The Pulvinus Is the Weak Point for Stem Lodging Resistance in Ripe Barley

Area of Science:

• Agricultural Science
• Plant Physiology
• Biomechanical Engineering

Background:

• Stem lodging in barley reduces yield and quality.
• Biometrical and mechanical traits partially predict lodging resistance.

Purpose of the Study:

• Investigate the impact of stem wetting and force application point on barley stem mechanical properties.
• Develop a quick manual method for assessing stem strength.

Main Methods:

• Utilized a three-point bending test with a height gauge.
• Compared loading force application on the node/pulvinus versus the internode.
• Assessed bending strength (B) and material strength (σb) in dry and wet conditions.

Main Results:

• The node/pulvinus complex is a weak point, reducing bending strength by 31-41%.
• Wetting stems decreased bending strength by 62% and material strength by 62%.
• Manual method showed similar reductions in bending strength (64%) and material strength (68%) upon wetting.

Conclusions:

• Stem wetting significantly compromises mechanical resistance in barley.
• The pulvinus is a critical weak point in mature barley stems affecting lodging resistance.
• Understanding these factors aids in identifying barley genotypes with improved lodging resistance.