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Best Ways to Treat & Prevent White Mold on Plant

White cottony fungal threads on the plant leaves are not only stressful to look at, but they also suck out nutrients and stunt growth.

Generally, improper sunlight, temperature, and moisture cause white mold on plants that can be treated by amending those care factors. They can be prevented by biological and cultural methods such as regularly applying neem oil.

Explore this article to get better ideas for dealing with the troubles caused by White Molds on Plants.

What is White Mold?

White mold is a fungal disease, easily characterized by white cottony mycelium on plant surfaces.

These fungal diseases are generally seen in plants after flowering and are established in flowers, stems, leaves, and pods. Moreover, they form white, fluffy fungal threads on the infected plant parts.

Initially, wet, dark, and sunken lesions spread irregularly on the infected plant parts, resulting from the fungus’s enzymes and acids.

White mold results in chlorosis, wilting, root rots, and in severe conditions, death of plants.

Infection of white mold fungi on plants
White Mold fungi can infect whole plant parts, including aerial parts and lower stems.

This fungi can infect many plants but are most significant in the legumes (peas, beans, and lentils) and the cabbage family.

Ingestion of plants or plant products infected by White mold fungi can harm humans and animals, as these fungi produce mycotoxins in the plant cells they contaminate.

Causes of White Molds on Plants [Reasons and Solutions]

Fungus Sclerotinia sclerotiorum initiates the contamination of white molds on plants.

Wind, rain splash, contaminated soils, and insects are some of the abiotic and biotic factors responsible for transferring fungi from one location to another. 

White mold infection on plants.
White molds penetrate the outer cell wall of plants only in the presence of moisture and favorable temperature, get inside them, and cause the disease.

However, the infection begins when the causal organism comes in contact with fresh plant parts.

You need to identify a few causes to treat and prevent white molds on plants.

1. Sunlight and Temperature

Fungal invasion in fresh plant parts is supported by low sunlight and optimum temperature. 

Most fungi, counting white mold fungi, are mesophilic and grow well at temperatures between 25-30°C.

Moreover, due to temperature rise, fungal infections are more prevalent in the summer than winter.

White mold fungi prefer to grow in dark or shady places where sunlight cannot reach them.

Direct exposure to sunlight can kill many fungi, including white mold fungi.

Treatments & Preventive Measures

  • If you are growing your plants during summer, plant them in shady areas to lower the temperature.
  • But when the surrounding temperature is low, you can place your indoor plants in direct sunlight to block fungal infection.
  • Pruning plants on comparatively cooler days would help prevent fungal infection.
  • Frequently mist your plants during summer heat and wipe them away immediately for cooling effects.

2. Excessive Moisture

Most plant diseases are caused by excessive moisture present on the plant surface. 

The growth of fungi occurs rapidly in moisture (80-85% humidity).

Fungi adore the presence of moisture on the surface of plant parts, so rainy seasons promote the prevalence of white molds on plants.

Also, rainfall washes the fungal spores from infected parts of the plant and transfers them to new plant surfaces.

Treatments & Preventive Measures

  • While watering your plants, water around root areas to prevent white mold infection in aerial plant parts.
  • Take care of water splashes, which can spread the fungus from one location to another.
  • Soggy soil invites fungus into the root of plants, so avoid prolonged soil wetness.
  • If your fruits under storage are getting white mold infection, place them in a clean, cold, and moisture-free room.

3. Soil Factors

Molds can thrive in a wide range of soil environments, so inhibiting their growth in the soil is difficult.

White mold fungi are frequently found in soil with acidic pH ranging from 2-5.

Furthermore, fungi are more prevalent in soil with large pores so they can respire easily.

Additionally, white mold fungi are seen in the soil with high humus content.

Treatments & Preventive Measures

  • White mold fungi are usually seen in soil with acidic pH, so add Lime to the soil and make them slightly alkaline.
  • Remove unnecessary organic matter from the soil.
  • White molds generally live in soil for 5 or more years, so crop rotation is essential.
  • Use fungicides such as Azoxystrobin and Captan for control of fungi in soil.

4. Physical Injuries 

White mold fungi can enter easily inside plants through wounds made by insects or humans and cause diseases.

Fungi must penetrate the host tissue to get inside; physical injuries help fungi do that.

Certainly, weather-related damage like hails and ice are also the reasons behind the damage to plants.

White mold infection is more common in post-harvest fruits, as human activities harm fruits during harvesting.

Moreover, insects and birds are equally responsible for plants’ physical injuries.

Treatments & Preventive Measures

  • Carefully handle plants during pruning, watering, and fertilizing.
  • Prune out the infected parts from plants using sterilized tools.
  • Cover the injured part with Mugwort or Neem leaves paste to prevent fungal invasion.
  • Place the pruned part of the plant facing sunlight so it can recover easily.

5. Nutrient Deficiency 

Nutrient deficiency in plants lowers their immune capacity, making plants more susceptible to fungal infection.

However, white mold fungi adore the potassium deficiency in plants.

Most nutrient deficiencies in plants occur due to a lack of nutrients in the soil.

Additionally, pH fluctuation and reduction in lignin deposition are consequences of nutrient deficiency in plants.

Apart from this, Nitrogen causes the production of antimicrobial compounds in plants, so nitrogen-deficient plants are more prone to fungal infection.

Moreover, deficiency of other nutrients, such as C and N, also increases the susceptibility to white mold fungi and causes the yellowing of leaves. 

Treatments & Preventive Measures

  • Generally, the initial symptom of nutrient deficiency is yellow leaves, so make sure to fertilize the soil more often.
  • Apply phosphate fertilizer frequently.
  • To increase the phosphate level in the soil, add lime to it.
  • Appropriate drainage of the soil can minimize the white mold infection on the roots of plants.

Supplementary Control Measures for White Molds

  1. Turning soil (tillage) 6-10 inches upside down can be helpful to bury the white mold pathogens inside the soil.
  2. Using disease-resistant varieties of crops like Black turtle and Drabo can minimize white mold prevalence on plants.
  3. Botanical fungicides such as Lemongrass and Neem oil reduce the abundance of fungi.
  4. While sowing, leaving 18-24 inches or more space between seeds is necessary to prevent the outspread of fungi.
  5. Try to avoid favorable conditions for fungi to infect plants.

FAQs about White Mold Fungi 

Is white mold problematic to humans and other beings?

Generally, these fungi produce toxins in the plant parts they affect.

If humans and other beings ingest those plant parts, they get short-term effects like allergy, nausea, and vomiting and some long-term effects like carcinogenic.

What are the favorable conditions for white mold fungi to infect plants?

White mold fungi are highly favored by excessive moisture, overfertilization, and high plant populations.

So, the best condition for white mold fungi is during rainfall in a warm environment.

Wrapping Up…

Interestingly, during winter, white mold fungi settle down in dead organic matter in the soil, and warm, moist weather, they infect the new plants.

While planting vegetables or indoor plants, look through your soil carefully. They may contain fungi or spores and can infect your new seedlings.

Good luck!