Since the first shipment of Taiwanese oranges was delivered to Shanghai last November, China has become a major market for local oranges and the steady deliveries have helped stabilize prices at home, a Council of Agriculture official said Sunday. The official pointed out that the government purchases premium quality oranges for export from fruit growers at guaranteed prices during the winter harvest season. Over the past six weeks, 912 metric tons of Taiwan oranges have been shipped to China -- an average of six to seven containers-full per week, according to the official. The steady exports to China have helped stabilize prices in the harvest season, when glut sometimes causes a steep price drop. Over the past weeks, the wholesale prices increased from an average NT$11 to NT$13 per kilo, thanks to the exploration of new markets, the official added. 