Sunflower Crop Progress June 14, 2009
Source: USDA Weekly Crop Weather, as of 6/14/09
WEATHER AND SOIL MOISTURE
Temperatures in the northern region were well under normal last week. Good rainfall again occurred in the key NE Kansas sunflower production region which includes portions of Nebraska and Colorado. Overall, soil moisture is good in most the sunflower regions.
EARLY RUST SPORES FOUND
The very early stages (pycnial and aecial) of sunflower rust have been found on wild and volunteer sunflower in ND, MN and NE. According to pathologists in MN and ND, economically significant epidemics of rust are more likely when the aecial stage is found this early in the season. This is due to early and abundant innoculum. Pathologists Hollingsworth and Markell note that it is very important to control volunteers and wilds, especially those bordering last year’s sunflower fields. Scouting for rust should begin soon after emergence. Rust is most damaging when infection is early. Rust is very controllable and its development is weather dependent. More information is available on the NSA website. (Source: NDSU Crop & Pest Report, June 11, 2009).
Cutworm appears to be an annual problem and many producers spray for the insect shortly after planting. Reports from Manitoba field surveys indicate cutworm pressure in some fields has required spraying and/or replanting. (Source: Manitoba Sunflower Crop Report #2).
There are no published reports of Downy Mildew in any locations.