Soybean Fertility Management

Nutrients are required for water transport and photosynthesis processes, and protein and oil production in the plant.  Nutrient deficiencies are one of the causes of leaf discoloration and/or chlorosis that might be observed in a soybean field and can decrease plant growth and reduce yield potential.  It is beneficial to understand the function of a nutrient and identify deficiency symptoms to know when to apply corrective steps.  Diagnoses from visible symptoms should be confirmed with results from soil tests and plant tissue analysis in some cases.

Soybean Fertility: Functions, Deficiency, Management

Planting Small-Seeded Soybeans

Like most other things in agriculture, soybean seed size is determined by the interaction of genetics and environment.  Hot and dry conditions, such as those experienced in some parts of the U.S. during the 2011 growing season, can result in smaller seed. Planting smaller seed may require adjustments to planting equipment.

Agronomic Spotlight – Planting Small-Seeded Soybean

Integrated Management for Sudden Death Syndrome in Soybean

Sudden Death Syndrome (SDS) is considered one of the top four yield robbing diseases in soybeans. Yield losses from SDS have ranged from slight to nearly 100%, depending on disease onset and severity. Average yield losses in the United States were estimated at $190 million a year. Managing SDS includes several steps to potentially reduce its impact on soybean yield potential.

Agronomic Spotlight – Integrated Management for Sudden Death Syndrome in Soybean

Managing the Effects of Crop Residue in Continuous Corn

Crop residue in continuous corn can be difficult to manage. If residue is not dealt with, it can decrease seed to soil contact, emergence, and vigor. Residue can also tie up nitrogen (N) during much of the season making it unavailable to the corn crop. Additionally, residue can harbor disease pathogens. While the speed of residue degradation is heavily influenced by weather and the environment, there are actions that can be taken during and after harvest, as well as in the spring to help decrease the negative effects of excessive crop residue.

Agronomic Spotlight – Managing the Effects of Crop Residue in Continuous Corn

Purple Seed Stain and Cercospora Leaf Blight in Soybeans

Purple seed stain and Cercospora leaf blight are caused by the fungus Cercospora kikuchii. Both phases of the disease are favored by wet conditions late in the season. With severe weather in August and September affecting the Southeast U.S. and East Coast, purple seed stain is showing up in soybean growing areas from Louisiana and Mississippi to Missouri….

Agronomic ALERT – Purple Seed Stain in Soybean

Agronomic Spotlight – Cercospora Leaf Blight in Soybean

Late-Season Frost Damage to Soybeans

The effect of late-season frost on a soybean crop depends upon the growth stage of the soybean plants. Yield losses due to frost are uncommon after soybeans have reached full maturity, the R8 growth stage. Temperatures that range from 30°F to 32°F can easily damage the top leaves on a soybean plant. When air temperatures drop lower than 30°F, the entire soybean plant can be killed. Fields with narrow-spaced rows (6 to 15 inches) seem to survive frost damage better than wide-spaced rows (30 to 38 inches) because of the limited air movement within the canopy.

Agronomic ALERT – Late-Season Frost Damage to Soybeans

Discolored Soybean Seed

Source: Lara Sweets, University of Missouri  |   September 26, 2011

This may be a year when soybean seed discoloration is a problem in Missouri. Soybean diseases are one of several factors that can cause discoloration and deterioration of soybean seed. The late season soybean diseases, which can lead to discolored soybean seed tend to be favored by wet conditions, including frequent rains, heavy dews and high humidity, as plants mature or if harvest is delayed due to wet conditions.  Read more

Soybean Bloom and/or Small Pod Abortion Due to Extreme Heat

During the early reproductive stages, a soybean plant may abort flowers and small pods as it adjusts to the surrounding environmental. The percentage of flower and/or pod shed is determined by how much fruit the plant can support to full development. While some flower and small pod shed is a normal occurrence, unfavorable growing conditions such as high temperatures or drought may cause the plant to abort many more flowers and/or small pods than usual. The loss of flowers and small pods can be alarming to many producers who may already be concerned for their crops struggling with unfavorable growing conditions.

Agronomic Alert – Soybean Bloom and/or Small Pod Abortion Due to Extreme Heat

Brown Marmorated Stinkbug in Corn and Soybean

The brown marmorated stinkbug (Halyomorpha halys) (BMSB) is a pest that was introduced into the US about 10 years ago. Like many recent invaders, BMSB is native to Asia and likely hitchhiked to North America in shipping containers. The BMSB feeds on the fruits and seed pods of a wide range of plants including corn and soybeans.

Brown Marmorated Stinkbug in Corn and Soybean

Early Season Soybean Leaf Malformation

Leaf malformation in soybeans can take on several appearances and be caused by several factors. Herbicides, such as chloroacetamides or plant growth regulators (PGRs) are often blamed for this injury; however, environmental conditions maybe the actual cause.

Agronomic ALERT – Early Season Soybean Leaf Malformation