Efficacy of Plant-Protection Products for Bacterial Leaf Streak Management on Hard Red Spring Wheat

Bacterial leaf streak (BLS) is one of the top foliar diseases of hard red spring wheat (HRSW) in the Northern Great Plains and is caused by Xanthomonas translucens pv. undulosa. Limited management tools and conducive conditions (high humidity and temperatures of 15 to 30 ○ C have likely contributed to recent BLS epidemics. The increase in popularity of susceptible varieties has prompted questions on the use of plant-protection products to suppress BLS and protect yield. The objective of this research is to evaluate the efficacy of 21 plant-protection products to manage BLS in HRSW. The plant-protection products were organized into two field studies (1) efficacy of biopesticides on BLS and (2) efficacy of bactericides on BLS. A total of four experiments were established for each study in North Dakota and South Dakota in 2021 and 2022. All plant-protection products were applied at Feekes 3-5 and again at Feekes 8-9. Moderate to high levels of BLS were observed in each experiment. Analyses suggested that none of the treatments in the biopesticide study or bactericide study provided consistent suppression of BLS and did not protect yield. The combination of these efforts will influence input decisions made by HRSW growers for the management of BLS.