‘New’ Technology for improving Cassava Productivity

CASSAVA

Components of ‘New’ Technology for improving Cassava Productivity

By Don McGlashan and Morris Taylor Research and Development Bodles Research Station

Cassava has been regarded as a rugged crop which is tolerant to many pests and diseases, weeds, poor soils and is grown mostly by subsistence farmers. This has contributed to keeping cassava yields in Jamaica at between 9-18 t/ha (4 - 8 ton/ac). While these yields are higher than the world averages of 8.8 t/ha. The potential yield of cassava can be as high as 70 t/ha.

To address the problem of low yields the following production package is recommended.

• Use of improved varieties
• Land preparation
• Planting material selection and treatment
• Weed control Fertilizer application
• Crop Protection

Improved Varieties

Choose varieties which are consistently high producers, matures in 9 -12 months and are tolerant to major pests and diseases.

Land Preparation

Plough to a depth of 3Ocm (12ins.), then harrow. Create ridges to heights of 30-60cm (12ins. - 24ins.). Higher mounds are required in heavy clays where drainage may be a problem. Ridge lands along the contour of the land. Avoid soil loss by erosion.

Planting Material Selection

Selection

• Select cuttings (seeds) from plants that are high yielding and free of diseases.
• Choose mature stems from plants 8 -12 months old.
• Avoid stem portions which are too young or too old.
• Stems from very old plants are often lignified with less food reserves. Root and shoot formation will be delayed.
• Stem cuttings which are too young are susceptible to attack by soil borne pathogens and sucking insects. They also tend to dehydrate quickly.
• Stem cuttings. (seeds) for planting should have at least 4- 6 nodes and should average about 20cm (8ins.) in length.

Seed treatment

• Use a clean sharp machete in seed preparation.
• Treat seeds by dipping in a fungicidal and insecticidal solution for 5-7 minutes.
• Allow to dry.

Seed treatment advantages

1. Disinfectant effect
2. Protectant effect
3. Accelerated sprouting, rooting and growth
4. Longer storage life.

This inexpensive treatment protects seeds from attack by soil-borne pathogens and by surface pests such as mites and mealy-bugs, thus greatly improving the sprouting percentages. When cuttings are treated, yields will increase by more than 25 percent.

Planting

Cassava cuttings may be planted vertically, at an angle or horizontally. Place at least two- thirds of the seed below ground.This will facilitate good root development and prevent seeds from drying out rapidly in case of prolonged drought.

Allow for 12,000 plants/ha (4,840 plants/ac) by placing seeds 0.9m x 0.9m (3ft. x 3ft.) across the field on the prepared ridges.

Time of planting Plant to coincide with the rainy season if no irrigation is available.

Weed Control

Newly planted cassava grows slowly and is vulnerable to weed competition.

Wezds can reduce yields as much as up to 50 percent. It is important to control weeds in the first 3-4 months after planting.

Weeds may be controlled by:

1. Hand weeding
2. Herbicides

Fertilizer

Fertilizer application is optional. Do not follow one crop of cassava after another. This is an important consideration from a nutritional as well as for pest control. If grown in the same area over two (2) seasons fertilizer must be applied.

Harvesting

Cassava varieties mature in 7 - 12 months.

Some signs of maturity

• uniform leaf fall
• uniform colour of leaves from dark green to pale green.
• the thin outer layer of the tubers is easily removed.

For best economic returns cassava should be harvested at 9 - 12 months.