Science Fair Project Ideas for Killing Plants

• For a successful science project, combine your love of botany with a scientific investigation of the factors that affect plant death. Whether you want to determine the most effective way to kill weeds or to establish ideal growth conditions to prevent plant death, a botany-based science fair project is a suitable way to combine your interests in plant life with your desire to engage the scientific process.

Herbicides

• Herbicides are a class of pesticides specifically designed to target unwanted or invasive plant species. Herbicides are classified in terms of the mode of application, active ingredients, degree of selectivity and toxicity. Design an experiment in which you test the effectiveness of several types of commercial herbicides in ridding an area of soil of unwanted weeds. Either create a grid in your own yard and document your application of the herbicide in each area, or create self-contained biomes to treat individually with various herbicides to display at your science fair table. Another option for investigating the effectiveness of herbicides is to compare homemade herbicides to commercially produced herbicides. Monitor not only the speed and effectiveness of plant death but also the peripheral damage to other plants and any permanent changes in the soil pH that may affect future growth. A chart that keeps track of the timeline of plant death for each type of herbicide is a suitable display for your science fair table.

Plant Tolerance

• Several factors impact plant growth, with each plant requiring a different sun exposure, watering schedule and soil nutrients in order to survive. An experiment that determines a plant's tolerance for varied conditions evaluates the hardiness of a plant in different climate or soil conditions. Choosing a native plant, flower or grass from your local area is one of the simplest ways to conduct your experiment. An investigation that determines drought tolerance might including watering one plant sample daily, one sample every three days and one sample weekly. Track the rate of wilting or growth stunting in each plant to determine whether or not drought is a factor that might kill the plant. Another option is to alter the soil pH in your samples by adding varying levels granular sulfate to lower the pH or hydrated lime to raise the pH. Determine the plant's tolerance threshold for soil acidity by monitoring plant growth throughout the experiment.

Watering Alternatives

• Plants require water for proper growth, and an overabundance or lack of water can cause plants to die. Design an experiment in which you examine the impact of other types of liquids in terms of sustaining or killing plants. Simple potted plants are best suited for this experiment. Collect a range of liquid materials to test, like orange juice, sugary syrup, oil, vinegar or carbonated beverages. In addition to "watering" your plants daily with their allotted liquids, also hypothesize about how the ingredients of each liquid might impact plant growth. A chart that depicts which liquids cause the most damage in the shortest amount of time is a suitable display option for your science fair display.