. The growth chamber was modified to obtain the following conditions inside the mini-tunnels: 24C (day) and 20C (night), 16 h light and near 100% RH. Plants were adapted to the new environmental conditions one day before inoculation with the pathogen. The number of plants in each of the three growth media was 14:5 (controls) without pathogen inoculation, and 9 with pathogen-inoculated leaves. The control plants were placed in separate mini-tunnels to the inoculated plants, each of which was grown in a different mini tunnel. The experiment was repeated three times.