Integrated Crop Management News
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April 5, 2022Authors
After working with or around pesticides, it is important to properly clean your work clothes. Even if you wear personal protective equipment (PPE) over your own clothes, pesticide residues can be carried on your clothing. Before entering your home, remove your shoes and change out of your work clothes. Keep your work clothes separate from other laundry.
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April 5, 2022Authors
While many farmers already applied nitrogen (N) for corn last fall, others are getting ready for spring preplant applications. Although the fertilizer supply has improved compared with last fall, the prices of N fertilizers have not changed much and are much higher than normal. And, while cash corn grain prices have increased in recent weeks, they are expected to decline later in the summer and the fall. Therefore, this situation warrants a careful review of N fertilization plans.
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March 10, 2022Authors
Chlorpyrifos (e.g., Lorsban and Warhawk) is an organophosphate (Group 1B) insecticide that has been used for many important field crop pests in the United States. In the past 15 years, chlorpyrifos, like many organophosphates, has come under scrutiny due to acute toxicity concerns to humans, especially children. In an effort to protect all ages of humans and the environment, EPA began the process of phasing out many uses of organophosphates.
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March 4, 2022Authors
Corn foliar fungicide trials done at six locations in Iowa in 2021: ISU Northwest Research and Demonstration Farm (NWRF), Sutherland; Northeast Research and Demonstration Farm (NERF), Nashua; Northern Research and Demonstration Farm (NRF), Kanawha; Southwest Research and Demonstration Farm (SWRF), Lewis; Southeast Research and Demonstration Farm (SERF), Crawfordsville; and the Ag Engineering and Agronomy Farm (AEA) near Boone.
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February 28, 2022Authors
Almost all soybean varieties resistant to the soybean cyst nematode (SCN) have been developed from a breeding line named PI 88788. The amount of SCN control varies among the varieties because they have different numbers of copies of the single SCN resistance gene. The Iowa State University SCN-resistant Variety Trial Program evaluates hundreds of commercially available resistant varieties for yield and SCN control each year. In a recently published journal paper, ISU agricultural economists estimated that information from the ISU SCN variety trial provided as much as $205 million of economic value to farmers from 2011 to 2016. This finding underscores the value of selecting and growing SCN-resistant soybean varieties that offer high yields and effective control of SCN.
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November 11, 2021Authors
The SCN-resistant Soybean Variety Trial Program at Iowa State University assesses the yield performance and SCN control provided by hundreds of SCN-resistant soybean varieties each year. Variety trial experiments are conducted annually in each of Iowa’s nine crop reporting districts. Harvest of the 2021 experiments was completed in late October, and processing of soil samples from the research plots to determine end-of-season SCN egg population densities is ongoing. The SCN data from one experiment, in Fruitland, Iowa, have become available. The results provide an eye-opening look at how much SCN reproduction occurred in 2021 as well as how control of SCN numbers can affect soybean yields.
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October 27, 2021Authors
There are several different breeding lines, called sources of resistance, that are available to develop soybean varieties that are resistant to the soybean cyst nematode (SCN). More than 95% of the resistant varieties available to Iowa farmers in the last 15 years have had resistance from the breeding line named PI 88788. As a consequence of continuous widespread use of this resistance, SCN populations in many fields throughout Iowa now have increased reproduction on varieties with resistance from PI 88788. Farmers are advised to grow soybean varieties with SCN resistance from other genetic sources in rotation with high-yielding varieties with PI 88788 SCN resistance. This article lists 36 varieties available for Iowa soybean farmers in 2022 in maturity groups I, II, and III with SCN resistance from two sources of resistance different from PI 88788.
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October 20, 2021Authors
Growing resistant varieties in rotation with nonhost corn and using nematode-protectant soybean seed treatments is recommended for integrated management of the soybean cyst nematode (SCN). ISU compiles a list of soybean varieties with resistance to SCN each year. This year’s publication was recently completed and is available online. There are 872 varieties in the publication, 96% with resistance from PI 88788, which has been used almost exclusively for 15 years. Due to prolonged widespread use of PI 88788 SCN resistance in Iowa, SCN populations have developed increased reproduction on varieties with PI 88788 resistance and SCN is causing increasing yield losses. This article discusses the situation and gives guidance on how farmers should manage SCN with so few choices of resistance genetics available.
