Powdery mildew is a serious problem in both field and greenhouse cucumber production and can cause serious infection and radically reduced yields. Today, Powdery mildew is the main disease in greenhouse produced cucumber. Disease control should preferably be both efficient and environmentally friendly, which is not easy to achieve at all times. Alternatives to chemical control of Powdery mildews are biological control, physical control, non-fungicide control and cultivation of resistant or tolerant varieties. Biological control can be described as the suppression of damaging activities inflicted of a harmful organism by one or more other organisms, which are called antagonists or natural enemies. In Sweden, there are currently no registered biological control products available to control cucumber Powdery mildew. The aim of this study was to investigate the effect of two biological control products in order to evaluate their ability to prevent or reduce Powdery mildew infection to an acceptable level in greenhouse produced cucumber. In the experiments, different application regimes were also studied.

Barley is one of the most important cereals cultivated in the Nordic countries. Climate change brings warmer and moisture climate which favors fungal diseases. In the cropland barley can be seriously infested with hard fungus attack. Since it is important that the yield bears a high quality it is of great importance to find varieties more resistant to attacks.Pathogenesis-related (PR) proteins are stress proteins induced in the plant in response to infection and abiotic stress (van Loon, 1997). PRs are shown to have antimicrobial activity differing between bacteria, fungi and oomycetes (Tandrup Poulsen, 2001).