LONDON (Dow Jones)--Crop technology company Plant Health Care PLC (PHC.LN) Monday said it signed a development and marketing deal for its yield-enhancing harpin product with agrochemicals giant Syngenta AG (SYNN.VX). Basel-based Syngenta intends to test different formulation of harpin and its own glyphosphate herbicide to develop a combined crop treatment product, Plant Health Care said. Financial terms weren't disclosed. Plant Health Care said the agreement isn't exclusive. -By Jason Douglas, Dow Jones Newswires; 44-20-7842-9272; [email protected] (END) Dow Jones Newswires July 26, 2010 02:37 ET (06:37 GMT)