Chlorophyll is the pigment that captures light for photosynthesis. Plants carry chlorophyll a and b, which absorb strongly in the blue (around 430-450 nm) and red (around 640-680 nm) and reflect green. Each molecule has a magnesium atom at its centre, and building it needs nitrogen, magnesium and iron, among other things.
In practice
Leaf colour is largely chlorophyll status:
- Pale or yellow older leaves: often nitrogen or magnesium moving to new growth, or natural late-flower senescence.
- Pale new growth: often iron, sulfur or root-zone/pH issues.
- Dark, glossy green: frequently excess nitrogen.
Chlorophyll breakdown in late flower reveals other pigments (carotenoids, anthocyanins) and is normal, especially with a nitrogen taper.
After harvest, chlorophyll still in the material breaks down during a slow dry and cure. Material dried too fast keeps a green, grassy, hay-like smell. Drying and curing, not flushing, decide that.
Don't confuse with
- Anthocyanin: purple/red pigment in the vacuole, not photosynthetic.
- Carotenoids: yellow-orange accessory pigments.
- Chlorosis: the symptom of losing chlorophyll.
Myth check
"Flushing removes chlorophyll" is a Myth. Chlorophyll is broken down by the plant's own senescence and by a proper dry, not by plain water at the roots. See the flush debate.
The process in chloroplasts that uses light energy to turn carbon dioxide and water into sugars and oxygen; cannabis uses the C3 pathway.The programmed ageing and breakdown of leaves and other tissues, in which the plant recycles nutrients (especially nitrogen) from old leaves to developing flowers and seeds.Sulfur (S) is a secondary nutrient taken up as sulfate, used in the amino acids cysteine and methionine; deficiency yellows new growth fairly evenly.pH measures how acidic or alkaline a solution is on a 0–14 scale; in growing it controls nutrient uptake, with soil best near 6.0–7.0 and hydro 5.5–6.5.Gradually cutting nitrogen in late flower, toward zero near the finish, while still feeding phosphorus, potassium, calcium, magnesium, sulfur and micronutrients; GenetixBay's alternative to flushing.A grassy, hay-like aroma in dried cannabis caused by drying too fast, over-drying or bacterial activity; in GenetixBay's view it never fully cures out.Feeding only plain water for days or weeks before harvest to "clean" the plant; GenetixBay rates it a Myth that harms yield, unlike a root-zone salt flush.Yellowing of normally green plant tissue caused by too little chlorophyll, from nutrient shortage, poor root uptake, pH lockout, light damage, pests or normal ageing.A water-soluble flavonoid pigment stored in cell vacuoles that colours leaves, stems and flowers red, purple or blue, set by genetics and enhanced by cool temperatures.
