What helps and what hurts herbicide performance? | Wheat School

"“When would I want to up it from a CoC to an MSO? A lot of that is based on environmental conditions,” he says. He explains that non-ionic surfactants are designed to improve sticking and spreading on the leaf surface, helping droplets stay in place and coat the plant more effectively. Oil-based adjuvants, meanwhile, take things a step further by helping herbicides penetrate waxy cuticles that develop during hot, dry conditions."

"“That becomes especially important when targeting stressed weeds such as wild oats growing in drought conditions, Carr says. In those cases, methylated seed oils can help improve herbicide uptake and overall weed control.”"

"“Carr notes that soil texture can indirectly influence herbicide performance as well. Lighter, sandier soils are often dustier and more prone to drought stress, both of which can reduce herbicide efficacy and increase antagonism in the spray tank.”"

"“As resistant weeds continue to spread, Carr says growers also need to think beyond simply adding more glyphosate to the tank. "We're having to put in other modes of action into the tank... so to get those other modes of actions to wo”"

Farmers invest heavily in crop protection products but can lose performance due to overlooked spray factors. Water quality, surfactants, and adjuvants influence whether a spray pass achieves effective coverage and uptake. Environmental conditions are a major driver for selecting adjuvants in a tank mix. Growers may switch from crop oil concentrate to methylated seed oil depending on weather and weed stress. Non-ionic surfactants improve sticking and spreading on leaf surfaces so droplets remain in place and coat plants. Oil-based adjuvants can enhance herbicide penetration of waxy cuticles formed during hot, dry conditions. This is especially relevant for stressed weeds such as wild oats under drought. Soil texture can also affect performance by increasing drought stress and spray-tank antagonism, particularly on lighter, sandier soils. Resistant weeds require adding other modes of action rather than increasing glyphosate alone.

Read at Realagriculture