Neem Oil For Powdery Mildew

Are the leaves turning white? Covering plant leaves like a raincoat can prevent fungal spores transported by the wind and splashing raindrops from producing powdery mildew, rust, and other damage.

According to scientists’ theories, neem oil shields plants from infection by preventing spores from germinating or penetrating the leaf. Throughout this post, you will be able to learn the top 5 neem oil for powdery mildew with the recipe to application procedure along with some research histories.

About Powdery Mildew 

Powdery mildew is among the most prevalent plant illnesses that frequently affect plants in the wintertime. A broad term known as “powdery mildew” is used to designate various fungal species that produce talc-like powdery white dust on leaf plant surfaces. Several powdery mildew varieties are largely harmful.

they have the power to destroy a variety of vulnerable plants and crops. Worse yet, aphid honeydew, mealybugs, or scale frequently cause mildew. To spread, the powdery mildew fungus needs hospitable circumstances. Powdery mildew spores increase as a result of excessive dampness and stagnating air.

Does Neem Oil Kill Powdery Mildew?

Seven glasshouse tests were conducted against powdery mildew on roses (Sphaerotheca pannosa var. rosae) at Sanremo, Italy, to determine the effectiveness of various antifungal substances, including salts, oils, plant extracts, plus the hyperparasitic fungal Ampelomyces Quis Qualis.

When used separately, these antifungal substances and the bioremediation agent A. Quis Qualis offered adequate control of powdery mildew in the context of a high disease incidence (55% of untreated leaves were infected in six out of seven trials).

The fungicide dodemorph, sprayed at regular intervals and produced an average efficiency of 75% throughout the trials, was the most effective treatment. Compared to other non-neem choices, JMS Stylet oil, canola oil, and Synertrol plus Neem extract offered adequate disease control with no phytotoxicity.

In another test, Erysiphe polygons were successfully eradicated by three neem extracts (Neem seed Kemal extract, Neem oil, and Neem cake extract), leaf extracts of Prosopis (Prosopis juliflora), Ipomea (Ipomea cornea), and the fungicides Mancozeb and Carbendazim. The pathogen that caused black gram powdery mildew was DC.

Neem seed kernel extract (5%), one of the plant extracts examined, was discovered to be the best at controlling the powdery mildew disease and boosting the grain production of black gram in a pot and field experiment.

Also, The Department of Horticulture, College of Agriculture, Marathwada Agricultural University, Parbhani, conducted a field experiment.

The same 15-day interval sprays five times after the first 30-day was conducted to study the efficacy of different fungicides, bioagents plus two neem options against powdery mildew of okra (Erysiphe cichoracearum) with Neem, non-neem inorganic, water and non-spray control treatments on the randomly selected leaf, seed, and fruit. 

After 30-45-60-75-90 days, Neem oil azadirachtin EC 1%, neem leaf extract 400 ml/plot resulted in better than water spray or unsprayed control results.

  • Better fruit yield (t/ha)
  • Higher test weight of fruits (g)
  • Higher test weight of seeds (g)
  • The higher number of fruits
  • The higher number of seeds
  • Lower disease severity PDI = percent disease intensity 
  • Lower PDC = percent disease control

Though the result came less good than from Karathane (dinocap 46% EC) 0.1 % or Thiovit (wettable sulfur 80 % WP) 0.3%, the latter two will give phytotoxicity and harmful chemical residue.

Neem Oil For Powdery Mildew: Pros & Cons

Before applying, it’s better to know Neem oil’s advantages and disadvantages.

Pros of neem oil for powdery mildew:

  • Non-harmful to pollinators and birds.
  • Acts effectively against OK mildew eggs and infestation.
  • No proven phytotoxicity and harmful chemical residues.
  • It’s cheaper and the best organic treatment for powdery mildew.

Cons of neem oil for powdery mildew:

  • Neem oil should never be used in warm weather over 80°-85° F or during the day unless it will cause heat burn.
  • Lesser effective as compared to its chemical counterpart Karathane and Thieves.
  • Harms beehives 
  • Bad smell for somebodies and pets

5 Neem Oil For Powdery Mildew

Our best picks are-

  • Cold-pressed Organic 100% pure Neem oil
  • Organic neem oil 1500ppm
  • Neem oil azadirachtin EC (0.5%-5%) 
  • Clarified hydrophobic neem oil (0.5%-5%). 
  • Neem leaf extract 400 ml/plot 

Remember- while interacting with sensitive plants, aim for 1% or lower unless the infestation shows signs of reduction after two weeks of use.

Neem Oil Recipe For Powdery Mildew: How To Mix Neem Oil For Powdery Mildew 

As for neem oil spray for powdery mildew, JMS style oil, canola oil, synertrol, and Neem extract are great options. 

Neem oil and baking soda for powdery mildew is also considered a broad-spectrum granular fungicide. Take 1 gallon of water, one tablespoon of baking soda, and 2.5 tablespoons of neem oil and shake hard.

For baking soda neem oil dish soap powdery mildew control, maintain a 2:2:1 tablespoon ratio. 

Neem oil doesn’t at all naturally dissolve in the water. This will float on the water’s surface when poured alone. Neem oil must be emulsified into the water using an emulsifier such as Dawn, Castile, or dish soap. For milder applications, choose a gentle or natural brand.

How To Treat Powdery Mildew With Neem Oil?

