Why do white spots appear on the leaves of tomato seedlings?

When light spots of unknown origin suddenly appear on the leaves of carefully grown tomato seedlings, the gardener is seized with anxiety about the future harvest. Why is this happening? How dangerous is it? What to do to "help out" a plant from trouble? Answering these questions of concern to gardeners, it must be said that there may be several reasons for such "spotting". In most cases, this is really a bad symptom that can signal a fungal or viral disease. But in some cases, the problem lies in improper care. Consider the possible reasons for the appearance of white spots on the leaves of tomato seedlings.

Sunburn

It is necessary to accustom tomato seedlings to the sun gradually and from the very first days, taking them out into fresh air, first for a few minutes, then for a longer period. When the sun becomes bright and hot in summer, the tomatoes will calmly bask on it, especially since this is a thermophilic culture. "Trained" plants are not afraid of sunburn.

Inexperienced gardeners sometimes neglect this rule and take out tomato seedlings in the sun only when they get stronger and the sun becomes bright. Unaccustomed to heat, the pampered plant immediately gets burns: white spots appear on the leaves, and sometimes the entire leaf turns white. First of all, the upper leaves suffer from burns, and the spots on them look like transparent. Especially severe burns will be if the plant is sprayed before the "walk".

You can try to save the seedlings by feeding it with "doping". This refers to the drug "Epin". It will help the plant recover from stress. It is better to process tomatoes with this preparation in the evening.

To prevent burns, seedlings must be "accustomed" to the sun gradually. If you have to plant seedlings unprepared for sunlight into open ground or a greenhouse, at first it should be covered with lutrasil.

Septoria

The appearance on the lower leaves of a tomato of cloudy white spots with a dark border, looking as if they are covered with a gray bloom, is a sign of a disease that is popularly called white spot. The scientific name for this disease is septoria. A little later, if you do not fight it, dark dots will appear in the center of the light spots, then the leaves will darken and fall off, and the disease will spread to the petioles, the stem may even reach the fruits.

Septoria is a fungal disease, infection most often occurs through the soil, but sometimes the reason lies in improper processing of seed material. If the seeds are not pickled before planting, the risk of septoria infection increases significantly. It is promoted by high soil moisture at high air temperatures. Therefore, the rapid development of septoria occurs in July.

If the tomato is sick recently, it is enough to remove only the damaged parts of it, otherwise you will have to part with the whole plant. Tomato seedlings affected by septoria are treated with Fitosporin by spraying with a solution of the required concentration (the drug is diluted in accordance with the manufacturer's instructions).

Cladosporium

This disease is also fungal, but if septoria more often affects plants in the open field, then cladosporia more threatens greenhouse plants. The spots that have appeared on tomato leaves as a result of this disease are not white, but rather light olive on the upper side, brown on the bottom. For this reason, cladosporiosis is often called brown or olive spot.The velvety bloom on the bottom of the leaf is the spore of the fungus.

The disease usually manifests itself during the flowering period or at the beginning of fruiting. It develops most rapidly at high humidity and lack of light. If you do not take any measures, then the leaves will curl, dry out and fall off, and the infection will reach the fruits. They will turn brown, gradually dry out.

You need to save the plant in the following way.

1. Tear off every single affected leaflet.
2. Prepare a copper-based spray solution. These include "Zaslon", "Barrier".
3. Treat the plant.

After that, it is necessary to look after the tomatoes so as not to miss the occurrence of possible relapses. If new signs of the disease appear, you will have to repeat the treatment.

Mosaic

Disease of tomatoes, which is called "mosaic", is viral. It is caused by Nicotiana virus J. It affects both greenhouse plants and those growing in open ground. Infection occurs through the seed, less often through the juice of seedlings when picking. When a plant is affected by this disease, its leaves become covered with spots, among which there are light green, almost white and dark. That is, the foliage acquires a mosaic color.

There are no effective means of combating this disease. All a gardener can do to save the harvest is to pull out diseased plants and throw them away so they don't infect their neighbors. For prevention, the site can be treated with a solution of potassium permanganate.

Advice

In order not to ruin tomato seedlings with your own hands, buy seed material only from trusted manufacturers and be sure to process it before planting.

Powdery mildew

With too much watering in hot weather, with sudden changes in humidity, light yellow spots may appear on tomato seedlings. If you turn the sheet over, white spots with a grayish bloom will be visible on it. This disease is powdery mildew, which is named for the color that has a bloom. Summons his marsupial mushroom.

For the treatment of a diseased plant, such drugs as "Tsineba", "Gaupsin", "Trichodermin" are suitable. Before starting treatment, damaged areas of tomato seedlings should be removed. Processing should be done in the evening. However, it is worth warning - even spraying may not give the desired effect. Therefore, it is better to try to prevent the disease: if it rains often, tomatoes should be sprayed with a solution of any of the above drugs.

Lack of trace elements

Proper care of tomato seedlings is very important, and it necessarily includes feeding the plant. If the fertilizer is chosen incorrectly, the consequences can be dire. If you have a question why spots appeared on the leaves of tomato seedlings, it makes sense to analyze whether you are feeding it.

If the lower leaves are covered with light spots, then this may signal a lack of one of the following substances:

• nitrogen;
• phosphorus;
• potassium;
• zinc;
• magnesium;
• molybdenum.

Spots on the upper, young, leaves may appear if the plant lacks:

• calcium;
• boron;
• sulfur;
• gland;
• chlorine;
• manganese.

The situation is fixable - you can go to the agro store and pick up suitable fertilizers.

The appearance of silvery spots on tomato seedlings may also indicate developmental anomalies. Such anomalies do not affect the quality and quantity of tomatoes and should not cause alarm.

If spots of white, grayish or yellowish-brown color appear on carefully grown tomato seedlings, and also have a velvety or cloudy bloom, then this may be a sign of a serious disease, fungal or viral. What to do in this situation? The main thing is not to panic. The first step is to inspect the plant in order to make a diagnosis as accurately as possible, and immediately start treatment. After all, the earlier it is started, the more chances you have to save the harvest.

In some cases, the problem of "spotting" is not a plant disease at all, but improper care. In this case, you need to make sure that the plant receives the trace elements it needs. If the spots are the result of sunburn, the plant can be saved, but it will no longer become strong, because the discolored leaves are not capable of photosynthesis.