(ShareCast News) - Plant Health Care has extended and expanded its distribution agreement with US agri-chemicals partner Sym-Agro.Under the expanded agreement, the Californian company will distribute its Employ product, which is based on PHC's proprietary Harpin technology improving crop health, and Myconate, which stimulate plant root growth, across more territories in the Western US agricultural markets.The new agreement widens the array of crops targeted."Sym-Agro has been a valued partner since 2011 and we are enthusiastic about the investments they have made in field trials, personnel and market development to power this expansion," said Paul Schmidt, CEO of Plant Health Care."We see continued growth in the specialty markets for these products and anticipate significant volume growth in our business with Sym-Agro."Shares in PHC were up 11% to 80.13p at 0925 GMT on Wednesday.