Researchers tested whether chamomile plant extract could act as a natural weed killer. They grew pea seedlings and exposed them to different strengths of chamomile leaf extract. The study found that chamomile extract does slow down pea plant growth, especially at higher concentrations. While this suggests chamomile might help control unwanted weeds in farming, the research was done in a laboratory setting with seedlings, not in real farm conditions. The findings could eventually lead to developing natural, environmentally-friendly alternatives to chemical herbicides.

The Quick Take

  • What they studied: Whether chamomile plant extract can slow down or stop the growth of pea plants, similar to how it might control unwanted weeds in crops
  • Who participated: Pea seedlings (young pea plants) exposed to different concentrations of chamomile leaf extract in a controlled laboratory environment. The exact number of plants tested was not specified in the study details.
  • Key finding: Chamomile extract reduced pea plant growth and seed germination, with the strongest effects occurring at the highest concentrations tested (8-10% extract strength). The extract also triggered the plants’ natural defense systems to activate protective enzymes.
  • What it means for you: This laboratory research suggests chamomile could potentially be developed into a natural weed control product for farming. However, this is early-stage research conducted in controlled lab conditions, not real farm fields, so more testing is needed before practical applications.

The Research Details

Scientists conducted a controlled laboratory experiment where they prepared an extract from chamomile leaves by soaking them in water. They then applied this extract at six different strengths (ranging from no extract to 10% concentration) to pea seedlings and carefully measured how the plants responded. The researchers tracked multiple aspects of plant health including how many seeds sprouted, how fast the plants grew, what nutrients they absorbed, and how their internal defense systems responded to the extract.

This type of study is called an allelopathy experiment—allelopathy is when one plant produces chemicals that affect the growth of other plants nearby. By testing different extract concentrations, the researchers could determine at what strength chamomile becomes harmful to pea plants and understand the plant’s biological response to stress.

The study measured both visible changes (like plant size and growth) and invisible chemical changes inside the plants (like stress hormones and protective enzymes). This comprehensive approach helped the researchers understand not just whether chamomile affects pea growth, but also how the plants respond at a biological level.

This research approach is important because it provides a foundation for developing natural weed control methods. Chemical herbicides can harm the environment and leave residues in soil and water. If plants like chamomile can naturally inhibit weed growth, they could offer a safer alternative. Understanding the mechanism—how chamomile actually affects plant growth—helps scientists determine whether this approach could work in real farming situations.

This study was conducted in a controlled laboratory setting, which means conditions were carefully managed and standardized. This allows researchers to isolate the effects of chamomile extract without interference from weather, soil differences, or other variables. However, laboratory results don’t always translate directly to real-world farming conditions. The study measured multiple biological markers, which strengthens confidence in the findings. The specific sample size (number of plants tested) was not provided in the available information, which makes it harder to assess the statistical reliability of the results.

What the Results Show

The chamomile extract successfully reduced pea plant growth and prevented seeds from sprouting normally. The effect was dose-dependent, meaning stronger concentrations caused more inhibition. At the highest concentrations tested (8-10%), the extract produced the strongest growth-suppressing effects.

Interestingly, the plants didn’t simply wilt or die passively. Instead, their bodies activated protective defense mechanisms. The plants produced more antioxidant enzymes—these are like the plant’s natural bodyguards that protect cells from damage. The plants also accumulated more protective proteins and carbohydrates, suggesting they were mounting a stress response.

At the same time, the extract caused an increase in harmful molecules called reactive oxygen species (H2O2 and lipid peroxidation), which are signs of cellular stress. This indicates that while the plants were trying to defend themselves, the chamomile extract was still causing internal damage.

The extract also affected how plants absorbed minerals. Potassium and calcium levels increased in the plants, while other protective compounds like proline and amino acids decreased. This suggests the extract disrupted the plant’s normal nutrient balance.

The study found that chamomile extract affected multiple aspects of plant biology simultaneously. The reduction in proline and free amino acids is particularly significant because these compounds normally help plants survive stress. Their decrease suggests the chamomile extract was overwhelming the plant’s natural stress-management systems. The surge in antioxidant enzyme activity shows that plants can sense and attempt to counteract the allelopathic effects, but this defense response requires energy and resources that could otherwise be used for growth.

This research adds to existing knowledge about allelopathy in plants. Many plant species are known to produce chemicals that inhibit the growth of competitors, and chamomile has been suspected of having these properties. This study provides experimental evidence supporting that suspicion and identifies specific concentrations at which the effect becomes pronounced. The findings align with previous research showing that plant defense mechanisms activate when exposed to allelopathic compounds.

This study has several important limitations. First, it was conducted entirely in a laboratory with seedlings, not in actual soil or field conditions where many other factors (weather, soil microbes, water availability, competing plants) would influence results. Second, the exact number of plant samples tested was not specified, making it difficult to assess the statistical strength of the findings. Third, the study only tested pea plants; chamomile’s effects on other crops or weeds might be different. Finally, while the study shows chamomile can inhibit pea growth, it doesn’t prove that chamomile extract would work effectively as a practical weed control product in real farming situations.

The Bottom Line

Based on this laboratory research, chamomile extract shows promise as a potential natural growth inhibitor and warrants further investigation. However, confidence in practical application is low at this stage. Before farmers should consider using chamomile-based products, researchers need to conduct field trials in actual growing conditions, test effectiveness against common weeds, and determine safe application methods that don’t harm desired crops.

This research is most relevant to agricultural scientists, farmers interested in sustainable weed control, and companies developing natural herbicides. General gardeners should not attempt to use chamomile extract as a weed killer based on this single laboratory study. People interested in sustainable agriculture and environmental protection may find this research encouraging as a step toward greener farming practices.

This is very early-stage research. If chamomile extract proves effective in field trials, it would likely take 5-10 years of additional research and regulatory approval before any commercial product could reach farmers. Realistic expectations should account for the significant gap between laboratory findings and practical agricultural applications.

Want to Apply This Research?

  • Users interested in sustainable gardening could track plant growth measurements (height, leaf count, visible health) when testing natural plant extracts on different species, recording the extract concentration used and days elapsed to monitor growth inhibition patterns.
  • Users could experiment with creating and testing their own plant extracts on non-essential plants in a controlled garden area, documenting which plant species show growth effects at different concentrations, building personal data on natural allelopathy.
  • Establish a long-term observation log tracking plant responses to various natural extracts over growing seasons, measuring germination rates, growth rates, and plant health indicators to identify patterns and optimal concentrations for different plant combinations.

This laboratory research demonstrates that chamomile extract can inhibit pea plant growth under controlled conditions. However, this is preliminary scientific evidence from a controlled study and should not be used as a basis for practical applications without further research. Do not apply chamomile extract to crops or gardens based on this single study. Consult with agricultural extension services or professional agronomists before using any plant-based products for weed control. This research has not been tested in real farming conditions and effectiveness in field settings is unknown. Always follow local regulations regarding herbicide use, whether chemical or natural.