How to treat eggplants for black spot

A sudden temperature spike or increase in humidity will trigger the development of bacterial spot in eggplants. The pathogen thrives in open ground and greenhouses. Temperatures between 25°C and 26°C and humidity levels between 85-90% trigger the process.

Prompt action can help prevent crop losses. Gardeners must act quickly and correctly, so first, they need to understand what triggered the bacterial infection.

Causes of the disease

Various errors rank first among all the negative factors leading to the development of bacterial spot. Botanists have identified the following list of causes:

• lack of sunlight or artificial light;
• incorrect watering regime;
• using too cold water for irrigation;
• lack of nutrients in the soil;
• incorrect choice of fertilizer type;
• too dense planting of nightshade crops in one area;
• the soil was not dug up after harvesting;
• the beds are strewn with plant debris;
• the presence of a disease outbreak in a neighboring area;
• carrying out work in the garden using non-disinfected gardening tools;
• handling seedlings without using gardening tools leads to microtraumas through which the pathogen penetrates inside;
• use of infected seeds for sowing.

The rate at which a bacterial pathogen develops depends largely on how it enters the area. It takes anywhere from several hours to several days for it to become active.

Symptoms of the disease

This bacterial disease has no defined time period when its occurrence becomes more or less likely. Bacterial spot can attack eggplant crops at any stage of the growing season. Initially, the leaf surface becomes covered with numerous small black spots. These can be identified by a distinct yellow border. Upon inspection of the stems and petioles, numerous elongated spots can be seen.

Within 7-9 days, they develop into raised spots with watery edges. Within 1-2 weeks, the affected areas become covered with multiple ulcers. The bacterial pathogen then infects plant debris and seeds in the garden.

Treatment of bacterial spot

Botanists classify this disease as one of the most complex. The use of biologically active substances and pesticides is only possible in the initial stages. In other cases, even partially infected plants must be immediately removed, along with the seeds. All removed plantings must be burned, otherwise re-infection of the eggplants is inevitable.

A gardener who notices the disease early has a chance to combat it with conservative methods. The affected bush should be removed, and any remaining plants should be treated with Fitoflavin-300. The procedure is as follows:

• take 20 ml of the substance;
• dissolving them in 10 liters of water at room temperature is a mandatory requirement;
• recommended consumption rate is 2 liters per bush;
• 2 treatments are carried out with an interval of 14 days;
• After treating seedlings, the protective effect lasts for 20 days.

Immediately after applying the preparation, the gardener adds bacterial agents. The most common ones include the following:

• "Gamair" (1 liter per bush) - take 1 tablet for every 10 liters of water;
• "Alirin" - 2 tablets for every 10 liters at a consumption rate of 1 liter per bush.

Both preparations are used no more than twice per growing season. Exceeding this number of applications is not recommended, as doing so may damage the seedlings.

In the event that the disease has manifested itself for 2 seasons in a row, it is necessary to completely replace the soil used.

Preventive measures

Seeds should be taken only from healthy plants or purchased from a specialist store. Even in this situation, preventative disinfection of the seeds in a weak solution of potassium permanganate is mandatory. The procedure lasts 20 minutes. Another practical recommendation is to practice crop rotation. Avoid planting one nightshade crop in a bed immediately after another. The following tips continue the list of precautions:

• regular removal of weeds and plant debris;
• providing seedlings in closed ground with an optimal temperature background;
• compliance with watering and fertilizing standards;
• Do not plant seedlings too close together in the bed.

A separate category of preventative measures includes the advice to use varieties resistant to many diseases. The list of such varieties is as follows:

• mid-season varieties: "Goliath", "Vikar";
• for greenhouses: "Nutcracker", "Purple Miracle", "Baron", "Bagheera";
• early varieties: "Amethyst", "Japanese dwarf";
• for open ground: "Orion", "Taste of mushrooms", "Eastern Express";
• late varieties: "Torpedo" and "Mishutka".

https://www.youtube.com/watch?v=_lX3iAmse3Y

Black bacterial spot is a bacterial disease that can only be treated in its early stages. Unfortunately, even if the seedlings are saved, gardeners cannot expect a good harvest. Another problem is that the infected bush becomes a carrier of the pathogen, so it is recommended to destroy it along with the seeds. Prevention, proper watering, and fertilization will help prevent the bacteria from spreading into open or closed soil.