The purpose of this project is to study the effects of ultraviolet radiation on germination and growth of edible plants. As earth's ozone layer becomes depleted, growth of agricultural crops may be adversely affected by increasing levels of ultraviolet radiation. My experiment describes the effects of ultraviolet radiation on germination and early growth of radish and peas. Hypothesis: UV radiation can impair radish and pea seed germination, and slow their plant growth. Methods and Materials: Ten seeds of radish and peas were germinated under ultraviolet radiation (test seeds) and under white light (control seeds) at room temperature. After germination, the pea and radish plants were grown in terrariums under ultraviolet radiation (test plants) and white light (control plants).
During the germination phase of the experiment, the timing for complete germination for all seeds was recorded. Height of all plants was measured weekly during the five-week growth phase. Results: All UV radiated and non-radiated peas and radish seeds germinated and produced viable plants. UV radiation did not impair successful germination. UV-radiated pea seeds (test seeds) germinated in 4 days (average), whereas non-radiated pea seeds (control seeds) germinated in 6 days (average). UV radiated radish (test seeds) germinated in 2 days (average), whereas non-radiated radish (control seeds) germinated in 4 days.
Both UV-radiated and non-radiated pea and radish seeds produced viable plants. However, 80% of radish plants, from radiated and non-radiated seeds, grown under UV radiation died within 2 weeks of planting. All pea plants survived under UV radiation. Pea plants grown under UV radiation had lower height (14.2 cm, average! compared to pea plants grown in white light (16.6 cm, average). Radish plants grown under UV radiation were taller (12 cm, average) compared to radish plants grown in white light (7 cm, average). Conclusion: The effects of UV radiation on edible plants can be easily studied using peas and radish. Ultraviolet radiation did not impair germination of peas and radish seeds. One possible explanation is that seeds have protective mechanisms against harmful effects of UV radiation on germination. However, plants, especially radish, were sensitive to the effects of UV radiation (80% died) during the early growth phase. Radish plants were more sensitive to the harmful effects of UV radiation compared to pea plants. Their lack of adaptation to UV radiation may be due to their inability to repair damaged DNA. Further studies are needed to explain this difference. Repeating these experiments, studying the effects of variables such as temperature, and further statistical analysis are needed to confirm these findings.