Global warming and increasing maize cultivation demand comprehensive efforts in disease and insect resistance breeding in north-western Europe

Maize productivity is threatened by global climate change. Climate change scenarios suggest that north-western (NW) Europe will get warmer and drier during the main crop-growing period. In general, more northerly regions will benefit, whereas more southerly regions will suffer suboptimal rain-fed farming conditions. In these latter regions in particular, the resulting probable lower realized on-farm maize grain and biomass yields must be safeguarded. Breeding for resistance against already existing and emerging diseases and insect pests is one component to achieve yield stability across years. Durable multiple-disease resistance will become especially crucial. Herein, we focus on disease resistance breeding approaches in maize, especially related to northern corn leaf blight and Fusarium ear rots, although virus and bacterial diseases will become more important as well. Continuous adjustments of disease resistance breeding strategies will be required. Insect pest resistance breeding must be improved considerably, as in a warmer world insects will thrive, probably causing detrimental direct (feeding, sucking, etc.) and indirect (vectors of pathogens, feeding wounds creating gateways for many pathogens, passive transport of inoculum across maize plants) effects. Four case studies on insects that are already prevalent in NW Europe or may be expected in the near future are covered in this review. Maize cultivars need to combine both durable multiple-disease and multiple-insect resistance, although the implementation of many different effective resistance resources in breeding programmes will be challenging, particularly if trade-offs among breeding goals appear.

Automated summary

Maize productivity is threatened by global climate change, especially in warmer and drier regions like north-western Europe. Breeding for disease and insect pest resistance is crucial to ensure stable yields, with a focus on durable multiple-disease resistance and improved insect pest resistance in a warmer world.