How to Improve Growth with Scientific Experiments

One reason I like to write this blog for HTGSupply.com is because they approached me for a scientific way to find the best LED  The first product I tested was the Tri-band LED.  If you have read other posts you know I have often suggested that good growers experiment with different fertilizers and  grow mediums for seed germination or even lights. I want to take the time to talk about what a scientific approach is because so often people fall victim to advertising that seems to be scientific but in fact is not.

I tried this product and it really made my plants grow great…

Ever heard that? If you add a product to all your plants you don’t know how it is affecting plant growth, even if the growing seems different from past years. Why? Because you need to compare plants with the product to those without the product growing in the same medium with all environmental conditions exactly the same. If you don’t COMPARE plants that are growing in the same area you really can not say if the fertilizer is making a difference or some other factor is…

HOW TO CONDUCT A SCIENTIFIC EXPERIMENT: To do to scientifically based test on a fertilizer* for example you need to use it on some plants, and NOT use it on others. You are creating two groups to COMPARE. You need to be able to compare the difference between plants that are exactly the same in all ways accept one, in this example the fertilizer. The group that gets the fertilizer is called the experimental group. An experimental group is the group in a scientific experiment that is exposed to what you want to test. The group that does NOT get the fertilizer is called the control group. Comparing the control and experimental group is the only way to know if the fertilizer makes a difference. Without this comparison it is just speculation, which makes a great commercial, but will not make you a better grower.
Having multiple plants in a group will help rule out alternate explanations of the experimental results, like the plants directly under the light grew better, or you watered some of the plants more or less etc. The easiest way to compare the groups is to compare the average (called the mean in statistics) of the group. Measure the height, or yield of the plants after harvest and compare the groups. There are a lot of other statistics you could do, but this will be a good place to start… I don’t want to get too into statistical analysis (:

Other than the fertilizer (or whatever you are testing) you need to make sure both groups have everything else the same. The same exposure to light, you can’t have on group next to the fan and the other on the other side of the room. All environmental conditions need to be the same, that is how you can scientifically say a fertilizer improves growth or not.

*Since plants need fertilizer maybe you don’t have to have a group with no fertilizer, you could have two or more groups each with different amounts of fertilizer. This would still allow you to COMPARE groups so you know if more or less fertilizer is changing plant growth. This may be a good way to find the optimal or best amount of fertilizer to add to your plants. You could also use two different fertilizers and compare the groups too. Basically, you can’t just add a fertilizer and draw any conclusions, you will always need something to compare, otherwise it is just your opinion and not science.

I am comparing  products containing beneficial bacteria and I posted the results here..

I have also tested mediums for seed germination.

Good Growing,
Dr. E.R. Myers