Here’s a chart showing Indian regions with high fluoride levels in drinking water and common tea brewing styles that may increase the risk of dental or skeletal fluorosis. The red line marks the WHO safe limit (1.5 mg/L). Regions like Andhra Pradesh and Telangana show both high water fluoride and strong tea brewing habits (like long boiling), elevating health risk over time.
Dental fluorosis is preventable. If no action is taken in 10 Years teeth deteriorate.
EARTH -SF -Variant CA ,Chelated Calcium Spray to Reduce Fluoride in Tea
A recent 2025 study showed that foliar calcium sprays (specifically chelated calcium) help reduce fluoride accumulation by:
Interfering with fluoride binding in the cell wall.
Altering the pectin structure in the leaf cell wall, reduces fluoride retention.
Changing gene expression related to cell wall formation and fluoride uptake (Luo et al., 2025).
We provide EARTH -SF which is chelated calcium made from EDTA, AMINO ACIDS and LIGNINS. Product contains 12 % Chelated Calcium. Spray 250 ml per 200 lit water per HA in Tea plantations.
Spray schedule (Assam-specific):
First spray: Pre-monsoon, just before the first flush (mid-March to early April).
Subsequent sprays: Every 20–30 days throughout the active plucking season (April to September).
Apply 4–5 sprays per season for best results.
Spray timing:
Early morning or late afternoon to avoid rapid evaporation.
Avoid spraying just before rain.
Notes:
Combine with surfactants or wetting agents for better leaf absorption.
Ensure good coverage on the underside of mature leaves where fluoride accumulates most
Chelated Calcium use in other crops and results –
1. Chelated Calcium in Vegetable Gardens
Chelated calcium (foliar spray):
Improves vegetative growth, chlorophyll content, and seed yield in crops like beans and artichokes when sprayed at key growth stages (El-Yazied, 2011), (Ismail et al., 2022).
Foliar applications of calcium-EDTA performed better than lime or dolomite soil applications in improving carrot growth and yield on acidic soils (Aparna et al., 2023).
Particularly effective under stress conditions (e.g., drought, salinity), delivering more bioavailable calcium than soil amendments.
2. Post-Harvest Preservation Effects
Strawberries sprayed with chelated calcium (e.g., calcium amino acid chelates or calcium citrate) had reduced decay and weight loss in cold storage and lower incidence of gray mold, improving storability and extending shelf life (Mandour et al., 2019).
Grapes and strawberries treated with chelated calcium showed firmer fruit and increased resistance to post-harvest spoilage, with improvements in berry quality and nutrient composition (Kilany et al., 2022), (Hassan, 2017).
Conclusion: Chelated calcium foliar sprays can significantly improve the post-harvest shelf life and quality of vegetables and fruits by enhancing firmness and reducing disease.
