BBQtoast
Well-Known Member
An informative picture showing the flavonoid, carotenoid cycles of cold stress and heat against controls.
If a crop was designated to be germinated at 18c/above and we drop to 15c we see such exspression. I quite often see this in my Tom's and cannabis seedlings until room temperature is increased to 20c and above.
At that level my soil adapts to the room temperature with a small dip during lights out. If your approaching winter and see a similar colour in your seedlings or new growth you may need to turn on or turn up your heating.
The internal cause lies in zeaxanthin cycles and similar pigments and is seemed to be an adjustment of photosynthetic efficiencies. So before you blame light or water or even pH first check it's not temperature and remember both tomatos and hemp would prefer it never to drop under 20c in the soil and air.
The experiment is a common one and you can find chilling stress responses for most plants over on Google.
