New Zealand Plant Protection 63 (2010): 278
Neofusicoccum luteum is a widespread fungal pathogen of grapevines. The germination and survival of N. luteum conidia was tested following storage at different temperatures and times. The conidia (105/ ml water) were incubated at 2, 8 and 20-23°C (ambient temperature) for 0, 2, 4, 24, 48, 72 h, 1, 2 and 3 weeks. The conidial suspensions were then microscopically examined for conidial germination, adjusted to 102/ml and 100 µl spread onto PDA to check for viability. At ambient temperature, 67% of conidia germinated after 2 h and 74% after 48 h. When held at 8°C, 23% of conidia germinated after 24 h and the proportion gradually increased up to 33% in 2 weeks, while at 2°C, 4% had germinated after 48 h increasing to 19% in 3 weeks. The maximum periods of viability of stored conidia (as determined by their ability to form colonies on PDA) was 48 h for ambient temperature, 2 weeks for 8°C and 3 weeks for 2°C. This research showed that N. luteum can germinate quickly at normal summer temperatures as well as at low winter temperatures, so can infect trimming wounds during summer and pruning wounds during winter.
Copyright © 2010 New Zealand Plant Protection Society (Inc.).