Sulfur, One of the nine
Sulfur (S) is one of the nine essential minerals required by plants for growth.
As sulfur problems are quite rare in comparison to other macro nutrient issues it can often be overlooked but this doesn’t make sulfur any less interesting or important to study.
Sulfur plays a role is several key functions within a plant including structural, metabolic, developmental, and production of terpinoid and flavonoid molecules.
Sulfur is also incredibly important in the formation of chlorophyll molecules, chlorophyll is what makes our plants green and allows photosynthesis to occur, sulfur also has a strong synergistic relationship with zinc, phosphorus and molybdenum.
S is an immobile or semi-mobile nutrient and means signs of a S deficiency usually show up on new growth.
New growth emerges a lighter green than usual and will progress to yellow unless something is corrected.
Due to the yellowing of the leaves a S deficiency is sometimes mistaken for a N deficiency, however the two are very different as N is a mobile nutrient it will present itself first on (lowest sets) older leaves.
The yellowing associated by a S deficiency will start at the base of the leaf and move out towards the edges. Other indicators are purpling (not red) of the leaf petioles and discolouration on the underside of the leaf.
If allowed to go untreated for an extended period of time plant growth will become significantly stunted and if the plant is in flower, flower formation will cease and existing flowers may die, even if they do mature the usual end results are significantly diminished in return.
SULFUR QUICK FACTS
- Sulfur exists in every living cell
- Synthesizes specific proteins & amino acids (methionine and cysteine)
- Sulfur critical during photosynthesis and for plant resilience
- Sulfur is not essential for photosynthesis, but vital for establishing.
- Sulfur is needed for seed production and maturation
- Sulfur is the key element in some organic compounds giving off odours i.e Garlic, onion, mustards etc.
- S is absorbed primarily as an anion in the form of SO42-