MLN Artificial Inoculation

The KALRO/CIMMYT MLN screening facility uses artificial inoculation in order to create optimal screening conditions for MLN and ensure a minimal risk of disease escape. Optimized procedures have been developed to ensure uniform, high MLN disease pressure at the screening site. NB: It must be noted that the Naivasha MLN facility operates under very strict phytosanitary quarantine procedures, is located in a site isolated far from any maize production and is located in a region where MLN has been endemic for several years. Artifical innoculation with MLN is only warranted under the strictest phytosanitary quarantine procedures.

An outline of the artificial inoculation procedure used at the Naivasha MLN screening facility is as follows:

1    Harvesting the viral inoculum from susceptible varieties under green house conditions (MCMV and SCMV produced separately)
 2    Chopping the infected leaves collected from the inoculated plants 
 3    Blending the chopped infected leaves for preparation of the mass inoculum 
 4    Sieving the infected, blended leaves to produce the mass inoculum
 5    Mixing the SCMV and MCMV inoculum during the field inoculation time
 6    Adding abrasive agent, such as celite, into the tank containing the MLN inoculum
 7    Spraying the screening nursery with the MLN inoculum, using a high pressure backpack sprayer