Occurrence of Sclerotinia Foliage Blight Disease of Cucumber and Pepper Plants under Protected Cultivation System in Egypt I. Chemical and Biological Control Measures in Vitro

During the winter season 2011, a sever Sclerotinia blight disease symptoms were observed on cucumber and Pepper plants grown in the Protected Cultivation Station, Ministry of Agriculture located at Tookh province, Qalubiya governorate, Egypt. Surveyed plastic houses at the previous location revealed that the recorded Sclerotinia blight disease incidence was 2.8 and 3.3% for cucumber and pepper plants, respectively. The isolated causal pathogens for cucumber and pepper foliage blights were identified as Sclerotinia sclerotiorum (Lib.) de Bary and S. minor Jagger, respectively. This is thought to be the first report of these fungi to cause foliage blights on cucumber and pepper in Egypt. As control measures antagonistic agents and fungicides against the growth both pathogenic fungi under in vitro conditions were evaluated. The obtained results showed complete growth inhibition was recorded for both S. sclerotiorum and S. minor at 100ppm of Topsin-M and Ridomil Gold, while Rizolex-T gave the same effect at 200ppm. The fungicide, Previcure had inhibitor effect on the mycelia growth of both fungi only at the high concentration 800ppm. Moreover, the antagonistic fungi (Trichoderma spp.) showed superior inhibitory effect against the growth of pathogenic fungi compared with bacterial isolates (B. subtilis & P. florescence). No significant differences between the tested antagonistic microorganisms and commercial biocides were observed.