Tips for pest-free turnips, mustard greens

By By Steve Strong / area horticulture extension agent
Nov. 12, 2003
Turnips and mustard greens grow great in the fall and winter garden. Getting a thick stand is difficult during dry years, but thanks to ample rainfall and recent cooler temperatures early-planted leafy crops should be flourishing by now.
Early pest control is very important in fall plantings, since leaf-feeders and other injurious insects begin causing problems while the weather is still mild. Check the crop every few days for visible pest symptoms. Problems can generally be handled with applications of a recommended insecticide.
While you're checking your crop for bugs, also keep a sharp lookout for early symptoms of fungus diseases that commonly attack during warm, humid periods. The most common fungus disease that affects leafy greens is White Spot, and it can blight an entire planting if left unmanaged.
Symptoms of this disease include circular, gray to brown or almost paper white spots. As the spots increase in size and number, the entire leaf may become so "shot-holed" that it is no longer suitable for harvesting.
The fungi responsible for white spot and some of the other diseases that affect leafy greens are carried over in the soil for a period of several years. You are also more likely to have blight problems if you planted your crop with seed saved from a planting where white spot was previously a problem.
That being so, it is best to start a new planting of turnip or mustard with new seeds (preferably those treated with a fungicide). Hopefully, these seed were planted in an area of your garden where greens haven't been produced within the past two years, to avoid leftover pest problems that could be lingering in the soil.
Rotation of the crop every three to five years is a very effective disease prevention strategy, but this practice alone won't stop a fungus infection in your greens. Use crop rotation in combination with other disease control measures to keep leafy green blight under control and improve crop quality.
If you aren't currently spraying your greens with a fungicide, consider giving the following control measures a try. Fungicides will protect greens from infection, provided spray applications are made early in the season, and are applied on a regular schedule every seven to 10 days according to label directions.
Do not wait until disease symptoms are widespread before applying a fungicide; initiate a fungicide application program while the leaves are still small and spot-free. For best results, begin spraying before disease strikes, and continue throughout the season with application of fungicides that contain copper as the active ingredient.
Kocide Df and other copper-based fungicides, available in one to two pound containers at many farm and garden supply dealers, may be applied to turnips and mustard, as well as collard greens every seven to 10 days. Dilute Kocide at a rate between one-half and one full tablespoonful per gallon of water.
Other formulations of copper-type fungicides may be available, including the standard copper sulfate powder that can be mixed with water at a rate of two tablespoons per gallon. An added advantage of these fungicides is the fact they may be mixed with a recommended insecticide, thus allowing a "one-shot" application for disease and insect control together.
Note: Read label directions for harvest restrictions. While there is a "zero" day waiting period for most copper fungicides, this may not be true for the insecticides. If you have questions about pest control in your fall garden, check with the County MSU Extension Office, or visit the Mississippi State University's Web site at www.msucares.com.