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October 14, 2021Authors
The 2021 cropping season had variable rainfall across Iowa. Since crop harvest began, rainfall also has been variable, and temperatures have generally been above normal. Therefore, it is not surprising to hear of variable but often higher than normal end-of-season cornstalk nitrate test levels and postharvest soil nitrate levels. Farmers and crop consultants should use caution in interpreting these results for N fertilization of next year corn.
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October 13, 2021Authors
The 2021 cropping season had very variable rainfall across Iowa with either drought or excessive rainfall. Highly variable landscape and soil moisture retention capacity in many fields also may cause high within-field yield variability. Reduced potential income due to low yield in some areas combined with currently very high fertilizer prices are creating significant uncertainty among producers about P, K, and liming decisions for the 2022 crop season.
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October 7, 2021Authors
The soybean cyst nematode (SCN) is a major yield-reducing pathogen of soybeans throughout Iowa and many other states. SCN-resistant soybean varieties have been used for decades to produce profitable yields and keep SCN numbers in check, but most resistant varieties have lost much of their effectiveness. Also, SCN reproduction in fields where soybeans were grown likely was much greater than normal in 2021 due to hot, dry weather. Collecting soil samples in the fall is advised to determine the SCN situation in fields. This article outlines guidelines for sampling fields for SCN, gives information on where to send SCN soil samples, and provides guidance on managing fields that are infested with SCN.
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September 14, 2021Authors
The derecho left many Iowa farmers with significant volunteer corn this growing season, and unfortunately some may be facing a similar situation for 2022 after late August storms flattened fields.
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September 7, 2021Authors
In a sudden turn of weather events, there have been several severe storms in the northeast and east central crop reporting districts of Iowa. These storms have created the potential for grain quality problems; of the most immediate need for action are those corn and soybean fields that have been flooded above the grain level. Fields with lodging will have more grain susceptible to flooding.
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September 2, 2021Authors
Fall armyworm is native to tropical regions in the western hemisphere. It can only successfully overwinter in the southern US (Texas and Florida), but the adults are strong flyers and capable of long-distance migration to northern states. Multiple migration events are possible each summer, and adults can be found in Iowa from June to August. This year, they are more abundant in the Midwest than usual and are causing late-season issues.
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August 12, 2021Authors
Since early August Iowa farmers have been reporting soybean fields or parts of fields with yellow or greenish-yellow leaves in the upper canopy which resemble early senescence and sometimes nitrogen (N) deficiency symptoms. The soybean growth stage is mainly R4 to R5. Several factors can cause these symptoms. Rainfall has been extremely variable this season in Iowa, with severe drought still persisting in some areas of the state.
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July 28, 2021Authors
Twospotted spider mites have been spotted in fields across much of Iowa already this summer, as much of Iowa is in moderate or severe drought (D1-D2, US Drought Monitor). I encourage you to scout for twospotted spider mites in crops. Twospotted spider mites can increase whenever temperatures are greater than 85°F, humidity is less than 90 percent, and moisture levels are low.
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July 21, 2021Authors
Mother Nature doesn’t always cooperate in the spring during the window for seeding forages. Thus, spring seeding may not have happened or stand establishment may be less than desired. Late summer provides an opportunity to establish forages or interseed into poor stands, assuming moisture is available. The recent rains may have some thinking about this, so below are some tips to consider helping a late summer seeding of forages be successful.
Plan now
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July 14, 2021Authors
Cornfields are starting to tassle and silk all over Iowa. Many insects like to feed on silks, so it is a critical time to assess pollination rates. This article highlights a few of the most common silk feeders of importance.
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July 13, 2021Authors
In the last decade, cover crops have grown in both interest and acres, yet there is still room for more adoption across Iowa and the region. It is obvious that cover crops require more management though and with that management there will undoubtedly be challenges. In just a few weeks the cycle for cover crop establishment, growth and termination will begin.
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July 13, 2021Authors
Rainfall has been extremely variable this season in Iowa. There has been severe drought in many areas of Iowa. In contrast, rainfall has been excessive in some areas of southeast and southern Iowa. Soybean with poor growth with pale green or yellowish color has been observed in low-laying fields or field depressions with poor drainage and frequent waterlogged soils since May.