Marisa E. Thompson
Question What is this white coating on the leaves of my chocolate tree, and what do you recommend to remove it?
By Bolepez, a representative of Kolfax County
Answer – In New Mexico this year, powdery mildew is responsible for those symptoms.
Flour mold is a common fungal disease that occurs throughout the country. Combined with the high humidity in the canopy, warm temperatures create favorable conditions for fungal spores to grow and spread the infection. The rainy season provides ideal conditions for powdery mildew in New Mexico. I once noticed signs of pink leaves and sprouts in the summer, but a nearby spraying head was spraying too much, creating unnecessary moisture in the forest.
Different species of fungi cause pollen in different plant species. However, the symptoms are very similar: a white, powder-like film covers the spots or completely the leaf tissue. Distorted leaf behaviors, such as curling and browning, can also occur. If you think your plants are infected with pollen, but you are not sure, you can always contact your local county extension agent for help (http://aces.nmsu.edu/county). For testing (http://plantclinic.nmsu.edu), your agent may decide to send samples of infected leaves to the NMSU Plant Diagnostic Clinic. These fungi do not harm humans and do not kill their host plants. However, the disease can cause leaf damage and early leaf fall, and is invisible. Photos of the chocolate tree in this week’s column can be found on the blog: https://nmsudesertblooms.blogspot.com.
Some plant species and species are more susceptible or resistant to powdery mildew. Rose, Zinnia, Eunice, lilac, locusts, crayfish, and squash are just some of the most endangered species. However, there are species that are more resilient, such as Hopi Crepe Myrt or “State Fair.”
We can’t stop the rainy season (not what we want), but we can slightly change the environment to make the plants less susceptible to fungus. One way to reduce humidity in a forest or tree canopy is to cut down the plant so that air can flow freely. If a small part of the plant is infected, it may be best to cut that single branch right now. Pruning is just another topic, but keep in mind that the best pruning times and techniques are currently dependent on plant species. Chocolate trees and shrubs should be pruned in late winter or early spring, so cutting too much can cause more stress than we can handle now. Next time, think about how you can better reduce the rainfall of your trees and shrubs.
After the leaves fall off, pick leaves around the plants that show symptoms. This is another good way to reduce future infections. These leaves should be discarded instead of fertilized or fertilized. Next time, you may need to get rid of the fungus, which can infect the plants again!
Healthy plants are resistant to powdery mildew. This is true of other pathogens. As you begin to see the symptoms in your plants, think about how you can better develop the plant’s immune system so that it can fight off all the infectious pathogens on its own. From watering to over-fertilizing or forgetting to cut, these actions (or actions) take their value one by one.
Although fungicides can be used to control powdery mildew, proper application time is essential for successful disease control. My advice is to sit back and enjoy the winter, as the powdery mildew is very likely to kill the infected plant and our rainy season is relatively near the end of the growing season. Within a few months, you will be planning the appropriate pruning and decontamination of fungal culture control plans.
Do you have powdery mildew? # Blemetintera. Post pictures on Facebook (DesertBloomsNM) or Twitter feed (infected plant tissue)@NMDesertBlooms)!
For more gardening information, visit the NMSU Extension City Garden at http://desertblooms.nmsu.edu/ and the NMSU Horticultural Publications page http://aces.nmsu.edu/pubs/_h/. Contact your local Cooperative Promotion Office at https://aces.nmsu.edu/county/.
Marisa E. Thompson, PhD, is an Extraordinary Urban Gardener in the Department of Extra Plant Science, based at the Center for Agricultural Sciences at the University of New Mexico State at Los Lunas.
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