Farmers hopeful as scientists close to finding maize lethal necrosis resistant seeds

maize diseaseScientists are on verge of finding a Maize lethal necrosis (MNL) resistant seed, a move that will see Kenya save 10 per cent of national maize production per year lost to the deadly virus that first surfaced in Kenya in 2011 according to the International Maize and Wheat Improvement Center (CIMMYT)

They are investigating 117 of 119 varieties which when artificially exposed to MLN were susceptible. They also identified some promising inbred lines and pre-commercial hybrids with resistance to MLN. The priority now is for these to be further developed into varieties that can be multiplied and commercialized by the east African seed industry.

This follows an international stakeholder conference held in Nairobi in mid May that brought together Scientists, policymakers and seed companies birthing numerous strategies that included practical solutions to strengthening MLN diagnostics and surveillance capacity. Other solutions included MLN-free seed production and safe exchange to non-endemic areas, which is a key step in controlling further spread and impact of MLN in sub-Saharan Africa.

Stakeholders also suggested crop rotation at least two months of maize free period, timely planting, pruning of infected crops, planting of certified seeds and crop diversifications as some of appropriate agronomic practices that reduce disease incidence and severity.


‘’We have a responsibility to work together and control the spread of this virus, ‘said Dr. Prasanna Boddupalli, Director of CIMMYT. He urged stakeholders to continue working   hard in developing maize varieties that can effectively resist the MLN viruses. He lamented that the virus which has spread in Kenya will soon affect her neighbors

“The maize lethal necrosis disease has caused losses worth millions of dollars for farmers and seed companies in the affected regions in sub-Saharan Africa, where maize is both a food and cash crop. It is also affects food consumers since farmers have no maize crop to release to the market. This therefore calls for urgent need to find a sustainable and widely applicable solution as key stakeholders,” said Dr. Agnes Kalibata, President of Alliance for a Green Revolution in Africa (AGRA).
Maize lethal necrosis is a result of a combination of two viruses, the Maize Chlorotic Mottle and any of the cereal viruses in the Potyviridae group, like the Sugarcane Mosaic Virus, Wheat Streak Mosaic Virus or Maize Dwarf Mosaic Virus .MNL is also referred to as Corn Lethal Necrosis (CLN).

Some of notable symptoms of this virus in maize include mild severe mottling on the leaves, usually starting from the base of young leaves in the whorl and extending upwards towards the leaf tips. Drying of thee leaf margins that progress to the mid-rib and eventually the entire leaf can also signify MNL attack. Necrosis (drying) of young leaves in the whorl before expansion, leading to a symptom known as “dead heart” and eventually plant death.