What are the common pests and diseases that could affect dragon fruits?
Anthracnose (Colletotrichum gloeosporioides) is a fungal disease that can infect dragon fruit. It causes halo-like concentric lesions on stems and fruit.
Bipoaris cactivora is a pathogen that causes black/brown spotting on pitaya blossoms and fruit. When the infection is severe, it manifests in branch/stem rot as well. Fusarium oxysporum has also been found to infect dragon fruit.
Cactus ‘Virus X,’ or cactus mild mottle virus, is a new virus afflicting pitaya. The infection appears as a splotchy mottling of light and dark green areas (mosaic) on branches.
Enterobacteria stem soft rot usually afflicts the tips of pitaya branches. Symptoms appear about 15 days from infection, wherein the tips of the plant soften, yellow, and begin to rot. Most of the time, this disease is fairly benign, although it is wise to cut off the diseased branch.
Botryosphaeria dothidea is another fungal infection that results in blotchy red/brown lesions on the stems of the cacti. Sometimes this looks like a ‘bull’s eye’ target, and sometimes there may be multiple spots coalescing together. This disease begins as yellowing on the infected branch.
Most diseases spread through unsanitary gardening practices, specifically unsanitary tools. It is important to sterilize the tools between uses. Tools can be sterilized with rubbing alcohol, hydrogen peroxide, or a very weak bleach/water solution. Some diseases are spread via contact between an infected plant and an uninfected plant, so it’s a good idea to allow some space between plantings. Otherwise, treatment for fungal diseases may consist of the application of a copper fungicide. But the best way to manage disease in dragon fruit is to practice sanitary practices.
Keep an eye out for sap-sucking bugs such as leaf-footed Leptoglossus. These insects are known to be a vector that can spread B. dothidea. Dragon fruit may also attract ants, beetles, and fruit flies, but for the most part, pitaya has few pest problems especially in comparison to other crops.
Source:
Common Pitaya Problems: Dragon Fruit Pests And Diseases