The Effect of Eucalyptus Oil on Pests and Weeds

Outline of research

Over a time period of three months an experiment will be carried out to investigate the effects of Eucalyptus oil on weeds and possibly pests. An area with plants affected by pests and weeds will be found by looking for damage to plants affecting their growth. Then drops of Eucalyptus oils will be placed around the affected area once a week for a period of three months with results being taken the following week before new application.

Hypothesis and Aims of Research

It is expected that the Eucalyptus oil will help to ward off destructive pests and weeds from more favourable plants that are often heavily affected by this. The aim of this experiment is to determine whether or both the invader Eucalyptus can be used to protect more favourable plants from weeds and pests.

Context of Research

If the hypothesis is proved correct through the experiment mentioned above this provides a solution to the use of dangerous pesticides and the growing problem of Eucalyptus, which is an alien invasive plant, outcompeting indigenous plant life. It offers a use for eucalyptus so that the amount of Eucalyptus trees in South Africa can be reduced through non – harmful means, while helping to maintain some of the more favourable plants in the country.

Review of Literature

A number of sources were used to help further research relating to the research question stated. In this review of literature these sources will be summarised and analysed regarding their reliability, validity, usefulness and possible limitations.

Eucalyptus Essential Oil as a Natural Pesticide

The value of the Eucalyptus tree besides aesthetic appeal is it’s use in the manufacturing of medicine, gum, oil and timber. Oil is of the highest value due to is use medicinally, in food and in perfumes and sprays. Biologically it’s use is in its ability to ward off fungi, and it’s function as a natural herbicide and pesticide. This study is important as it provides an applicable solution for the issues involved with synthetic pesticides, both economically speaking as well as environmentally. This source is valid in its relation to the research question. It helps to further or improve my research question and it is peer reviewed as multiple authors with authentic credentials were involved in the study. This source can also be considered reliable due to the credentials of the authors, with a balanced, informative and objective style of writing. The facts recited seem trustworthy as they are in line with other paper and sources referred to. This source was also useful in its significance as the question or experiment being carried out is very similar to my own. It provides new insight on previous uses for eucalyptus and it also provided further benefits to adding eucalyptus to an environment that can help further the experiment and help my analysis of the results, as it would explain certain occurrences and whether they were beneficial or not. However a limitation to this source would be that the full article is hard to acquire as you need special access or it must be purchased. Therefore, the details if the experiment and the result are not accessible and the full reliability and usefulness of the source cannot be analysed.

Repellent Activity of Essential Oils

The use of synthetic pesticides and the their affects on people’s health and the environment around gas encourages researchers to find a natural solution to this issue as well as the issue of pests and weeds. Research into natural pesticides, specifically essential oils and their impact when used as such have come up with extensive results. Research into the repellent energy of these essential oils have been researched and are found to be related to Monoterpenes and sesquiterpenes.(Neripan,Verbelab, Stashenkob), The period of protection from insects is also improved by the addition of essential oils and the reason for the repellent activity of this plant is related to the release of a lot of hormones. The use of natural oils allows a more efficient and cost effective form of pesticides and protection. This is a valid source as it was gained empirically, meaning through proper observation and experimentation, it is peer reviewed and contains biologically accurate terminology and methodology. It can also be considered reliable for the same reasons and the style if writing contains little to no bias and is very informative. It is useful as it provides a reason why an investigation such as this would need to be carried out as synthetic pesticides are now more harmful than beneficial and it also provide the biological reason for eucalyptus being able to ward off weeds and insects. This source has the same limitation and the previous one as it is inaccessible and therefore a full analysis of the experiment is not possible.

Plant-Based Insect Repellents

Another potent natural pesticide used is lemon eucalyptus essential oils, which is normally used in cosmetics, however it serves a good purpose in warding off plant eating and damaging insects. It was found to be effective against mosquitoes, however it evaporates quickly and is only effective for a few hours or maybe a day. However, it can be modified and the use of this as a pesticide is favourable as it helps prevent malaria and it is considered to pose no harm to human health. This source is valid as it is empirical data from a primary source where this data was collected originally and not taken from previous experiments. This research is also peer reviewed, although a limitation is that only two researchers are involved meaning we do not have a broader outlook or review on the topic. The usefulness of this source is that shows the effects of a different species of Eucalyptus and how that is still valuable. It also expresses the limitations of Eucalyptus oil when not modified for certain conditions.

