wilt (aborting of new fruitlets) can be associated with the temporary depletion of nutrient reserves by leaf growth which is related to the Leaf Area Index (LAI) factor. Trees with low LAI due to drought, pruning works, insect damage, etc tend to flush more vigorously than trees with good canopy.

The two nutrients required in largest amounts are K and N with regard with yield / crop production. Nutrient requirements appear to increase significantly after the pods have passed the critical period of cherelle wilt.