How to Prevent Eggplant Pests and Diseases

Eggplant tree

Eggplants, like other vegetable crops, are susceptible to pests and diseases. By following all the recommendations for outdoor cultivation, you can minimize the number of treatments for eggplant pests and diseases. And by using biological protection on private farms, you can get eco-friendly products.

Agronomic Measures to Protect Eggplant from Diseases

The main measure to reduce the intensity of fungal disease infestation of eggplant is the spatial isolation of cultures, i.e., cultivation in crop rotations and return to the same location no earlier than 3–5 years. Eggplant should be placed only in the recommended predecessors: beans, melons, carrots, cucumbers, onions, early cabbage, etc. Plant only healthy eggplant seedlings with no signs of pests or diseases. Avoid overgrowing plants and excessive fertilization, especially with nitrogen. Plant and sow only approved eggplant varieties, preferably not resistant to a single disease, but a group of diseases.

Preparing the Soil for Growing Eggplant Seedlings in the Open Field

Since autumn, the soil has been incorporated with humus, mature compost, and mineral phosphorus, and potassium fertilizer. Make 11–13 Lb (5–6 kg) of organic matter, one cup of wood ash, 30 g of calcium superphosphate, and 20 g of potash on 11 sq. ft. of medium fertility soil. If the soil is poor, double the application rate. On heavy soils, apply at least 1 bucket of mature humus. To increase the water and air permeability of the soil, fall sowing and other seeding have been used successfully recently. The soil should be turned to the full length of the shovel. Late deep digging has destroyed some home nests of black Mole cricket.

Destruction of Mole Cricket

In spring, level the area under the eggplant with a rake to remove soil crusts and slow down water evaporation. When the weather warms up, and the soil in the 4–6inch (10–15 cm) layer of roots warms up to 57–59°F (14–15ºС) or 1–2 weeks before planting seedlings in the open ground, you carry out the extermination of Mole cricket. Mole cricket is harmful to almost all crops so that you can treat the whole garden at the same time.

Preparing Bait for Mole Cricket

Unfortunately, the most effective method for eliminating Mole cricket involves using chemicals. Exercise caution during this process and adhere to hygienic practices. Depending on your garden's size, prepare an appropriate amount of any grain crop (such as wheat, rye, or oats), or coarse grains like peas, cooking them until half done. Drain any excess water. To this mixture, add 2–3 tablespoons of sunflower oil (preferably unrefined and aromatic) and 1–2 amp or an alternative pesticide with a strong odor. Thoroughly mix the ingredients, using double gloves or a flat stick for safety.

Bait Application

Section the field into squares by creating shallow furrows 1–2 inches (2.5–5 cm) deep at intervals of 12–16–20 inches (30–40–50 cm) using a sharp hoe. Moisten these furrows slightly with water, ensuring most of the trench is damp. This attracts Mole crickets from dry soil to the moist areas. After watering, place the prepared bait into the trench and cover it with a 0.8–1.2 inch (2–3 cm) layer of soil using a rake. The Mole crickets, affected by the insecticide, will suffocate in the soil, moving towards the surface. This process can last 3–4 days. Start removing the Mole crickets 2–4 hours later to prevent poisoning birds and domestic cats. Consistent baiting over 2–3 years can eliminate 80–90% of this pest from your vegetable garden.

Planting Eggplant Seedlings

Plant seedlings in prepared soil during stable, warm weather typical for the region, ensuring soil temperature at the root level of 4–6 inches (10–15 cm) is at least 59°F (15ºC). Mature eggplant seedlings should have 5–7–9 leaves on a straight stem, 1–3 buds, and a well-developed root system. In the evening, immerse domestic seedlings in nursery containers filled with a mildly colored manganese solution of a rooting agent or other root-forming agents. Plant the seedlings in prepared holes before 10–11 a.m. or after 4 p.m. If the seedlings are purchased from a market, soak them in the same solution for 3–4 hours, dip the roots in clay putty, and plant them in the ground, previously sprayed with a 1% solution of Bordeaux mixture. The eggplants will take 1–2 weeks to establish roots. During this time, they can lose moisture quickly, especially on sunny days, leading to wilting leaves and loss of initial buds. To protect them, cover the eggplants with a single layer of non-woven polypropylene spandex (or similar material), secured on tall stakes 12–16 inches (30–40 cm) high to prevent sun scorch. Remove this temporary cover when active growth begins.

