Effect of storage in controlled atmosphere on post-harvest infections of Phytophthora brassicae and chilling injury in Chinese cabbage (Brassica rapa L pekinensis (Lour) Hanelt)

Heads of Chinese cabbage (Brassica rapa L pekinensis (Lour) Hanelt) were inoculated with Phytophthora brassicae De Cock and Man in't Veld and stored at 1.5 degrees C in the following concentrations of CO2/O2: 0.5%/20.5% (control), 0.5%/1.5% or 3.0%/3.0%. In experiments with cv 'Nerva', stored for 94-97 days, the infection caused by P brassicae was significantly higher (p < 0.05) in the controlled atmosphere (CA) treatments than in the control. However, in vitro growth of P brassicae on agar was slower (p < 0.001) in the CA treatments than in the control. Chilling injury (brown midribs) found in cv 'Parkin' was highest in heads from the control. Storage in 0.5% CO2/1.5% O2 significantly (p < 0.001) reduced this disorder, and the lowest percentage of brown midribs was found in 3.0% CO2/3.0% O2. No chilling injury was found in cv 'Nerva'.