Isoxaflutole 20% SC Herbicide: A Premier Weed Control Solution

Technical Specifications

Mode of Action

1. Absorption Mechanism
   • Root Uptake: When applied to the soil, isoxaflutole is efficiently absorbed by the young roots of germinating weeds. Its unique chemical structure allows it to pass through the root cell membranes and enter the plant’s vascular system.
   • Limited Foliar Uptake: Although root uptake is the primary route, there is also some foliar absorption when the herbicide comes into direct contact with the leaves of emerged weeds. However, compared to root – absorbed isoxaflutole, the amount absorbed through foliage is relatively small.
2. Biochemical Disruption
   • Once inside the plant, isoxaflutole inhibits the enzyme 4 – hydroxyphenylpyruvate dioxygenase (HPPD). This enzyme is essential for the biosynthesis of plastoquinone and tocopherol, which are precursors for carotenoid synthesis.
   • Without carotenoids, plants lose their ability to protect chlorophyll from photo – oxidation. As a result, the chlorophyll molecules are damaged, leading to the loss of green color in the plant.
3. Symptom Progression
   • Initial Symptoms (3 – 5 days): In the early stages after application, the first visible sign is the appearance of bleaching or whitening in the new growth areas of the weed. This is due to the disruption of carotenoid – mediated protection of chlorophyll.
   • Advanced Symptoms (7 – 14 days): As the lack of carotenoids continues to take its toll, the bleaching spreads throughout the plant. The leaves wilt, become necrotic (turn brown and die), and eventually, the entire weed collapses and dies.

Application Guide

Application Best Practices

• Water Volume: For ground applications, use 200 – 400 L of water per hectare. This volume helps in achieving even coverage of the herbicide over the soil surface or the foliage of emerged weeds. In the case of aerial applications, adjust the water volume according to the specific guidelines of the application equipment, but generally, a lower volume may be used while still ensuring proper distribution.
• Adjuvants: Adding a non – ionic surfactant at a rate of 0.2 – 0.5% v/v can enhance the performance of Isoxaflutole 20% SC. The surfactant helps in improving the wetting and spreading of the herbicide on the leaf surface (for post – emergence applications) and also aids in better soil penetration and adsorption.
• Tank Mixes
  • In maize fields, Isoxaflutole 20% SC can be tank – mixed with other herbicides like atrazine to broaden the spectrum of weed control. Atrazine is effective against many broadleaf weeds, and the combination with isoxaflutole can control both grasses and broadleaf weeds more comprehensively. However, always conduct a jar test before large – scale tank mixing to ensure compatibility.
  • In sugarcane fields, it can be combined with herbicides such as glyphosate (for non – selective control in non – crop areas within the sugarcane plantation) or other grass – specific herbicides to target specific weed problems.
• Weather Conditions: Apply on calm days with temperatures between 15 – 28°C. Avoid spraying when rain is expected within 24 hours, as rain can wash away the herbicide before it has a chance to be absorbed by the weeds or penetrate the soil. High – temperature conditions can increase the volatility of the herbicide, so it’s best to avoid applications during extremely hot weather.

Key Advantages

1. Broad – Spectrum Weed Control
   • Isoxaflutole 20% SC can effectively control over 50 different species of annual grasses and broadleaf weeds. This includes many common and problematic weeds in maize and sugarcane fields, such as crabgrass, foxtail, lambsquarters, and pigweed. Its broad – spectrum activity makes it a valuable tool in integrated weed management programs, reducing the need for multiple herbicide applications.
2. Systemic Efficacy
   • Its systemic nature ensures that once absorbed, the herbicide is translocated throughout the plant. This means that it can reach all parts of the weed, including the roots, shoots, and growing points. As a result, it provides comprehensive weed control, even for weeds with extensive root systems or those that have emerged at different growth stages.
3. Crop Safety
   • When applied at the recommended rates, Isoxaflutole 20% SC shows excellent selectivity in maize and sugarcane. These crop plants are able to metabolize isoxaflutole rapidly, converting it into non – toxic compounds, while the target weeds are unable to do so, leading to their death. This selectivity allows for effective weed control without harming the desired crops.
4. Long – Lasting Residual Activity
   • Isoxaflutole provides significant residual soil activity. After application, it remains in the soil for a certain period, preventing the germination of new weed seeds. This residual activity can last for several weeks, depending on factors such as soil type, temperature, and moisture. As a result, it reduces the frequency of re – applications and helps in maintaining a weed – free environment in the treated area for an extended time.
5. Flexible Application Options
   • It can be used both pre – emergence and in early post – emergence stages. Pre – emergence applications target germinating weed seeds, providing early – season weed control. Early post – emergence applications can be used to control small, emerged weeds. This flexibility in application timing allows farmers to choose the most appropriate method based on the weed growth stage and field conditions.

