 |
ProCrop |
Plan Sunflower Disease Management Before Planting
Disease management options to consider include destruction of volunteers, use of fungicide-treated seed, field selection and hybrid selection.
Rust first shows up on volunteer sunflower. Destruction of volunteers in the field and in nearby areas will help greatly to reduce early season buildup of rust.
With the number of downy mildew races present in North Dakota, resistant hybrids have not been used, but recently hybrids resistant to all races in North Dakota have been released. Downy mildew is most likely to occur in low spots of the field, but can be widespread across the field if heavy rains occur shortly after planting. Apron seed treatment used to provide excellent downy mildew control against all races, but now the downy mildew fungus has developed resistance to Apron. The percent of the population that is resistant varies from field to field.
Premature dying, which is frequently caused by phoma girdling, and sclerotinia (white mold), are more common in fields where sunflower follows sunflower.
Generally a three-year rotation may be adequate to reduce premature dying, but if a field has a history of sclerotinia, a longer rotation should be used. For example, if more than 1-2 percent sclerotinia stalk rot occurred in a field, at least a four-year rotation should be practiced, with all susceptible crops avoided until four years have elapsed. Sclerotinia head rot was common in 2000 and 2001. Fields that were planted to sunflower in those years should be avoided, if possible. Be especially careful to avoid highly susceptible crops such as dry beans and canola.
Back to Disease -
Sunflower Men
Back to Rust - Sunflower Menu
Back to White Mold - Sunflower Menu
Back to Sunflower Menu
Back to Main ProCrop Index
