Elevated quinolizidine alkaloid content in grains of sweet narrow‐leaved lupins when intercropped with oats

Intercropping NLL with oat elevates the grain QA content to levels of toxicological relevance. The extent is variety-interaction dependent, presumably due to oat allelopathy. The evidence points to an indirect stress mechanism: allelopathic cues from the oat crop place NLLs under physiological stress, which in turn stimulates NLL to accumulate additional QAs in the grain. Additional mixed cropping experiments and breeding against QA accumulation in NLL grains should be pursued to understand and alleviate this issue. © 2026 The Author(s). Journal of the Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.