Safety & Environmental Notes

• Toxicity
  • Mammalian Toxicity: Isoxaflutole has relatively low mammalian toxicity. The oral LD₅₀ (rat) is greater than 5000 mg/kg, indicating a low risk of acute toxicity to humans and animals if ingested. However, as with any agricultural chemical, proper handling and safety precautions should always be followed.
  • Aquatic Toxicity: It has moderate toxicity to fish and aquatic invertebrates. Avoid direct application into water bodies or areas where runoff is likely to enter water sources. Maintain a buffer zone of at least 50 meters from water bodies during application. In case of accidental spills near water, take immediate measures to contain and clean up the spill to prevent water contamination.
• Environmental Fate
  • Soil Degradation: In soil, isoxaflutole degrades mainly through microbial action. The half – life in soil (DT₅₀) typically ranges from 10 – 30 days, depending on factors such as soil type, temperature, and moisture. In well – drained, warm, and moist soils, the degradation process is relatively faster. This relatively short half – life helps in minimizing long – term soil residues and reduces the risk of carry – over effects on subsequent crops.
  • Volatility: Isoxaflutole has low volatility. This reduces the risk of vapor drift to non – target areas, such as neighboring crops or sensitive habitats. However, proper application techniques, such as using appropriate nozzles and application pressures, should still be followed to avoid any potential off – target movement.
• Storage
  • Store Isoxaflutole 20% SC in a cool, dry place away from direct sunlight. The storage temperature should be maintained between 5 – 30°C. Keep the product in its original, tightly – sealed container to prevent contamination and maintain its efficacy. Store it out of reach of children, pets, and food products.

Packaging & Compliance

• Standard Packs
  • Available in 1 – liter, 5 – liter, and 20 – liter HDPE (High – Density Polyethylene) containers. These containers are designed to be leak – proof, durable, and easy to handle. They are clearly labeled with product information, safety instructions, application guidelines, and relevant regulatory information.
• Custom Solutions
  • For large – scale agricultural operations or distributors, custom packaging options may be available. This can include private labeling with specific brand names and multilingual instructions to meet the needs of different regions.
  • The product complies with all major regulatory requirements in various countries. In the United States, it is EPA – registered. In Europe, it meets the EU’s strict regulatory standards. Regulatory support can be provided for countries in Asia – Pacific, South America, and other regions to ensure proper registration and use.
• Shelf Life
  • Under recommended storage conditions, the shelf life of Isoxaflutole 20% SC is 2 – 3 years. Regularly check the product for any signs of degradation, such as separation, clumping, or changes in color or odor, before use. If any signs of degradation are observed, do not use the product and contact the manufacturer for further advice.

FAQ

1. Can Isoxaflutole 20% SC control perennial weeds?
   • While Isoxaflutole 20% SC is primarily designed for annual weed control, it may have some impact on certain perennial weeds, especially those in their early growth stages. However, for established and deep – rooted perennials, it may not provide complete control. Multiple applications or the use of other herbicides specifically formulated for perennial weed control may be required in such cases.
2. What is the pre – harvest interval (PHI)?
   • Maize: The PHI is typically 60 days. This means that the last application of Isoxaflutole 20% SC should be made at least 60 days before the maize harvest to ensure that no harmful residues remain in the harvested crop.
   • Sugarcane: The PHI for sugarcane is around 90 days. Always check the product label for the most accurate and up – to – date PHI information, as it may vary slightly depending on local regulations and specific crop varieties.
3. Is it safe to use near water sources?
   • Due to its moderate aquatic toxicity, Isoxaflutole 20% SC should be used with caution near water sources. As mentioned, maintain a buffer zone of at least 50 meters from water bodies during application. Avoid spraying on slopes where runoff is likely to carry the herbicide into water sources. In aquatic environments, follow the specific application rates and guidelines for controlling aquatic weeds to minimize impact on non – target aquatic organisms.
4. How can I manage herbicide resistance when using Isoxaflutole?
   • Rotate Isoxaflutole with herbicides from different mode – of – action groups. For example, in one season, use Isoxaflutole, and in the next, use a Group 15 herbicide like acetochlor. Also, avoid consecutive annual applications of Isoxaflutole in the same field. Mixing it with other herbicides with different modes of action can also help in reducing the selection pressure for resistant weeds. Regularly monitor the weed population in your fields for any signs of resistance development and adjust your weed management strategy accordingly.
5. Can it be used in organic farming?
   • No, Isoxaflutole is a synthetic herbicide and is not approved for use in organic farming systems. Organic farming relies on non – synthetic methods such as mechanical weeding, mulching, and the use of certain approved natural herbicides.

Field Performance

• Maize Field Trials in the Midwest, USA: In a series of field trials conducted over multiple seasons, application of Isoxaflutole 20% SC at 105 g ai/ha (pre – emergence) provided over 90% control of common broadleaf weeds like lambsquarters and pigweed. Crabgrass control was also above 85% when applied at the recommended rate. This led to an average yield increase of 12 – 18% compared to untreated plots.
• Sugarcane Farms in Brazil: At a dosage of 120 g ai/ha, Isoxaflutole effectively controlled annual bluegrass and goosegrass, with control rates reaching up to 90%. Purslane control was also significant, at around 88%. The reduction in weed competition resulted in better – quality sugarcane stalks and an average yield improvement of 10 – 15%.

Residue Limits