How to properly apply copper sulfate from late blight on tomatoes: step-by-step instructions and useful recommendations

The loss of tomato yield in case of late blight is 70% or more. However, there are effective drugs to combat such a formidable disease. One of them is copper sulfate.

Consider how to prepare a solution and process tomatoes with it, so that the cultivation work does not end with the death of plants, but is rewarded with a rich harvest.

What is late blight

Phytophthora (lat.phytophthora) is a genus of oomycete fungi that cause late blight... More than a hundred species of this pathogen are known, affecting coniferous and deciduous trees, raspberries, and strawberries. Summer residents are familiar with late blight of tomatoes and potatoes.

How to properly apply copper sulfate from late blight on tomatoes: step-by-step instructions and useful recommendations

Fungal spores remain in the soil, on tops and weeds, in seeds and remain viable for 3-4 years even in harsh climatic conditions. Phytophthora spreads from site to site on the soles of shoes, is carried by wind and rain for several kilometers from the source of infection. Spores are activated at moderate temperatures (15–20 ° C) and relative humidity over 75%. For phytophthora germination, drip moisture is needed.

In central Russia, late blight begins to manifest itself in late July - early August... This is facilitated by cold snaps with prolonged rains, sudden temperature changes during the day, causing abundant dew and fog.

3-4 days after infection, tomato plants show signs of disease:

  • dark, without clear boundaries, spots on leaves and stems, which quickly grow and merge together;
  • depressed brown spots of irregular shape on fruits;
  • after 2-3 days, a gray bloom is visible on the surface of the spots - the sporulation organs of the fungus.

On a note. With late blight, the rot is solid (dry), in contrast to the putrefactive lesions caused by bacteria and other fungi.

What is dangerous for tomatoes

The particular danger of phytophthora is its rapid reproduction... After 3-4 days, all plants in the garden are affected. The bushes darken and wither.

Crop losses can be catastrophic... Fruits affected by rot are not edible, either fresh or for conservation.

Pathogen spores accumulate in the soil, which jeopardizes the future planting of tomatoes.

How to properly apply copper sulfate from late blight on tomatoes: step-by-step instructions and useful recommendations

Copper sulfate from phytophthora

In the fight against late blight, budget copper sulfate has proven itself (crystalline copper sulfate hydrate). It is produced in the form of a blue crystalline powder, readily soluble in water. The substance belongs to the 3rd hazard class (moderately toxic) and is available in the assortment of any gardening store.

How does

The fungicidal effect of copper sulfate is based on the interaction copper ions with protein and enzyme complexes of cells. These biochemical reactions cause irreversible changes and denaturation of proteins, which leads to the death of fungal spores.

Read also:

Processing tomatoes from late blight in the greenhouse: a review of the best tools

How to deal with late blight on tomatoes in a greenhouse using folk methods

The best varieties of greenhouse tomatoes that are resistant to late blight


Copper sulfate is used only for prevention, for the full treatment of late blight, special drugs of narrow action are required. The reason is that copper-containing compounds only affect spores, and do not affect the germinated mycelium.

Copper sulfate solutions:

  • dressing seeds before planting;
  • during the growing season, seedlings and adult bushes are sprayed;
  • disinfect the soil and greenhouse structures.

2 hours after application, the components of the drug begin to actively act... The therapeutic and prophylactic effect lasts up to 2 weeks.

How to prepare a solution

The required amount of crystals is dissolved in 500-700 ml of warm (40-50 ° C) water... With stirring, bring the volume to 10 liters. Filter the resulting liquid before pouring it into the sprayer.

Attention! To avoid oxidation, do not use metal dissolving dishes.

Proportions and instructions for preparation

For soil treatment, seed preparation and spraying solutions of different concentrations are used on the sheet.

Purpose of processing Solution concentration Cooking method
Soil disinfection 1% Dissolve 100 g of the drug in 10 liters of warm water.
Seed preparation 0,1% Dissolve 1 g (1/5 teaspoon) of the substance in 1 liter of water.
Spraying tomatoes 0,2% Grate 200 g of laundry soap and dissolve in 1 liter of hot water. In a glass liter jar, separate 20 g (one matchbox without a slide) of copper sulfate. While stirring, pour the solution into soapy water and bring the volume to 10 liters with cold water.

