Submitted to: HortScience
Publication Type: Abstract Only
Publication Acceptance Date: 6/23/1998
Publication Date: N/A
Technical Abstract: Foliar application of a mixture of methionine and riboflavin was effective in reducing the severity of powdery mildew [Sphaerotheca macularia (Wallr. ex Fr.) Jacz. F. sp. Fragariae] infection in 72 strawberry progenies and over 110 clonal genotypes. This biocidal activity was enhanced by supplement of copper, iron, and surfactants [such as sodium dodecyl sulfate (SDS), Triton X-100, or Tween-20]. Compounds free radical scavengers (n-propyl gallate, thiourea), or antioxidants (alpha- tocopherol, beta-carotene) reduced its biocidal activity. Plants treated with the MR formulation (26.6 uM riboflavin, 1mM D,L- methionine, 1mM copper sulfate pentahydrate and 1 mg/ml SDS) or 29% SP formulation of MR not only showed decreased powdery mildew infection but also showed increased chlorophyll content and leaf area and improved fruit quality. Results in this study suggest that treatment with mixture of methionine and riboflavin is beneficial to strawberry plants and may serve as an alternative to fungicides for controlling powdery mildew.