Gibberellic acid is a plant growth hormone. Here’s what it looks like:


I got some from United Nuclear. Plants normally produce GA, and it’s what regulates their growth. So, if you introduce more to a plant, it will grow faster. There’s a ‘sweet spot’ of concentration you have to hit, or else the plant will die. It’s a very small concentration, no greater than 10 mg/L. GA stimulates the cells of germinating seeds to produce mRNA that codes for hydrolytic enzymes. That stimulates mitosis in leaves, and increases the speed that seeds germinate. It also causes plants to experience cell elongation, breaking and budding, seedless fruits, and can be used to break the dormant cycle. GA plays an important role at the beginning of a plant’s life as well. Before a seed has sprouted, it can’t photosynthesize, so it uses stored energy reserves in the form of starches inside the seed. GA signals hydrolysis by inducing the synthesis of an enzyme called α-amylase. That enzyme then hydrolyzes the starch into glucose, which the seed uses for cellular respiration.

I performed controlled experiments on 3 different plants: a tomato plant, a small cactus, and rose bushes. I had two of every plant, each in it’s own pot, and kept them physically next to each other during the experiment. The control was given only water, and the second plant was treated with a dilution of 5 mg/L. I took photographs of the plants with a reference ruler next to them over the course of several weeks. Here’s an example of one of those pictures:


And here are the final results:

The tomato plants died, because of the Florida summer heat.


That’s the rose bushes. My little brother is standing there for scale. The one on the left was treated with GA, the one of the right was not. There was some growth, but the plants didn’t start at the same height to begin with, so it looks more dramatic than it really is. But the one that was treated definitely grew faster than the control and grew about 2 inches more than the control did during the same time period.


The GA treated cacti grew about 0.5 inches more than the control did.

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