Systemic protection of the newly developed leaves of potted tomato plants from late blight.

OXPT, CHT, AZ, MPD, MFX, OXPT+CHT, OXPT+AZ, OXPT+MPD, or OXPT+MFX were sprayed at 100-ppm ai onto 5-leaf plants. The plants were inoculated with isolate 164 of P. infestans 17 days later, at the 10-leaf stage. A- Percent of leaf area blighted at 7 dpi on the five bottom-treated leaves. B- Percent of leaf area blighted at 7 dpi on the top five newly grown leaves. Different letters above columns indicate significant differences between means (t-test, α = 0.05). Note that OXPT+MFX provided the best systemic protection.