Bacterial Leaf Streak of Wheat: Inoculation Methods and Epidemiology

Abstract

Xanthomonas translucens pv. undulosa, is the causal organism of bacterial leaf streak (BLS) in wheat (Triticum aestivum). Experiments were conducted to examine the influence of the environment in disease spread from inoculated central points. Inoculations at the three, four, and five leaf, booting, and heading growth stages, indicated that early inoculations produced higher and more consistent levels of BLS than inoculations made at later stages. Warm temperatures favored higher BLS severities in all experiments. The spread of BLS from the inoculated center point was promoted by wind speeds greater than or equal to 3 m/s during periods of leaf wetness. In a second experiment, five trials were conducted to evaluate methods of inoculation. Four methods were evaluated using either a CO2-powered backpack sprayer or a gas-powered mist blower. Severity and uniformity were improved using methods with attachments to the gas-powered mist blower in comparison to the other treatments.