Growers of glyphosate-tolerant crops such as corn, soybeans and sugar beets can now add zinc and manganese to their early season glyphosate applications with the new Sysstem-Ready™ nutrient formulation from Agro-K Corporation that is compatible with the herbicide.

Glyphosate molecularly combines with metals (chelation) such as zinc and manganese, locking them up so they lose mobility and efficacy when applied to the crop. The chelation process also negatively impacts the herbicidal activity of the glyphosate. Until Sysstem-Ready, growers have had to wait eight or more days for the residual glyphosate in crop tissue to move out through root exudates. Then growers could make another pass across the field with the nutrients.

“In Sysstem-Ready foliar formulations, the zinc and manganese are linked to highly systemic phosphite ions that resist glyphosate chelation, enabling rapid nutrient absorption and mobility within the crop plant,” said Chapman Mayo, President of Minneapolis-based Agro-K. “This makes the nutrients available during peak demand, increases the flush of new roots, and accelerates maturation to produce better yield.”

Zinc is the cornerstone for leaf, root and vascular system development while manganese is a key player in photosynthesis, nitrogen assimilation and other essential bio-chemical reactions within the plant.

“In recent years with wet spring weather, it’s been difficult enough for growers to get their glyphosate on in a timely manner, much less come back with a pass for nutrients. Sysstem-Ready makes it possible to accomplish both treatments in a single tank mix,” Mayo said. “A one-pass nutrient plus glyphosate application also helps growers avoid unnecessary costs for energy, wear and tear on equipment, delays due to adverse weather, and soil compaction. Sysstem-Ready also fits other post-emergence herbicide programs that do not rely on glyphosate.”

Wet, cool spring conditions limit nutrient availability for root growth. Zinc and phosphorus can be especially difficult for young plants to extract fast enough to provide optimum early season growth. Other soil factors can limit zinc availability, making foliar applications of zinc critically important.

The Sysstem-Ready™ phosphite ions give the zinc and manganese systemic movement through the plant and down into the roots to keep the plant physiology at optimal level.

“If the nutrients don’t reach into the roots because they’ve been immobilized, the crop is going to have difficulty fending off disease and will come up short in yield even though the vegetative tissues appear normal and functional,” said Dr. Don Huber, professor emeritus in the Botany & Plant Pathology Department of Purdue University. “Adding micronutrients to the soil doesn’t always help because soil micro-organisms rapidly immobilize nutrients. That’s why it’s so important that these phosphite ions can provide high levels of mobility within the plant after a foliar application.”

The benefit of adding the nutrients to glyphosate was demonstrated in 2008 trials in the Western Corn Belt conducted by Dr. Philip Westra, professor in the Department of Bioagricultural Sciences and Pest Management at Colorado State University, and by commercial field trials.

The CSU trials showed that with Sysstem-Ready™ added to the tank mix with glyphosate there was no statistically significant reduction in control of weeds such as green foxtail, pigweed, kochia, and barnyard grass. There was nearly twice as much total plant weight in sampled corn plants treated with the tank mix vs. glyphosate alone. Dr. Westra attributed this added biomass to better plant development and vigor.

The CSU corn replicates averaged 10 bu/acre more with the tank mix over glyphosate alone. The CSU soybean trials showed a 7.4 bu/acre improvement with the tank mix over glyphosate alone.

In replicated commercial field trials with glyphosate-tolerant sugar beets, the tank mix produced a yield increase of 4.5 tons/acre.

“I was generally pleased with the nutrient system,” said Dr. Westra. “I thought the crop plants that received Sysstem-Ready™ with the glyphosate had more color and shine, better root systems, and better overall vigor. They appeared healthier, and this may be due to the disease resistance that important nutrients like manganese provide. Crops in high alkaline and calcareous soils may be particularly responsive.”

The Sysstem-Ready™ technology also is available in calcium, magnesium, and potassium formulations. Each is compatible with the other. For more information about Sysstem-Ready and other Agro-K products and research, phone 800-328-2418