1996年，乐亭县由中国科学院动物研究所引人了新型种子包衣剂──根保，在夏玉米掖单十三、唐抗五、乐丰一等品种上进行了多点试验和大区示范。试验示范面积达1645亩平均亩增产玉米61．2公斤，增产率19．8％；商投资1．2元，增加效益70－80元。根保的主要成分包括高效低毒内吸 In 1996, Laoting County was introduced by the Institute of Zoology, Chinese Academy of Sciences, a new type of seed coating agent - root Paul, Yedang thirteen in the summer corn, Tang anti-five, Lefeng first varieties were tested and large District demonstration. Experimental demonstration area of ​​1645 mu The average yield of maize 61.2 kg, 19.8% increase rate; business investment 1.2 yuan, an increase of 70-80 yuan. Root Paul’s main components include high efficiency and low toxicity systemic absorption