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Have Our Scn Sorrows Been Drowned?, Gregory L. Tylka Jun 2019

Have Our Scn Sorrows Been Drowned?, Gregory L. Tylka

Integrated Crop Management News

Those looking for any bit of good news in all of the rain-soaked suffering we have endured this spring have asked if the extreme overabundance of moisture has drowned soybean cyst nematode (SCN). Unfortunately, the answer is no.


Tissue Testing For Field Crops Requires Cautious Use And Interpretation, Antonio Mallarino, John E. Sawyer Jun 2019

Tissue Testing For Field Crops Requires Cautious Use And Interpretation, Antonio Mallarino, John E. Sawyer

Integrated Crop Management News

In-season plant tissue testing can be useful in diagnosing nutrient deficiencies in field crops, but it must be used with caution. Extra care is needed this year given the unusual crop planting and growing conditions.


Corn Rootworm Egg Hatch Peaking In Southern Iowa, Erin W. Hodgson Jun 2019

Corn Rootworm Egg Hatch Peaking In Southern Iowa, Erin W. Hodgson

Integrated Crop Management News

Corn rootworm egg hatch in Iowa typically occurs from late May to the middle of June, with an average peak hatching date of June 6 in central Iowa. In 2019, the average hatching date will be behind the average, due to cool spring temperatures. Development is driven by soil temperature and measured by growing degree days. Research suggests about 50% of egg hatch occurs between 684-767 accumulated degree days (base 52°F, soil). Most areas in Iowa have reached peak corn rootworm egg hatch (Fig. 1).


Stalk Borers Worth Scouting In Iowa This Summer, Erin W. Hodgson Jun 2019

Stalk Borers Worth Scouting In Iowa This Summer, Erin W. Hodgson

Integrated Crop Management News

Within the last week, I have heard about higher-than-normal stalk borer infestations along field margins compared to previous years. According to degree-day tracking of 2019, the caterpillars should be moving from overwintering hosts to corn throughout Iowa this week.


Japanese Beetles Get A Slow Start To 2019, Erin W. Hodgson Jun 2019

Japanese Beetles Get A Slow Start To 2019, Erin W. Hodgson

Integrated Crop Management News

Several reports from ISU Field Agronomists have indicated Japanese beetles are emerging in southern Iowa. The emergence is about 7-10 days behind the last few years, due to slowly accumulating degree days in 2019. Literature shows Japanese beetle adults need about 1,030 growing degree days (base 50°F) to complete development and will continue emergence until around 2,150 degree days. Based on accumulating degree-day temperatures in 2019, Japanese beetle adults should be active in some areas of southern Iowa this week (Figure 1).


Soybean Gall Midge Confirmed In Iowa And Nebraska, Erin W. Hodgson Jun 2019

Soybean Gall Midge Confirmed In Iowa And Nebraska, Erin W. Hodgson

Integrated Crop Management News

Last year, the widespread outbreak of soybean gall midge took many farmers and entomologists by surprise. There was significant field edge injury and economic loss in at least 65 counties in Iowa, Nebraska, Minnesota, and South Dakota. A small team organized a concerted effort to learn more about the life cycle, biology and management of soybean gall midge in 2019. The first step was to establish emergence cages in various habitat types to better understand where they overwinter. We used the “corn rootworm” style traps to collect adults emerging from the ground. A series of traps in Iowa, Nebraska and ...


Submitting Samples To The Plant And Insect Diagnostic Clinic, Edward R. Zaworski, Lina M. Rodriguez Salamanca Jun 2019

Submitting Samples To The Plant And Insect Diagnostic Clinic, Edward R. Zaworski, Lina M. Rodriguez Salamanca

Integrated Crop Management News

With the crops of Iowa in the ground, it is time to start thinking about seedling diseases. The Plant and Insect Diagnostic Clinic is a resource for corn and soybean growers assessing their field throughout the season.