Application methods for Neem oil for powdery mildew need some basic fact knowledge. Products containing neem oil can be found in various forms, including dust, granules, wettable powder, cake, and concentrate. You can buy ready-to-use spray bottles of solutions or make your own by combining concentrates. Give it at least 4 to 7 days to take effect, and repeat applications as directed if necessary. The following are the sort of applications for neem oil for plants:

Dormant spraying:  To kill overwintering garden pests and their eggs, apply when plants are dormant. Neem oil should be applied on a dry, windless day for the best results. Spraying should be postponed until at least 40 degrees Fahrenheit and avoided if a freeze is expected.

Foliar mist: To prevent pests and diseases throughout the growing season, apply neem oil directly to leaves whenever possible.

Drenching the soil: Neem oil is diluted with water and placed into the ground or potting soil as a “soil drench.” Sucking insects will consume the solution when the roots spread systemically throughout the plant. To eliminate fungus gnats, treat soil-borne fungal diseases, and eliminate insects, eggs, and larvae lurking in the soil, employ this technique outside or on indoor plants.

Plant-wise use of neem oil for powdery mildew:

For Houseplants: Spray foliage or soak soil every seven days to combat powdery mildew infestations until all pests have disappeared. Every three weeks, spray the ground as a prophylactic precaution.

Ensure you thoroughly coat the tops and undersides of leaves while spraying vegetation. To guarantee they aren’t sensitive to that, test a little area of each plant first. To forestall stains or other damages, keep from getting oil on fabrics and furniture.

For Fruit plants: Apple, cherry, nectarine, pear, peach, and plum trees can benefit from neem oil application. Use to get rid of powdery mildew.

Neem oil can best be applied when trees are dormant to destroy over-wintering larvae and eggs of powdery mildew. Utilize neem oil as a deterrent or to get rid of pests during the growth period. Apply as a soil drench or foliar spray. Neem oil concentrate should be diluted with water before mixing with liquid soap. Cover a sizable area using a pump sprayer, then repeat as necessary. Be warned, though- fruit trees may suffer harm or even die if sprayed too regularly.

For Vegetables: Neem oil can eliminate pests, including aphids, beetles, cabbage worms, maize earworms, tomato hornworms, and whiteflies that cause vegetable problems. Additionally, it can treat fungi-related ailments such as leaf spots, mildew, rust, stem rot, and wilt.

For Lawns: Neem oil helps treat fungus-based diseases like a red thread, rust, and grey leaf spot, as well as common lawn pests like grubs and Japanese beetles. Sunken, discolored, or dead grass patches could be signs of an infestation or disease. Use a neem oil mixture as a soil drench or foliar spray on the afflicted areas.

Garden plants: Neem oil can be used to treat pests and illnesses on a variety of decorative plants. Determine which approach will be most successful after evaluating and diagnosing the issue.

Also, never use Neem Oil on plants under excessive stress from disease, drought, etc. Spray one foliage of one plant with Neem Oil when the sun goes down, then wait 24 hours to ensure the plant is not vulnerable to burning. And avoid scorched, curled, or semi-burnt leaves or buds. This way, your plants won’t experience “burning” from the neem oil mixture reaction to the sun once it has dried overnight.

Tips for applying neem oil against powdery mildew in short:

  • New seedlings shouldn’t be sprayed because their foliage can burn quickly.
  • Neem oil may harm delicate plants, so test a small area and watch for leaf damage after 24 hours.
  • To avoid causing leaf burn, avoid applying in direct sunlight. Apply in the morning or the evening.
  • Avoid applying neem oil after transplanting plants to prevent shock or if plants are stressed by overwatering or overwatering.
  • To treat pests or diseases successfully, ensure that foliage is completely coated.
  • Never use it in extremely hot or cold weather.

How Often To Apply Neem Oil For Powdery Mildew?

Azadirachtin has a half-life of three to forty-four days in soil. In water, the half-life ranges from 48 minutes to 4 days. regarding the nature of the weather, dirt, and tree, neem oil dosage for powdery mildew should be applied accordingly. On average, spraying every 7 to 14 days with 2.5 Tablespoons per gallon of water is recommended.

Using Neem Oil For Powdery Mildew On Pumpkins

To treat the pumpkin patch, apply neem oil if the chosen vines have finished their bloom cycle. That’s right; you should only use neem oil if there aren’t any flowers.

Using Neem Oil For Powdery Mildew On Cannabis

Except for the flowering period and the time between harvest, neem oil against powdery mildew for cannabis plants can be applied as foliar sprays and as a drench to wet the soil.

Using Neem Oil For Powdery Mildew On Cucumbers

Spray the cucumbers’ tops and the leaves undersides where powdery mildew is likely to be hiding.

Using Neem Oil For Powdery Mildew On Peonies

Throughout the summertime, spray your peonies every 10 to 14 days, particularly in excessively shaded and crowded areas.

Using Neem Oil For Powdery Mildew On Roses

Spray one teaspoon of 100% pure neem oil per quart of water from leaf to petals.

Using Neem Oil For Powdery Mildew On Succulents

1L warm water, one teaspoon (5ml) neem oil, and 1-2ml emulsifier (mild dish detergent or mild liquid soap). Apply once every seven days.


Following the “green revolution” of the twentieth century, people have sought organic, non-toxic, and safer pesticides for their gardens. According to the EPA, neem oil is completely organic and non-toxic to humans and animals. In recent years, neem oil has grown in popularity as a 100% natural and healthy pesticide.

Never use a pre-mixed commercial neem spray as quality degrades quickly, and never combine Neem with isopropyl alcohol. Never use raw neem oil as a foliar spray on sensitive plants or parts, and perform a little test application to assess the results before going for the final.

If one follows these few simple rules, Neem will become the plant’s best nature-conserving friend to treat powdery mildew attacks successfully. Stay happy, and keep your plans healthy.

Similar Posts