Wilting of Bell Pepper (Capsicum annuum L.) Causal Organism Isolation and a Successful Control Approach

摘要

An experiment was conducted at "Green House Project Farm", Watagoda, Sri Lanka from April 2011 up to August 2011 to identify the causal organisms and suggest an integrated control approach for wilting of bell pepper plants in green houses. Pathogens were isolated from infected plant parts and soil media. Six media treatment methods including Carbendazim only, Metham Sodium only, Plastic potted, Thiram and Carbendazim alternatively, Thiram only and Steam, each with two levels of irrigation including full and half irrigated were tested in field in a seven in to two factorial RCBD design. Statistical analysis of data was done by Minitab 15. Under stereo microscopic observation Fusarium spp., Pythium spp. and Phytophthora spp. were the prominent pathogenic species. Oomycetes (Pythium spp. and/Phytophthora spp.) were significantly detected m the roots and fungi Fusarium spp. were detected in stem parts and soil. It was appeared that the primary infection of Pythium spp. and Phytophthora spp. killed theroot cells resulting root rot. Secondary infection of Fusarium spp. through broken root cells develops up to the stem and above ground parts, hindering the vascular flow and finally causing withering of the plant in green houses. The lowest wilt percentage was recorded in Metham and Steamed treated plants. The successful media sterilization was by Steaming and followed by Metham. Irrigation levels were not significantly correlated with plant wilting. However, the results of the study suggested that wiltsuppression could be achieved by placing the steam treated plants disconnecting the contact with ground.