Staying On Top Of Weeds In 2019, Robert G. Hartzler, Meaghan J. B. Anderson Jun 2019

Staying On Top Of Weeds In 2019, Robert G. Hartzler, Meaghan J. B. Anderson

Integrated Crop Management News

While good progress has been made toward getting crops in the ground, the adverse early spring conditions are likely to complicate weed management throughout the 2019 growing season. The most important step in minimizing problems is to scout fields regularly to identify problems quickly and allow timely adjustments to management.


Nitrogen Fertilization Options With Delayed Or Rescue Applications, John E. Sawyer Jun 2019

Nitrogen Fertilization Options With Delayed Or Rescue Applications, John E. Sawyer

Integrated Crop Management News

It’s been a wait-go-stop (repeat) corn planting season this spring. Whether you planted early or are just now getting corn planted, it seems planting windows were short and rushed. In some cases this meant planting (corn/soybean) and worrying later about getting nitrogen (N) applied. And in some areas of Iowa, wetter than normal conditions are raising questions about supplemental N application. What are the options for sidedress N?


It’S Time To Think About Sampling For Nematodes That Feed On Corn, Gregory L. Tylka Jun 2019

It’S Time To Think About Sampling For Nematodes That Feed On Corn, Gregory L. Tylka

Integrated Crop Management News

As Iowa’s corn crop gets slowly planted and established in 2019, it’s time to turn thoughts towards pests. Plant-parasitic nematodes that feed on corn can cause damage and yield loss. Some nematode species are damaging to corn at very low population densities (numbers). But most species are not harmful until population densities reach many hundreds or more per 100 cm3 (a little less than a half-cup) of soil. And then there are some nematode species that are not thought to be harmful to corn at all. It is very common for Iowa fields to have several different ...


Springtime Precipitation – A Tool For Estimating Nitrogen Application Need For Corn, John E. Sawyer Jun 2019

Springtime Precipitation – A Tool For Estimating Nitrogen Application Need For Corn, John E. Sawyer

Integrated Crop Management News

Wet springtime conditions typically raise questions about the status of applied nitrogen (N). Or the question, do I need to apply additional N to my cornfields? At this time we do not know what the weather/precipitation will be for the entire springtime, but the extended period of wet conditions this spring is of concern. A summary of long-term N rate trials with continuous corn and corn rotated with soybean conducted at seven ISU research and demonstration farms in Iowa from 1999 to 2016 has been an on-going basis for indicating the potential for needing an N rate greater than ...


Cover Crop Options With Prevented Planting Fields, Mark A. Licht, Hugo Ramirez-Ramirez, Brian J. Lang, Aaron Saeugling, Katana Lippolis May 2019

Cover Crop Options With Prevented Planting Fields, Mark A. Licht, Hugo Ramirez-Ramirez, Brian J. Lang, Aaron Saeugling, Katana Lippolis

Integrated Crop Management News

Whether it's too much rain or perfectly timed rain, many fields are flooded or too wet to continue planting in many parts of Iowa. Delayed and preventative planting crop insurance dates are fast approaching with an unfavorable weather forecast. Decisions surrounding your delayed and prevented planting provision need to involve a conversation with your crop insurance provider. There is a nice article available on the Ag Decision Maker website that talks about the insurance provision implications. Additionally, there is are articles addressing Late Corn Planting Options and Late Soybean Planting Options; these articles discuss late planted yield potential. Each ...


Considerations For Baleage With First Crop Alfalfa, Dan Loy, Garland Dahlke, Erika Lundy May 2019

Considerations For Baleage With First Crop Alfalfa, Dan Loy, Garland Dahlke, Erika Lundy

Integrated Crop Management News

Earlier this spring, we discussed using the PEAQ method (Predictive Equations for Alfalfa Quality) to help determine when to harvest first crop alfalfa. Looking at the PEAQ measurements made around the state, we are getting close to taking the first crop alfalfa. However, the wet conditions could present some challenges with putting up the first cutting of alfalfa in a timely fashion and maintaining feed quality.


