Abstract:
Gherkin (Cucumis sativus L.) is most popular vegetable, Cucumis sativus L. was recently found to
have an unidentified disease while being grown in a protected area in the Gampaha district. The
disease caused elder plants to yellow as one of its symptoms. The lowest leaves of infected plants
get yellow and dry, and they quickly wilt. ln the early stages of the disease, the roots are unharmed,
and the leaves transform from pale green to golden yellow. With the goal of identifying the new
disease affecting Cucumis sativus L. this study compared the effectiveness of a few selected bio
pesticides and synthetic pesticides in addition to identified the cause organisms, management
strategies, and techniques for its prevention. Three pathogen types were isolated and they were
identified as Aspergillus niger sp. (pathogen type one), Didymella spp. (pathogen type two) and
one bacteria spp. (pathogen type three). Three synthetic fungicides (Homail, Daconil,folicur) and
three biological control agent (Trichoderma viride, Trichoderma harzianum and Pseudomonas
fluorescens ) were tested in vitro against the causal organisms. T5 (Pseudomonas fluorescens
+Trichoderma harzianum) and T9 (Foliar), T11 (Homail) were most effective in controlling
pathogen type one and T2 (Trichoderma viride), T5 (Pseudomonas fluorescens + Trichoderma
harzianum), T8(Trichoderma viride + Pseudomonas fluorescens + Trichoderma harzianum) and
T9(Foliar ),T10 (Dacon) and T11 ( Homail ) were the best treatments in controlling pathogen
type two.
