At the mention of home-made tomatoes in your head colorful pictures - sauce of your own preparation; banks with canned tomatoes, neatly made on the shelves of the pantry; Tomatoes in salads or simply juicy fruits directly from bush! And so you go out into the garden to once again inspect and water your plantations, and see something strange on the bushes with tomatoes. The leaves are covered with grayish-brown spots, brown stems are visible on the stems and petioles. What is it? Most likely, your tomatoes are infected with a fungus.
About fungal diseases of tomatoes
Alternaria- a disease caused by spores of a fungus called Alternaria solani. This pathogen can affect almost any terrestrial part of tomatoes - stems, leaves, fruits. The disease does not always lead to the death of plants, but greatly weakens them and significantly reduces yield. Favorable conditions for the development of fungi are wet weather and abundant dew. Disputes of the pathogen can persist in the soil and even overwinter on affected plants that did not have time to be removed last year during the autumn harvest. As a rule, most pests and diseases affect first of all the weakest plants.
Signs of an alternative - the appearance of spots on the leaves, which then turn yellow and fall off. At first the spots look small, but in time they increase in size. The lesions are noticeable on the stems of plants. When the infection reaches the fruit, round stumps of dark color appear near the stalk, and they can be seen on both ripe and unripe tomatoes. Your plants will be able to survive this attack, but this will affect the quality and quantity of fruits. Alternioriosis is a rather unpleasant disease, but it is so damaging to plants as late blight.
Late blight- a dangerous fungal disease, the causative agent of which are spores of Phytophthora infestans, which in translation means "destroying plant". This mushroom can really not only ruin the entire crop, but also infect other plants. Spores can be carried by wind from one site to another. The infected plant should be excavated and destroyed (it can not be used for compost!).
Late bluish-gray spots, which eventually grow brown, and the leaves themselves curl, wither and fall off. Skin brown spots of an indeterminate shape can also be found on fruits. Often spots on leaves and fruits are bordered by white mold. Explicit signs of late blight appear from the middle of summer, when favorable conditions for rapid development of the fungus occur - cool and damp weather. A dangerous disease can kill plants in just one week.
Methods for the prevention of fungal diseases of tomatoes
Cultivation of the most resistant to diseases varieties of tomato:
- The Iron Lady;
- Jasper (red cherry);
- Lemon drop (yellow cherry);
- Prudence is purple;
- Red currant.
Even better, if you can find grafted tomatoes - they are characterized by active growth and stamina.
Prevention of alternaria:
- Buy seeds and seedlings only from reliable sources, never use seedlings offered by friends or neighbors.
- When planting, observe a sufficient distance between the plants for good air circulation.
- Add a layer of mulch on top or use a special red plastic for tomatoes, which cover the soil. This will provide a barrier between the leaves and the ground, in which there may be spores of fungi.
- Regularly inspect the plants, especially in wet weather or with a sharp change in weather conditions.
- If you notice something even remotely resembling a fungal disease, immediately begin regular spraying of bushes with safe means - copper-containing organic fungicides and biofungicides. Both are harmless for vegetables used for food. Alternate these funds in about a week (with the simultaneous use of their effectiveness may be reduced). Be careful when using copper-containing medications - spray them early in the morning so as not to harm the bees; means can accumulate in the soil and lead to its toxicity, so on the place where you often use the means with copper, tomatoes may not grow Every year.
- At the end of the summer season, do a thorough cleaning in the garden and get rid of all plant residues.
- During an outbreak, try to save healthy plants, even if you need to transplant them into containers.
Prevention of late blight:
- Do not leave any plants for the winter and remove all the sprouted bushes of tomatoes and potatoes. Potatoes can be a carrier of spores.
- Use trellises and plant supports or a layer of mulch or a special shelter (see p. above) to prevent foliage from contacting the soil.
- Water the planting under the root and avoid excess moisture. Watering is best done in the early morning, so that the plants and the top layer of the soil have dried up before nightfall.
- As a preventive measure, biologically active preparations containing beneficial bacteria can be used.
- A solution of hydrogen peroxide is another safe and effective means for sterilizing plants and protecting against late blight.
Keep in mind that all of the above mentioned means are suitable only for the prevention of the disease. If the plant is already infected, it must be destroyed (burnt) without any regret. Do not compost sick plants, because phytophthora is a contagious disease that can spread not only to your plants, but also to planting your neighbors!
Although in the conditions of a cool and humid climate it is very difficult to combat tomato late blight, The use of preventive measures will still help to reduce the likelihood of outbreaks of this dangerous fungal disease.