Integrated Crop Management News

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Mild Winter Favors Bean Leaf Beetle Survival

Bean leaf beetle adults (Photo 1) are susceptible to cold weather and most 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 their overwintering habitat and migrate to available hosts, such as alfalfa, tick trefoil, and various clovers. As the season progresses, bean leaf beetles move to soybean and other hosts. While adult activity can begin before soybean emergence, peak abundance often coincides with early-vegetative soybean.

Survival Effects of Fluctuating Temperatures on Insects

The weather this year has been quite variable – several warm days followed by a cold, snowy week in April is just one example of the dramatic changes we’ve experienced in air temperatures (Figure 1). Each winter, we receive the question “Will insect pests be worse/better this year?”, and cold snaps during the spring cause people to wonder “Do fluctuating temperatures affect pest populations?” The short answer to these questions: it depends, but probably not.

Keeping Bees in CRP

Over the past two decades, scientists and beekeepers alike observed drastic declines in bee populations. On average, beekeepers lose significantly more honey bee colonies each year and fewer native bee species are spotted in the wild. This is especially apparent in the Midwest where research conducted at Iowa State University observes multiple factors that contribute to the decline in bees and other pollinators. According to an annual Bee Informed Partnership survey, Iowa beekeepers typically lose between 40-60% of their hives each year.

Performance of Preemergence Herbicides on Waterhemp Control in Soybean

The battle against waterhemp is complicated mainly because of its extended emergence period (early May until August). Preemergence (PRE) soil residual herbicides serve as a foundation for managing waterhemp, but require follow-up treatments with effective postemergence (POST) products due to late-emerging plants. Group 15 herbicides (HG 15) are commonly used for PRE waterhemp control. However, an increased selection pressure from these herbicides used in corn-soybean rotations has resulted in the evolution of HG 15 resistance in waterhemp populations, recently documented in Illinois.

Seedcorn Maggots Flying in Iowa

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). Feeding can delay development or kill the plant. Infestations tend to be field-wide instead of in patches like for many other pests. To confirm seedcorn maggot injury, check field areas with stand loss and look for maggots, pupae and damaged seeds (hollowed out seeds or poorly developing seedlings).

Preemergence Herbicide Application Timings: Pros and Cons

Preemergence herbicides are the foundation of herbicide-based weed management systems, and effective use of these products is essential to protect crop yields and reduce selection pressure for herbicide resistant weeds. In a perfect world, applying preemergence herbicides immediately after planting would provide the greatest likelihood of maximum performance, but equipment and labor availability limit many farms from using this approach. This article will provide a brief overview of the pros and cons of different application strategies.

Are You Planting on a Level Playing Field?

Springtime on a farm is typically filled with the hustle and bustle of gearing up for planting season. This is the time of year when most farmers focus on de-winterizing the sprayer, changing oil in the tractors and checking the seed meters on the planter. If you use a field cultivator, it is also important to make sure it is properly adjusted to help provide a uniform seedbed for the upcoming planting season. Whether this is the first season or the thirtieth season for the field cultivator, there are a few items to check before making your way to the field this spring.

Spring Forage Fertilization Considerations

Fertilization is just as important for forages as it is for row crops to maximize productivity. This article addresses spring fertilization considerations for forage crops and pastures.

Nitrogen considerations

Nitrogen (N) applications can either be a one-time, annual application or can be split applied. Suggested N application rates for single application are in Table 1 and rates for split applications are in Table 2.

Table 1. Suggested N application rates for a single annual application

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Nitrogen considerations

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