Photo of the week: Not all salts created equal in rapid blight development

Although high soil salts (high EC) are often associated with the occurrence of rapid blight, it turns out that it is really sodium that makes turf susceptible to this disease. It's for this reason that disease samples can sometimes have acceptable levels of total soil salts, as this sample did, but still get a whopping case of rapid blight. The very high soil sodium (120 ppm) in the soil was responsible for the rapid blight epidemic in this case.…