Controlling of downy mildew on maize using a combination of varieties and mycorrhizae

Abstract Downy mildew is one of the main diseases of maize caused by Peronosclerospora philliphinensis . Plants infected with downy mildew will not give optimal results. Downy mildew is commonly controlled by a combination of resistant varieties and systemic fungicides. The continued use of systemic fungicides is known to have a negative impact on non-target organisms and the soil. The use of biological agents is a solution to eliminate the use of fungicides in combination with resistant varieties. This study aimed to evaluate the effectiveness of combining varieties and arbuscular mycorrhizal fungi (AMF) in controlling downy mildew on maize. The study was conducted in greenhouse conditions, using a randomized block design with twelve combinations of varieties, mycorrhizal and inoculation of pathogen treatments, namely V1M0P0, V1M0P1, V1M1P0, V1M1P1, V2M0P0, V2M0P1, V2M1P0, V2M1P1, V3M0P0, V3M0P1, V3M1P0, and V3M1P1. V1 Annoman variety (susceptible check), V2 JH29 variety (moderate) and V3 Pertiwi 6 variety (resistant check). Each treatment was repeated five times, with two plants in each experimental unit. All treatment combinations carried out observations of plant height, number of leaves, and diameter. Observations of disease incubation, incidence, and severity of disease were carried out on six treatment combinations inoculated with the P. philliphinensis . The results showed an increase in plant vegetative growth in the combination treatment of varieties and mycorrhizae in the absence of pathogen infection (V1M1P0, V2M1P0, and V3M1P0). The disease incidence and severity suppression of downy mildew was shown in the combination V3M1P1 treatment with the same incidence of 50% and disease severity of 46% at 28 days post inoculation. The results of this study indicate the need for the right combination of controls for the purposes of effective disease management in plant cultivation.