Lodging in Cereal Crops: Part 2 – Timing of Lodging & Impact to Yield

In Part 1 of Lodging in Cereal Crops, we reviewed how lodging impacts yield potential and learned the effects of lodging on final yield will depend largely on growth stage, weather conditions that occur after lodging, and of course the severity of the lodging.  In Part 2, we’ll look a bit deeper at impact of lodging timing on yield potential.

The greatest yield losses will occur when plants lodge in the ten days to two week period following head emergence; losses can range between 15 to 40% depending upon when lodging occurs and how the plant subsequently recovers.

When a crop lodges before flowering, the stem may regain its upright position through ‘goose-necking or elbowing’ if good weather conditions occur afterwards.  However, since plant growth and development has been altered, it can impact flowering, reduce the photosynthetic capability of the plant, and affect carbohydrate assimilation.   Depending on how severe the lodging is and how the plant recovers, lodging at this stage of development can impact both number of kernels per head and individual kernel weight.

If the crop lodges after flowering, the heads will not regain their upright position.  Lodging at this stage of development has more of an impact on kernel weight but severe lodging could also impact the number of kernels per head.

As the crop approaches maturity, yield losses from lodging decrease; losses are due to incomplete grain filling resulting in smaller kernels and lower test weights.  However, yield reduction may instead occur due to increased harvest losses, i.e. neck breakage and loss of whole heads.  If faced with significant lodging within a field, producers who opt to straight combine will likely incur higher losses as opposed to swathing first.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD

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Lodging in Cereal Crops: Part 1 – Effect on Yield

Lodging in cereal crops has become a common site in many fields across Manitoba over the past few weeks.  Lodging is often caused by weather conditions, such as rain, wind and/or hail.  However, other factors including fertility program (high nitrogen) and crop management practices (variety selection, seeding date, seeding depth, seeding rates, disease control) all can impact the crop’s susceptibility to lodging.

Effect of Lodging on Yield:

The biggest question that normally surrounds lodging is the impact on yield.  Lodging may reduce yield in a number of ways:

  • Lodging interferes with photosynthesis and carbohydrate movement in the plant, potentially impacting both number of kernels per head and individual kernel weight.
  • Foliar diseases may increase due to a more humid microclimate within the lodged crop.
  • Loss of un-threshed heads can lead to harvest losses, particularly if lodging has resulted in stem breakage.

In addition, lodging can contribute to uneven maturity and decreased harvest efficiency.  Harvest of a lodged crop takes more time and can be more difficult depending upon severity of the lodging.  Harvest efficiency may be impacted due to a reduction of travel speed and more straw entering the combine due to a lowering of the header/knives to accommodate the lodged crop.

However, the effects of lodging on final yield will depend largely on growth stage, weather conditions that occur after lodging, and of course the severity of the lodging.

Submitted by:  Pam de Rocquigny, Provincial Cereal Crops Specialist, MAFRD

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