Diseases of Eggplant During the Growing Season

Throughout the growing season, eggplants can suffer from various diseases, including root rot, tracheal mildew (Fusarium, Verticillium, Phytophthora), leaf spot, and columnar diseases. Fungal and bacterial rots can severely affect the root system, leading to the plant's death. In addition to root rot, eggplants are also susceptible to fungi, bacteria, and viruses that harm the above-ground parts and fruits. Control of these diseases involves several methods:

  1. Biochemicals that are harmless to plants, humans, animals, and beneficial insects like bees.
  2. Chemical products that effectively combat diseases but can negatively impact human health and leave residues in agricultural products.
  3. Chemical agents in the form of plant decoctions and infusions, which possess fungicidal and insecticidal properties.

Organic Farming: Minimizing Chemical Use

To foster organic products in rural areas, it's advisable to limit chemical agents. Modern private gardeners can grow crops using natural-based protective agents (like effective fungi and bacteria microbiota), known as EM preparations. These preparations act as antagonists to disease-causing microflora in soil and plants, eliminating pathogens.

Addressing Eggplant Diseases with Biological Agents

When eggplants exhibit unexplained wilting, it may signal root fungal decay. Biological agents based on effective fungal microbiota are applied for soil treatment. To minimize treatment frequency, a tank mixture of several biological agents can be formulated.

Remember! Prepare each biological agent solution separately as per instructions and check their compatibility. If compatible, combine the individual solutions into one mixture.

These mixed solutions enhance the effect against pathogenic microbiota. Fungal-based bio fungicides infiltrate and destroy the mycelium of harmful fungi, while bacterial fungicides act like antibiotics. For soil disinfection, both dry formulations and working solutions of other EM preparations, including unique organic (EM) concentrates, are effective.

Systems for Treating Soils with Biological Agents

Biological agents require systemic applications over time, especially after rain or in wet conditions. To reduce treatment frequency, use them in tank mixtures, offering protection against multiple diseases simultaneously.
Possible tank mixtures for soil treatment include:

  1. Trichodermin + Ampelomycin + Glyocladin + Binoram
  2. Glyocladin + Binoram
  3. Trichodermin + Bactophyte
  4. Planriz-Bio + Coniothyrium, etc.

Excessive treatment doesn't always yield positive results. Begin treating plants early, with the first soil treatment 10–12 days after sowing seedlings.

Plant Treatment Systems Using Biological Agents

For visible plant diseases (bud drop, leaf yellowing or curling, etc.), apply biological agent solutions every 7–10 days during growth. Supplement these solutions with micronutrients at budding and second fruit harvest stages. Add Gamair or similar to a pre-made soil spray mixture for enhanced effectiveness. No remedies exist for viral diseases (like Mosaic virus); affected plants should be removed and burned.

When using bio fungicides, accurately identify the disease and follow specific treatment recommendations. Misdiagnosis renders the product ineffective. If unsure, use a tank mix targeting multiple pathogens.

Chemical Protection of Eggplants Against Diseases

Chemical treatment of vegetable crops in homes or small gardens is not recommended due to their long degradation period and residual effects on humans, animals, and beneficial insects. If chemicals are used, cease treatment a month before harvest and follow recommended guidelines.

Chemicals vary in compatibility and specificity, leading to increased treatment frequency. New chemical agents, efficient in low doses with short waiting periods (3–20 days), are emerging. Exercise extreme caution with chemicals, avoid increasing doses during dilution, and use personal protective equipment to prevent exposure.

