Cylindrocladium Black Rot (CBR) is a challenging disease to control. It is characterized by the presence of brick-red reproductive structures (at left) growing at the crown of infected plants. Root systems of severely infected plants deteriorate, lack secondary root growth and turn black.
Pods and pegs are also susceptible to damage (inset). In advanced stages, the pegs and pods are severely rotted and dark brown or black in color. Fungal survival structures, known as “microsclerotia,” survive in the soil, in the rotted crop debris, and can remain on the peanut seed as well.
In recent years, it has been shown that CBR can be transmitted via seed, though at a very low rate. If possible, obtain seed produced in fields free of the disease.
For management of CBR:
2. Folicur and Abound are labeled for the “suppression” of CBR. These fungicides may reduce symptoms of disease and possibly increase yields above other fungicides. However, the results are sometimes variable and disappointing.
3. Varieties with some level of resistance are now available. If CBR is present, consider planting a variety such as Carver, Georgia-03L, Georgia-02C or Georgia-01R.
4. CBR is more severe in fields where the peanut root-knot nematode also occurs. Managing nematodes may offer some suppression of CBR as well.
5. Fumigation with metam sodium (e.g. Vapam) at 10 gallons per acre directly beneath the row 10 days prior to planting is currently the best management strategy for the control of CBR.