Crop & Pest Report


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Lodging in Small Grains (07/26/18)

In many areas of North Dakota, small grains are shorter than normal this season due to warm temperatures during vegetative development.

Lodging in Small Grains

In many areas of North Dakota, small grains are shorter than normal this season due to warm temperatures during vegetative development. Though shorter plants tend to be less prone to lodging, there are areas where lodging has occurred as a result of the intense storms that have recently passed through the region. The following are a few questions and answers about lodging:

What causes lodging? Lodging occurs when plants are unable to stay upright due to the pressure of wind and the weight of rain on the leaves and spikes. Lodging that occurs early in the growth of the plant is often referred to as root lodging since the bending of the plant occurs at its base. Once plants approach maturity and become brittle, stem lodging can also occur when the stem bends or breaks further up the plant.

What is the yield loss associated with lodged plants? Lodged plants that are still green and that are actively photosynthesizing have less green tissue exposed to the sun. This effectively reduces the rate of photosynthesis. Some research has shown that there is a 1% yield loss for every day that the plant is lodged while still green. Yield losses in mature plants are associated with combine losses. Lodged fields also take longer to combine. When rained on, kernels in lodged mature plants can lose quality which might result in a discount at the elevator.

Will lodged plants straighten themselves? Lodged plants that are still green may regain all or some of their vertical height. This occurs as cells in the shaded portion of the stem elongate. As an example of this potential, the lodged plots pictured above recovered fully within 10 days of when this picture was taken. Plants that have previously lodged will be more prone to lodge again if conditions are favorable for lodging. As plants approach maturity, their stem cells are done elongating and the mature plants won’t return to the upright position ideal for harvesting.

What factors are associated with lodging? Weather is the main driver of lodging. High winds, particularly when coupled with rain, are the cause of lodging. Variety choice can play a key role in the amount of lodging. Shorter varieties tend to be the most resistant to lodging. There are important exceptions to this rule, however (i.e. it is possible that a relatively tall plant with strong straw can resist lodging even when shorter plants have already lodged). Therefore, it is important to carefully consider the lodging score when selecting a variety and not just plant height. High plant populations tend to result in more lodging. Varieties that are prone to lodging should not be planted in higher populations than recommended. Stems that are crowded close together tend to be smaller and these plants will often have a less extensive root system. Excessive nitrogen can also predispose a crop to lodging. In our plot work this year, if there was any lodging at a location, it was fairly easy to pick out plots that had seeding rates greater than 1.4 million seeds, or that had received more than the recommended nitrogen rate.


Joel Ransom

Extension Agronomist for Cereal Crops

This site is supported in part by the Crop Protection and Pest Management Program [grant no. 2017-70006-27144/accession 1013592] from the USDA National Institute of Food and Agriculture. Any opinions, findings, conclusions, or recommendations expressed are those of the website author(s) and do not necessarily reflect the view of the U.S. Department of Agriculture.

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