FIG. 4.

Effect of in vitro UV irradiation of phage on disease control efficacy. A mixture of phages active against Xanthomonas campestris pv. vesicatoria was subjected to different levels of UV irradiation in vitro and then used for treating tomato plants before inoculation with Xanthomonas campestris pv. vesicatoria strain 73-5R. (A) Disease severity as measured by average number of lesions per leaflet. Error bars indicate the standard error. (B) Reduction in disease severity by the phage treatment compared to that by the non-phage-treated control.