The passiflora, or passion flower, genus consists of approximately 500 species of flowering plants, most of which are vines. Passion flowers grow naturally across the globe, particularly in South America, the United States and Australia. The passion flower is subject to a number of diseases. Catching a disease in its early stages can help save the plant in many instances.
Bacterial spot is a major passiflora disease that causes a host of symptoms, starting with small, angular spots on the foliage of the plant. The spots are dark green, and are encircled by a larger outline. If the problem persists, the spots grow into large brown lesions, eventually causing leaf wilt and lower fruit production. Bacterial spot can reach the vascular system of the plant, eventually killing the entire plant. Bacterial spot is best prevented rather than treated. Fertilising regularly with a nitrogen-rich fertiliser can help, as malnourished plants are more likely to catch the disease. Clip off infected leaves with sterilised equipment to help prevent the further spread of the problem.
Also commonly called Cladosporium rot, scab is a disease that causes small spots on leaves, flowers and buds. The spots eventually turn into bumpy, scabby scar tissue, which can stunt the development of the fruit and cause stems to break. Young plants are more susceptible to the disease than mature plants, and high humidity can encourage its development. Gardeners can help prevent scab by growing passiflora vines in an area with good ventilation. Prune away infected growth, taking care to use sterilised equipment that is cleaned after each use. Infected plant parts must be destroyed to prevent further infection. Fungicides such as copper oxychloride have proven to be effective against the disease.
Cucumber Mosaic Virus
Cucumber mosaic virus (CMV) is a virus transmitted to a variety of plants, including passiflora plants. The virus is caused by several different host aphids, and may be transferred from plant to plant via a gardener's tools or hands. CMV causes symptoms such as yellowish, mottled patches on leaves, stunted stem growth and distorted, curling foliage. There is no effective chemical control available for the treatment of cucumber mosaic virus; gardeners must remove and destroy infected plants before the virus spreads to healthy ones. Gardeners can help prevent the disease by keeping the vine's environment weed-free, as CMV can linger in a number of weeds, particularly chickweed and groundsel.