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L-Proline 99% Crystalline Powder

High-Purity Plant Osmoprotectant & Cold/Drought Stress Biostimulant

Nova-Agri Biotech supplies L-Proline 99% Crystalline Powder (CAS 147-85-3, C5H9NO2) — a high-purity amino acid plant biostimulant and osmoprotectant used in foliar sprays, fertigation and biostimulant formulations to protect crops against drought, frost and salinity stress. L-Proline is a naturally occurring amino acid that plants accumulate under stress; supplementing it externally helps crops maintain cell turgor, stabilize membranes and keep photosynthesis running during cold snaps, heatwaves and dry periods. Key specifications: assay ≥99%, white crystal or crystalline powder, 100% water-soluble at 20 °C, pH 5.9–6.9, moisture ≤0.3%, heavy metals Pb/As/Cd/Hg ≤1 ppm, verified by a batch COA for every shipment. Packed in 25 kg bags (custom OEM packaging available), MOQ 500 kg. Standard lead time: approximately 10 working days to Shanghai port after payment confirmation, with a batch COA for every shipment. As a leading L-Proline manufacturer in China, we offer direct bulk supply and full technical documentation for agrochemical distributors and formulators worldwide. For formulators: add 2.0–10.0 kg per 1,000 L (0.2%–1.0% w/v) in liquid biostimulant blends, 5.0–20.0 kg per metric ton (0.5%–2.0% w/w) in dry blends, or 10.0–30.0 kg per 1,000 L (1.0%–3.0% w/v) in high-concentration concentrates diluted 1:500–1:1,000. For field use: apply 200–500 g/ha as a foliar spray (working solution 0.02–0.05% w/v, approx. 200–500 ppm; dilute approx. 1:2,000–1:5,000 in water) 24–48 hours before expected frost or heat events; 1.0–2.0 kg/ha via drip irrigation during prolonged drought or high-EC salinity stress; or 0.5–1.5 g per kg of seed for seed treatment.

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High purity L-Proline 99% crystalline powder supplied by China factory

Technical specifications

CAS No.
147-85-3
Molecular formula
C5H9NO2
Molecular weight
115.13 g/mol
Shelf life and storage
24 months; store in a cool, dry place below 25 °C, away from direct sunlight

Package

25kg bag

Active Ingredient(s)

Assay
99%

Physical and Chemical Properties

Solubility in 20℃ water
100%
pH
5.9-6.9
Moisture
0.3%
Appearance
White Crystal or Crystalline Powder

Heavy Metals

Lead
≤ 1ppm
Arsenic
≤ 1ppm
Cadmium
≤ 1ppm
Mercury
≤ 1ppm

Key benefits

  • Superior Cold & Freezing Stress Defense: Prevents ice crystal formation within plant cytoplasm, preserving cell membrane integrity during sudden spring frosts and winter cold spells.
  • Drought, Heat & Salinity Stress Tolerance via Rapid Cellular Osmoregulation: Regulates osmotic pressure during extreme drought, heatwaves, and saline conditions without disrupting critical enzymatic activity or cell hydration.
  • Enhanced Pollen Fertility & Fruit Set: Promotes pollen tube germination and flower tube elongation, significantly reducing blossom drop and ensuring higher fruit set rates under unfavorable weather.
  • Potent Antioxidant & ROS Scavenger: Neutralizes toxic free radicals accumulated during stress events, delaying leaf senescence and maintaining chlorophyll activity.
  • 100% Soluble & Clean Dissolution: Fine crystalline powder that dissolves instantly into clear solution with zero insoluble residues, ideal for precision fertigation, drip irrigation, and drone spraying.
  • Direct Factory Bulk Supply: Sourced directly from a certified L-Proline manufacturer, supported by flexible packaging and custom OEM formulation service.

