Fig 14. Suppression of downy mildew development by daytime solar heating applied to infected basil plants (6 dpi) in four Houses B, C, D and E being covered with PE for 2, 4, 6 or 7 hours, respectively during a single day.

House A was PE-uncovered and served as control. A- Temperature (black lines) and RH (blue lines) during the experiments in Houses A-E (please note the different temperature scales). B- Percentage of sporulating leaves two days after exposure of plants to heat (8 dpi) in Houses A-E. Different letters indicate significant differences between means at α = 0.05 (Tukey’s HSD test). C- Percent sporulating leaves of potted basil plants placed as traps for 24 hours in Houses A-E and thereafter being incubated for 20 h in a dew chamber to promote infection. Sporulation was assessed 7 dpi. Different letters indicate significant differences between means at α = 0.05 (Tukey’s HSD test).