What is Allelopathy?

This experiment is designed to test the allelopathy of two different treatments, Eucalyptus (Eucalyptus cinerea) and Lemon (Citrus limon). The two treatments will be tested on radish seeds (Raphanus sativus) to investigate the effect of the treatments on the germination of the radish seeds. Allelopathy is the beneficial or harmful effects that one plant has on another plant by the release of chemicals. Allelopathy studies the interactions among plants, fungi, algae and bacteria with the organisms living in a certain ecosystem, interactions that are mediated by the secondary metabolites produced and exuded into the environment (Francisco A Macías, José MG Molinillo, Rosa M Varela, Juan CG Galindo 2007). The plants use

- Traits such as resistance to pesticides may cause overpopulation in unfavorable plant species, such as weeds. This resistance could also be passed on to species of insects that the pesticides were made for, thus negating the effect of the pesticide in the first place.

Plants are found everywhere on earth, up high on the ridge and down low in caves and caverns. The types of plants that live in these places depends on many factors. These factors are separated into two different categories, the biotic factors and the abiotic factors. Some of the biotic factors include, predation, competition, and habitat destruction. Plants with limited competition and large amounts of resources will be in a higher abundance than plants with limited resources and higher competition rates will be confined to areas and either out competed or will be the dominant species. Certain plants adapt to these factors and thrive and others don’t do as well. Some of the abiotic factors include, sunlight, water, temperature, and wind. These

might affect the fitness of each variant. In other words which factors might increase plant growth, survival,

also damage the plants and prove to be a detriment to its lifetime. Plus, plants

Plant compounds play a very important role in the defense of plants and in this experiment the plant defense compounds of caffeine and Kava-kava were tested on Daphnia magna to test if there was a change in heartbeat of the organism. The purpose of the experiment was to see how these compounds affected the Daphnia magna. The t-values for both the caffeine and Kava-kava were calculated to be 1.82 and 1.62, which were both smaller than the obtained t-critical value of 2.57. A conclusion was drawn that there was no statistically significant difference in heart rate after the plant defense compounds of caffeine and Kava-kava were added compared to before they were added.

As plants aren’t, by their nature, very mobile they have developed a variety of ways of protecting themselves from all things herbivorous. Many have evolved spikes, stings and even just an unpleasant taste. However, many went down the route of the ultimate deterrent – being so poisonous that anything eating them was unlikely to ever do so again.

Germination of seeds, and early stages of growth are important determinants in interspecies competition (Mangla et al. 2011). Higher proportions of B. gracilis seedlings to B.rapa will allow B. gracilis to gain an advantage both in germination, and in development of its roots and shoots. B. gracilis can then establish itself and sequester resources (water, sunlight soil nutrients) for growth and survival before B. rapa. Additionally, it was predicted that the mean biomass (root and shoot) of B. gracilis would increase as the ratio of B. gracilis to B. rapa increased. Multiple roots of long length in B. gracilis will be favoured as they can better compete in water and nutrient acquisition against B. rapa (Craine and Dybzinski 2013). Increased ability to acquire nutrients thereby increases the availability of nutrients B. gracillis has to grow, increasing shoot length and thickness. On this basis, the mean height of B. gracilis was predicted to increase as the ratio of B. gracilis to B. rapa increased as

Valladares, F., E. Gianoli, and J.M. Gomez. 2007. Ecological limits to plant phenotypic plasticity. New Phytologist 174:749-763.

This hormone can also regulate dehydration, salinity and temperature stress responses including stomatal closure. It can help regulate the growth of roots and shoots, flowering and production of leaf types. However, the role of ABA in plant defence appears to be more complex, and vary among different types of plant-pathogen interactions. ABA has shown to be involved in the negative regulation of plant defence against various biotrophic and necrotrophic pathogens. Exogenous application of ABA enhances susceptibility of various plant species to bacterial and fungal pathogens.

Megaloblastic anemia occurs when the synthesis of DNA is inhibited during red blood cell production. The number of red blood cells is lower than normal, and they are bigger sizes than normal. This means there are less red blood cells making it into the blood stream. Deficiencies in vitamin B12 and folate can cause this.

situation cannot be fair when chemicals are used. Humans today expect that when they kill a plant

Brassinosteroid molecules although present at low concentration in plants but still they have been reported throughout the plant kingdom and also they are broadly distributed from lower to higher plants. They have also found to be present in different plant organs such as flowers, anthers, seeds, pollens, roots, stems, leaves and grains, although brassinosteroid level varies among them according to organ type and tissue age. Like young and growing shoots contain higher brassinosteroids as

Allelopathic chemicals can also exist in soil, affecting the surround plants and those planted afterwards. Studies have shown that Leucaena leucocephala, a tree promoted for water conservation and revegetation, contains a toxic amino acid in its leaves and foliage that prevents the growth of other trees but not its own seedlings. Research has also shown that this species reduces the yield of wheat and increases the yield of rice. Other allelopathic plants include mango, box elder, broccoli, and Eucalyptus.

All plants are subjected to a multitude of stresses throughout their life cycle. Depending on the species of plant and the source of the stress, the plant will respond in different ways. When a certain tolerance level is reached, the plant will eventually die. When the plants in question are crop plants, then a problem arises. The two major environmental factors that currently reduce plant productivity are drought and salinity (Serrano, 1999), and these stresses cause similar reactions in plants due to water stress. These environmental concerns affect plants more than is commonly thought. For example, disease and insect loss typically decrease crop yields by less than ten percent, but severe