Pepper-maize intercropping affects the occurrence of anthracnose in hot pepper

Abstract

Hot pepper, an economically important crop species, is generally susceptible to anthracnose disease. Management of hot pepper anthracnose relies on costly fungicide sprays, which have severely limited the development of the hot pepper industry in China. As an alternative management strategy, we evaluated the performance of hot pepper (P) intercropped with maize (M) at different intercropping ratios on anthracnose disease and yield. Compared with monocropping, intercropping significantly reduced anthracnose incidence and delayed the onset of the disease. The mechanisms by which the intercropping system reduced anthracnose incidence included interfering with spore dispersal, decreasing the incidence of sunscald, and altering the microclimate. A significant difference in the percentage of marketable hot pepper fruit was observed between intercropping (P4|M1, P5|M1 and P6|M1) and monocropping systems. The hot pepper fruit yield in the P6|M1 system (19.5–32.7 t/ha) was equivalent to that in the monocrop system and had a land equivalent ratio > 1 (1.32, 1.36). Considering the reduction in anthracnose incidence and increased land utilization efficiency, the hot pepper-maize (P6|M1) intercropping system is a favorable measure for controlling hot pepper anthracnose. This work provides a foundation for the sustainable management of hot pepper anthracnose and increases the understanding of the mechanisms underlying the reduction of anthracnose in the hot pepper-maize intercropping system.