Frogeye leaf spot (FLS), caused by the pathogen Cercospora sojina, is a common soybean foliar disease of many soybean-producing regions worldwide. In the U.S., the disease is established in southern production regions and has recently become prevalent in the Midwest and Upper Midwest. It’s believed that the range expansion and increased disease severity are caused by widespread planting of susceptible varieties, warmer winter temperatures, and the increased adoption of conservation tillage practices, which, together, lead to increased inoculum levels. FLS does not always cause yield loss, but yield loss of up to 60% has been reported with severe infection rates.

The initiation of flowering on a soybean means that the plant is transitioning into the reproductive growth stage. Most full-season soybeans enter reproductive growth approximately 45 to 55 days after planting. Double crop soybeans will typically enter reproductive growth approximately 34 to 38 days after planting. During this time, the plant has the ability to compensate for any plant injury or adverse growing conditions. Soybeans are prolific flower producers, although more than half are typically aborted prior to pod development.

Sudden Death Syndrome (SDS), caused by Fusarium virguliforme, is a soybean disease that has grown in importance for farmers over the past 20 years. Today, it is ranked second only to soybean cyst nematode (SCN) as the most detrimental cause of annual damage to soybean yields. As the soybean-growing region has expanded to the North and the West, SDS continues to spread to new fields and to larger areas of fields that have already been infected. The severity of SDS damage varies from area to area and field to field, but yield reductions associated with SDS typically range anywhere from 20 to 70%.

During rainy springs, fields may flood or even stay saturated for long periods of time. Flooded fields have two forms: saturated or waterlogged (where only the roots are flooded) or submerged (where the entire plant is under water). Saturated or waterlogged soils are more common than completely submerged plants, but they can both be damaging to yield.

Early-season frost damage is a stressful physiological event that can slow plant development. The net impact of early-season frost will depend on the health of the plant before the frost, the extent and duration of the freezing temperatures, and the growing environment following the frost.

Do you know how, when, and where should you tissue test? Do you know how to handle your samples once you pull them? What should you be thinking about when evaluating the results? 
 

Planters have continued to roll across fields in the Midwest over the last few weeks and soybeans have finally started to emerge. Now is a great time to evaluate your stands and see if there are any issues that need to be addressed.
 

By now many of you are probably aware that the EPA has approved the use of the herbicide XtendiMax™ with VaporGrip™ technology for in-crop use in dicamba tolerant soybeans. The Roundup Ready 2 Xtend® soybeans will have tolerance to both glyphosate as well as dicamba. Currently, the XtendiMax label only has a two-year registration. The EPA has reserved the right to rescind the label if they feel the product is being misused, is having a negative impact on the environment and general public impact, or is having a high number of off-target incidents.

The cool temperatures we have experienced over the last several nights have led to questions regarding frost damage. We are seeing some signs of frost damage here at our Ohio Practical Farm Research (PFR)® location, however we won’t know the severity of this damage until three to five days following the frost event. With the low temperatures leading up to this recent frost event, the hardening off process had started making our crops more tolerant of cool temperatures. Wet soils and dew present helps to maintain soil temperatures, thereby decreasing the risk of injury.

This year can be called the year of leaf diseases! We have seen gray leaf spot, northern corn leaf blight, and even southern rust. Corn has filled out well, but stalk quality is a concern as plants have cannibalized with the late dry stress. Harvest will be a chance for us to evaluate our fungicide applications. Many diseases came in late and the residual from the fungicide may be gone. In some cases, these diseases may not have affected yield dramatically. If you are planning to go corn after corn, consider what diseases you had and plant a hybrid with good tolerance to them.