Role of maize residues in transmission of maize chlorotic mottle virus and effect on yield

Abstract

Maize chlorotic mottle virus (MCMV) is the only established member of the genus Machlomovirus and it is imperative in the development of maize lethal necrosis (MLN) disease. Infection of maize plants with MCMV can cause loss of 10 to 59% in grain yield, while up to 100% in co-infection with cereal infecting potyviruses. The study was carried out to determine the role of MLN disease infected maize residues in transmission of MCMV in the soil and effect on yield. Sowing of commercial hybrid varieties, H614 and WE1101 was done at 0, 15, 30, 45, 60 and 90 days after incorporation of MLN infected maize residues in the soil. Data collected consisted of virus titre, number of plants with disease symptoms and severity score, plant height and grain yield. Area under disease progress curve (AUDPC) was calculated using the MLN severity data. The highest MCMV titre of 0.2 was detected in H614 sown in freshly incorporated MLN infected residues. Highest disease incidence at 31.9 and 100% was noted in the field and screen house respectively. Maximum disease severity at 21.3 was record in H614 plant sown immediately after incorporating the residues. The highest reduction in plant height at and grain yield at 3.6% and 44.8% respectively was attained in plants established in media incorporated with freshly MLN infected residues. The study confirmed that MCMV was transmitted through MLN infected maize residues in the soil with notable reduction in grain yield. Farmers should be encouraged to practice proper disposal of MLN diseased infected materials practice crop rotation with noncereal crops