Investigation and Infection Source Analysis of Root Knot Nematode Disease of Panax notoginseng in Lancang County, Yunnan Province

• Zhuhua WANG, 
• Wenpeng WANG, 
• Yibin LIU, 
• Chunhe JIANG, 
• Kuan YANG, 
• Youyong ZHU, 
• Yang WANG, 
• Xiahong HE