According to Mr Kang Zhiqian deputy secretary general of China Construction Machinery Association, the excavator sales volume of China's main construction machinery enterprises in April 2011 stood at about 20,000 sets, down by 50% MoM from March 2011. In addition, the sales volume of loaders and bulldozers also saw sharp drops in April, with that of loaders plunging 30% MoM, the largest drop since April…