Blackbird Damage is an Important Agronomic Factor Influencing Sunflower Production

From 2001 to 2013 (except 2004), the National Sunflower Association sponsored a comprehensive production survey of physiologically mature sunflower (Helianthus annuus) fields in the Canadian province of Manitoba and eight states in the United States. Trained teams of surveyors randomly stopped at one sunflower field for every 4,047 – 6,070 ha (10,000-15,000 acres). Each team evaluated plant stand, yield potential, disease, insect, weed, and bird damage for each field. We pooled data gathered during the most recent 5-years (2009 to 2013) of the survey and found that sunflower damage caused by blackbirds and plant lodging ranked fifth (behind plant spacing, disease, drought and weeds) as the most limiting factors on production. We found that overall annual economic losses from blackbird damage averaged $US13.5 million and$US4.9 million for oilseed hybrids and confectionery hybrids, respectively. We suggest elements of a multi-faceted bird management plan that might help reduce damage

On-Farm Cropping Trials For Northwest and West Central Minnesota, 2005

This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.A summary of research conducted by University of Minnesota Extension Service on farms in Northern Minnesota in 2005. Areas of research include forages, corn, soybeans, small grains, organic production, and more

Sunflower Treated with Avipel (Anthraquinone) Bird Repellent

Maturing sunflower (Helianthus annuus L.) is susceptible to damage by birds, especially blackbirds (Agelaius phoeniceus and Quiscalus quiscula). The National Sunflower Association (NSA) identified Blackbird damage as a major issue in the production of sunflower throughout the US. In 2007 bird damage was identified as the number one yield limiting factor in 9% of surveyed fields in North Dakota (Graph 1)

Sunflower Treated with Avipel (Anthraquinone) Bird Repellent

Maturing sunflower (Helianthus annuus L.) is susceptible to damage by birds, especially blackbirds (Agelaius phoeniceus and Quiscalus quiscula). The National Sunflower Association (NSA) identified Blackbird damage as a major issue in the production of sunflower throughout the US. In 2007 bird damage was identified as the number one yield limiting factor in 9% of surveyed fields in North Dakota (Graph 1)

On-Farm Cropping Trials For Northwest and West Central Minnesota, 2006

This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.A summary of research conducted by University of Minnesota Extension Service on farms in Northern Minnesota in 2006. Areas of research include alfalfa, corn, soybeans, small grains, organic production, weed control and more

On-farm cropping trials for northwest and west central Minnesota, 2004

This archival publication may not reflect current scientific knowledge or recommendations. Current information available from the University of Minnesota Extension: https://www.extension.umn.edu.A summary of research conducted by University of Minnesota Extension Service on farms in Northern Minnesota in 2004. Areas of research include forages, corn, soybeans, small grains, organic production, and more

The economic impacts of blackbird (Icteridae) damage to sunflower in the USA

BACKGROUND: Blackbird (Icteridae) damage to ripening sunflower (Helianthus annuus L.) has been a persistent economic issue in the USA for the last five decades. To quantify losses, we surveyed blackbird damage from 2001 to 2013 (excluding 2004) to physiologically mature sunflower in eight states: North Dakota, South Dakota, Texas, Nebraska, Minnesota, Colorado, Kansas, and Vermont. RESULTS:We pooled data gathered during the most recent 5 years (2009 to 2013) of the survey and found losses averaged $US2.5 million and$US11.3 million for confectionery and oilseed hybrids, respectively. Three states, North Dakota, South Dakota, and Nebraska, had sufficient acreage and bird damage to warrant economic analyses using a regional economic model. The average annual total (direct plus indirect) economic impact of bird damage to sunflower production for North Dakota, South Dakota, and Nebraska was $US18.7million,$US7.3 million, and $US2.6million, respectively. CONCLUSION: This study provides a better understanding of the broader economic implications of bird damage to sunflower by estimating the macroeconomic impacts of lost sunflower production in the region. Additionally, the findings of this study may be used to inform decisions regarding bird management policy by providing policymakers with information to determine the downstream value of bird management and the possible benefits of improved methods that further mitigate losses

Subsurface drainage effects on soil penetration resistance and water table depth on a clay soil in the Red River of the North Valley, USA

