Oxyfluorfen Herbicide: Application, Crop Use, and Weed Control
Oxyfluorfen is a potent herbicide utilized extensively in agricultural settings to manage unwanted vegetation. Known for its effectiveness in controlling a wide array of broadleaf weeds and certain grasses, it is a critical tool for farmers in regions such as the USA and Australia to maintain crop health and maximize yields.
Key Facts
- Common Tradenames: Sold as "Goal 2E" and "Oxyfluorfen 240".
- Residual Effect: Can provide weed control for up to 3 months post-application.
- Application Flexibility: Does not require soil incorporation, irrigation, or rainfall to activate.
- Risk Factor: Excessive rainfall immediately after spraying may cause contact burning on crop leaves due to splashing.
- High Impact: Controls witchweed, which can otherwise reduce corn yields by up to 90%.
Application Methods and Rates
The application of oxyfluorfen varies depending on the region and the specific needs of the crop. In the USA and Australia, application rates can reach up to 1500 g/Ha. Specifically, in Australia (2024), active ingredient rates typically range from 0.36 kg/Ha to 1.92 kg/Ha.
For certain strategies, it can be used as an 18 g/Ha "spike" when combined with a standard rate of glyphosate, a common non-selective herbicide. Historical data from 1981 indicates that "Goal 2E" (containing 23.5% oxyfluorfen) was used on approximately 8% of US soy, 1.6% of corn, and between 50% and 90% of fruit trees.
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Target Crops
Oxyfluorfen is versatile and compatible with a vast range of agricultural produce. Its use spans across several categories of crops:
- Tree Fruits and Nuts: Apples, apricots, avocados, custard apples, kiwi fruit, longan, lychees, mangoes, peaches, pears, plums, walnuts, almonds, macadamias, and pecans.
- Vineyards and Specialty Crops: Grapevines, passionfruit, pawpaw, rambutan, tobacco, and Duboisia.
- Vegetables: Onions and brassica crops, including broccoli, cabbages, and cauliflower.
- Field Crops: Pyrethrum, as well as cotton and winter cereals (applied before sowing).
Weed Control Capabilities
Oxyfluorfen is primarily valued for its ability to manage broadleaf weeds—plants with wide leaves as opposed to narrow, blade-like leaves. It effectively controls black nightshade, lambsquarters, ragweed, cutleaf groundcherry, jimsonweed, smartweed, prickly sida, pigweed, velvetleaf, and witchweed, while suppressing morning glory and cocklebur.
Beyond broadleaf plants, it also targets various grasses. It controls barnyard grass, fall panicum, giant foxtail, and large crabgrass, and provides suppression for yellow foxtail, seedling johnsongrass, and broadleaf signalgrass.
The importance of this control is highlighted by specific pests: black nightshade is particularly problematic for soy farmers because its tough stems can clog harvesting machinery and its poisonous berries are difficult to separate from the soy crop. Additionally, witchweed infestations are devastating to corn, potentially slashing yields by 90%.
Summary of Oxyfluorfen Specifications
| Feature | Details |
|---|---|
| Typical Application Rates | 0.36 kg/Ha to 1.92 kg/Ha (Australia 2024) |
| Residual Control Duration | Up to 3 months |
| Primary Target Weeds | Broadleaf weeds and specific grasses |
| Key Tradenames | Goal 2E, Oxyfluorfen 240 |
| Critical Risk | Contact burning from post-spray rainfall splash |
Frequently Asked Questions
Does oxyfluorfen require water to work?
No, oxyfluorfen does not require rainfall, irrigation, or soil incorporation after it has been applied to be effective.
What happens if it rains heavily immediately after application?
Excessive rainfall shortly after spraying can splash the herbicide onto crop leaves, which may lead to contact burning.
How long does the weed control last?
Oxyfluorfen provides long residual control of emerging weeds for up to 3 months. In some instances, control was observed even when soil levels dropped below 10 ppb.
Which crops are most commonly treated with Goal 2E?
Based on 1981 estimates, it was heavily used on fruit trees (50-90%), soy (8%), and corn (1.6%).
Why is controlling black nightshade important for soy farmers?
Black nightshade is problematic because its tough stems can clog harvesters, and its poisonous berries are difficult to separate from the harvested soy.