Plant Health Care's Harpin crop-productivity technology has been shown in tests to increase the marketable yield when used on potatoes.The company, which uses natural biological solutions to modify how plants grow, saw its share price enjoy its own growth spurt as it revealed that recent trials by independent crop consultants in the US had produced a 4.4% greater marketable yield at harvest and a reduced loss in long-term (7-8 month) storage from 4.6% in the untreated spuds to 1.9% in the treated tubers. The storage improvements alone are worth about $4 per ton, Plant Health Care asserts, which equates to $20,000 for a 5,000 ton storage building. "We had already seen evidence in smaller-scale studies that the long-term storability of potatoes increased following in-field Harpin treatment, so it is very encouraging to have those results verified on a larger scale," said Paul Bystrak, a field scientist at the firm. "We have also demonstrated similar results in a variety of crops ranging from lettuce to citrus, so the financial savings potential for the grower should prove to be very attractive," Bystrak predicted.Steve Holland, a crop consultant who conducted several of the trials, commented:"The growers we worked with in the Columbia Basin have become extremely proficient at storing potatoes, so it was heartening to see the additional benefits realized by the use of Harpin in storage. In addition, substantial benefits were also realised in each of the other trials that were focused solely on studying the yield benefits."Plant Health Care's shares rose to a 52-week high on the release of the rest results. JH