Pea Powdery Mildew and Pea Performance in Pea-Cereal Intercropping Under Temperate Continental Field Conditions: Yield, Seed Physical Quality, and Land-Use Efficiency Under Low Natural Disease Pressure.

Pea-cereal intercropping may combine ecological disease regulation with improved land-use efficiency, but field evidence for pea powdery mildew responses on the pea component under temperate continental conditions remains limited. A two-year field experiment (2017/2018 and 2018/2019) was conducted in Novi Sad, Serbia, to evaluate the effects of intercropping on pea powdery mildew disease index (DI%), pea grain yield, seed physical quality traits, and land-use efficiency. Winter pea cv. Kosmaj was grown as a sole crop or in mixed intercropping (70% pea + 30% cereal seeding rates) with wheat, triticale, rye, or oat in a randomized complete block design with four replicates. Powdery mildew DI% was assessed at BBCH 71-75, while pea grain yield, thousand-seed weight (TSW), hectoliter weight (HLW), and yield-based land equivalent ratio (LER) were determined at harvest. Under the low natural disease pressure recorded in the study, intercropping was associated with lower DI% than sole cropping (approximately 2.8-fold lower on seasonal means;