Shares in Plant Health Care (PHC) jumped on Wednesday after the company said that it will receive a payment after one of its partners reached a project milestone.PHC, the AIM-listed provider of biological products to the agriculture markets, said that Germains Seed Technology, its partner in developing the 'Harpin alpha-beta' seed treatment of sugar beets, is to start large-scale trials of the product in the US during this year."This decision to move to the next stage of testing has triggered a milestone payment to the company," PHC said.Germains has been evaluating the use of the Harpin alpha-beta since September 2010. PHC Chief Executive Officer John Brady said: "This is a very positive development in our relationship with Germains and gives us further confidence in the potential of our Harpinaß protein products."We are extremely gratified with this development, and while the milestone payment is welcome, of greater significance is that sugar beet can now be added to the list of important crops which respond favourably to Harpinaß seed treatment."This list includes Brassica crop (sugar beet), a legume (soybeans) and a cereal grain (maize), as well as other fruit and vegetable crops.Shares were up 6.67% at 88p in afternoon trade.