Suggested dosage & application

For Formulators & Fertilizer Manufacturers (Industrial Blending):

  • Enriching Liquid Biostimulant Formulations: Add 2.0 kg – 10.0 kg of L-Proline 99% powder per 1,000 Liters of finished liquid (0.2% – 1.0% w/v) to power high-end "Anti-Frost & Drought Recovery" biostimulant lines.
  • Water-Soluble NPK & Micronutrient Powder Blends: Incorporate 5.0 kg – 20.0 kg per Metric Ton (0.5% – 2.0% w/w) to boost plant metabolic resilience and pollen vitality.
  • Foliar Pollen & Flowering Concentrates: Blend 10.0 kg – 30.0 kg per 1,000 Liters (1.0% – 3.0% w/v) for targeted pre-flowering foliar sprays diluted at 1:500 to 1:1,000 in orchards.
  • OEM Customization: We offer tailored bulk particle sizes, private label packaging, and full technical COA dossiers.


For Commercial Field Application (End-Users & Growers):

  • Foliar Spraying: Apply 200–500 g/ha (diluted approx. 1:2,000 to 1:5,000 in water; working solution 200–500 ppm). Spray 24–48 hours prior to expected frost/heat events or during pre-bloom and fruit set windows.
  • Drip Irrigation / Fertigation: Apply 1.0–2.0 kg/ha during prolonged drought, high-EC salinity stress, or early root initiation.
  • Seed Treatment / Priming: Use 0.5–1.5 g per kg of seeds to increase seedling emergence uniformity under low temperatures or high salinity.

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Frequently asked questions

01How does L-Proline 99% powder function as a plant osmoprotectant?

L-Proline 99% is a key amino acid osmolyte naturally synthesized by plants. When applied topically or root-fed, it rapidly accumulates in cells to maintain hydration and osmotic balance during severe stress (drought, frost, or heat). It prevents cytoplasm dehydration while protecting essential enzymes and cellular structures.

02Why is L-Proline particularly effective against cold temperatures and sudden spring frost?

During cold stress, water inside plant cells can freeze, rupturing cell walls and membranes. L-Proline acts as an organic cryoprotectant, lowering the freezing point of cell sap and stabilizing membrane lipids to prevent chilling damage and tissue necrosis.

03How does L-Proline improve flower fertilization and fruit set?

Pollen grains and pollen tubes contain naturally high concentrations of proline, which supplies energy for rapid germination. Exogenous application of L-Proline 99% before flowering enhances pollen tube growth, improves fertilization efficiency, and prevents flower drop caused by cold or dry winds.

04Is L-Proline 99% powder compatible with other amino acids and fertilizer inputs?

Yes. L-Proline 99% exhibits outstanding chemical stability and water solubility. It is fully compatible with glycine betaine, humic acids, seaweed extracts, chelated micronutrients (Zn, B), and standard NPK fertilizers in tank mixes.

05Can I request bulk OEM packaging and free laboratory samples from your factory?

Yes. As a direct L-Proline manufacturer in China, we provide 100g–500g free laboratory samples for quality evaluation. We also offer OEM L-Proline packaging options with custom labels for global distributors.

06Can L-Proline be used together with glycine betaine?

Yes. L-Proline and glycine betaine are complementary osmoprotectants with different protective strengths — proline excels at cold and frost defense and cell membrane stabilization, while glycine betaine is especially effective against heat and salt stress. Many growers tank-mix both in one foliar program, or use proline for early-season frost protection and betaine for heatwaves. Both are fully compatible in water-soluble blends.

07What is the MOQ, packaging and lead time for L-Proline 99% crystalline powder?

L-Proline 99% crystalline powder is packed in standard export packaging 25 kg/bag with OEM customization available. MOQ is 500 kg; lead time is about 10 working days to Shanghai port, and every shipment includes a batch COA.

08How should L-Proline 99% powder be stored?

Store sealed in a cool, dry place below 25 °C, away from direct sunlight and moisture. Shelf life is 24 months from the manufacturing date; keep the packaging tightly closed after use.

09What is the CAS number and molecular formula of L-Proline 99%?

L-Proline has CAS 147-85-3 and molecular formula C5H9NO2.

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