  Since 1993, the Red River of the North Valley in North Dakota (ND) and Minnesota (MN), in the USA has experienced increased annual rainfall which has caused localized seasonal soil waterlogging and inhibited crop yield potential in the unique, high water table clay soils of the region.  Subsurface (tile) drainage has been increasingly considered by farmers to help reduce excess water in the crop root zone.  Producers desire to manage the water table for optimizing yield and trafficability of the field.  The objective of this research was to evaluate differences in soil penetration resistance and water table depth between subsurface (drained) and non-subsurface drained treatments (undrained), using water control structures, in fallow, and cropped soybean (Glycine max L. Merr.) and wheat (Triticum aestivum L. emend. Thell.) cultivars on a Fargo-Ryan silty clay soil near Fargo, ND, USA in 2009 and 2010.  The experimental design was a randomized complete block in a split-plot arrangement with four replicates.  The whole plot treatments were drained and undrained (control structures opened and closed, respectively).  Soil penetrometer readings and water table depth were measured weekly.  Yields of each crop were not different comparing drained and undrained treatments in 2009 and 2010.  The depth averaged drained penetration resistance was 1,211 kPa compared with 1,097 kPa for undrained treatment, averaged across 2009 and 2010.  The depth-averaged drained penetration resistance values for fallow, soybean, and wheat were 1,077, 1,137, and 1,420 kPa, respectively.  The undrained values for fallow, soybean and wheat were 1,001, 1,021, and 1,267 kPa, respectively, all significantly lower than the drained treatments, indicating that the drained soil is capable of a higher load carrying capacity compared to the undrained soil.  The average depth to the water table was greater on drained soil compared to the undrained soil both early and late in the growing season.  Forty two percent of the variation in the penetration resistance can be explained by the level of the water table below the surface.  Water control structures can be used to manage the water table level and soil penetrations resistance.  The ability for land managers to enter drained fields with farm equipment earlier will likely extend the length of the growing season and potentially increase crop yields in this region.   Keywords: subsurface water management, penetration resistance, controlled drainage, water table depth, trafficability, US

The "Unfriending" Problem: The Consequences of Homophily in Friendship Retention for Causal Estimates of Social Influence

An increasing number of scholars are using longitudinal social network data to try to obtain estimates of peer or social influence effects. These data may provide additional statistical leverage, but they can introduce new inferential problems. In particular, while the confounding effects of homophily in friendship formation are widely appreciated, homophily in friendship retention may also confound causal estimates of social influence in longitudinal network data. We provide evidence for this claim in a Monte Carlo analysis of the statistical model used by Christakis, Fowler, and their colleagues in numerous articles estimating "contagion" effects in social networks. Our results indicate that homophily in friendship retention induces significant upward bias and decreased coverage levels in the Christakis and Fowler model if there is non-negligible friendship attrition over time.Comment: 26 pages, 4 figure

Soybean Management for Seed Composition: The Perspective of U.S. Farmers

The soybean [Glycine max (L.) Merr.] compositional quality is mainly provided by the seed concentration of protein and oil. These traits are critical for sustaining global use, and although there is demand for high protein soybean, no mechanism to differentiate production is in place. At the opposite end of the supply chain, farmers are remunerated on a mass basis without having any incentive regarding seed composition. This study evaluated farmers\u27 perspectives and knowledge on soybean quality and their propensity to adopt quality improvement technologies. Farmers from the main U.S. producing regions (n = 271) were investigated with a self-administrated survey containing 21 questions during 2020 and 2021. Our results show that 84% are unaware of the current protein and oil levels from their own production. A small portion (1.4%) make management decisions (e.g., choice of genotypes or monitor quality) based on the implications on seed quality. However, practices already in place are likely to enhance the quality of seed, namely N nutrition (via rhizobia [12.9%] or fertilizer [5.9%]) and late-season crop protection (17.1%). If farmers are financially rewarded by US$0.50 per bushel, a mindset change may occur. Based on these results, we concluded that shifts in the U.S. production system targeting protein or oil markets are possible, and the constraints are mainly related to on-farm management. However, the challenges for improving the U.S. soybean competitiveness in global or niche markets also rely upon other segments of the production chain, specifically breeders, technology suppliers, and logistical structure