Response of some maize (Zea mays L.) varieties to natural infection of Maize streak virus in the Western Highlands of Cameroon

Viruses are a limiting factor in maize production worldwide. Maize streak virus (MSV) significantly reduces maize yield in Africa and causes production losses ranging from 30 to 100%. In Cameroon, the incidence of maize streak disease ranges from 10 to 60% depending on the agro-ecological zone; and this is due to the susceptibility of the varieties used. A natural screening of 12 maize varieties for resistance to MSV was conducted at Institute of Agricultural Research and Development (IRAD) at Foumbot in 2019 and 2020, during the dry and rainy seasons. Prior to the trial, vector abundance was determined in the different localities of the Western Highlands of Cameroon. The incidence and severity of maize streak disease (MSD) was assessed at symptom onset for all varieties. The presence of MSV in leaf samples was confirmed by the Triple Antibody Sandwich Enzyme-Linked Immunosorbent Assay (TAS-ELISA). The results showed that leafhoppers were more abundant in the Foumbot locality. MSV infections are higher in the dry season than in the rainy season. The maize varieties KASSAÏ, ACR06, ATP and MADJSYN VAR2 are less susceptible to MSV. These varieties could be used in the control of maize streak disease to limit yield losses.