Forage Options With Prevented Planting Fields, Mark A. Licht, Hugo Ramirez-Ramirez, Brian J. Lang, Aaron Saeugling, Katana Lippolis May 2019

Forage Options With Prevented Planting Fields, Mark A. Licht, Hugo Ramirez-Ramirez, Brian J. Lang, Aaron Saeugling, Katana Lippolis

Integrated Crop Management News

Whether it's too much rain or perfectly timed rain, many fields are flooded or too wet to continue planting in many parts of Iowa. Delayed and preventative planting crop insurance dates are fast approaching with an unfavorable weather forecast. Decisions surrounding your delayed and prevented planting provision need to involve a conversation with your crop insurance provider. There is a nice article available on the Ag Decision Maker website that talks about the insurance provision implications. Additionally, there is are articles addressing Late Corn Planting Options and Late Soybean Planting Options; these articles discuss late planted yield potential. Each ...


Delayed Planting And Diseases In 2019, Alison E. Robertson, Daren S. Mueller, Ethan Stoetzer May 2019

Delayed Planting And Diseases In 2019, Alison E. Robertson, Daren S. Mueller, Ethan Stoetzer

Integrated Crop Management News

This growing season, delayed planting, combined with continued cool and wet conditions have taken their toll on crops that were planted in the brief periods of optimum weather. Given that there is already delayed emergence, and the wet and cool weather patterns are expected to continue, we could very well see continued delayed growth and development of crops. This means that we can also expect reaching grain fill later in the growing season, which creates a window of opportunity for plant diseases to impact total yield. The earlier a plant disease occurs during grain fill, the more likely it is ...


Weeds In A Wet Year, Robert G. Hartzler May 2019

Weeds In A Wet Year, Robert G. Hartzler

Integrated Crop Management News

The delays in planting get the headlines (for good reason), but another issue with prolonged wet periods is the inability to manage weeds and cover crops in a timely fashion. The following is a brief review of some of the problems that may be encountered.


Late-Spring Soil Nitrate Test (Lsnt) Use In 2019, John E. Sawyer, Antonio Mallarino May 2019

Late-Spring Soil Nitrate Test (Lsnt) Use In 2019, John E. Sawyer, Antonio Mallarino

Integrated Crop Management News

Nitrogen (N) fertilization for this year’s Iowa corn crop has been complicated by frequent and sometimes excessive rainfall from late last fall through this spring. Many farmers who normally apply N in the fall couldn’t, and spring preplant N application and corn planting has been challenging in many areas with the wet and extended cold soil conditions. Therefore, many farmers are uncertain about the N availability for corn, early post-emergence assessment of soil N supply, and the potential for supplemental sidedress N application.


Evaluating Soybean Stands, Meaghan J. B. Anderson, Rebecca K. Vittetoe May 2019

Evaluating Soybean Stands, Meaghan J. B. Anderson, Rebecca K. Vittetoe

Integrated Crop Management News

As of May 20, an estimated 27 percent of Iowa’s soybean crop is planted according to the USDA-NASS Iowa Crop Progress Report. Early-planted soybeans have been exposed to stressful conditions following multiple rainfall events, cold temperatures, and wide temperature swings in the last several weeks. We previously posted an article on evaluating corn stands, and many of the same issues are important when evaluating soybean stands.


Recycling Pesticide Containers, Kristine J. P. Schaefer May 2019

Recycling Pesticide Containers, Kristine J. P. Schaefer

Integrated Crop Management News

Handling and disposing of empty pesticide containers is a necessary part of pesticide applications and recycling containers is an environmentally friendly and responsible way of disposing of them. In 2018 763,078 pounds of pesticide containers 55 gallons and smaller were collected and recycled for the state of Iowa. Iowa ranked number one in the Midwest for containers recycled in 2018.


