Streptomycin Sulphate 9% + Tetracycline Hydrochloride 1% Bactericide Uses

Streptomycin Sulphate 9% + Tetracycline Hydrochloride 1% is a systemic antibiotic combination bactericide, registered for use in India under the Insecticides Act, 1968, formulated as a soluble powder (SP). It is registered for the control of bacterial diseases — such as bacterial blight, bacterial leaf spot, canker and bacterial wilt — across a range of field, vegetable and fruit crops, and is one of the very few chemical tools available for managing bacterial (as opposed to fungal) plant diseases in Indian agriculture. This page lists its mode of action, key benefits and what is known about its crop-wise recommended dosage, with dosage figures flagged clearly where independent sources did not agree.

Which Problem Is This For? (Symptom Guide)

Not sure whether what you're seeing in the field matches this bactericide's use case? This guide helps you match field symptoms to the correct problem — this exact 9%+1% streptomycin-tetracycline composition is sold under a number of Indian brand names, none of which were confirmed on WebSearch as belonging to the major multinational agrochemical companies, so no specific brand is named here.

Mode of Action

This product combines two different antibiotics in one formulation — streptomycin sulphate and tetracycline hydrochloride — both of which act on the bacterial ribosome, the cell structure responsible for protein synthesis, but at different binding sites. Streptomycin binds to the bacterial ribosome's 30S subunit and causes misreading of the genetic code during protein synthesis, producing faulty, non-functional proteins that are directly lethal to the bacterial cell (bactericidal action). Tetracycline also binds the 30S ribosomal subunit, but at a different site, where it blocks the attachment of transfer RNA and thereby halts protein synthesis, which is primarily bacteriostatic (it stops bacteria from multiplying rather than killing them outright). Because the two antibiotics interfere with the same overall process (ribosomal protein synthesis) via different mechanisms, using them together gives broader-spectrum and more robust suppression of plant-pathogenic bacteria than either active alone, and reduces (though does not eliminate) the chance that bacteria resistant to one antibiotic will also survive the other. Being water-soluble, the combination is absorbed and moves to some extent within treated plant tissue, giving both protective and limited curative activity against bacterial disease.

Features & Benefits

• One of the very few effective chemical options for managing bacterial (as opposed to fungal) plant diseases, which do not respond to ordinary fungicides.
• Broad-spectrum activity against a range of plant-pathogenic bacteria across cereal, vegetable and fruit crops, useful in integrated disease management programmes for blight, canker and wilt.
• The dual-antibiotic combination (two different modes of action against the bacterial ribosome) gives more robust control than either antibiotic used alone, and helps slow — though does not prevent — the development of resistant bacterial populations.
• Water-soluble powder (SP) formulation mixes easily and moves to some degree within treated plant tissue, giving useful protective coverage of new growth after spraying.

Recommended Usage of Streptomycin Sulphate 9% + Tetracycline Hydrochloride 1% Bactericide

The table below gives the spray/seed-treatment concentration (in parts per million, ppm) for each crop, now confirmed against the Government of India's CIB (Central Insecticide Board & Registration Committee) official bactericide dosage list for this exact Streptomycin Sulphate 9% + Tetracycline Hydrochloride 1% SP composition, which resolves the source conflict previously flagged here (see the note below the table).

The ppm concentrations above are taken directly from the CIB official bactericide dosage list for this exact 9%+1% SP composition, which could not previously be confirmed here because two independently reviewed manufacturer labels gave meaningfully different dilution rates (roughly 0.33–0.53 g/litre on one label versus roughly 0.1–0.2 g/litre on another — a two- to three-fold spread). CIB's figures resolve that conflict for rice, citrus, potato, cotton, tomato and chilli, and are the figures now shown above. CIB does not list a figure for cauliflower or pomegranate under this exact composition, so those two crops still have no confirmed dose here — continue to use the exact dose and spray interval printed on your specific product's current label for these two crops. Because this is an antibiotic used on food crops, where both under-dosing (which can encourage antibiotic-resistant bacterial populations, a real and documented global concern with agricultural streptomycin use) and over-dosing (residue and phytotoxicity risk) carry genuine consequences, always follow the exact concentration and spray interval above (or your product's current label where CIB does not cover the crop), and consult your local agricultural extension office if in doubt.

How to Use

1. Confirm the target disease matches the symptom guide above, since this product works only against bacterial diseases — it has no effect on fungal diseases, which need a fungicide instead.
2. Mix the exact dose stated on your product's current label into the specified volume of water and stir until fully dissolved, since this is a soluble powder (SP) formulation.
3. Spray at the first appearance of symptoms for best results — bactericides are far more effective as an early, protective treatment than once bacterial disease is already well established and causing visible plant collapse.
4. Ensure thorough coverage of the affected plant parts, and avoid spraying during the hottest part of the day, as high temperatures can reduce antibiotic stability in the spray solution.
5. Do not exceed the number of sprays or the spray interval stated on the label — repeated, indiscriminate use of streptomycin-based products is a documented contributor to antibiotic resistance developing in plant-pathogenic bacteria, reducing the product's future effectiveness for all farmers.

Precautions & Safety

• Wear appropriate PPE — mask/respirator, gloves, goggles and full-sleeved clothing — while mixing and spraying, and avoid inhaling the fine powder while opening the pack.
• Antibiotic resistance in plant-pathogenic bacteria (for example in Xanthomonas and related genera) is a well-documented, real-world concern linked to overuse of streptomycin-based sprays in agriculture; use this product only when bacterial disease is confirmed or strongly suspected, strictly at the labelled dose and frequency, and as part of a broader integrated disease-management approach rather than as a routine preventive spray.
• Avoid tank-mixing with strongly alkaline materials, such as lime or Bordeaux mixture, which can chemically degrade the antibiotic actives and reduce effectiveness; do a small jar-compatibility test before mixing with an unfamiliar product.
• Since this product is commonly used on food crops close to harvest for bacterial disease control, strictly observe the waiting period (PHI) stated on your product's current label before harvesting treated produce.
• Store in the original, tightly closed container in a cool, dry place away from direct sunlight and heat (antibiotic potency degrades faster in heat and light), food and feed, and out of reach of children and livestock.
• Wash hands, face and any exposed skin thoroughly with soap and water after handling or spraying, and change out of contaminated clothing before eating, drinking or smoking.

Brand names mentioned on this page are registered trademarks of their respective owners and are referenced here for identification purposes only; FarmMate is not affiliated with or endorsed by these brands. This page is for general information only — always consult your local agricultural extension office and confirm the current product label before use.