Comparison of the Infection Biology of and on .

Leaf blight caused by is one of the most important diseases of planted in the subtropics and tropics. In contrast, the better-known , though also a primary pathogen of , causes less damage to trees in these areas. Although is an aggressive pathogen, nothing is known about its infection biology. In this study, the conditions for infection and disease development caused by and were evaluated and compared on a × hybrid clone. The optimal temperature for germination ranged from 25 to 30°C for and 15 to 20°C for . The germination of these pathogens was favored under conditions of light and high levels of RH. Penetration by and occurred via stomata, and the hyphae colonized the intercellular spaces of infected leaves. Symptoms were clearly visible 3 weeks after inoculation by both pathogens, and reproductive structures started to develop in substomatal cavities at 4 weeks after inoculation. The results of this study will facilitate the establishment of rapid screening trials based on artificial inoculations aimed at reducing the impact of disease caused by