The Interactions Between Plant Hormones and Nutrients in Relation to Plant Growth
Surat Singh
Burnaby South Secondary
Floor Location : M 088 V

Both external (light, water, air, nutrients) and internal factors (hormones, proteins) play an important role in regulating plant growth and development. The purpose of my experiment was to find out how plant hormones and nutrients interact to regulate the bean plant growth. I studied the effect of four types of plant hormones or inhibitors, (i) gibberellic acid (GA, which promotes cell division and leaf growth), (ii) chlorocholine chloride (CCC - a gibberellic acid inhibitor), (iii) benzylaminopurine (BAP, a synthetic cytokinin that promotes cell division), and (iv) naphtheleneacetic acid (NAA, which affects cell elongation and root growth), on the growth of green bean plants. The effect of these plant hormones, with and without a fertilizer mixture of NPK 20-20-20 and bone meal, on the green bean stem height, leaf length, leaf width, chlorophyll levels and protein levels was measured over the span of three days (short term) and nine days (long term). The plants that had received both giberellic acid and fertilizer had a substantially higher stem height growth increase (174.17%) after 9 days compared to the other treatment groups. The plants that received the mixture of NPK 20-20-20 had a higher overall growth percentage increase for every factor measured, than the green bean plants that had received no fertilizer. Finally, a cytokinin (BAP or zeatin, with or without the fertilizer mixture) was more effective than other treatment in increasing the leaf chlorophyll levels. The importance of this experiment is that a specific combination of nutrients and plant hormones can be used to increase the growth of different plants.