Processing rules

In contact with skin and mucous membranes copper sulfate causes burns and irritation, therefore, when using it, they use protection for the eyes, hands and face (glasses, gloves, bandage).

Soil preparation

Disinfect the soil with 1% fungicide solution... The soil, both in open beds and in greenhouses, is prepared in the fall:

  • remove all plant residues and weeds;
  • dig up and break up the lumps.

The earth is spilled with a solution of copper sulfate, spending no more than 2 liters per 1 m2... The soil and containers intended for growing seedlings are abundantly moistened from a spray bottle with the same solution.

Attention! In cases of constant mass destruction by late blight, a 3-5% solution of vitriol is used. Cultures treated with such a means are not planted for a year.

Seed treatment

To get rid of phytophthora spores and other pathogenic microorganisms, tomato seeds are pickled with a weak (0.1%) solution of copper sulfate.

The seeds are soaked in solution for a day. Then they are taken out, washed thoroughly with running water and dried, making sure that they do not stick together.

And more about the fight against late blight on tomatoes:

Boric acid from phytophthora on tomatoes

Will brilliant green for tomatoes help from late blight and how to use it

Plant processing

Tomato bushes are sprayed over the leaf until signs of late blight appear at the rate of 1 l of 0.2% solution per 10 m2... A solution of higher concentration will burn the plant tissue.

The scheme of work is as follows:

  • the first treatment is carried out a week after planting seedlings in a greenhouse or open ground;
  • the second spraying - with the onset of night cold snaps in August;
  • if the summer is rainy, the fungicide solution is applied every 2 weeks.

Plants are treated in dry, calm weather, always wetting the inner side of the foliage. The last spraying is carried out at least 7 days before harvesting..

Attention! Copper sulfate is not absorbed by the plant, but remains on the surface of leaves and fruits. Therefore, tomatoes are thoroughly washed in running water before use.

How to properly apply copper sulfate from late blight on tomatoes: step-by-step instructions and useful recommendations

What to do in case of overdose

Uncontrolled use of copper sulfate and other copper-containing preparations leads to the accumulation and excess of copper in the soil.

Poisoning of tomatoes occurs, which manifests itself in the form of chlorosis of the leaves:

  • the processes of chlorophyll formation are disrupted, the activity of photosynthesis decreases;
  • leaves turn yellow and fall off prematurely.

If similar symptoms appeared soon after treatments plantations with copper sulfate:

  1. Spill the beds once with plenty of water (10-12 liters per 1 m2).This will help transfer excess minerals into the deeper layers of the soil.
  2. Stop using copper-containing drugs and use other drugs against late blight (for example, "Fitosporin", "Planriz", "Furacilin").

How to properly apply copper sulfate from late blight on tomatoes: step-by-step instructions and useful recommendations

Tips and tricks from experienced farmers

Many summer residents and farmers are familiar with late blight of tomatoes. A few tips from experienced vegetable growers will come in handy in the fight against this dangerous disease:

  1. Bushes overloaded with fruits are the first to become ill. Leave 3-4 tomatoes on the first three clusters, thin out the foliage on the lower and middle tiers. It is important to do this on tall and large-fruited varieties.
  2. Do not use sprinkler irrigation for watering. Water droplets on the tops are friends of phytophthora. It is more correct to carry out root (manual or drip) watering.
  3. More often late varieties suffer from phytophthora - their fruiting and mass ripening occurs during the period of activity of the fungus. It is safer to plant early or mid-season varieties.


Late blight leads to partial or complete loss of yield. The disease develops in cool, wet weather and affects plants both in open beds and in greenhouses.

To prevent infection of tomatoes with late blight, solutions of copper sulfate (copper sulfate) are used. The agent is used to disinfect the soil, pickle seeds, spray adult plants during the growing season. However, the drug only kills the spores of the fungus. Therefore, when signs of late blight appear, narrowly targeted fungicides are used.

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