Control of pythium root rot in carnations

These tests showed that when Pythium vexans (isolated from carnation roots) was introduced into soil mixes, it reduced the top growth and yield of Red Sim carnations. No other symptoms were visible on the plants. Control measures using ethazol as a preplant at 50 ppm, diazoben as a preplant at 25 ppm, or diazoben as a drench at 100 ppm at weekly or biweekly intervals also gave control. The ethazol preplant and diazoben drenches at weekly or biweekly intervals may be slightly toxic. Additional experiments on control are in progress.