Maize virus progress

This article showed how maize streak virus-resistant maize could reduce crop losses.

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After several years of research into maize streak, a medium-season yellow dent hybrid that is resistant to this disease has been entered for registration.

“This follows government trials of resistant cultivars during the 1989/90 season,” says Mike Barrow, a researcher with the Pioneer Seed Company in KwaZulu-Natal.

He points out that several maize-streak virus (MSV)-resistant inbreds and populations have recently been released to the private sector by the Department of Agriculture in South Africa. However, so far no MSV-resistant hybrids have been registered for sale by any seed company in Southern Africa.

The development of maize germplasm that is resistant to MSV has been the goal of several breeding programmes in Africa for a long time. The disease occurs in all African countries south of the Sahara.

Researchers in Ibadan, Nigeria, have been at the forefront of this research. Recently they released several resistant populations and inbreds.

Following research in Zimbabwe, MSV-resistant germplasm has been developed, but as yet no material has been released.

Barrow says that in South Africa, SA 31, the first hybrid specifically developed as MSV-resistant, showed good tolerance to the disease. However, this hybrid was soon superseded by susceptible, but more adapted higher-yielding hybrids.

Another yellow hybrid, SA 34, was released in 1975 after extensive testing, but suffered a similar fate to SA 31.