Wheat and faba bean intercropping and cultivar impacts on morphology, disease, and yield

Abstract

AbstractModern agriculture relies heavily on synthetic fertilizer and pesticide inputs. Pressure is increasing to find alternatives that reduce such inputs. In comparison to monocultures, intercropping can reduce plant diseases and increase yield, thereby reducing inputs and maximizing land use efficiency. However, knowledge gaps remain regarding which crop and cultivar combinations maximize such benefits. Here, we grew two wheat (Triticum aestivum L.) and six faba bean (Vicia faba L.) cultivars in monoculture and intercrops over three seasons and measured plant morphology, disease prevalence, and yield. Wheat ear development was slower in monocultures but varied by cultivar and year. Wheat cultivars senesced faster in monocultures versus certain faba bean intercrop combinations. In both wheat cultivars, Fusarium spp. severity was higher, while yellow rust (Puccinia striiformis f.sp. tritici Westend.) was lower in monocultures versus intercropped plots but varied by year and faba bean cultivar. Chocolate spot (Botrytis fabae Sardiña) in faba bean was higher in the cultivar ‘Louhi’ when grown in monoculture. Wheat cultivars yielded higher in monoculture versus intercropped plots. Faba bean yield was higher in monocultures but depended on wheat cultivar and year. Land equivalent ratios (LER) were not affected by interactions between cultivars or years but were always above one in intercropped plots. This indicates that it is always more efficient for yield to intercrop. Our results show that the benefits of intercropping with different wheat and faba bean cultivars varied, indicating that specific goals (i.e., disease suppression and yield) should be considered when selecting wheat–faba bean cultivar combinations.