Opuntia Vulgaris Diseases

Corky Scab

• This common disease of the Opuntia family is caused by poor cultivation of the prickly pear. Over-watering is a common precursor, and inadequate ventilation around the plant may also bring on corky scab. Symptoms are the development of unsightly brown spots on older stems. The disease is usually superficial, only affecting the outer layer of the plant, and rarely causes more than aesthetic damage. In severe cases flowering and fruiting may be reduced.

Phyllosticta Pad Spot

• This fungus is typical of the desert Opuntia species, most commonly the engelmanni. Black lesions appear on the affected plant tissue, and these lesions contain the fungus spores. The spores are easily carried on wind to other plants, causing it to spread. It attacks moist plants, and infestation is often heaviest on the humid lower pads of the cactus. Once the cactus dries out, the fungus becomes inactive.

Sammon's Virus

• Another disease attacking Opuntia, the virus is related to the tobacco mosaic virus. It appears as pale yellow rings with a mosaic pattern on the plant pads. It is transmitted through the plant's sap, but appears to be largely harmless even to heavily infected plants.

Uses of Opuntia

• Both the fruit and pads of the prickly pear are prized food items. The fruit may be eaten raw or made into jellies. The pads taste similar to green beans. The needles of the plant are sometimes used as pins, sewing needles or toothpicks. The wood of the plant, after edible flesh has been removed, is used in carpentry. The prickly pear has many medicinal uses, as well, and is touted to treat anything from dysentery and mastitis, to cough and venereal disease. It is also thought to be helpful in the treatment of Newcastle disease in poultry.