Plant Treatment Systems Using Insecticides

For combating eggplant diseases like gray rot, Phytophthora, bacterial spot, and blackleg, utilize treatments such as Bordeaux mixture, copper sulfate, and liquid copper (Cu2+) fungicides. Protection measures typically commence 3–4 weeks after germination, extending to 2–3 weeks post seedling plantation. Treatment intervals range from 7 to 14 days, influenced by weather conditions.

Eggplant Pest Control

Eggplants are primarily threatened by aphids and the Colorado potato beetle. Aphids, small sucking insects, can rapidly devastate eggplant plantings by draining the sap from stems, leaves, and flowers. Colorado potato beetles, capable of destroying up to 80% of a crop, breed several generations each season. Targeting these pests also helps control spider mites, another damaging sucking pest.

Biological Methods of Protecting Eggplant from Pests

Biopesticides, derived from effective fungi (avermectins), bacteria, and soil entomopathogenic nematodes, serve as biological agents against insect pests.

Bacteria-based biopesticides effectively eliminate larvae of biting and sucking pests, with Bitoxybacillin being a common choice. These agents are versatile, applicable to vegetable, fruit, and berry crops, and perform well in protected areas.

Fungal-based biopesticides like thiamethoxam and imidacloprid are instrumental in early-stage pest eradication and can be applied even during harvest. Penicillin pesticides specifically target nematodes, crucial for eggplant seedling development and early cultivation phases.

Note! EM fungi-based biological insecticides are effective in humid conditions around 77°F (25ºC). Apply these after watering, in the morning, or after 4 pm. Store cautiously as they lose efficacy when frozen or exposed to sunlight. Compatibility checks are necessary when tank-mixing with bio fungicides, and adherence to dosage and treatment duration is vital.

Using Chemical Agents to Protect Eggplants from Insect Pests

To control sucking and biting pests, treatments like Confidor Extra are used on eggplants. Given their harmful nature, cease treatments before flowering. Typically, 1–2 sprays are adequate, with the first as a preventative step and the second following after 2 weeks. In cases of epiphyte infection, apply these preparations or a mixed solution every 10 days. Remember! Complete all chemical treatments before the onset of extensive flowering.

Folk Remedies for Protecting Eggplants from Pests and Diseases

Traditional methods for safeguarding eggplants typically involve creating herbal decoctions and infusions to spray on affected crops. It's important to recognize that a single application is often insufficient, and repeated sprays can be more impactful than initially perceived. While these natural remedies can be effective against pathogens, they may also carry some chemical properties that are not ideal for human health. Common practices include soot dusting, Dendrobium decoction spraying, mugwort use, or applying chemically treated Dioscorea pills during the growing season.

Walnut Leaf Infusion: To combat aphids, create an infusion with fall walnut leaves. Fill a metal bucket 2/3 full with the leaves, pour boiling water over them, and seal tightly to infuse through fall, winter, and spring. For application, dilute 0.26–0.52 gallons (1–2 liters) of this concentrate in 2–2.5 gallons (8–10 liters) of water and spray on plants after testing on a single plant for 3–4 hours.

Herbal Decoctions: Some gardeners advocate for preparing decoctions from mugwort, chamomile, and yarrow, using these to spray the plants.

Ash Spraying: Control aphids by spraying a grass ash infusion. Mix 1–1.5 cups of ash in 2.5 gallons (10 liters) of water, let it sit for a day, strain, and spray. Add green or laundry soap for better adherence.

Compound Decoction for Pests: To target Colorado beetle larvae and aphids, blend one cup each of dandelion leaves, onion, and garlic in 2.5 gallons (10 liters) of water with 1–2 tablespoons of soap. Let it soak for 2–3 hours, strain, and spray. This mixture is effective against spider mites, aphids, and Colorado beetle larvae at any development stage.

Various folk concoctions exist with differing effects. Each gardener can test and choose the most effective solution. Adhering to agricultural techniques and timely interventions can ensure a good harvest with minimal reliance on pest and disease control methods.