Soybeans

Starting clean, or weed-free, is a critical component of any weed management program. In 2022, growers experienced either a lack of or higher cost of glyphosate-based herbicides that are typically used to control weeds prior to planting soybean. In a study sponsored by the Maryland Soybean board and conducted at the University of Maryland’s Central Maryland and Wye Research and Education Centers, different glyphosate-based and non-glyphosate based herbicide treatments were evaluated for their ability to provide effective preplant weed control (Table 1). These treatments included both single and sequential herbicide applications.

Italian ryegrass is a winter annual weed that often needs to be managed prior to soybean planting. In Maryland, populations of Italian ryegrass have been confirmed to be resistant to group 1 (Axial, Select) and group 2 (Harmony, PowerFlex) herbicides, but recent populations have appeared to develop resistance to glyphosate (Figure 1). With limited herbicide options, preplant control of Italian ryegrass will be challenging for growers.

Agronomy News is a statewide newsletter for farmers, consultants, researchers, and educators interested in grain and row crop forage production systems. The topic for this edition is Double Crop Beans, Not So Fast, Herbicide Field Day, July IPM Insect Scouting Tips, Hemp Twilight Tour, Corn Disease Update, 4R Field Day, Poison Hemlock Identification and Management, Tar Spot: New Disease of Corn, Soybean Board Field Day, 2021-2022 Cover Crop Sign-Up, LEAD Maryland Fellowship Applications, Maryland Commodity Classic, MDA Pesticide Exams, MDA Pesticide Disposal Program, Weather Outlook, and Regional Crop Reports.

Podworms in Soybeans

Current corn earworm pheromone trap captures in Maryland and Delaware and pest management recommendations.

Reports of slug damage to emerging soybean seedlings (Glycine max) have increased in recent years, though their activity is highly variable from field to field, and within a field from year to year. Spring, 2021 weather was both cool and wet, conditions that many slug species find ideal. Slug eggs overwinter in the soil, hatch in the spring, and the juvenile slugs can begin causing damage to crops in just a week’s time after hatching (Hammond et al. 2009).

Agronomy News IPM Insect Scouting Tips

The Crop Protection Network (cropprotectionnetwork.com) is a national working group comprised of Extension agents and specialists from across North America that provide data through publications regarding pest management in agronomic crops. The website and publications can be a great resource for your operation. The following are the most recent fungicide efficacy tables for foliar diseases of corn and soybean.