Based on the shortage of VI and VII seed this year, some growers may find themselves planting an earlier maturing variety than they are accustomed to. This may seem scary but really, managing these earlier varieties isn’t that different from managing late maturing varieties. Here are a few things to know about managing early varieties.
Plant Development
It is important to remember the lower the maturity group, the earlier the variety tends to quit growing and the earlier each stage of development will occur. This holds true for both determinate and indeterminate varieties. Since early varieties quit growing earlier, they don’t have as many days after planting to get big enough. Planting earlier may give early varieties a few extra days of growth.
Insect Management
Earlier maturing varieties may be more likely to be impacted by insect damage. If an early variety is attacked by foliage feeding insects before bloom, the plant won’t have as much time to put on new leaves. Since the plant reaches bloom earlier, insects that attack the plant at this time will be attacking earlier in the year than they would be for a later variety. Beneficial insects may not be quite as numerous at this time. Scouting and timely insecticide applications are critical to minimize impact on yield.
Harvest
Early maturing varieties reach physiological maturity sooner in the year than late varieties. This may put their harvest in conflict with harvest of other crops. Unfortunately, many (but not all) of these earlier varieties shatter much sooner after reaching physiological maturity. Most of these varieties can’t be left in the field very long so it’s critical to harvest in a timely manner. In some years, when the beans are dry enough to harvest, many of these earlier maturing varieties will still have green stems. There is usually not enough green tissue left to take up enough Gramoxone or sodium chlorate to be an effective harvest aid so the only option is to slow down the combine.
This article is adapted from recommendations by Dr. Jim Dunphy, NCSU Soybean Extension Specialist.