Potato Review

26 POTATO REVIEW JANUARY/FEBRUARY 2021 BIOSTIMULANTS “Biostimulants have a valuable role to play in mitigating the e ects of stress.” Dave King, Head of Technical, Syngenta tubers. Application mid-season can reduce the number of tubers misshapen owing to stress, whilst pre-harvest treatment can prevent harvest damage and reduce shrinkage in store. Field trials observations David King has also seen di erences in responses to biostimulant use in eld trials, although acknowledges that sheer scale and complexity of the company’s latest research makes de ning speci c stress factor e ects harder to pinpoint. And for crops, or particularly varieties, evolved and selected to perform in relatively cool and lower light UK conditions, they can be ill-prepared for changing climatic conditions. He believes that biostimulants could be crucial in helping those varieties to better cope with challenges. In the Syngenta trials, it was crops that had been most impacted by the e ects of stress, where untreated yields have been most severely limited, that showed the greatest response to biostimulant use. at makes their use imperative as a way for more e cient use of available input resources, Dave said. “Fertiliser use, for example, is under ever greater scrutiny for environmental and economic impacts, along with carbon footprinting and soil health. Where biostimulants can help develop root structures and plant physiological e ects to get nutrients into the plant and better utilised it can improve yields from reduced inputs, and cut risk of environmental loss.” Furthermore, with legislative pressure restricting the crop protection arsenal for agronomists, along with societal desire for reduced pesticide use, biostimulants o er the potential to achieve the best possible results of what is available, as well as opening opportunities new product development. “Biostimulants and crop protection products are entirely complementary. We know that where plants are under stress they are more susceptible to infection by disease pathogens and the e ects are more severe. Alleviating that barrier to plants’ natural health increases the opportunity for crop protection to work most e ectively,” said Dave. In potatoes, for example, the incidence of Alternaria is closely associated with a whole range of stress factors, including nutrient, heat and moisture, and with a clear link to varietal susceptibility. Timing of infection also has a signi cant implication for nal yield e ects. Biostimulants would o er the opportunity to alleviate some stress factors that could reduce risks of infection, which could prove especially valuable where crop protection options to manage Alternaria are set to be further limited by legislative withdrawal, he said.