Strawberry leaf spot
Everyone can really grow strawberries, but what if the plants grown outdoors turn red or brown? It is usually associated with one of two very common fungal diseases. It appears mainly on the plates of old leaves, sometimes it affects petioles and peduncles. Tiny purple spots form on the affected leaves and grow larger.
Brown spots on the leaves of the homemade strawberry appear in late spring, when the temperature is already quite high, but the weather is still wet. These conditions favor the formation of spores during periods of heavy rain and humidity. They survive the winter on dry strawberry leaves and other parts of plants, and in the spring they move to new foliage.
The spores are caused by different pathogens that are independent of each other but often occur together. The fungus Mycosphaerella fragariae causes white spot disease, while the pathogen Diploccarpon earliana causes red spots.
Spots on strawberry leaves can range from dark purple to red. Gray or almost white centers with reddish-purple or brown borders develop over time. In warm, humid weather, uniform rusty-brown spots without light centers may occur. As the disease progresses, the spots increase in diameter and may coalesce together, resulting in leaf death. Spots may also appear on the underside of the leaves, but they are less intense in color.
Where does leaf spot come from?
Pathogens that spread the disease can enter the garden on infected plants, or through wind-blown spores from neighboring strawberries. Once in the garden, the fungus spreads mainly during periods of heavy rain and humidity, by spraying when watering from sprinklers.
How to prevent common strawberry leaf spot?
Fungal disease: treatment. If strawberries are affected by common leaf spot, it is impossible to cure the plants. If the disease is detected at an early stage, its development can be slowed down with the help of fungicides.
An important advantage of Fitosporin is the absence of toxicity. Harmless to beneficial insects.
Note! Common leaf spot is often just an aesthetic problem and the use of fungicides may not be justified.
How to keep strawberries from leaf spot? Plantations intended for cultivation are processed mainly. As an active ingredient, fungicidal preparations containing captan, myclobutanil or copper are chosen. Copper-containing fungicides are used only before flowering. A product containing myclobutanil is alternated with a fungicide having a different active ingredient. This will help prevent resistance of the pathogen to myclobutanil.
Note! When creating a bed with strawberries, you need to think about planting resistant varieties of strawberries. The shiny, dark green leaves of the bush are a sign of the plant’s resistance to certain diseases: powdery mildew, mites or spotting.
On peduncles located at the level of the leaves or higher, the berries are almost not affected by gray rot.
Resistant strawberry varieties:
- early: “Diamond”, “Elsanta”, “Honey”;
- varieties of medium ripening: “Crown”, “Deroyal”, “Kent”;
- late non-sick varieties: “Zenga Zengana”, “Holiday”, “Fernando”.
The best prevention is healthy certified seedlings and watering is not from above, when water flows into the core of the plant, where there is an ideal moist environment for pests and diseases. Not too dense planting bushes also helps.
Wetting provides a moist environment more conducive to infection by the fungus and results in the spread of the pathogen from plant to plant. In the garden with strawberries (weeding, thinning plants or picking fruit), when it is wet, do not work. You need to wait until the leaves dry.
At the end of the growing season, strawberry residue is removed to reduce the number of areas where the fungus can survive the winter. For strawberries fruiting in June, mowing may be beneficial to combat common leaf spot.
Plant strawberries in a sunny position in well-drained soil. Proper plant spacing optimizes air circulation, and creates a drier environment that is less favorable to the common leaf spot pathogen.
Additional Information! Strawberry leaf spot rarely kills plants, but their ability to harvest solar energy to turn into vegetable sugar is limited, which can impair their quality and productivity.
Other diseases and pests of strawberries
There are many more pests and diseases of strawberries. Her fungal disease is of particular concern.
Gray rot is the most harmful lesion of strawberries. It especially spreads in rainy weather. It affects fruits at all stages of development, leaf petioles, peduncles and inflorescences. Infected immature fruits turn brown, ripe ones become soft and rot. Other affected parts of the plants also turn grey-brown due to the cover of the fungal infection. Growing strawberries on mulch provides some prevention.
Strawberry Powdery Mildew – A white mold that appears mainly on the underside of the leaves, but can affect other parts of the strawberry as well. Some varieties can resist this strawberry disease. To prevent the appearance of powdery mildew, spraying with wood ash helps. 3 tablespoons are diluted with 10 liters of water and insisted for two days. After that, 40 g of soap are added and strawberry plantings are sprayed. Treatment is not delayed, the fungus can cause noticeable damage and spreads quickly.
Snails, slugs eat not only leaves, but also berries, which spoils the presentation of fruits, leads to losses. The main methods: the fight against chemicals, folk methods, mechanical elimination.
One of the weevils or the flower beetle lays its eggs in strawberry buds. The larvae gnaw the flower buds, which fall to the ground. Otherwise, it destroys up to 80% of the crop. You can use folk remedies for weevil, which repels insects from strawberry beds so that females do not lay eggs in buds. For example, a beetle is afraid of wood ash, and if you powder the bushes and the surface of the earth around them with it, you can not only scare away insects from the site, but also make an excellent top dressing.
The strawberry mite is not visible to the naked eye, but can do a lot of damage. It infects small, undeveloped leaves in the center of the plant and prevents its proper development. Strange-looking leaves and fruits may well be a sign of the presence of a strawberry mite. The leaves curl up and change color to red. Dealing with ticks at home is not easy. It is better to destroy the plants completely, and plant new seedlings after a while.
Infected plants are burned immediately.