2012 NSA Crop Survey Report
Wednesday, January 2, 2013
filed under: Research and Development
By Hans Kandel
Every autumn for the last 11 years (with the exception of 2004), the National Sunflower Association has conducted in-depth surveys in producers’ fields throughout the main sunflower growing regions of the United States as well as Manitoba, Canada.
During the fall of 2012, 27 trained teams including agronomists, entomologists, pathologists, crop consultants and/or producers randomly stopped at 211 sunflower production fields, which represent approximately one field for every 10,000-15,000 acres in sunflower- producing counties. Each team evaluated plant stand, yield potential, disease, insect and weed control for each field. In addition, a seed sample was taken to observe insect damage in the laboratory. The teams determined the most-limiting and second most-limiting yield factors for each field. They also assessed bird damage and agronomic practices used in the field.
A yield estimate was calculated based on plant stand, head size, seed size, seeds per head and percent loss due to bird feeding. The 2012 average surveyed sunflower yield was 1,670 lbs/ac, with an average per-acre plant population of 16,687. The corresponding numbers in the 2011 crop survey, which encompassed 155 fields, were 1,642 and 15,766, respectively.
Determination of yield-limiting factors was based on the surveyors’ judgment after considering all production aspects in the field.
The limiting factors may be different in the various states. For instance, drought may have been less severe in North Dakota, Manitoba and Minnesota compared with southern states, whereas Dectes long-horned beetle damage was mostly concentrated in the southern sunflower production regions.
Overall, the most limiting factor in 2012 was drought, followed by plant spacing within the row, weed competition, plant disease and bird damage. The plant spacing difficulties consist of either a skip within the row or areas where plants grow too close together, causing one of the plants not to contribute to the sunflower yield. Equal distribution of plants is essential to obtaining the maximum yield.
Irregular plant spacing within a row has consistently ranked as either the top or second limiting factor since the first survey was conducted in 2002.
Irregular plant spacing in the row may have been caused by poor seeding conditions, failure to adjust the planter, driving too fast, poor germination, disease, insect damage or other factors. The average yield of 28 fields with plant distribution issues was 1,678 lbs/ac, compared with 21 fields with no stand problem or other problems yielding 2,158 lbs. Producers should pay attention to their management and refine their technique while seeding sunflower. Planter calibration may be the first step to reducing skips and get better plant spacing within the row.
In 2012, no limiting factor could be determined in 13% of the fields; and in 34% of the fields, “no problem” was reported for the second limiting factor. The “no problem” category indicates that the evaluators felt the field reached its maximum yield potential for the 2012 growing season. During the last three seasons, surveyors did not find a second most yield limiting factor in about 30% of the fields.
The diseases of most concern in sunflower are rust, Sclerotinia and Phomopsis. In 2012, sunflower leaf rust incidence (percent of fields in which rust was found) was higher in Kansas, Minnesota, and North and South Dakota compared with 2011. Sclerotinia head rot in fields with the disease was up in North Dakota and Manitoba, while head rot was absent in Minnesota, South Dakota and the High Plains states. Phomopsis severity was less in 2012 compared with 2011.
Dectes long-horned beetle was found in 60, 57, 57, 38 and 29% of the fields in Kansas, Colorado, South Dakota, Texas and North Dakota, respectively. The percentage of plants with Dectes increased this year in Colorado and North Dakota. The highest percent severity of long-horned beetle (plants with the insect in those fields with Dectes present) was found in Colorado, followed by South Dakota and North Dakota.
Seed weevil damage was found in 50% of the samples submitted from Nebraska and South Dakota. Of all the samples evaluated, 20% had damaged seeds — and of those samples with damage, the average number of seeds with seed weevil activity was 2.8%.
Bird damage was reported in 61% of the surveyed fields in North Dakota, 50% in Minnesota, 40% in Vermont, 36% in Manitoba, 25% in Nebraska and 22% in South Dakota. The average damage over all the surveyed fields was 2.7%
Broadleaf weeds continue to be more of a problem than most grassy weed species. Palmer amaranth is a major problem weed in Kansas and was recorded as being present in 100% of the surveyed fields. In Texas, 88% of the fields contained Palmer amaranth. In fields where surveyors mentioned weeds as the most-limiting factor, the average yield was 1,551 lbs/ac, which is about 70% of the yield in those fields where no yield-limiting factor was reported.
The data generated by this national sunflower crop survey can be used by producers to make better management decisions. The information is also providing trends over time, and survey data will be used to help define research priorities in improving sunflower crop production and the bottom line for producers.
Summaries of each crop survey since 2002 can be found on the NSA website at www.sunflowernsa.com.
Hans Kandel, extension agronomist with North Dakota State University, coordinates the annual sunflower crop survey.