One might think that it’s possible that by increasing urine production, caffeine is using more water, thus dehydrating you, and that it might do the same to a plant. Hypothetically, if caffeine is dehydrating a plant, than the plant would accumulate ABA (a plant growth regulator) and it would grow less (Davies and Tardieu et al, 1994). However, while caffeine causes more urine to be produced in humans, it doesn’t cause them chronic dehydration (Armstrong and Casa et al, 2007). So if it is less likely that caffeine would affect plants through dehydration, how else does caffeine affect plants? There have been a few studies researching exactly how caffeine affects plants.
In Studies on the effect of caffeine on growth and yield parameters in Helianthus annuus L. variety Modern, Khursheed, Ansari, and Shahab studied caffeine’s effect on the Common Sunflower. Seeds of the Helianthus annuus L. variety Modern (the Common Sunflower) were raised with caffeine concentrations from .05-2% to test the mature plant height, days to maturity, yield parameters, and the height on the 30th day of sowing. As a result, seeds treated with a lower dose had a stimulatory effect while seeds treated with a higher dose had an inhibited effect (Khursheed and Ansari et al …show more content…
Are they all true and that the results depend on the concentration? Does caffeine affect different species of plants differently? Other than their inconsistency, they didn’t explain much else other than the plant’s growth. What these studies didn’t explain, were other effects of the caffeine treatment.
They didn’t include other quantitatively measurable effects such as if the plants that had a stimulatory effect also lived longer or shorter, how long the caffeinated plants grew in comparison to the control, etc. In Studies on the effect of caffeine on growth and yield parameters in Helianthus annuus L. variety Modern, the authors didn’t say how long the caffeinated plants lived (Khursheed and Ansari et al 2014). Ranson informed us that the caffeinated plants took longer to germinate, but he didn’t inform us about how long the plants lived (Ranson, 1912).
They also didn’t include qualitatively measurable effects such as if the color was different in the caffeinated plants, the thickness of the plant and/or its leaves, etc. The only one of the studies to record other qualitative effects was The Effects of Caffeine upon the Germination and Growth of Seeds in which it noted that the thickness was effected by the caffeine treatment (Óscar Montes-Zavala and Fernando Dianez et al,