This leaf disease attacks plants throughout the year but is prevalent during the dry months. If left untreated, the black leaf spot spreads rapidly, and severely weakens plants. It is important to realize that black leaf spot is a fungus that originates in the soil and is always present. Proper care and knowledge can greatly reduce the occurrence of this disease.
Steps
Step 1. Identify the disease
Symptoms of black leaf spot are small, round, and black, 1mm to 1cm large patches on the upper side of the leaf. The fungus actually lies beneath the surface of the leaf.
The leaf tissue around the patches turns yellow and the leaves drop prematurely
Step 2. Check the crop
As soon as you see signs of leaf spot, remove infected leaves with shears, pruners, or by hand.
Gather all the debris around the base of the plant. Burn the leaves and debris, or throw them away right away. Never put infected leaves or debris in the compost pile, as this will spread the disease. Do this throughout the year, whenever black leaf spot appears.
Step 3. Use chemical controls
Some gardeners use sprays to control the disease. For best results, this should only be done after crop controls and, reasonably, when the choice to remove diseased leaves would leave the plant bare.
Step 4. The fungus resides beneath the leaf surface and is therefore difficult to control with a surface type spray, systemic fungicides are better suited for fungus control
Always follow the instructions on the packaging. Treat the plant at the beginning of the day, once the dew on the leaves has dried, or later, as long as there is time for the treatment to dry completely before sunset.
Step 5. Practice prevention
The spray may contain the spread but overall it does not stop the black leaf spot. The healthier the plant, the less likely it is to get sick. The growing requirements of the plants must be respected, planting where they can sunbathe, and receiving proper ventilation will also help enormously; also use appropriate irrigation practices, water the roots and not the leaves. Mulching the flower beds helps to avoid splashing from the soil to the leaves and thus reduces the chance of reinfection. If you use an irrigation system to water the lawn, make sure that the plants are not sprayed on the leaves, or that they have time to dry before evening.
Advice
- Do not use a high nitrogen fertilizer to feed plants as this causes rapid growth which is usually weak and promotes disease and pests. (30/10/10)
- Maintain plants by watering them properly, at the root, not the leaves.
- Keep clean. If you prune an infected plant with a couple of pruners, sterilize the pruners with bleach and water, with a commercially available sterilizer that is safe for plants, or sterilize the tools you have used with fire, in order to kill the pathogens of the disease. before pruning a healthy plant.
- If the leaves fall to the ground, pick them up, and throw them in the trash can, otherwise you may have problems later.
- Use systemic fungicides to treat the fungus, it is advisable not to use a combination of pesticide and fungicide, unless you also have pest problems.
- Occasional foliar feeding is ok, use balanced fertilizers or fertilizers with a high value of the intermediate number to favor blooms, such as a 20-20-20 or a 15-30-15, make sure that the plants are perfectly dry before evening.
