When temperatures heat up, you need to know how the most common herbicides respond to heat.
Florida is well-known for its hot temperatures. Florida growers need to know how the most common herbicides respond to high temperatures so that they are not wasting their input dollars, misapplying herbicides, or damaging their crops. A recent Citrus Industry Tip of the Week article shared how common herbicides respond to heat and tips for applications. See the information below.
Heat and Common Herbicides
Systemic herbicides like glyphosate and selective grass-killers such as sethoxydim (e.g., Poast Plus) or fluazifop-butyl (e.g., Fusilade): “When temperatures exceed 90°F, many weeds reduce or halt their metabolic processes, which impacts herbicide effectiveness.”
Recommendations: “To maximize effectiveness, apply systemic herbicides early in the morning after weeds have had a chance to recover from the previous day’s heat.”
Contact or non-translocated herbicide like carfentrazone-ethyl (e.g., Aim): if these herbicides are “applied in hot and humid conditions and drifts onto citrus foliage, it can cause more severe damage to the trees.”
Recommendations: Apply when it is not hot nor humid, paying attention to drifting dangers.
Herbicides such as 2,4-D (e.g., Embed Extra): These herbicides can “become volatile in hot conditions, turning into vapor that can be carried long distances by light breezes. This volatility increases as temperatures rise above 85 to 90°F. “
Recommendations: “If possible, postpone applying these herbicides on days when temperatures are expected to exceed 90°F. To reduce evaporation, use larger spray droplets by lowering the spray pressure or increasing the nozzle size.”
The article also adds that “Hot weather can cause weed cuticles to become waxier, which makes it more difficult for herbicides to penetrate. Changes in leaf angle due to heat may also reduce the amount of herbicide that contacts the leaf surface. To tackle these issues, use approved surfactants to enhance herbicide penetration and schedule herbicide applications during the cooler parts of the day to ensure the herbicide contacts the leaves effectively when they are in their optimal position.”
Griffin Fertilizer is committed to helping both growers and ranchers make sound agronomic and economic decisions in order to maximize the health of their grove and pasture. As a full-service custom dry & liquid fertilizer blender and crop protection product distributor, we will continue our mission to further advance Florida agriculture. For questions -or concerns about your farm or pasture, contact us and one of our team will be in touch.
