Onion bulb extract

Onion bulb extract (Allium cepa) is a natural botanical preparation categorized as an organic plant protection product. It acts primarily through its high concentration of phytochemicals, including sulfur-containing compounds like allicin and various volatile oils.

The primary mode of action is as a repellent, where the intense scent of the extract interferes with the chemical receptors of insects. By masking the natural attractants of host plants, it effectively disrupts the colonization process of various pests.

Furthermore, the extract exhibits significant fungistatic and bacteriostatic properties. These compounds disrupt the cellular integrity of fungal pathogens, effectively inhibiting spore germination and preventing the growth of mycelium on the leaf surface.

Application of the extract is also known to induce systemic acquired resistance in plants. It triggers the activation of defensive genes, causing the plant to produce proteins that enhance its tolerance to biotic and abiotic stress factors.

As a completely biodegradable substance, it leaves no toxic residues in the soil or produce, aligning with the principles of sustainable and regenerative agriculture practices.

This extract is used to manage a range of soft-bodied insects, including aphids, whiteflies, thrips, and spider mites, which can cause significant damage to vegetable and horticultural crops.

It is also effective against a variety of fungal pathogens such as powdery mildew and downy mildew, providing a protective barrier on the plant foliage during high-humidity conditions.

• Aphids and plant lice.
• Spider mites.
• Powdery mildew fungi.
• Various bacterial leaf spots.

The application rate is typically determined by the concentration of the extract and the specific crop sensitivity. Generally, a dilution of 1% to 5% is used for foliar applications via standard sprayers.

Applications should follow a preventative schedule, starting early in the growing season. Treatments are generally performed every 7 to 10 days to maintain an effective repellent barrier on the plant tissues.

Best results are achieved when spraying is done during late afternoon or cloudy weather to minimize the breakdown of volatile active compounds caused by direct ultraviolet radiation.

Thorough coverage of all plant surfaces, particularly the underside of leaves, is essential to ensure that the repellent effect covers the entire foliage area effectively.

Combining the extract with other botanical preparations can enhance the duration of effectiveness and create a broader spectrum of protection against various environmental threats.

The most significant limitation is the short residual effect. Due to the high volatility of the active components, protection may be lost rapidly following heavy rainfall or irrigation.

The substance lacks systemic movement within the plant, meaning it provides only localized protection. Therefore, it is ineffective against internal pests or infections that have already established deep within the plant tissues.

When handling concentrated forms of the extract, safety precautions such as eye protection are necessary, as the volatile compounds can cause significant irritation to mucous membranes.

The stability of the working solution is low; it should be prepared fresh for each application, as the bioactive ingredients degrade quickly when exposed to air and light.

While generally safe for pollinators, the intense odor may temporarily influence the foraging behavior of bees, so careful timing of applications is recommended to minimize disruption.