By Ryan Buetow *
During the 2019 sunflower growing season, trained teams — including agronomists, entomologists, pathologists and extension agents — surveyed fields across North Dakota, South Dakota, Minnesota, Kansas, Colorado, Nebraska and Texas.
The majority of the fields surveyed were in North Dakota with 84 completed surveys and South Dakota with 29 completed surveys. Each team evaluated plant stand, yield potential, disease, insect and weed issues for each field. A yield estimate was calculated based on plant stand, head size, filling of the head, seed size, percent filled seeds and percent loss due to bird feeding.
The 2019 average surveyed sunflower yield across completed surveys was 1,957 lbs/ac across all states. The North Dakota estimated yield averaged 1,781 lbs/ac (Table 1), slightly higher than the 2017 average of 1,766 lbs/ac.
Table 1: 2019 Fields Surveyed Per State, Oil Sunfower & Confection Sunflower Fields in
Percent, Yield Estimate & Per-Acre Plant Population
| |
Fields
# |
Oil SF
% of Fields |
Confection
% of Fields |
Yield
Lbs/Ac |
Plants
Per Ac |
Dryland
% |
| North Dakota |
84 |
80 |
20 |
1,781 |
16,376 |
100 |
| South Dakota |
29 |
86 |
14 |
2,229 |
16,748 |
97 |
| Minnesota |
6 |
83 |
17 |
2.252 |
17.598 |
100 |
| Colo.-Kan.-Neb. |
14 |
87 |
13 |
2,372 |
13,010 |
79 |
| Total |
133 |
85 |
15 |
2,230 |
14,959 |
70 |
While 2017 had drought as the number-one yield limiting factor, the opposite was the case in 2019. With excessive moisture in 2019, disease was a major issue across a majority of fields and was the number-one limiting factor noted in North Dakota and a major issue in South Dakota (Table 2).
Table 2: North Dakota & South Dakota #1 Limiting Yield Factors, as Reported in the 2017 & 2019 Crop Surveys
(% of Fields)
| Yield Limiting Factor |
North Dakota
#1 Limiting Factor |
North Dakota
#1 Limiting Factor |
South Dakota
#1 Limiting Factor |
South Dakota
#1 Limiting Factor |
| |
2017 |
2019 |
2017 |
2019 |
| Disease |
17 |
21 |
9 |
21 |
| Plant Spacing |
10 |
12 |
24 |
28 |
| Lodging |
3 |
13 |
4 |
3 |
| Drought |
32 |
1 |
40 |
0 |
| Weeds |
12 |
1 |
0 |
3 |
| Insects |
1 |
6 |
2 |
10 |
| Birds |
9 |
11 |
0 |
7 |
| Uneven Plant Growth |
3 |
0 |
4 |
3 |
| Other |
6 |
15 |
0 |
0 |
| No Problem |
5 |
6 |
7 |
14 |
Plant spacing within the row has been a consistent issue across survey years. However, this year there was a spike in the amount of lodging in the field. With wet conditions and high winds, portion of the field with ground lodging was a frequently seen issue, and the incidence of disease exacerbated the lodging. Surveyors also commented on the maturity of the crop, with concerns of the crop maturing in time for harvest, given delayed planting and cooler conditions in the fall. As of mid-December, these concerns still stood for many growers.
Nearly all of the fields I assisted in surveying in southwestern North Dakota had some incidence of Sclerotinia. Additional prevalent diseases noted this year were Rhizopus, Phomopsis and Phoma. Other diseases such as downy mildew, rust and Verticillium were present to a lesser extent.
Observing disease is a major component of this survey — not only finding what disease is an issue, but where. These observations can help guide research into addressing these issues. Dr. Febina Mathew with South Dakota State University has taken the lead on collecting Phomopsis samples from surveyed fields to identify which species of the fungus is prevalent in the field and where we can find Phomopsis helianthi and where we find P. gulyae.
Along with the in-field observations, seed samples were also sent in to Jarrad Prasifka’s lab with the USDA-ARS in Fargo, N.D. Dr. Prasifka has been observing the amount of insect damage to the seed. Red seed weevil, an issue in previous years, was not as prevalent this year; and overall, less damage was shown to the seeds than in 2017.
There are many observations incorporated in this survey, and when combined with previous surveys, we can track certain issues. The survey also provides a great learning experience or refresher for county extension agents, new and experienced, on issues we face in sunflower production, and allows us to get out into the field to see things across a wide range of environments. You can’t manage what you don’t measure, and the NSA Sunflower Production Survey allows us to measure yield components and yield limiting factors across space and time.
Editor’s Note: An expanded report on the 2019 sunflower crop survey results will be presented at the NSA Sunflower Research Forum being held on January 8 and 9 in Fargo, N.D. That presentation will in turn be posted on the NSA website — sunflowernsa.com — following the Forum.
* Ryan Buetow is extension cropping systems specialist at North Dakota State University’s Dickinson Research Extension Center.