What symptom does strawberry leaf spot disease have? How to prevent and cure?

Strawberry is a kind of fruit with high economic value, which is rich in nutritional value and is deeply loved by consumers. In the process of strawberry planting, diseases are easy to occur, especially leaf spot. What are the symptoms of strawberry leaf spot? How to prevent and cure?

What are the symptoms of strawberry leaf spot?

The main results are as follows: 1. Strawberry leaf spot is dark purple spot at the initial stage, and becomes nearly round or oblong after enlargement, the edge is dark purplish reddish brown, the center is gray to grayish brown, slightly fine wheel pattern, so that the whole spot is snake-eye-like.

2. Strawberry leaf spot disease will produce a white powdery mildew layer on the surface of the disease spot when the humidity is high, and many small black spots can be produced on the disease spot in the later stage. In severe cases, the disease spot on the strawberry leaf is dense, and the diseased leaf is necrotic and scorched in a short time.

3. Too many disease spots of strawberry leaf spot will cause leaf withering, a large number of diseases will affect leaf photosynthesis, reduce plant disease resistance, and seriously blacken the growth point of strawberry plants.

Second, how to control strawberry leaf spot?

1. Clear the weeds in the field and around before transplanting, concentrate on burning or retting fertilizer, turn the ground deeply to kill stubble, promote the decomposition of disease and residue, and reduce the source of disease and insect.

2. Reasonable rotation, better rotation of flood and drought.

3. The disease-resistant varieties with strong growth potential, high fruit setting rate, cold tolerance, shade tolerance, Botrytis cinerea, virus disease, powdery mildew, bud blight and so on should be selected, and the disease-free seedlings with pure varieties, strong growth and developed root system should be selected for the mother plant.

4. Three days before transplanting, spraying a mixture of diseases and insect pests, transplanting with soil, transplanting with medicine, and eliminating diseases and weak seedlings when transplanting, this is one of the important measures to control diseases and insect pests. Before covering the soil moisture, the seedlings were sprayed with a mixture of disease and insect control agents, combined with the seedling condition, if the growth potential is weak, 0.3% urea can be added.

5. Select the fields with convenient drainage and irrigation, open the drainage ditch, lower the groundwater level so that there is no stagnant water in the rain; clean up the ditch system in time after heavy rain to prevent moisture retention and reduce the humidity in the field, which is an important measure to prevent diseases, because many diseases are caused by high humidity, so we should pay attention to it.

6. Fields with many soil germs or serious underground pests should be applied with medicine and soil for disease control and pest control in holes or ditches before transplanting.

7. Compost retted by enzyme bacteria or rotten organic fertilizer shall not be used with bacteria, and the organic fertilizer shall not contain disease residues of undergraduate crops.

8. Adopting the technology of soil testing and formula fertilization, properly applying phosphorus and potassium fertilizer, strengthening field management, cultivating strong seedlings and enhancing plant disease resistance are helpful to reduce the disease.

9. Plastic film mulching cultivation can prevent germs from harming aboveground plants in the soil.

10. Timely control of insect pests, reduction of plant wounds, reduction of pathogen transmission; timely removal of diseased leaves and diseased plants, and out-of-field burning, disease point application or quicklime.

11. Scientific irrigation should be applied during high temperature and drought in order to increase field humidity, reduce the harm of aphids and gray planthopper and spread virus. Continuous irrigation and flood irrigation are strictly prohibited. Preventing water droplets from splashing during watering is an important measure to prevent the disease.

12. For those cultivated in the greenhouse, before transplanting or seedling preparation and after harvest, thoroughly remove the disease and residual leaves, spray medicine on the surfaces such as greenhouse film, soil, walls and shelves, disinfect and disinfect them properly, and properly release air and moisture, or during the summer leisure period, irrigation in the greenhouse, covering the ground with plastic film, closing the shed for a few days, using high temperature sterilization; strict quarantine, strict inspection of entry seedlings, as soon as they are found, immediately destroyed, it is strictly prohibited from transporting seedlings to other places.