Seedcorn Maggots Flying In Iowa, Erin W. Hodgson May 2019

Seedcorn Maggots Flying In Iowa, Erin W. Hodgson

Integrated Crop Management News

Seedcorn maggot is a seed and seedling pest of corn and soybean. Plant injury is especially prevalent during cool and wet springs. The larvae, or maggots, feed on germinating corn and soybean seeds or seedlings (Photo 1). They can feed on the embryo, delay development or kill the plant. Infestations tend to be field-wide instead of having a patchy distribution like for many other pests. To confirm seedcorn maggot injury, check field areas with stand loss and look for maggots, pupae and damaged seeds (e.g., hollowed out seeds or poorly developing seedlings).


Alfalfa Weevils Active In Northern Iowa, Erin W. Hodgson May 2019

Alfalfa Weevils Active In Northern Iowa, Erin W. Hodgson

Integrated Crop Management News

Keep alfalfa weevils in mind while scouting for stands and evaluating for winter injury. A recent ICM News article gave some great tips for assessing winter injury and providing additional resources. Adult alfalfa weevils become active and start laying eggs as soon as temperatures exceed 48°F. Alfalfa weevil eggs develop based on temperature, or accumulating degree days, and hatching can start around 200-300 degree days. Start scouting alfalfa fields south of Interstate 80 at 200 degree days and fields north of Interstate 80 at 250 degree days. Based on accumulated temperatures since January, weevils could be active throughout southern ...


Late Soybean Planting Options, Mark A. Licht, Ashlyn Kessler, Sotirios Archontoulis May 2019

Late Soybean Planting Options, Mark A. Licht, Ashlyn Kessler, Sotirios Archontoulis

Integrated Crop Management News

This spring's weather conditions may be slowing down corn planting but soybean planting has not yet been impacted. As of May 5, soybean planting progress is estimated at 8% compared to 11% for the 5-year average (USDA-NASS, 2019). However, because of recent rains and corn planting delays there is concern that soybean planting will soon fall behind. In this article, we discuss the soybean yield potential and maturity selection considerations as planting progresses into late May and possibly June.


Scouting For Black Cutworm 2019, Ashley Dean, Erin W. Hodgson, Adam Sisson May 2019

Scouting For Black Cutworm 2019, Ashley Dean, Erin W. Hodgson, Adam Sisson

Integrated Crop Management News

Black cutworm (BCW) is a migratory pest that cuts and feeds on early vegetative-stage corn. Black cutworm moths arrive in Iowa and other northern states with spring storms each year. These moths lay eggs in and around crop fields, and emerging BCW larvae can cut seedling corn. This pest is sporadic, making it essential to scout fields to determine if management is needed. Scouting for BCW larvae helps to determine if an insecticide application will be cost effective. This year, delayed corn planting can coincide with emergence of BCW larvae so scouting should be done early on to protect seedlings ...


Estimate Alfalfa First Crop Harvest With Peaq, Rebecca K. Vittetoe, Brian J. Lang May 2019

Estimate Alfalfa First Crop Harvest With Peaq, Rebecca K. Vittetoe, Brian J. Lang

Integrated Crop Management News

Every spring, alfalfa growth and development is different due to variations in climatic, variety, stand age and other crop production factors. With the 2019 growing season being off to a cooler than normal start, this has slowed alfalfa growth this spring. This is a good reminder that while calendar date may be one method used to determine when to harvest first crop alfalfa, this method is not the best method to use. Instead, the PEAQ method (Predictive Equations for Alfalfa Quality) developed by the University of Wisconsin does a better job.


Another Harsh Winter For Bean Leaf Beetle, Erin W. Hodgson, Adam Sisson May 2019

Another Harsh Winter For Bean Leaf Beetle, Erin W. Hodgson, Adam Sisson

Integrated Crop Management News

Bean leaf beetle adults (Photo 1) are susceptible to cold weather and most will die when air temperatures fall below 14°F (-10°C). However, they have adapted to winter by protecting themselves under plant debris and loose soil. Each spring, adult beetles emerge from overwintering habitat and migrate to available hosts, such as alfalfa, tick trefoil, and various clovers. As the season progresses, bean leaf beetles move to preferred hosts, like soybean. While initial adult activity can begin before soybean emergence, peak abundance often coincides with early-vegetative soybean.


