Effect of moisture on symptom development and colonization of Fusarium species on maize leaves

Abstract

Maize plants, fifteen-day old, were inoculated with three Fusarium species on the 4 mature leaf and 6 immature emerging leaf. The plants were grown under (1) 50-60% and (2) 80-90% relative humidity (RH). The symptoms of Fusarium were found on immature emerging leaves at high and low RH. Symptoms of F. graminearum occurred the fourth day after inoculation (DAI), followed by F. verticillioides and F. proliferatum in the 7 and 8 DAI. The holes, necrotic lesion, streaks depended on which Fusarium species were involved. Humidity regimes had a significant effect on re-isolation frequency of leaves infected by F. verticillioides but did not influence by F. proliferatum and F. graminearum. The humidity regimes affected on DNA content of F. graminearum and F. proliferatum but there was no significant influence to F. verticillioides DNA. This study showed maize plants cultivated in dry or wet season may be affected by Fusarium species.