A centralised maize lethal necrosis disease screening facility established in Naivasha five years ago has released 15 disease-resistant hybrid maize varieties in Kenya, Tanzania and Uganda.

After screening more than 150,000 maize germplasms, the team validated genomic regions in maize that confer resistance to maize lethal necrosis disease (MLND). They then transferred the resistant genes to 30 varieties adapted for Africa, using molecular marker assisted breeding.

The process, which would take up to seven years with conventional breeding, took three years. MLND is a viral maize disease caused by co-infection with maize chlorotic mottle virus (MCMV) and other viruses such as the sugarcane mosaic virus.

It causes yield losses of up to 100 per cent, threatening food security in Kenya, Uganda, Tanzania and other endemic countries.

The MLND Screening Facility in Naivasha was established by the International Maize and Wheat Improvement Center (CIMMYT) in partnership with the Kenya Agriculture and Livestock Research Organisation (Kalro).

While addressing participants at the CIMMYT Annual Partners Field Day last week, Director of the CIMMYT Global Maize Programme Dr Prasanna Boddupalli said that there has been no further spread of the disease in southern Africa and West Africa in the last four years.

MLND resistant varieties will cushion farmers against massive losses attributed to the disease not just in Kenya, but all over Africa with the exception of Southern Africa.

According to the 2014 Survey on MLND by Kalro about 78,000 hectares of maize crop were affected by MLND leading to a loss of more than 11 million bags.

Dr Boddupalli said that several seed companies are implementing voluntary maize chlorotic mottle virus control programmes and standard operational procedures to minimise the risk of seed transmission.

He warned that MLND still persists in the region, though the incidence has reduced in some countries like Kenya, Rwanda and Uganda. However, MLND is still high in areas with continuous maize cropping. It is also present in some seed production fields.

With the adoption of resistant varieties, it is hoped that the disease will soon be eliminated.

The disease can destroy entire harvests of maize and is thus a severe food security risk in East Africa, where it is prevalent. It also threatens the livelihoods of millions of farmers.

Trade linkages between eastern and southern Africa also exposes the latter to the risk of ‘importing’ the disease.