Anthracnose is a common fungal disease in most corn production areas of the United States. These symptoms are caused by the fungus Colletotrichum graminicola. This fungus can cause many issues in corn including early- and mid-season leaf blight, top dieback, and stalk rots. In severe cases, these diseases can lead to premature death of infected plants, stalk lodging and reduced harvestability, and loss of grain yield.
Categories: Agronomy, Agronomy Talk
Corn grain yield, typically measured in bushels per acre, can be broken down into distinct components that each contribute to the weight of harvested grain. While genetics govern some yield components, much of the harvested yield is directly affected by environmental conditions and management practices. Yield components include number of plants per acre, number of ears per plant, the number of kernels per ear, and the weight of each kernel.
Rapid Growth Syndrome (RGS) can result in some unsightly plants, but it is of little concern when it comes to plant health and yield. Symptoms include leaves twisted in the whorl that have a wrinkled appearance, followed by bright yellow new leaves. Affected plants are distributed at random throughout the field.
Non-GMO corn production requires additional management considerations, particularly in areas with strong insect
pressure. With careful planning, scouting, and season-long management, non-GMO corn production can be successful.
European corn borer (ECB) (Ostrinia nubilalis [Hubner]) was introduced to the eastern United States in 1917 and quickly became an economically important pest of the Corn Belt. With the introduction of transgenic Bt (Bacillus thuringiensis) corn in 1996, damage from this pest has been mitigated.
Potassium (K) plays vital roles within corn plants for carbohydrate, nutrient, and water flow. It is instrumental in gas exchange from the plant to the atmosphere as it regulates the opening and closing of the stomata of the leaf; it is also a key component in cell walls which add to stalk strength. Potassium is essential for photosynthesis, maximizing water use efficiency, helping maintain plant health, increasing test weight of grain, and nitrogen use efficiency. A corn plant requires almost as much K as nitrogen (N); however, when looking at soil test values across the Midwest, soil test K values have been falling. This is largely due to increased grain yields removing higher amounts of K from the soil and insufficient K applications.
Tags: corn, Agronomy, Agronomy Talk, soil tests, potassium, corn development, POTASSIUM deficiency
University data has shown that soybean yields can be reduced by up to 35% due to competition with weeds. Problematic weeds such as waterhemp can produce over 800,000 seeds/plant while marestail can produce over 200,000 seeds/plant. Therefore, a handful of escapes can lead to a substantial increase in the seed bank, making future management more difficult and putting weed control at the top of farmers' minds.
Phytophthora root and stem rot is a common soil-borne disease in soybeans that is caused by the watermold, Phytophthora sojae. Phytophthora often occurs in poorly drained soils; it is most economically damaging in low-lying areas and fields that are prone to flooding.
Tags: corn, Agronomy, Agronomy Talk, PHYTOPHTHORA ROOT, PHYTOPHTHORA STEM ROT, corn diseases
Ear and kernel development is a lengthy process for a corn plant. It begins at the V5 growth stage as the plant determines kernel rows around and then continues to V12 where the potential maximum length of the ear is determined. Next comes the pollination stages where the maximum number of kernels is established and then finally, R5 when the maximum kernel size is established.
Any stresses, natural or manmade, during this process, can lead to abnormal ear set. Many of the abnormal ears and their causes are detailed below. Accurate diagnosis of these abnormalities can help prevent future problems in the field.
Tags: corn, Agronomy, Agronomy Talk, CORN STRESS, Ear DEFORMITIES, ear stress, ear formation
In recent years, the Dectes Stem Borer (Dectes texanus texanus) has become a regular pest in soybean fields throughout the lower Midwest.
Tags: soybean, Agronomy, Agronomy Talk, dectes stem borer, soybean pests
Soybean gall midge is a new pest in soybeans, first documented in Nebraska in 2011 and South Dakota in 2015. In 2018, damage was documented in 66 counties in four states (Nebraska, Iowa, South Dakota, and Minnesota) with that number increasing by 19 additional counties so far in 2019 including the northwest corner of Missouri. It was not until the fall of 2018 that the species was identified.
Tags: soybeans, Agronomy, Agronomy Talk, SEED TREATMENT, insecticides, pest, gall midge, pest management
Harvesting downed corn is one of the worst jobs on the farm. Year in and year out, there are many abiotic stresses or plant pathogens that will affect standability and ease of harvesting a corn crop. One of the most prevalent issues causing decreased standability of corn is the presence of crown rot and stalk rots. These diseases take advantage of compromised stalk tissue, and degrading it below the ear causing lodging and stalk breakage. There are, however, ways to improve the process of harvesting downed corn that can make it much smoother.
Tags: harvest, corn, Agronomy, stalk rot, down corn, standability
Short husking is best described as “corn ears outgrowing their husks.” It results in more exposure of the ear tips to environmental conditions and increases the potential for reduced grain quality.
Tags: harvest, corn, stalk lodging, short husking, heat stress, drought stress
Ears on the ground prior to harvest is frustrating and often misunderstood. Pest damage, weather stress, reduced nitrogen (N) uptake, and genetics can all contribute to dropped ears. However, identifying the causal agent may help you implement strategies and management practices to minimize ear drop in the future.
Tags: harvest, corn, Agronomy, Ear Drop, Corn Yield Limiter
Planting delays, poor ear formation, and lack of standability are just a few reasons why some farmers may want to consider taking their corn crop for silage. When making this decision, there are a few factors to keep in mind. These include how to optimize silage quality, tonnage, agronomics, and pricing of the crop.
Tags: Agronomy, Silage, harvesting for silage, tonnage, milk line
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.
Tags: soybeans, Agronomy, soybean growth, soybean growth stages, soybean development
Corn rootworm (CRW) is a pest that, if left unmanaged, can cause economic damage in most of the Corn Belt. Damage can result from root-feeding while they are in larval form and from adult beetles clipping silks during pollination.
Tags: corn, Agronomy, Beck's Agronomy, corn rootworm, corn pests, beetles, corn root damage
Green snap, also called brittle snap, is the breakage of a corn plant usually prior to tassel during the rapid growth period of corn from about the V5 (5 visible leaf collars) – R2 (silk).
Tags: corn, Agronomy, Agronomy Talk, GREEN SNAP, brittle snap
Iron deficiency chlorosis (IDC) is a physiological disorder caused by a lack of iron in the soybean plant which creates the “chlorosis” symptoms. Plants with IDC have yellowing (chlorosis) beginning between the veins and progressing to a generally chlorotic canopy. Other symptoms include reduced plant growth and ultimately, lower yields. Yield reductions from IDC are a primary limitation for some farmers in certain fields.
Tags: soybeans, Agronomy, Agronomy Update, IDC, iron
Crown rot infections are caused by both fusarium and pythium species. These fungi enter the plant via the root system during periods of prolonged saturation, predominately between the V2 and V7 growth stage. Because these fungi persist in higher moisture environments, infections are more prevalent in wetter soils, tighter clay soil textures, higher magnesium soils, and ponded areas of fields. While these infections occur early in corn development, they can persist much longer as the visual signs are not easily detected until later in the grain fill period.
Tags: corn, Beck's Agronomy, Corn Disease, crown rot