Evaluating Corn Stands, Rebecca K. Vittetoe, Meaghan J. B. Anderson May 2019

Evaluating Corn Stands, Rebecca K. Vittetoe, Meaghan J. B. Anderson

Integrated Crop Management News

As of May 6 2019, 36 percent of Iowa’s corn is planted according to the USDA-NASS. Under cool conditions (50 to 55oF soils), it may take more than three weeks for corn to emerge whereas corn in 70oF soils can emerge in less than a week (Licht et al., 2001). Cool and wet conditions at or around planting delay emergence and provide seedling disease pathogens, like Pythium, a favorable environment and longer time to infect corn seeds or seedlings (Munkvold and White, 2016; Robertson and Munkvold, 2007). The cool and wet conditions could also result ...


Late Corn Planting Options, Mark A. Licht, Mitchell Baum, Sotirios Archontoulis May 2019

Late Corn Planting Options, Mark A. Licht, Mitchell Baum, Sotirios Archontoulis

Integrated Crop Management News

Corn planting began a couple of weeks ago and according to the May 5 USDA-NASS Crop Progress and Condition report only 36 percent of the corn crop is planted; 15 percent behind the 5-year average. The greatest progress has been in central and west central Iowa at 56 percent and 57 percent, respectively. Since May 5 there has been limited opportunity for planting to occur. Current weather forecasts for May 8 to 14 indicate two inches of rain and 20 to 30 lower than normal GDD accumulation across Iowa, which may cause additional planting delays.


Step Two In Flood Recovery Of Pastures Is Renovation, Beth Doran, Joel L. Dejong, Brian J. Lang May 2019

Step Two In Flood Recovery Of Pastures Is Renovation, Beth Doran, Joel L. Dejong, Brian J. Lang

Integrated Crop Management News

As flood waters recede, the renovation of flooded pastures is just beginning. Now is a good time to check pasture plants for survival. Forage production is a function of the plant species, and their density and growth. Evaluate live plants (plant vigor), plant density, and desirable species versus weeds.


Soybean Aphid Egg Hatch Starting In Northern Iowa, Erin W. Hodgson May 2019

Soybean Aphid Egg Hatch Starting In Northern Iowa, Erin W. Hodgson

Integrated Crop Management News

Iowa’s most significant soybean insect pest, soybean aphid, has host-alternating biology. This species has multiple, overlapping generations on soybean in the summer and moves to buckthorn in the winter. Fall migration to buckthorn is based on senescing soybean, and decreasing temperatures and photoperiod. For the majority of the year, soybean aphids are cold-hardy eggs near buckthorn buds (Photo 1). As spring temperatures warm up, soybean aphid eggs hatch and produce a few generations on buckthorn before moving to soybean (Photo 2). Tilmon et al. (2011) goes into more detail about the life cycle and biology of soybean aphid.


What's Behind Iowa's 2019 Soybean Yield Gaps?, Ethan Stoetzer, Mark A. Licht, Daren S. Mueller May 2019

What's Behind Iowa's 2019 Soybean Yield Gaps?, Ethan Stoetzer, Mark A. Licht, Daren S. Mueller

Integrated Crop Management News

Over the last five years, the North Central region of the U.S. has been responsible for 82 percent of the nation’s soybean harvest. Due to the region’s importance to soybean production for its various uses in feed, biodiesel and other widely used products, the North Central Soybean Research Program (NCSRP), through funding from the Soybean Checkoff Program, has sponsored on-farm surveys to farmers in the region to evaluate trends in farming practices and management systems. These responses have helped surveyors develop correlations between total annual yield numbers and particular crop management practices.