In late summer or early fall, gardeners often encounter dark spots on tomatoes, which gradually spread over the surface. This is the so-called late blight on tomatoes. Methods of dealing with it include the use of certain chemicals and alternative methods of prevention. Consider in detail what this disease is and how to deal with it.
Late blight
Blight is considered the main disease of tomatoes in film greenhouses and in open ground. Moreover, late cultivars are affected in the soil. This is due to the fact that favorable conditions for the spread of the disease (dew drops that occur when the difference in day and night temperatures) develop in late summer or early autumn.
If stains are detected, gardeners immediately realize that they may have late blight on tomatoes. "What to do?" they ask a question. First you need to find out whether this is true, because spots can be with other diseases.
Blight affects fruits, stems and leaves. Brown spots appear on the edges of the leaves, and a white bloom of sporulation appears below. On stems and petioles spots of elongated shape, without plaque. The fruits are covered in places with hard brown rot. Source of infection - affected plantings
potatoes and oospores that are stored in the soil on plant debris.
Phytophthora on tomatoes: control methods taking into account the rules of growing a crop
- Places for tomatoes need to be constantly changed and not planted with potatoes, since spores remain in the soil for a long time.
- Tomato seeds are disinfected with potassium permanganate or vitaros, since fungus spores can also be on them.
- The tops of potatoes and tomatoes are burned or buried deeply, as the spores are carried downwind and stored in the soil until next year.
If you are looking for an answer to the question of how to protect tomatoes from late blight, then be aware that following these three rules will significantly reduce the risk of a disease. Also, you need to plant only strong plants, take care of them in a timely manner and feed them: strong tomatoes are less prone to late blight.
In carbonate greenhouses, it is recommended to grow stable hybrids formed in 1 stem without thickening, and the greenhouses themselves should be well ventilated. Watering plants during infection is recommended 1 time per week in the absence of rainfall.
Phytophthora on tomatoes: scientific methods of struggle
Special preparations are now available for spraying the tomato culture. Popular tools based on hay sticks - Fitosporin-M, Baxis, Alirin-B, Gamair. When using them, the attached instructions must be observed. Of the stimulants of immunity, the well-known "Immunocytophyte", "Epin", "Zircon".
There are broad-spectrum fungicides that protect against a complex of diseases. These are “Quadrice”, “Ridomil Gold”, “Mefenoxam”, “Mancozeb”, “Thanos”, “Famoxadon”, “Tsimoxanil” and others. Copper sulfate is also used, but it is already a thing of the past, and it does not always help.
Remember that this is an insidious disease that can destroy the entire crop - late blight on tomatoes. Methods of control can consist in spraying plants and observing simple techniques of agricultural technology, such as changing beds, disinfecting seeds and removing residual potatoes and tomatoes. Practice shows that this is enough so that the fungus does not affect the culture.