Problems during Seedling Establishment:
Figure 1 – Seedcorn maggot (Delia platura) larvae feed on and burrow into the seed. Seed fails to germinate. Feeding on cotyledons and first leaves causes misshapen plants. Favored by cold, wet weather where germination is delayed.
Figure 2 – Soil crusting inhibits seedling emergence. Damaged cotyledons and shoots can result.
Figures 3abc – Seed decay, pre- and post-emergence damping off, and seedling diseases caused primarily by Rhizoctonia and Pythium species. Also, poor quality seeds or seeds infected with seed-borne pathogens that cause diseases such as Common Bacterial Blight, Halo Blight, Anthracnose and Macrophomina, as well as those damaged by insects such as bruchids.
Figure 4 – Herbicide carryover or current year applications can injure crops. Peas in this photo turned white from over application of clomazone.
Factors that favor establishment
- High quality seed lots with high percent germination
- Germination tests for carry-over seed
- Insecticide/fungicide treated seed
- Good crop rotations to minimize soil pathogens
- Well drained soil; pH 6.0 – 7.0
- Proper soil temperatures (>60°F or 16°C). Most beans are warm season crops and do not tolerate cold soil or frost.
- Adequate soil moisture at planting
- Observe recommended herbicide plant-back intervals
- Avoid soils with high salinity
- Good weed management; weeds compete with seedlings
Courtesy of B.A. Nault, J.R. Kikkert and G.S.Abawi, Cornell University and Howard F. Schwartz, Colorado State University, Bugwood.org