Crystal Srizone Herbicide (Atrazine 50% WP) – Pre & Post-Emergent Weed Control for Maize & Sugarcane

Crystal Srizone is a selective, systemic herbicide from Crystal Crop Protection, formulated as Atrazine 50% WP (Wettable Powder). It belongs to the triazine group of herbicides and is designed for effective weed management in maize and sugarcane crops. Srizone works by inhibiting photosynthesis and enzymatic activity in targeted weeds, providing broad-spectrum control over annual grasses and broadleaf weeds.

What makes Srizone a practical choice for farmers is its dual-action capability — it can be used both as a pre-emergence herbicide (applied to soil before weeds germinate) and as a post-emergence herbicide (applied as foliar spray on young, actively growing weeds). This flexibility allows farmers to adapt their weed management strategy based on field conditions and weed pressure. The product offers long-lasting residual protection, reducing the need for repeated manual weeding and helping crops establish better without competition from weeds.

Srizone is classified under the Blue toxicity category (moderately toxic) and is intended for agricultural use only. It is available in pack sizes of 500 g and 1 kg. Please note that due to local regulations, this product is not supplied to Kerala State.

Key Benefits

• Dual-mode application – Effective both as a pre-emergence soil application and post-emergence foliar spray, giving farmers flexibility in weed management timing.
• Broad-spectrum weed control – Controls a wide range of annual grasses and broadleaf weeds including Echinochloa spp., Digitaria spp., Amaranthus viridis, Xanthium strumarium, Polygonum spp., and many more.
• Long-lasting residual action – Provides extended protection in the field, reducing the frequency of repeat applications and manual weeding.
• Selective safety – When used as per recommended dosage, it is selectively safe for maize and sugarcane crops while effectively controlling weeds.
• Reduces manual labour – Minimizes dependence on manual weeding, saving time and labour costs during the critical crop establishment phase.
• Supports better crop yield – By reducing weed competition for water, nutrients, and sunlight, Srizone helps crops establish strongly and achieve better yield potential.

How It Works

Crystal Srizone contains Atrazine 50% WP, a systemic herbicide from the triazine chemical group. Once applied, it is absorbed by the roots (in pre-emergence soil application) or by the foliage (in post-emergence foliar application) of target weeds. The active ingredient moves systemically within the weed plant.

Atrazine works by inhibiting the photosynthetic electron transport chain — specifically, it blocks the Hill reaction in photosystem II. This stops the plant from converting sunlight into energy. Within a few days of application, susceptible weeds show symptoms such as chlorosis (yellowing) of leaves, followed by necrosis (tissue death) and eventual plant death. The systemic movement ensures that even parts of the weed not directly sprayed are affected.

Because of its residual activity in soil, Srizone continues to control germinating weed seedlings for an extended period after application. This dual action — immediate control of existing weeds and residual prevention of new weeds — makes it a highly effective tool for integrated weed management in maize and sugarcane fields.

Technical Specifications

Recommended Dosage & Application

Spray Solution Guide (for knapsack sprayer):

• Maize: Mix approximately 60–120 g of Srizone in 15 litres of water per knapsack sprayer.
• Sugarcane: Mix up to approximately 240 g of Srizone in 15 litres of water per knapsack sprayer.

Method of Application:

• Pre-emergence (Soil Application): Apply to moist soil soon after sowing but before weed seeds germinate. Ensure good soil moisture for effective activation.
• Post-emergence (Foliar Spray): Apply as a uniform foliar spray when weeds are young and actively growing (early post-emergence stage).

Important: Drip irrigation application is not recommended. This product is designed for foliar/soil spray application only.

When to Use

Pre-emergence use: Apply Srizone immediately after sowing maize or sugarcane, before weed seeds start germinating. The soil should be moist at the time of application for best results. This timing prevents weeds from emerging and competing with the crop during the early growth stages.

Post-emergence use: Apply when weeds are young and actively growing — typically within 2–4 weeks after sowing, depending on weed emergence. Early application on small, tender weeds gives the best control. Avoid applying on mature or stressed weeds as effectiveness may reduce.

For both methods, ensure there is adequate soil moisture. Do not apply on waterlogged or saturated soils. The product works best when applied during the cooler part of the day (morning or evening) to reduce evaporation and improve absorption.

Step by Step Usage Instructions

1. Calculate the required quantity: Based on your crop and field size, measure the correct dosage of Srizone (see dosage table above). Use a weighing scale for accurate measurement.
2. Prepare the spray solution: Fill the spray tank with half the required amount of clean water. Add the measured quantity of Srizone powder while stirring continuously. Add the remaining water and mix thoroughly until the powder is fully dissolved and evenly suspended.
3. For pre-emergence application: Apply the solution uniformly to the soil surface immediately after sowing. Ensure the soil is moist for proper activation of the herbicide.
4. For post-emergence application: Spray uniformly on the foliage of young, actively growing weeds. Ensure good coverage of weed leaves for effective absorption.
5. Clean equipment: After spraying, thoroughly clean all spray equipment with water. Do not dispose of leftover spray solution or rinse water near water bodies or drainage channels.
6. Post-application care: Avoid entering the treated field for at least 24 hours after spraying (re-entry period). Do not disturb the soil unnecessarily after pre-emergence application, as this may reduce herbicide effectiveness.

Compatibility

Conduct a small-scale compatibility (jar) test before mixing Srizone (Atrazine 50% WP) with other pesticides or fertilizers. Mix small quantities of the products in water in a clear container and observe for any signs of physical incompatibility such as clumping, separation, gel formation, or excessive settling. If any adverse reaction is observed, do not mix them together. Always follow the mixing order: wettable powders first, then emulsifiable concentrates, then adjuvants.

Precautions & Safety

• Personal Protective Equipment (PPE): Wear gloves, protective clothing, a face mask, and goggles while handling, mixing, and spraying the product.
• During application: Avoid inhalation of dust or spray mist. Do not eat, drink, or smoke while handling the product. Wash hands and face thoroughly with soap and water after use.
• Avoid spray drift: Do not allow spray to drift onto nearby non-target crops, water bodies, or grazing areas. Atrazine can damage sensitive crops.
• Storage: Store in a cool, dry place away from direct sunlight. Keep the product away from food, feed, and drinking water. Store out of reach of children and animals.
• Disposal: Do not reuse empty containers. Dispose of them safely according to local regulations. Do not contaminate water sources with product or container residues.
• Re-entry: Do not allow people or livestock to enter treated fields for at least 24 hours after application.

Side Effects & Phytotoxicity

• Atrazine can cause injury to crops if applied on waterlogged or saturated soils. Ensure proper drainage before application.
• Overdosing or application on stressed crops (due to drought, pest damage, or nutrient deficiency) may increase the risk of crop injury.
• Do not use on sandy soils with low organic matter without proper guidance, as herbicide leaching may occur and affect crop roots.
• Atrazine is known to persist in soil and may affect sensitive rotational crops. Follow recommended crop rotation intervals as per local agricultural guidelines.

PHI / REI & Storage

• REI (Re-entry Interval): 24 hours after spraying.
• Shelf Life: 2 years from the date of manufacture when stored under proper conditions.
• Storage Conditions: Store in a cool, dry place away from direct sunlight and moisture. Keep the container tightly closed when not in use.