Re: Why is the celery with red coloring wilting and the blue is healthy?

Hi there,

Well I went to the supermarket and got all things needed to repeat your experiment. Food colouring was not made by the same manufacturer, but I followed the formula that you sent me.

I did not find any significant difference between the red and the blue colouring based on what I did. I realised after carrying out the experiment that I could have improved on it by placing some celery in ordinary water as well.

I found that both sets of celery stalks survived but the red did look a little bit worse off. However, to prove a significant difference I would have had to use a much larger number of celery stalks (of all different shapes and sizes) than what I had.

On both stalks I noticed some damage which I think may be from swelling. In one of the red stalks, the swelling caused cracks in the stalk, which must have done some damage to the plant transportation system, leading to limpness. This is just my theory. Red may damage more than blue, but I would be looking at shrinking/swelling as the means of damage instead of the interference of light absorption. There also remains the small possibility of some toxic effect. Water is flowing through these plants but the colouring does not. It builds up with time within the plant as you probably noticed. I was looking at the leaves for toxic effects but I did not see anything. Food colouring is fairly inert stuff, which is why it is used in foods.

Your idea about the food colouring was an interesting idea. I did not think that photosynthesis was an issue because it would have taken much longer to have an effect. Even after a week there were still several areas on the leaves where photosynthesis could continue. You could do a control here and have some celery in the dark to see what happens. I hope this provides some help

Richard Kingsley