’07 Crop Survey Results
Saturday, December 1, 2007
filed under: Birds
The National Sunflower Association (NSA) has been conducting intensive field surveys since 2002. The 2007 survey was carried out by volunteers from universities, USDA, county extension agents and private seed companies. This year, volunteers in Manitoba, Canada, also participated in the survey.
A total of 159 fields were surveyed, representing approximately one field per 10,000 acres. All surveyors used the same format. Data were submitted to and complied by Duane Berglund, recently retired North Dakota State University extension agronomist.
“The survey results provide the basis for university and public research programs,” notes Steve Kent, NSA Research Committee chairman. “The research committee establishes priorities based on the survey findings. We want to direct limited grower and industry checkoff funds to problems and opportunities that are identified out in the field.”
“Surveyors do extensive analysis of plant health, insect infestation, bird damage, populations, plant distribution within the field, tillage systems and weed identification,” Berglund adds. “This is the fifth year of the survey, so we are beginning to see trends. For instance, levels of weed infestations were greatly reduced this year compared to past years. Bird damage in North Dakota and Minnesota appears to be declining as well, compared to prior years.”
— Yield-Limiting Factors —Drought was not a yield-limiting factor in 2007 as it was in 2006. The most common impacts on yield in North Dakota were diseases and inconsistent plant populations. It should be noted that surveyors can indicate “no problem” when fields are well managed. Thirty percent of the fields in North Dakota and Minnesota had “no problem,” which is very encouraging.
The most important yield-limiting factors in South Dakota were plant population and lodging, while in Kansas they consisted of drought, weeds and plant spacing. Plant spacing and drought were cited in Colorado, while weeds, birds and diseases were the major production problems in Manitoba.
Based on the survey results, bird damage appears to be on a decline in the Dakotas and Minnesota, having peaked in 2002. However, bird damage was higher in South Dakota this year compared to the previous two years. It is, however, important to point out that the surveys are generally taken in mid- to late September, prior to the movement of the large migrating roosts. So not all of the damage is going to be captured in the survey.
Dr. George Linz of USDA’s Wildlife Services observes that more birds use corn fields for feeding in late August and early September. “It’s [during] this four-week period from the last half of August to middle September that at least half of the damage is taking place. Seeing these numbers is positive — and hopefully reflects the work done in cattail control and earlier harvest with desiccation in those bird hot spots,” Linz says. Regardless of the numbers, blackbirds continue to of major concern.
— Insects & Diseases —2007 was a “buggy” year. The head moth population was large throughout the usual High Plains region and reached well into the Dakotas with significant populations. The banded sunflower moth was also well represented in sunflower fields in the northern half of North Dakota and Minnesota this year, with many fields being sprayed. One crop advisor predicted that growers in northern North Dakota would lose at least 300 pounds per acre without a timely insecticide treatment for banded moth.
Seed samples were collected from each surveyed field and analyzed by USDA-ARS research entomologist Dr. Larry Charlet. The lab analysis will determine the extent of seed damage by any of the seed-boring insects.
Of concern is the increasing number of long-horned beetle (Dectes) larvae being found. There are no insecticidal controls for this stem-boring insect at present, and the insect seems to be moving from Kansas into South Dakota and south central North Dakota. Delayed harvest can result in lodging. This insect certainly has grabbed the attention of sunflower researchers and the NSA.
Red rust was the most prolific disease found throughout all of the growing regions. Severity of the disease, however, was not of economic consequences in most situations. Most of the infection appeared late in the season and thus had minimal or so impact on yield, according to USDA-ARS plant pathologist Tom Gulya. Gulya collected 160 rust samples from both cultivated and wild sunflower from all of the producing states. His lab is now in the process of identifying rust races. Once that’s completed, he will be testing a cross section of commercial hybrids to determine which hybrids are resistant to the prevalent races found in 2007.
Sclerotinia was not a serious disease, due to the drier fall conditions. However, head rot did occur in October in several areas due to an extended rainy and foggy period. The lack of a killing frost contributed as well. That damage was not captured in this survey since the field survey had already been taken.
— Weeds —The 2007 incidence of kochia and all other broadleaf weeds was much lower in the Dakotas and Minnesota, according to the survey results. Berglund relates this to good activation of pre-emergent herbicides this year because of more rainfall at planting. “Farmers had much better incorporation with timely rains before emergence. Farmers also have more herbicide choices now with post-applied products for broadleaf and grassy weeds,” he remarks.
The sunflower survey coordinator added that Kansas and Colorado broadleaf weed incidence was much higher in 2007 compared to previous years. “Farmers have been complaining about Palmer Amaranth, and the survey indeed indicates the seriousness of this weed in those two states,” according to Berglund.
A complete report on the 2007 sunflower production survey will be available in early January on the NSA website. Maps will also be available showing the distribution of insects, for example. Previous years’ surveys are posted at this site for comparisons. The 2007 results also will be presented at the 2008 NSA Research Forum, January 10 and 11 in Fargo N.D.