|Better Farming Series 16. Roots and Tubers (FAO, 1977, 58 p.)|
|How to grow cassava|
CONTROL OF WEEDS
Weed when the cassava plants are 20 to 25 centimetres high, that is, 3 or 4 weeks after planting.
Weed a second time 1 or 2 months after the first. Earth up the plants at the same time; this greatly helps the formation or tubers, and prevents the wind from blowing the plants down.
After this, the cassava plants are big enough to prevent weeds from growing.
When rain spoils the mounds, they must be remade.
When the soil of the mounds gets too hard, break it up with a hoe, so that water and air can get in to nourish the roots.
CONTROL OF DISEASES
Cassava is often attacked by what is called mosaic disease.
Leaves of plants attacked by mosaic look as though crumpled, and show light spots. If the attack is serious, yields are sharply reduced.
Means of controlling mosaic disease are not yet known. To avoid it, do not take cuttings from plants attacked by the disease.
Choose varieties of cassava that have been bred for resistance to the disease.
To prevent mosaic spreading in a region, burn all the plants attacked by the disease.
Rot damages the roots, especially after 10 months of leafy growth.
Rot often occurs when the cassava field has been flooded for several days. The tubers turn soft and give off an unpleasant smell; they are no longer any good for human or animal food. This means a big loss to the farmer.
To avoid rot, do not plant cassava in a place that is often flooded.
If a cassava field is flooded after heavy rain when the tubers are already ripe, you must get the cassava out of the ground very quickly, before it starts to rot.
CONTROL OF PESTS
Agoutis, rats and rabbits are the chief rodents that may cause great damage in a field of cassava. These animals eat the stems, the young shoots, and especially the roots.
- Wild boars, pigs and other animals
Other animals such as the wild boar and the pig are equally damaging to cassava.
They are very fond of it, and with their powerful snouts they push over the plants and dig up large quantities of roots.
Control all these animals by putting poison in the fields, by laying traps, or by digging deep ditches round the cassava plantations.
- In very dry regions, when cassava is planted a long time before the rains, termites eat the cuttings.
To avoid this damage, wait for the rainy season before planting,
Or you can dip the cuttings in insecticide just before planting them.
- Thrips and certain other insects feed on sap by piercing the stems and leaves of cassava. Other insects eat the leaves and the young shoots. When they come in large numbers they may cause great damage. They are controlled with insecticides such as BHC.
- Red spiders are tiny red creatures no longer than 0.5 millimetre.
Large numbers of them live on the lower surface of cassava leaves. The same red spiders attack castor oil, cotton and rubber plants. They feed on the sap of the plant by piercing the leaves. The leaves attacked get brown spots on the underside. The plants attacked do not grow well, and do not yield much cassava.
To control red spiders, the plants may be sprayed with soapy water and nicotine, with rotenone, white oil, etc.
When diseases, animals and insects cause serious damage, you should quickly inform me agricultural extension officer. He will tell you what to do to control diseases effectively or to get rid of pests.