SPECIAL REPORT: Taking precautions to avoid chronic pests in bid to raise production

Sunday April 14 2019

A researcher from the University of Western

A researcher from the University of Western Australia, Dr Laura Boykin, displays results of cassava diseases to farmers in the field. photos | COURTESY 

Over 800 million people in the world depend on cassava as their staple food, while in Africa the number goes to 300 million people. In Tanzania, cassava is also a staple food being among five common foods.

Cassava have been produced in Tanzania for a long time, however the production has been low. Most of farmers have been harvesting up to 10 tons per acre while the international standard is 25 tons per acre.

In order for a farmer to increase production, good farming practices should be adhered. One of them is soil testing. A farmer must know a favourable soil for cassava growing.

The suitable soil for cassava production shouldn’t be clay type nor being with rocks because it will limit roots to increase size. It shouldn’t also be lowland nor should it be flooded with water, but rather alluvial soil.

Also a farmer should observe if there some chronic pests and diseases in order to take precautions during production.

The best time to plant cassava seedling is from October to March when short rainy season starts up to annual rain.

It will help seedling to grow well by getting enough water.

Seedlings should be selected from a matured stem and it is cut into pieces of 25-30 centimeters depending on the eyes. The cutting should have at least seven eyes.

For agribusiness, the farmer should select short term variety which take up to six months to mature, such like 130, Mkumba, Mkuranga 1, Kipusa, Chereko, Nziva, Kizimbani, F10-30R2 and Pwani.

To avoid diseases, seedling should be prepared by tissue culture. It’s a technique used to clean plants out diseases especially inherently diseases from one generation to another. During plantation, 2/3 of `the cutting should be buried within the soil. Normally cassava cutting are planted into terraces of 1 to 1.5 meters depending on the type the seedling and soil fertility. An acre can take up to 10,000 cuttings.

After planting, the file should be kept clean by removing weeds throughout the season. If weeds would not be removed they can decrease productivity for about 40 per cent.

A farmer can also plant other crops with the cassava farm like legumes such like beans or pea nuts which increases soil nutrients.


The most common cassava disease is s Cassava Mosaic which makes leaves to have yellow spots, makes soft stem and roots fails to store food.

It is commonly affecting farmers in the Sub-Sahara region and it is transmitted by white flies (Bemisia tabacci). If the disease persist a farmer will harvest almost nothing.

Other diseases are caused by fungal, bacterial and oomycete.

Depending on the soil fertility, a farmer can also add fertilizer or composite manure in case of infertility especially lack of nitrogen, potassium and phosphorus.

For short term varieties, yields will be ready after five to six months, while long term could take up to eitht to ten months.