2017 ASHS Annual Conference

Raspberries are a high value crop grown commercially in California as well as other parts of the world. Very little research has been done on this crop under commercial conditions due to difficulties with multiple harvests, multiple pickers, and lengthy growing season. This summary of 2 years of research evaluated the effect of a commercial formulation of Ascophyllum nodosum (Acadian Bioswitch^TM Technology, Acadian LSC) on yield of raspberries grown and harvested under commercial conditions from 2015-2017. A. nodosum extract was injected in the commercial drip system at 4.6 l/ha every two weeks beginning at “cut back” in October and continued until harvest was final and crop was cut back again in March. In 2016 the A. nodosum treated plots yielded 3,549 6-kg trays per ha while the control yielded 2744 trays, amounting to a 29% yield increase. In 2017 the treated plots yielded 3992 6-kg trays per ha while the control yielded 3472 trays, amounting to a 15% yield increase. The yield increase seen in these studies may have been due to improved tolerance to stress as indicated by significant reductions in two spotted spider mites in the A. nodosum treated plots both years. Additionally, there were more fruit per meter of floracane in the treated plots indicating that a reduction in internode length may also have played a role in the yield increase seen in these studies. Future research should elucidate the mode of action.