Integration of fertility management, cultivar selection and alternative spray treatments to optimize control of foliar diseases of greenhouse grown tomatoes

Summary

Powdery mildew caused by Leveillula taurica (Lev.) Arn. is one of the most serious foliar diseases of greenhouse and open field tomato. The disease is currently controlled with the use of organic fungicides and sulphur, the latter being the only product permitted in organic crops. The aim of this study was to investigate the potential of controlling the disease by integrating: a) hybrids of low susceptibility to the disease, b) organic fertilisers (chitin) and c) alternative spray treatments. Some of the combinations of the above factors were highly effective in decreasing the percentage of disease severity. Specifically the combination of the hybrid of low susceptibility with the addition of chitin in the substrate and the spray treatment Milsana®+chitosan, was equally effective to sulphur. These results indicate that the combination of the above factors could probably be used as an alternative to sulphur for control of L. taurica in the greenhouse.