Status of Maize Lethal Necrosis Disease in Zambia

Abstract

Maize is a staple food in Zambia and contributes immensely to food security for smallholder farmers.  Disease outbreaks such as Maize Lethal Necrosis Disease (MLND) can be a key constraint to maize production. This disease is caused by synergistic co-infection with Maize Chlorotic Mottle Virus (MCMV) and any virus from the family Potyviridae, particularly, Sugarcane Mosaic Virus (SCMV), Maize Dwarf Mosaic Virus (MDMV) or Wheat Streak Mosaic Virus (WSMV). In 2011, an outbreak of MLND affecting almost all of the currently grown commercial varieties posed a challenge to maize production in Kenya and it has since been reported in DR Congo, Ethiopia, Kenya, Rwanda, Tanzania, and Uganda causing yield losses of up to 100%. Despite MLND having been reported in some neighboring countries, there is no information on the status of the disease in Zambia. Additionally, there is a lot of grain and seed trade between Zambia and other countries among which MLND has been reported. The aim of this study was to establish: (a) the status of MCMV; (b) agricultural practices used by farmers and (c) insect vectors associated with MLND.  A survey was conducted in nine (9) provinces of Zambia during 2014/2015 and 2015/ 2016 cropping seasons. Farmers’ maize fields were sampled at every five to ten-kilometer interval and tested using rapid diagnostic kits capable of detecting MCMV.  Four hundred and nineteen samples collected all tested negative for MCMV. Zambian Agricultural Research Institute (ZARI), with all stakeholders in the maize value chain should continue implementing measures aimed at preventing the introduction of MLND in Zambia.