IPM Practices for Soybeans
Relatively few insects and diseases have been reported to cause significant problems on soybeans in New York. While our experience with soybean pests is limited, field observations combined with pest reports from adjacent states and Ontario, Canada, have been encouraging. In addition to having few economically important pests, incorporating soybeans into New York field crop rotations provides an additional benefit by helping to break up the life cycles of many common corn and alfalfa insects and diseases.
Key soybean pest management considerations:
- Use sound soybean production agronomic practices. Choose a well-adapted, disease-resistant variety from an appropriate maturity group. Plant soybeans in a timely manner on a suitable site with proper field and seedbed preparation, fertility, and soil pH. Use of clean, certified seed is highly recommended. If bin-run seed is used, have seed checked for germination, seed-borne diseases, and presence of weed seed.
- An effective weed management program will minimize early-season competition and help protect potential yields. Conduct spring and fall weed surveys to identify and assess troublesome weeds and improve information to tailor and time weed management programs. Standard pre- and post emergence herbicide control programs are quite effective for minimizing weed competition. Another weed control option for soybeans planted in 30-inch row spacing is banding of herbicides in a 10-inch band over the top of soybean rows at planting and use of timely cultivation(s) to minimize weed pressure. This option has shown much promise. Banding of herbicides reduces herbicide use on 30-inch row spacing by about 66 percent.
- Seedcorn maggot is occasionally a problem under cool conditions in fields with high organic matter content, such as manured fields. Insecticide seed treatments, combined with high plant populations and the remarkable ability of soybeans to compensate for some stand reduction, will generally minimize stand losses from this pest. Mexican bean beetles and Japanese beetles are often conspicuous visitors to soybean fields in mid- to late summer. Adult beetles feed on soybean leaves, causing a skeletonized and brown appearance. While this damage may be very visible, damage is rarely economic. Bean leaf beetle, another foliage feeder causing concerns in adjacent states, has been observed in NY, but, to date, has not been found at economic levels. Indeterminate soybean types can tolerate up to 35 percent defoliation until bloom, about 20 percent while pods are small and soft, and about 35 percent when pods are hardening. Treatment for pest damage below the percentages listed is not recommended.
See the tables below for suggestions on IPM activities and common pests by crop growth stage and seasonal occurrence.
For more information about IPM visit http://nysipm.cornell.edu/agriculture/livestock-and-field-crops or contact your local Cooperative Extension Field crops Staff to discuss any unusual field problems you may observe.
|Pre-emergence (after planting but before emergence)||Weed assessment, seed diseases/damping off (Pythium, Phytophthora, Rhizoctonia) seed corn maggot, white grub, wireworm, watch for "occasional" pests/problems||Vertebrate damage (birds, rodents), planter problems, poor seed germination, poor soil/moisture conditions|
|Early Season (seedling to fourth leaf stage)||Weed assessment, stand counts, seedling diseases/roots rots (Pythium, Phyophthora, Rhizoctonia, Fusarium), seed corn maggot, white grob, wireworm, cutworm, slugs, soybean aphid, watch for "occasional" pests/problems||Planter problems, fertilizer burn, poor soil/moisture conditions, herbicide injury, frost damage, drought, nutrient deficiencies, vertebrate damage (birds, rodents, ground hogs, deer)|
|Mid-Season (vegetative stafes to first bloom)||Weed assessment, Phytophthora, Rhizoctonia, Fusarium root rots, soybean aphid, foliar disease, soybean rust, watch for "occasional" pests/problems||Defoliators (Japanese beetle, Mexican bean beetle, green cloverworm, bean leaf beetle), thrips, potato leafhopper, vertebrate damage, spider mites, hail, poor soil moisture conditions, herbicide injury, nutrient deficiencies|
|Reproductive (flowering to pod fill)||Soybean aphid, soybean rust, downy mildew, pod and stem blight, anthracnose, brown spot, white mold/Sclerotinia, Phytophtora pod and stem rot, weed survey, watch for "occasional" pests/problems||Defoliators (Japanese beetle, Mexican bean beetle, green cloverworm, bean leaf beetle), thrips, potato leafhopper, vertebrate damage, spider mites, hail, poor soil moisture conditions, nutrient deficiencies, lightning|
|Weeds||Weed Survey||May-June, September-October|
|Diseases||Damping off, seedling diseases||May-July|
|Phytophtora, Rhizoctonia root rot, brown spot, soybean rust||June-September|
|Sclerotinia (white mold)||July-October|
|Pytophthora pod and stem blight||August-October|
|wireworm, white grubs||May-June|
|soybean aphid, two spotted spider mites||June-September|
|defoliators (Japanese, Mexican bean, & Bean leaf beetles)||July-September|