Diagnosing plant diseases: what do we ask and why do we ask for it?

Diagnosing a plant disease or other injury is like going to a medical doctor who must ask several questions before making an accurate diagnosis and recommending a treatment. If you withhold information, it can lead to a misdiagnosis. The same goes for crop diseases. Plant pathologists, specifically diagnosticians, are often asked “What is wrong with my plant; followed by, what can I do to manage the problem?” In most cases it may be too late to save the specific plant, but a correct diagnosis is important to prescribe methods that prevent the problem on other plants or in the future. So how do we go about diagnosing plant diseases? Proper identification of diseases and of the causal agents is vital in prescribing a sound disease management strategy, avoiding further losses and preventing the waste of time and money. Often, we rely on symptoms for the identification of a disease. As similar symptoms can be produced by different causal agents, the use of symptoms alone in most cases is an inadequate method for disease identification. While other methods for identification are available, it may also take a week or more to accurately identify the disease-causing agent. So, what can diagnosticians do? Asking many questions related to the plants’ environmental and cultural factors to help eliminate or identify possible causes of the problem. To help gather this information we provide disease diagnosis request forms for you to fill out when requesting our free diagnostic services. It is important that you use the form relevant to the laboratory you are submitting a sample to. QDAF Plant Disease Enquiry Form USQ Centre for Crop Health Plant Disease Diagnosis Submission Form Disease testing services around Australia Information gathered from these forms is crucial in helping narrow the problem down to a few suspects, which will require further study in the laboratory before making a final diagnosis. Regardless of the outcome, a recommendation will be given as to what should be done with the problem