LAUSR

Verticillium wilt (Verticillium dahliae Kleb.) is a fungal disease of sunflower plants causing vascular bundle jamming, leaf wilt, and plant death, all of which affect sunflower production. We devised an artificial inoculation field test to investigate Verticillium wilt incidence during different stages of sunflower growth including seedling, flowering, and maturation stages, to assess the impact of different disease appearance period on plant growth and production. We hypothesized that time of symptom appearance may be a key factor for sunflower development. The results showed that Verticillium wilt dramatically inhibited sunflower growth and production in all three developmental stages. The disease incidence of Verticillium wilt, considered as percentage of symptomatic plants, was higher than 60% at the maturation stage and lower than 20% at the seedling stage. However, the greatest yield suppression was identified at the seedling stage, while yield inhibition was relatively limited during the flowering and maturation stages. Therefore, the earlier the symptom appearance is established in sunflower development, the greater is the suppression of plant growth, indicating that seedling management is crucial in controlling the Verticillium wilt. The outcomes of this study would contribute to the development of disease control strategies to improve sunflower production.