Alfalfa weevil feed on the terminal and upper leaves of the alfalfa plant. This feeding reduces hay quality and weakens alfalfa stands if left uncontrolled. Alfalfa fields should be scouted now, looking for this pest.

Alfalfa weevil have four instar stages and typically feed on the upper plant canopy. As larvae grow, they will continue to feed, resulting in an economic crop loss.

To scout fields, randomly collect 50 alfalfa stems (10 stems at 5 different locations) and tap them into a white bucket. Calculate the average number of larvae per stem. If an average of one or more larvae per stem is reached, which is the economic threshold, control should be made. South facing field slopes generally have infestations first as they tend to warm in early spring.

Early harvest may be used to control weevil. If so, harvest 7-10 days prior to early bloom. If you use mechanical control, be sure to scout stubble for adult weevil feeding in the crowns of the plant.

If you choose to use an insecticide, there are many insecticides available which will provide excellent control. Be sure to apply insecticides when air temperatures are above 60 degrees F as lower temperatures may reduce control. In addition, use proper carrier rates to increase coverage.

CHECK SOYBEAN

SEED TAGS FOR

GERMINATION

Soybean seed quality issues were found in many states last fall with delayed harvest. Many fields had diseases of Phomopsis seed decay and purple seed stain. Many fields also had dead and moldy seeds.

Growers should carefully look at seed tags and adjust seeding rates based on the seed germination. Often germination rates are lower than you would typically find. Seed treatments target pathogens but do not repair damaged seed. Again, the seed tag represents the germination of the seed.

With lower germination rates, one should target a minimum of 120,000 plants per acre. Consider planting conditions and past experience in your individual fields as many things can kill stands after emergence. Adjust seeding rates upward so you have a sufficient soybean stand.

For more information, contact Wayne Flanary, Field Specialist in Agronomy, University of Missouri Extension at 660-446-3724.