White spots on tomato leaves: causes and treatment
Many gardeners who are just starting to grow vegetables naively assume that the only evil that can happen to their tomatoes is late blight. Indeed, this is a very terrible disease, and it is extremely difficult to treat, but this is not the only misfortune waiting for shoots valuable to the heart. White spots on tomato leaves are a serous competitor to numerous diseases and pests, destroying the aerial parts of tomato seedlings.
Peculiarities
Tomato belongs to a number of capricious and environmentally demanding crops. In order for plants to develop well, they must receive an equivalent amount of heat, light, moisture and nutrients. A minimal violation - a jump in temperature, high humidity, too bright a glow of the sun or a draft can provoke stress in still fragile plants, which will lead to a deterioration in the condition of the leaves: they lose turgor, become lighter, and sometimes white spots appear on them.
Spotting can be provoked by various factors, and it is not always harmless. Whiteness can appear both on the leaves of adults and young tomatoes (seedlings). The place of ripening also plays an important role. Green mass can deteriorate in plants from a greenhouse and even in representatives grown in the open field.All plants, without exception, are equally susceptible to such an unpleasant phenomenon as white spots on the leaves, although, as practice and life experience of gardeners show, most often plaques occur on greenhouse tomatoes.
Usually the lowest leaves turn white first, and then the trouble covers the entire plant. Initially, the spots are difficult to recognize, and with careless inspection and complete disregard for the grower, they are well visualized and subsequently quite difficult to remove.
The shape and size of plaques can be very different and depend on the cause of their occurrence.
Why do they appear?
Uncharacteristic modifications of tomato leaves are the first reason that signals gardeners that the future harvest is in jeopardy. Noticing any deviations from the norms provided for by the variety, you should immediately look for a solution to get rid of the trouble. However, before you start looking for a suitable treatment method, you need to find out the cause of white spots.
Experienced gardeners know that whitish spots are evidence of one of two scenarios: either a sunburn or a bacterial infection.
The most harmless culprit in the formation of white spots on green shoots is sunburn. Among beginner growers, this situation is quite common, although experienced specialists sometimes sin. If the gardener, in order to harden the seedlings, took it out into the street and left it in direct sunlight for a long time, then the reason for the appearance of plaques most likely lies precisely in this. Someone might think that yellow and dry leaves are a sign of a burn, but this is not always the case. Light spots also indicate a burn.
Due to the influence of ultraviolet light, tomato leaves can turn completely white.The burn quickly spreads through the tops, and if the plant is not shaded, it can burn out.
The reason for the more serious nature of the formation of white spots is a bacterial disease. In nature, there are quite a few diseases that destroy vegetable crops. Septoria is considered the most common in tomatoes. Both adults and young seedlings suffer from this disease. If dirty white spots were visualized on the aboveground part of the tomatoes, this means that the tomatoes are really sick with septoria.
In the place where the unnatural mark appeared, a fungus quickly multiplies, which destroys not only the plant he has chosen, but also all his fellows growing nearby. The fungus spreads quickly in the garden, especially if conditions suitable for reproduction have formed on the street - high humidity combined with very sunny weather.
Powdery mildew is another fungal disease that is quite aggressive, so not only tomatoes are afraid of it, but also other vegetables that live near the affected plant. The main condition for the appearance of a pathogenic fungus is high humidity. The ambient temperature does not play a role, maybe even + 30C. At first, only the leaves are covered with white spots, then all other parts of the plant. The disease proceeds rapidly, in one day the entire tomato planting can die.
The appearance of a white coating on the stem and leaves of the plant is also evidence of a bacterial disease. Vegetable culture is very difficult to treat and most often dies. To save her, you need experience and understanding of how to work with disinfectant solutions.
Entire plantations of tomatoes are destroyed by a disease with the beautiful name of mosaic.A distinctive feature is small multi-colored spots, among which there are many white ones.
The first symptoms in the form of white spots on the leaves are caused by a disease of vegetable crops - late blight. An unnatural color appears on the inside of the green mass. Then the fruits begin to change - an ugly brown crust appears on the skin of the tomatoes. The berry becomes hard, softens after a while and eventually deteriorates.
Oedema or swelling of the leaves. This is not a disease, but can also cause white spots. Due to excessive watering, especially at low temperatures, water drops remain on the surface of the leaves, under which later transparent, and then white bulges are formed. In a small amount, they are seen as white dots scattered over the sheet, but in large volumes, it seems that the surface of the sheet is completely swollen.
