This agronomy brief covers the damage caused by the most common early-season soybean pests, how to identify them, and how to manage them.
Categories: Agronomy, Agronomy Talk
This agronomy brief covers the damage caused by the most common early-season corn pests, how to identify them, and how to manage them.
Soybean yields ultimately depend on the number and weight of the seeds harvested per acre. Soybean yield is determined by nodes per acre (plants per acre x nodes per plant), pods per node, seeds per pod, and seed weight.
Black cutworm (BCW) (Agrotis ipsilon) is an insect pest in many areas of the world. It can cause significant economic damage to corn, soybean, cotton, and other crop species. In the Corn Belt, BCW larvae are primarily known for the damage they cause to newly emerged corn plants. Their feeding can result in cut off seedlings near ground level, thus, the name “cutworm”.
Fusarium Head Blight (FHB), also called head scab, is a disease that can affect many small grain crops, but its economic impact is the largest on wheat. The causal pathogen of this disease is Fusarium graminearum, and it can significantly impact yield and grain quality. The disease can produce many mycotoxins. Deoxynivalenol (DON), also known as vomitoxin, is the primary mycotoxin screened for at grain delivery points.
Starter fertilizers are relatively small amounts of plant nutrients, placed near the seed at planting. The two most common application methods are in-furrow, also called pop-up, and 2x2. While some planter setups are not a true 2 in. over and 2 in. below the seed, all banded starter fertilizer that’s not placed in the planting furrow is referred to as 2x2.
While cover crops provide a variety of benefits, cover crop termination in the spring requires additional management practices. Spring cover crop termination varies by cover crop species, the goals of cover cropping, whether that cover crop will be used in the spring (i.e., forage), weed pressure and species, and the proceeding cash crop.
Western bean cutworm (WBC) is a relatively new pest to field corn in the Midwest. While WBC is native to North America, it has primarily been a pest of specialty crops up until the early 2000s. Like European corn borer and earworms, WBC is part of the Lepidoptera family of corn pests, meaning they resemble caterpillars. Even though they look much like corn borers and earworms, their feeding and life cycle is quite different.
Soybean aphids (Aphis glycines Matsumara) are a piercing and sucking insect that have been affecting soybeans in the U.S. since the early 2000s. Aphids tend to be a problem in late-planted soybean fields during years with dry conditions and moderate temperatures. The insects themselves are small (1/16 in. long), pear-shaped, and yellow-to-green in color. They have black extensions on the body toward the back legs that are often called “tailpipes.” Winds deposit aphids in fields, so the infestation works from the top of the plant to the bottom. Aphids are most damaging in dry field conditions but shy away from heat, so look for them on the underside of leaves.
Soybean cyst nematode (SCN) in the United States was first observed in 1954 in North Carolina, and it has continued to spread throughout most of the major soybean growing areas (Tylka and Marett 2014). The expansion of SCN across the U.S. and Canada is depicted in in Figure 1. to the left. It is the most damaging pest in soybeans by a large margin.
Twenty years of Beck’s Practical Farm Research (PFR)® data indicates that one key to optimizing soybean yield over time is early planting. Early planting of soybeans increases the number of nodes, which creates additional pods and higher yield.
Top priorities for prevent plant (PP) acres in the spring include; tiling, tillage, residue, cover crops, weeds, nutrients, soil health, and insects.
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.
Tags: soybeans, Fungicide, frogeye leaf spot, foliar disease, soybean disease, Leaf Lesions
As farming becomes more complex and time becomes more precious, farmers are searching for ways to increase revenue and manage input costs on every acre. This leads us to ask, what soybean management practices can save you time, make the most sense agronomically, and make you money?
Manganese (Mn) is important in a soybean plant for its role in the activation of enzymes and in the process of photosynthesis. Additionally, Mn is known to regulate potassium (K) uptake.
We know that different nutrients are required at different times for optimum soybean yields. Current soybean biomass production shows a two-fold increase from the 1930s, and yields show a three-fold increase. With these drastic changes in genetics, it only makes sense that we would also see changes in nutrient uptake. In addition to genetics, there is evidence that environmental factors like temperature, moisture, and soil fertility influence nutrient uptake.
In corn-after-corn systems, the high amount of residue can immobilize nitrogen and make it unavailable to the following crop. Robust® and Res Plus are products the help to feed microorganisms in the soil. By supporting microbial communities, these products lead, in turn, to increased microbial degradation of corn residue in corn-after-corn systems. Applying these products in the fall may help speed up residue breakdown so the carbon penalty is paid off earlier in the growing season. This would allow for a transition from immobilization to mineralization of residue-bound nitrogen (N).
Nitrogen (N) is a mobile nutrient. When we look at the N cycle, we think of NO3 - is the N form most readily taken up by the plant, followed by NH4 +. Loss of N when applying urea or UAN can occur as ammonia volatilization (lost in gaseous form). In the case of UAN applications, N loss can also occur in the form of NO3 - leaching if a heavy rain follows or denitrification. Two ways to prevent N loss are more accurate timing and more precise placement. If we can supply N to the plant when it needs it, this allows less time for N loss. If we supply N near the base of the plant where it can more easily access the nutrient, this could increase N use efficiency.
When it comes to insecticides in corn and soybeans, it's important to remember that different pests are present at different points in the season. Whether or not an insecticide is warranted can be determined by a few factors. What insects are present? Does this field have a history of a particular insect pest? Are these insects present at a level that will impact your yield and ROI?
Fungicides are used in corn for a number of reasons. First and foremost, they can prevent or mitigate disease. How a fungicide works will depend on its mode of action. In addition to controlling disease, fungicides also work to increase water use efficiency in the plant, photosynthesis, nitrate reductase activity, timing for ear fill, and stress tolerance. One way to increase this stress tolerance is through the mitigation of ethylene production.