Streptocarpus Dimetris

Recently I was experimenting with a few different fertilizers. One of them was liquid organic fertilizer that I thought showed great result with my streps. However knowing how subjective conclusion can be if experiment done without proper controls I decided to try semi scientific approach.

Since organic fertilizer are very expensive and not always easy to find, I decided to check its effectiveness by comparison with two inorganic fertilizers. Both have about 20-10-20 formula with all necessary micro elements in it. One of inorganic one was Peat Lite special 20-10-20 (on the photo set of seven plants on the right)

In order to do my experiment, I did not fertilize plants(DS-Little Plushy Arctic Fox) for about 6 weeks. I only use Reverse Osmosis water. There were under the fluor. light and they grow very rapidly. By the end of 6 weeks all plants looked quite week and the color of the foliage was light green. They obviously needed fertilizer. Each fertilizers I tried in two different concentration (these concentration I found in precious experiments) Each concentration was applied to seven identical plants. Concentrations of organic and inorganic fertilizers were equalized according to their N-P-K numbers. Fertilizers were dissolved in Reverse Osmosis water.

Here is the final result of one of my experiments. You can see 3 sets of seven plants. All 21 plants were practically identical when experiment begun. Unfortunately I did not photograph it then. I did not plan to post it to the forum. Right set of plants looks the best. Middle one is the worst.

Experiment lasted 4 weeks. Surprisingly, organic fertilizer did not show any advantage over two inorganic ones. So far I think that fertilizer Peat-Lite Special 20-10-20 is the best one. In my next experiment I will compare Peat-Lite Special 20-10-20 to another inorganic fertilizers, that are more readily available.
Concentration interval 1/8-3/8 tbs/G was the best one. Now I use 1/8 tbs/G in each watering.
To make it easy I make very concentrated solution and add curtain amount to my Reverse Osmosis water.

Please note, that experiment was conducted when growing condition was ideal. When plants are dormant during the winter (without additional light), this concentration might be not necessary (even harmful) to the plants.
Also I did that experiment only once and only with one hybrid. There are many different factors that can influence the result of experiment like this one.

I was quite surprised that I did not see any benefit of organic fertilizer, that have all amino acids. I was even more surprised when I dig into the literature. It looks like that only recently scientists started to study absorption of amino acids (from organic fertilizer. There are not amino acid in regular inorganic fertilizers) by plants roots. So far, there are not hard evidence that amino acid absorption by plant's root play any significant role in plant grow. That is exactly what my little experiment showed.

I am not a plant scientist. It would be great, if anybody with relevant background comment on this matter.

Olga Makarova, PhD (Molecular Biology, not Botany:-( )

Thank you. The result is obvious