White spots on the leaves and fruits of tomatoes can also appear due to a lack of a trace element such as boron in the soil. You can feed the plants with fertilizer.
Due to inexperience, some novice gardeners personally provoke the appearance of white spots on the sheets of their wards. The trouble is due to the wrong technology for processing chemicals. To overcome the pest (slugs, Colorado potato beetle, aphids, and the like), growers use special spraying agents, but by preparing an overly concentrated solution and treating green spaces with it, gardeners, to their horror, may notice white plaques on tomatoes.
Vegetable growers in recent years have seen a trend towards the fact that vegetables grown in greenhouse conditions are more susceptible to various diseases and other troubles.It is on such plants that dry white or silver spots often appear on the leaves.
According to experts, damage to the shoots is in no way associated with any disease, most likely it is a sign of deviation during development caused by changes in the content or genetic specificity of some varieties.
But also white spots on leaf plates can occur due to a lack or excess of nutrients. For example, magnesium and zinc are indispensable elements in the formation of chlorophyll, they are involved in the process of photosynthesis. If there is a shortage of useful components, the above processes are disrupted, as a result, light spots appear on the sheet plates.
An excessive amount of potassium and sodium salts in the soil is also expressed in leaf spot. If a lot of organic matter (manure) was introduced into the soil, you can see a rainbow picture on vegetable crops. It is better to combine organic fertilizers with mineral fertilizers, but not to use one thing.
It is quite simple to distinguish a leaf burn from being damaged by a dangerous infectious agent. To do this, you need to carefully examine the tomato and remember in what environmental conditions he lived and what kind of care he received. These conclusions will help determine the cause of the appearance of white plaque.
What to do?
If signs of a fungal disease appear on tomato seedlings, there is no need to panic prematurely. Plants can be cured, of course, if all signs have been identified at an early stage of their formation.
Treatment should begin with pruning. It is necessary to cut off all diseased leaves. The tool that will be used for this procedure must first be decontaminated: hold it over a fire or wash it with soapy water / a strong solution of potassium permanganate.
Live sections should be sprinkled with ashes, crushed coal, or treated with the same solution of potassium permanganate. Healthy tomatoes, as well as the ground below them, should be sprayed with a Bordeaux mixture or other fungicide.
Regarding sunburn, there is also first aid. You can help a burnt plant with special anti-stress agents, for example, Epin, Zircon, succinic acid. They will increase the resistance of vegetable crops to negative environmental factors, add strength to the tomato. Of course, even these preparations cannot return burnt leaves, since burnt plant tissues are not restored.
Prevention
Even the modern agricultural industry has not yet been able to find a fast-acting way to treat the affected tissues of vegetable crops. Very often, gardeners have to say goodbye to their plants, which they could not keep track of in time.
It is easier to carry out preventive measures than to treat plantations of plantings for a long and painful time. It is necessary to loosen the soil more often and inspect the plants for infectious lesions, treat them with preventive drugs.
Many vegetable growers have their own method of planting and breeding tomatoes in the garden. And thanks to this knowledge, they almost never have to deal with the problems of diseases.
First of all, each grower selects the best place for planting. They should be a fairly illuminated area, but not in an open area, a little shaded. Soil moisture should also be moderate.
If the plant does not receive the required amount of light from the first day of its stay on unprotected ground, it becomes lethargic. Subsequent contact with the rays will bring even more harm to the unhardened foliage.You can avoid such a nuisance by proper placement, namely: planting tomato bushes closer to the shady part of the garden.
It is possible to protect only planted tomatoes not only from ultraviolet radiation, but also from various diseases. To do this, you need to prepare the land for the selected vegetation, in this case tomatoes. Add substances to the soil that help plants fight ailments.
Preventive measures that help vegetable crops avoid contact with the fungus include:
- seed treatment with a disinfectant before planting in a nutrient medium;
- compliance with the rules of planting - there should be no crowding in the beds, the plants should be ventilated;
- it is necessary to observe the irrigation regime, the water must be warm;
- every three years you need to change the place where the tomatoes will grow;
- after harvesting, dry tops and all plant debris must be burned, thus destroying the spores of the fungus;
- remove weeds in the garden in time - parasitic plants are carriers of fungal spores.
If vegetables grow in a greenhouse, you should always keep the humidity level normal, ventilate the room, and disinfect the soil and the greenhouse itself every year after harvesting.
For information on what to do if the seedling leaves turn white, see the next video.