Aerial technologies to increase spray deposits on wheat heads
| Problem: | Fusarium head blight (FHB) has become a major disease of wheat and barley, resulting in producer losses of $2-3 billion over the past ten years. |
| Objective: | Explore aerial application technologies with promise of increasing spray deposits on wheat and barley heads at flowering. |
| Approach: |
Spray rate and droplet size with conventional aerial hydraulic nozzles to optimize deposits on wheat heads – This will be a range-finding study to determine the influence of spray rates of 2 and 5 gpa and spray droplet sizes of 150 and 300 µm volume median diameter. These parameters describe the lower range of normal aerial application practice. Study protocols similar to those of Bouse et al. 1992 and Kirk et al. 1992 will be used in this study. Spray rates with aerial rotary atomizers (very fine droplets with Micronaire or ASC nozzles) to optimize deposits on wheat heads – Previous research has shown that small droplets deposit more effectively on small targets and large droplets deposits more effectively on large targets (Kirk et al. 1992). A study with rotary atomizers that effectively produce a relatively narrow range of small droplets with 2 and 5 gpa spray rates will be designed to exploit the small droplet – small target phenomenon. A study protocol similar to that used by Kirk et al. 1993 will be used for the study. Multi-direction flight paths to increase deposits on both sides of wheat heads – Several FHB researchers have indicated that fungicidal sprays need to be deposited on all sides of wheat or barley heads to maximize protection of the head. Limited small-plot research with ground sprays reported by Hart et al. 2001 indicate that sprays from both sides of the plots reduced the severity of FHB and reduced levels of deoxynivalenol. A promising treatment, based on high deposits on wheat heads, will be selected from the previous two studies and used in single and double pass treatments. |
Ivan W. Kirk