Article in Pestology 25(11): 1-10 November 2001
K.V.B.R.Tilak
K.Udaiyan

Bananas and plantains are an important food source for over 100 million people in Sub-Saharan Africa. In the east African highlands and most of the Great Lakes region, bananas are a major staple food and a source of income for over 50 million smallholder farmers. East Africa produces 16.4 million metric tonnes per year – about 20% of the world output. 

However, many biotic and abiotic factors greatly reduce productivity for banana cultivated under traditional African farming systems. For instance, in 2001, an outbreak of banana bacterial wilt (caused by Xanthomonas campestris pv musacearum) broke out in Uganda leaving in its wake a trail of crop destruction and utter misery among affected farms.

The International Institute of Tropical Agriculture (IITA) estimates economic loss due to diseases in Uganda alone to be at a staggering US$ 200 million. AATF is collaborating in a public/private sector partnership project to develop Banana Bacterial Wilt-resistant transgenic bananas from east African preferred germplasm.

striga is a parasitic weed that attacks cereal crops, retarding plant growth, resulting in stunted and withered plants. There are several species of Striga. In cereals, only two species are of economic importance. These are the purple-fl owered Striga hermonthica and redfl owered Striga asiatica. Striga hermonthica is the most destructive. 

Which crops are susceptible to Striga infestation? 

Striga infests cereal crops such as maize, millet, sorghum, upland rice and Napier fields throughout Sub-Saharan Africa. 

How does Striga damage the cereal crop? 

Striga attaches itself to the roots of host plants and siphons the nutrients and water intended for plant growth. This stunts and discolours the plant, finally causing it to wither resulting in grain yield losses. Striga is most damaging to the crop before emerging from the soil. Early signs of Striga attacks are folded leaves and wilting even where there is sufficient soil moisture. Some crops act as trap crops or false hosts. They stimulate the Striga seeds to germinate. However, the Striga seedling cannot successfully attach to the trap crops in order to feed and hence it dies. 

What are the other names of Striga? 

Striga is also known as witch weed because of the twisted discoloured growth of affected plants. In west Kenya, farmers’ refer to it as Kayongo (Luo), Oluyongo (Luhya), and Imoto (Teso). In Tanzania it is known as Kiduha in Kiswahili.