Pivonia, S., Arava Research and Development, Sapir 86825, Israel
Gerstl, Z., Institute of Soil, Water and Environmental Sciences, Volcani Center, ARO, P.O. Box 6, Bet Dagan 50250, Israel
Maduel, A., Arava Research and Development, Sapir 86825, Israel
Levita, R., Arava Research and Development, Sapir 86825, Israel
Cohen, R., Department of Plant Pathology, Newe Ya'ar Research Center, Ramat Vishay 30095, Israel

Sudden wilt (vine decline) of melon caused by Monosporascus cannonballus is a problem in arid and semiarid regions worldwide. Preplanting soil disinfestation with methyl bromide, a common treatment for disease management, has been banned in many countries, raising the need for alternative disease-control measures. Soil fungicide application during the growing season is one possible treatment. Twelve fungicides were evaluated in vitro for M. cannonballus suppression, seven of those were evaluated under field conditions. The fungicides azoxistrobin, prochloraz and pyraclostrobin + boscalid exhibited high and similar efficacies in controlling sudden wilt disease under field conditions. Fludioxonil applied at high rates was also effective but was phytotoxic. Fluazinam, the first fungicide found capable of suppressing sudden wilt and one which has been used in Israel since 2000, was less effective. The results indicate that two applications of a fungicide during the short fall season should be sufficient for effective control of the disease. In the long spring season, at least three applications are needed to protect the melon crop. Melon fruits were examined for fungicide residues and only boscalid residues were found. This fungicide was therefore limited to the first application before fruit set. © 2010 KNPV.