Can white spots kill my plant?
Written by
Nguyen Minh
Reviewed by
Prof. Charles Hartman, Ph.D.White leaf spots can be fatal if left to their own devices. A customer presented a tomato plant to us that had completely fallen over due to being confused with sunburn. Severely infected plants are essentially starved as the white spots block photosynthesis and inhibit the flow of nutrients. The quicker a response, the more likely you can differentiate a plant that can be saved from one that is a complete loss.
Fungal Killers
- Powdery mildew coats leaves, blocking sunlight absorption
- Root rot spreads upward from soil-borne fungi
- Cankers girdle stems, halting water transport
Bacterial Dangers
- Blight clogs vascular tissues like plant arteries
- Leaf scorch mimics drought stress irreversibly
- Soft rot destroys cell walls in days
Secondary Risks
- Weakened plants attract borers and beetles
- Defoliation exposes fruits to sunscald
- Stunted growth reduces yield by 90%
Early intervention has the potential to preserve as much as 80% of infected plants. I saved a lemon tree by pruning out all the spotted leaves and applying copper fungicide within forty-eight hours. With signs of infection, delaying treatment can result in systemic collapse - once cankers have risen to the main stems, your chances of recovery drop well below twenty percent.
Use neem oil sprays to prevent secondary invasions. When plants are weakened, they send out stress chemicals and toxins that will attract pests. A client had a rose bush that survived the mildew treatment but died because of borers. Use kaolin clay as a protective barrier after treating the original infection.
Enhance airflow and sunlight without delay. After spacing my zucchini patch plants three feet apart and also trimming the foliage down its base - the patch bounced back. The combination of space and reduced humidity - a staggering 40% - helped eliminate the fungal growth. When you attend to a plant's environment, you are just as important as the method you apply in treatment.
Read the full article: White Leaf Spots: Causes and Solutions