Potentiality of Plants as Source of Insecticide Principles

The research of this study has shown that specific chemical compounds within certain plants such as Eucalyptus are known to either kill or repel insects and modification of these compounds lead to possible uses in fumigation and week as use in pesticides. Specific pests that were susceptible to the use of eucalyptus was damaging ticks often found on crops. This study found the use of natural pesticide valuable for the prevention, detection and control of dangerous pests.(Safia Zoubiri, Aoumeur Baaliouamer)

The validity of this review is evident in its reference to previous investigations and experiments. It’s direct relation to my experiment would be that it tests for multiple species including Eucalyptus globulus. It also provides research from recent experimentation and older experimentation. It is reliable due to the high credentials of all researchers involved as well as all the results referred to yielded similar results to one another and my own. It is useful as it is a secondary source, this means that the results used were gathered form multiple other experiments and it provides the different results for comparison with my own. It also offered a point of the oils not being long lasting which is accurate, however the Eucalyptus oil used in my experiment seemed to last longer as some effects were noticeable a week later.

Chemical composition and insecticidal activity of plant essential oils from Benin against Anopheles gambiae (Giles) Authors: Annick D Bossou, Sven Mangelinck, Hounnankpon Yedomonhan, Pelagie M Boko, Martin C Akogbeto, Norbert De Kimpe, Félicien Avlessi and Dominique C K Sohounhloue

Nine different plant species were gathered from Benin a placed in the same conditions where they were dried, free from light and at room temperature. (Annick D Bossou, Sven Mangelinck, Hounnankpon Yedomonhan, Pelagie M Boko, Martin C Akogbeto, Norbert De Kimpe, Félicien Avlessi and Dominique C K Sohounhloue.) Essential oils were also diluted before use. Although, eucalyptus was not the most effective of all the oils tested, it still was effective to some extent as it came out with similar results to the previous reviews used. The research question of this study is relevant and logical as well as linked to previous experiments. Appropriate terminology and biblical language is evident in the results gathered making this source valid to my study. The objective use of language as well as the consistency of the results with other experiments mentioned in this literature review makes the source more reliable, it’s reliability is also emphasized by it’s thorough experimental design. The value in this study is that it sheds light on the importance of experimental design and ensuring the most accurate results possible. It also offer a unique perspective by showing it in comparison to other essential oils which may have been and were more effective. A limitation is the strict conditions under which this experiment was conducted, which makes it questionable whether or not these results are applicable to other circumstances.

Discussion And Analysis of results

The results gathered through the three month period of experimentation show that the Eucalyptus oil did have a small affect on the plants and insects in the area. After the application of the Eucalyptus there was a reduction in the amount if damage found on the remaining leaves with an improvement in growth. As was mentioned in the sources used for my literature review the hormones released did ward off animals and other plants, (Neripan,Verbelab, Stashenkob) as there was a slight decrease in life within the 15cm diameter measured out. It was more cost effective, however my research shows that larger concentrations of Eucalyptus oil would be needed for a more noticeable change or for change on the scale of synthetic pesticides. My experimental design may have been improved if I had an accurate number of insects in the area to be able to give more precise results, as well as a way of ensuring that result were not due to external factors, for example a change in season. Another way of improving my experiment may have been to have planted a different plant with the 15 cm diameter half way through the experiment to examine any possible affects on growth more accurately.

Conclusion

In conclusion, eucalyptus oil is a possible option to replace synthetic insecticides and herbicides as they do affect the amount life within a close radius to areas of application. Less insects were visible, no new competition arose with new plants or weeds. The wellbeing of the plant being experimented on was maintain by avoiding direct application. Therefore, the invader Eucalyptus globulus can be used to create a harmless and natural pesticide and benefit the environment.