Purple spots appeared on tomato leaves: why this could happen and how to save your tomato harvest

Experienced gardeners know that developmental disorders can be determined by the appearance of tomato bushes. Solanaceae quickly respond to errors in care and, with their appearance, require immediate intervention from the farmer. Many tomato diseases are accompanied by the appearance of spots of various colors. Some formations are harmless, others can cause the death of the entire crop.

What to do if purple spots appear on tomato leaves, why is it dangerous and how to fix the problem? The answers are in our article, supplemented with useful photographic materials.

Symptoms and problem detection

The appearance of spots on tomato foliage is a symptom that cannot be ignored. The source of the problem can be determined by the color and appearance of the formation.

The purple color of the foliage most often indicates the need to replenish the soil.. The color, uncharacteristic for tops, is produced under the influence of the anthocyanin pigment. The lack of useful microelements forces plants to intensively produce this substance.

The color of the tops does not change quickly. First, the lower leaves change color: pink or lilac spots form on them below, which over time acquire a rich purple color. The leaf blade becomes dull, the veins become coarser, and spots appear and spread to the rest of the shoots.

Why is it dangerous?

A change in the color of seedling leaves from green to purple is considered harmless if is not accompanied by the appearance of plaque. But you still have to take measures to preserve the health of the plant. In advanced cases, degradation of the seedlings is possible, which can cause its death

Leaves that have turned purple may begin to curl.. Changes occur in the trunk: it loses its elasticity and becomes brittle. The villi covering the stem lengthen and become stiff.

The flowering process is delayed, which affects the number of ovaries. If you do not pay attention to this problem in time, the fruits grow slowly and grow small. The seeds on such a plant do not ripen, so collecting seed material is pointless. The plant loses its resistance to low temperatures and becomes sickly. Its root system may begin to die.

Why do purple spots appear on tomatoes? This often indicates errors in cultivation.: This may be a temperature imbalance or soil imbalance.

Possible reasons

Eat several reasons for foliage changing color to purple. Let's look at each of them in detail.

Phosphorus deficiency

The element is necessary throughout the entire period of growing tomatoes. Its deficiency is especially dangerous in the first stage of seedling development. Tomatoes accumulate micronutrients and then use them up as they grow.

About other tomato diseases:

Saving tomatoes from late blight

Black spots on tomato leaves in a greenhouse

Holes appeared in tomatoes - how to save your harvest

Effect of phosphorus on tomatoes:

• participates in metabolic processes;
• serves as a source of energy;
• enhances the growth of the root system;
• accelerates flowering and fruit ripening;
• increases sugar content and the amount of pulp in tomatoes;
• increases productivity.

Lack of phosphorus negatively affects all parts of the plant.. The stems and foliage of the seedlings acquire a dark green color, eventually turning into a crimson-purple color. Plant growth stops, which affects its yield.

Signs of phosphorus deficiency:

• purple spots appear on the lower leaves;
• formations spread throughout the plant, including the trunk;
• the foliage is curling up, rises up and presses against the stem;
• the trunk becomes fibrous, hard and brittle;
• the root system is depressed.

Important! Phosphorus deficiency affects the absorption of nitrogen necessary for seedling growth.

Incorrect temperature

Too low or high temperature leads to to impaired microelement absorption. The leaves acquire a purple tint when the air temperature drops to +14 °C or rises to +40 °C.

Soil imbalance

Solanaceae are a demanding crop that depends on the balance of the soil. A lack of nutrients can lead to the death of the plant.

The following elements are important for the health of tomatoes::

• magnesium;
• potassium;
• nitrogen;
• zinc.

The lack of any element negatively affects the growth and productivity of the plant.. You can determine the imbalance of the soil by the tops: with a lack of phosphorus, the lower leaves suffer, while a lack of magnesium affects the upper, young leaves.

Important! Blue discoloration of seedling stems at the base may indicate an overdose of manganese during soil disinfection. In some cases, color change is just a feature of the variety or hybrid.

Seedlings may turn purple due to excess alkali in the soil. Neutral or slightly acidic soil is suitable for growing tomatoes. An excess of acids and alkalis leads to the fact that liquid phosphorus fertilizers return to solid form without having the desired effect.

