Vegetable prices had doubled since Typhoon Sam destroyed crops, sellers said yesterday. Prices displayed at market stalls showed Chinese white cabbage was up to $12 a catty from $5 on Saturday and the usual bitter squash price of $4 was up to $8. Supply had dropped by 30 per cent and wholesale prices had increased by 40 per cent according to Lai Kwok-yan, general manager of the Vegetable Marketing Organisation. 'Vegetables from the mainland decreased from 600 tonnes to 488 tonnes, and domestic supply is around 20 tonnes compared with about 70 tonnes before the typhoon,' he said. The shortage is compounded because crops from remote fields on the mainland could not be transported to markets due to traffic chaos caused by the effects of the storm. One seller, Mr Wong, who has run a stall in North Point for seven years, said: 'The domestic supply is very limited and so is that coming from the mainland.'