Fig. 4.

J02 and chitosan suppress black spot caused by Alternaria brassicicola on detached cabbage leaves. (A) Images of cabbage leaves after being treated with J02 broth cultures at an appropriate dilution and challenged with A. brassicicola. J02 was cultured in MRSSG (a modified De Man, Rogosa and Sharpe [MRS] medium containing surimi and glycerol, pH 4.1) for 3 days and broth cultures were used for biocontrol experiments after mixing with 1% chitosan. In the absence of J02, A. brassicicola induced larger lesions on spots treated with MRS and chitosan (right panel) compared to those treated with water only (left panel), likely due to the notion that A. brassicicola could obtain nutrients from MRS and grow faster. (B) Quantitative analyses of black spot severity reduction after application of J02 and chitosan in relation to water or MRS medium control. Means followed by the same case letters in each panel were not significantly different P ≤ 0.05).