Corn hybrid selection begins with maturity
As growers make their final planting preparations, some may be asking themselves whether the hybrid selections they made in late fall/early winter are still the right ones today. Especially factoring in the continuing reality of low corn prices, Syngenta agronomists are recommending that growers still contemplating their seed decisions keep the following in mind.
Most selection decisions begin with relative maturity (RM) – these ratings are relative to physiological maturity and largely driven by a combination of growing degree days (GDDs) planting date.
When building a plan for the 2016 growing season, it’s important to identify the GDD range and average required for a hybrid to reach physiological maturity (black layer) within your local geography. Planting multiple hybrids of varying maturity will reduce risk in three main areas:
- Agronomics (emergence, stalk strength, disease tolerance)
- Harvest management (harvest moisture)
- Genetic diversity (yield, drought tolerance)
Traditionally, about 60 to 70 percent of a grower’s portfolio is focused on the core RM zone (i.e. 100-day RM), with 10 to 20 percent focused on earlier RM and the remainder on later RM. Keep in mind that there is typically more yield variability within a given RM group – or put another way, more yield stability across multiple RM groups.
According to the University of Minnesota, grain moisture at harvest also increases steadily with increasing relative maturity. On average, grain moisture at physiological maturity increases by 0.25 to 0.5 percent with each one-day increase in relative maturity. Selecting hybrids of appropriate maturity is important for a balance between yield potential and managing grain moisture at harvest, ultimately helping to grow more corn.
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