Seed certification as a means of curbing emerging diseases: A case study of Maize Lethal Necrosis (MLN) in Kenya

Abstract

Maize lethal necrosis (MLN) is an important constraint in maize production in sub-Sahara Africa that threatens food security and poses challenge in trade. It was first reported in Kenya in 2011 and has since spread to other countries in the region. In Kenya, the disease is caused by a combination of Sugarcane mosaic virus (SCMV) and Maize chlorotic mottle virus (MCMV), which are vectored by aphids and thrips, respectively. Maize is the main staple food in Kenya and therefore, with the advent of the MLN, there was need to establish mechanisms aimed at combating the spread of the disease. This resulted in the amendment of seed certification protocol which included testing of seed. In consultation with seed stakeholders, KEPHIS incorporated guidelines for MLN inspection in maize seed certification program where all maize seed crops should be inspected four times including preliminary, first, second and third inspections. A seed sample was taken before seed dressing for laboratory test to ensure the lot is free from MLN. Imported seeds were also tested for MLN before being accepted into the country. Furthermore, there have been concerted efforts by breeders and researchers to develop and screen maize lines for resistance to MLN. Other strategies that have been put in place include control of vectors and use of certified seed which are free from MLN. Amendments in seed certification program that were implemented in Kenya have led to drastic reduction of MLN. It is further hoped that resistant maize lines from the breeding program will further support the effort to manage the disease.