Fighting methods

Once a symptom is identified, measures must be taken immediately to preserve the harvest.. It is important to correctly identify the source of the problem so as not to destroy the plants. Purple spots are not treated with medications; this problem is caused by care errors. The situation can be corrected by increasing the temperature and adding additional fertilizing.

Maintaining optimal air temperature

Cold has a negative effect on young plants. If seedlings are grown at home, it is necessary to protect them from the penetration of cold air. In greenhouses, all windows and doors are closed, and additional heaters are installed. For irrigation use only warm water. If tomatoes grow in open ground, during cold weather they are covered with additional film material.

Seedlings may turn blue even in the first days of hardening. You can start placing pots with plants in the open air at a temperature of +18 °C. Experienced gardeners believe that adaptation to open air can be carried out even at +16 °C - this will make the seedlings more resistant to adverse weather conditions.

Read also:

How to get rid of blossom end rot

Effective treatment of Fusarium wilt of tomatoes

Fertilizer application

Fertilizing is applied only when the possibility of plants freezing is excluded.. If the air temperature is favorable and the seedlings turn purple, this is a sign of starvation.

If there is a lack of phosphorus, plants need to be fed. For this, 2 tbsp. l.superphosphate is dissolved in 1 liter of boiling water and the mixture is infused for 10 hours. Before use, the volume of the solution is adjusted to 10 liters. The mixture is suitable for watering a bush at the root; 0.5 liters of liquid is enough for one plant.

In addition to root treatment, you can spray the seedlings with 0.5% fertilizercontaining phosphorus.

Fertilizers will help replenish microelement deficiency:

• "Superphosphate";
• "Double superphosphate";
• "Ammophos";
• "Diammophos".

Instructions for the correct application of phosphorus:

1. Fertilizer granules are applied dry when digging the soil or dissolved in water for irrigation.
2. A month before adding phosphorus, acidic soil must be limed.
3. Phosphates are used after the end of the season so that by spring they can be completely absorbed by the soil.

Gardeners who are afraid to use mineral fertilizers on their plots can feed the seedlings with wood ash, bone meal or humates. A natural source of phosphorus is composts based on herbs: wormwood, feather grass, hawthorn, thyme and rowan berries.

Important! An excess of phosphorus is detrimental to tomatoes.

You can determine an excess of a microelement by signs: yellowing and falling leaves, the appearance of brown and yellow spots.

For magnesium deficiency use feeding - 2 g of magnesium sulfate is diluted in 1 liter of water.

Preventive measures

Soil balance is an important factor for obtaining a good harvest.

Phosphorus deficiency is easy to prevent, applying fertilizers on time:

1. When planting tomatoes, add superphosphate to the soil - 15 g for each bush.
2. After planting the seedlings, treat the plants with a solution - 10 tsp per 10 liters of water. "Nitrofoski", "Azofoski" or "Nitroammofoski".
3. Spray the bushes in the morning and evening with a solution of “Superphosphate”.
4. During mass flowering, feed the plants with Ammophoska.
5. Use potassium monophosphate for root and foliar treatment 2 times per season.

Agrotechnical techniques:

• after the end of the season, clear the area of ​​vegetation;
• add dolomite flour, lime or chalk to the soil;
• during autumn digging, add humus or compost;
• in autumn and spring, sow green manure plants: legumes, cereals, cruciferous plants.

Tips and tricks from experienced farmers

You can solve the problem of purple spots in a few hours - carrying out foliar treatment with phosphates.

There are several secretsThings you need to know for those struggling with this difficulty:

1. Wood ash helps alkalize the soil, so it should be used sparingly.
2. You can determine an excess of phosphorus in the soil by planting early varieties of radishes in the garden. Excessive microelement content will lead to a high percentage of root bolting.
3. Phosphate rock is another type of fertilizer. Works well with acidic fertilizers and manure. For more efficient use, it is placed in compost.

Conclusion

If purple spots appear on the seedlings, this is an alarming signal. However, with a quick response, the change in leaf color will not affect the plant in any way. Eliminating the cause of discoloration is simple - just control the air temperature or apply the necessary fertilizers.

If the bushes turn purple due to phosphorus deficiency, the deficiency is eliminated using root and foliar treatment. The result will appear the next day. It is important to correctly identify the source of the problem so as not to harm the plant.