Submitted to: Plant Management Network
Publication Type: Other
Publication Acceptance Date: 5/16/2008
Publication Date: 5/16/2008
Publication URL: http:////www.plantmanagementnetwork.org/edcenter/seminars/ApplicationTechnology/
Citation: Derksen, R.C. 2008. Application Technology Research for Asian Soybean Rust Management. Plant Management Network. Available at: http://www.plantmanagementnetwork.org/edcenter/seminars/ApplicationTechnology. Interpretive Summary:
Technical Abstract: Fungicides are currently the only means for managing potentially devastating Asian Soybean Rust (ASR) infection in the U.S. ASR is likely to first infection those portions of the soybean canopy closer to the ground. Infection is most likely to occur once the canopy is nearly fully developed and most difficult to treat. The objective of this research was to study the effect different application strategies had on the fate of fungicides in a mature and dense soybean canopy. Fluorescent tracers, water sensitive paper, and fungicide residue analysis were used to evaluate all of the application strategies. Factors evaluated included droplet size, spray pattern, spray volume, and the use of air-assisted spray delivery. Much more residue was found on leaf tissue sampled from the middle canopy section than the lower canopy section. Much more fungicide residue was also found on leaf tissue compared to stem tissue. Coverage and spray deposit measurements showed that medium spray quality nozzles performed better than nozzles producing coarse or fine sprays. Air-assisted delivery performed better than conventional flat fan treatment across both years. Twin-fan pattern nozzles that had 60 degrees of separation between spray patterns than the twin-fan pattern nozzles that had 60 degrees of separation between spray patterns. There was some indication that spray volume was not a good predictor of the amount of spray residue found on plant tissue and artificial targets. However, high spray volume produced higher spray coverage. This research demonstrates application techniques that may offer the best chance for placing fungicides in the lower canopy area of narrow-row planted soybeans canopy’s where they will be most effective.