Answer (provided by Dennis Lange, MAFRI Farm Production Advisor at Altona):
Before you considering cancelling you soybean seed, here are a few things to consider:
- Variety Choice: Is the variety suited for your growing region? If you chose a variety based on maturity ( found in Seed Manitoba 2013) and you are planting in May, you should reach maturity before reaching a killing frost, based on a normal growing season.
- Soil temperature: Soybeans like warm soils to germinate and grow. The warmer the soil, the quicker the beans come out of the ground. For example, with soil temperatures at 10°C soybeans take 14-17 days to emerge vs. 7-10 days when soil temperatures are at 15°C.
- Seeding Date: Know the seeding deadlines in your growing region. If in Soybean Area 1, full coverage deadline is June 6. If in Soybean Areas 2, 3 or new crop insurance test area, your deadline is May 30. For further information contact MASC to determine which area you are in. Table 1: Soybean Yields by Seeding Date (2008-2012)
Using MASC seeding information from 2008-2012, yield potential differs depending on seeding date by Risk area.
- Risk Area 12 (includes Red River Valley) – highest yield potential was seeded during the 2nd week of May.
- In Western Manitoba:
- Risk Area 1 – best yields when seeded in the 4th week of May, followed by week 3
- Risk Area 2 – best yields in the 2nd week of May, with weeks 3 and 4 equal
- Risk Area 3 – best yields in the 3rd week of May, followed by the 4th and 2nd weeks
- Risk Area 4 – best yields in the 2nd week of May, with yields dropping in 4th week
- Risk area 15 – similar to Risk Area 4 trends with best week the 2nd and yields dropping in the 4th week of May
In conclusion, if you are planting a variety that is suited for your growing region and planting in May, you should be confident that growing soybeans this year is still the right decision. Beans like warm soil so typically, planting in the 2nd or 3rd week of May when soil temperatures are warmer, allows the beans to get out of the ground quicker. But, waiting until June to plant, increases the risk of fall frost damage and yield reductions.