Small Grains

 

Hail Damage

Mary E. Burrows, Montana State University, Plant Sciences and Plant Pathology
 Jeff Stein and Ned Tisserat

 

Cause:  Environmental

·         Hail can occur anytime throughout the growing season and usually strikes acrosssmall areas. One field will be affected while the neighboring fields may be left alone.

 

Key Symptoms:

·         Large area of field with wheat plants that have damaged (sometimes shredded) leaves, broken stems, or damaged heads.

·         Hail damage at the boot stage may cause the head to be entrapped in the boot, not allowing it to emerge normally, which results in a gnarled or misshaped head.

·         Hail may cause damage to the whole head or only slight damage to areas where the hail stones struck.

·         When a hail stone hits a wheat head it can damage the spikelets and knock the grain out of the florets.

·         Hail stones can break the stems over and this usually results in shriveled kernels in these heads.

 

Damage:

The Kind of damage and amount of loss due to hail is determined in part by the crop growth stage.

·         Before jointing, small grains are least susceptible to hail damage. The spike is still below ground and protected from injury.

·         Hail damage occurring during jointing or the boot stage is difficult to assess. Spikes can still pollinate and fill, and regrowth from new tillers can occur.

·         The greatest yield reduction from hail damage occurs in the milk stage.

·         Hail damage occurring at other growth stages from boot to ripe kernels is variable and further influenced by environmental conditions following the hail damage.

 

 

 

Management Approaches

Cultural management practices

·         If possible, the wheat can be baled and fed to cattle or used as bedding.

·         If hail occurs after grain fill, volunteer wheat can be a big issue in the next crop. Eliminate the green bridge by spraying herbicide and waiting at least 2 weeks before planting.

 

 

Categories: Small grains, Diseases, Hail damage

 

Date: 02/06/08


Supported in part by:
Western Region IPM Center, EPA Region Vlll, National Plant Diagnostic Network, Great Plains Diagnostic Network, USDA CSREES, Colorado State University, Montana State University, South Dakota State University, the University of Nebraska - Lincoln,and the University of Wyoming.