Numerous insects and diseases can damage soybeans in the mid-southern United States. Soybean pests may cause economic losses throughout the growing season, or only cause damage during a particular stage or at a particular time.

In either case, scouting for pest presence and applying control measures (if available) when thresholds have been reached should prevent economic losses.

Effective scouting is done in time to detect a pest's first appearance before it reaches an economic threshold. Treatment of some pests detected by scouting at an early stage may prevent problems later in the season.

Insects that should be monitored to prevent economic losses in soybeans are shown in the accompanying table. Three-cornered alfalfa hopper and bean leaf beetle populations should be monitored both early and late in the season, while others should be monitored during reproductive development.

Bean leaf beetle

Most insects that defoliate soybeans generally appear late in the season or do not cause economic damage prior to bloom. However, it's a good idea to periodically scout during vegetative development to determine that defoliation by insects before bloom does not exceed 35%. That's the level that an insecticide is justified.

Insect defoliation of soybeans is more critical after R1 (beginning bloom). Start scouting more frequently to ensure defoliation does not exceed about 20% during reproductive development. Scouting for pod feeding insect damage should begin at or soon after R3 (beginning podset).

Stinkbugs are the most important Midsouth soybean insect and feed on developing pods and seeds. Scouting should begin no later than R3 regardless of the time of year, and continue through R7 (beginning maturity) to prevent levels that will damage seed.

Stinkbug

Numerous insects and diseases can damage soybeans in the mid-southern United States. Soybean pests may cause economic losses throughout the growing season, or only cause damage during a particular stage or at a particular time.

Several important diseases, like sudden death syndrome (SDS), stem canker, phytophthora root rot and charcoal rot of soybeans have no curative control. SDS and stem canker can be managed or avoided by using less-susceptible or resistant varieties.

Sudden death syndrome (SDS)

Phytophthora root rot

Charcoal rot

Previous     |    Page 1 of 5    |     Next