Vascular Diseases

• Vascular diseases affect the roots and stem of the painted daisy by disrupting the movement of fluids and nutrients through the vascular system. The two most common types of vascular disease are fusarium wilt and verticillium wilt. Fusarium wilt often causes wilting along one side of the plant, with yellowing foliage and stunted growth. Fusarium spread occurs with the movement of contaminated soils and infected cuttings. Verticillium wilt may be spread in the same way, and often turns up after the blossom buds have appeared. Leaves begin dying from the ground to the top of the plant. The University of Delaware Cooperative Extension recommends not replanting painted daisies or other chrysanthemum varieties in areas infected by either type of wilt.
  
  

Foliage Diseases

• Many diseases affect the foliage of painted daisies. Various types of fungal and bacterial infections result in leaf spot, a condition characterized by yellow spots that turn black over time. Infected leaves should be hand-picked and destroyed. Powdery mildew leaves a white, ash-like powder on the surface of leaves and stems. Infected leaves eventually wither and die. With high humidity encouraging the growth of powdery mildew, it's important to place plants so that they get good exposure to air circulation. Painted daisy plants infected by rust, blight or other viruses should also be removed from the garden and destroyed. The best prevention against these diseases is to use clean tools, limit pests and weeds, and maintain proper spacing.
  
  

Root Diseases

• The fungi pythium and rhizoctonia result in lesions around the stems and roots of painted daisy plants. The foliage above the affected stem or root begins to wilt and eventually dies. Remove and destroy all infected plants. Infection from the bacterium Agrobacterium tumefaciens results in crown gall, or a swelling at the crown of the plant. The Clemson Cooperative Extension recommends the destruction of infected plants and the purchase of disease-free rooted cuttings for replanting.
  
  

Flower Diseases

• Ray blight and ray speck affect the ray flowers of the painted daisy. Daisies feature two different types of flower: ray flowers and disk flowers. The ray flowers are the long "petals" of the daisy bloom while the disk flowers make up the colorful center. The small, individual flowers form what is considered a daisy flower. The ray-blight-producing bacterium Didymella ligulicola produces a black rot that causes deformed, one-sided flowers, and the blight may spread throughout the stem and lower leaves of the plant. Ray speck results from a Stemphylium lycopersici infection. Small, brown lesions appear in the ray flowers, often resulting in blossom death. Providing good air circulation and reducing wet foliage aids in the management of ray blight and ray speck.