D.R. Phillips, N.B. Gersbach
A petiole spotting condition known in Japan as gomasho threatens the future of Chinese cabbage exports from Western Australia. In 1986/87 more than 4,000 tonnes were exported. The condition is often symptomatically insignificant in the field but develops rapidly in cool storage on wong bok (round) types.

Numbers of affected leaves and intensity of spotting on mature heads were shown to increase rapidly during cool storage at 1°C, reaching a peak between 14 and 28 days.

Spotting was marginally worse where high rates of nitrogen (500kg/ha N) or phosphorus (550kg/ha P) were used in the field and at high soil pH (8.3). Ammonium nitrate gave more spotting than urea while soil and foliar applied manganese had no effect.

Cultivar differences were identified, with useful tolerance in China Pride, WR Green 60, Treasure Island, Chief and Aichi. Of these, China Pride, WR Green 60 and Treasure Island showed commercial potential. Cultivars widely grown in Western Australia, Kasumi II, Hong Kong and Orient Express all proved to be highly susceptible.

Phillips, D.R. and Gersbach, N.B. (1989). FACTORS INFLUENCING PETIOLE SPOTTING (GOMASHO) IN CHINESE CABBAGE.. Acta Hortic. 247, 117-121
DOI: 10.17660/ActaHortic.1989.247.19

Acta Horticulturae