Summer crop choice in northern farming systems: pathogen and AMF impacts

Abstract

Key findings • Summer crop choices are complex and should consider the effects they have on pathogens and beneficial soil biota, such as arbuscular mycorrhizae fungi (AMF). • Mungbean resulted in the greatest increase in AMF populations. However, mungbean also elevated the disease risk for charcoal rot and the root lesion nematode (Pratylenchus thornei, (Pt), compared with sorghum, cotton, maize, sunflower and millet. • Growing summer crops generally reduces the risk of fusarium crown rot (FCR) for the following winter cereal crops, but there is variation in this effectiveness. • Maize, cotton, sorghum and mungbean appear to be potential alternative hosts for the winter cereal pathogen Bipolaris sorokiniana (common root rot), while sunflower appears not to be. • Quantifying individual summer crop choices on pathogen levels has highlighted research areas requiring further work to improve managing these biotic constraints across the northern farming systems.