Conventional and molecular assays aid diagnosis of crop diseases and fungicide resistance

For the past decade, we have been developing techniques for monitoring pre- and postharvest diseases of tree fruit, nuts and vines at the UC Kearney Research and Extension Center (KREC). We have also advanced new methods to monitor pathogen resistance to fungicides, which growers can now use to make decisions on disease management. Although accurate, the conventional techniques are time-consuming and only provide results after 5 to 21 days. Molecular methods offer the possibility of faster, more reliable and efficient tests. We have developed such methods to monitor, diagnose and quantify crop pathogens. We have also used these new molecular techniques to answer complex questions on the biology of tree fruit and nut pathogens, the origin of their inoculum sources, changes in their population structures and the epidemiology of the diseases they cause. We are now working on molecular techniques that could supplement the conventional ones we have developed for vine diseases. Private diagnostic laboratories have been using a number of these conventional techniques and plan to adopt some of the molecular ones in the near future.