Fall Freeze and Prussic Acid
El inglés es el idioma de control de esta página. En la medida en que haya algún conflicto entre la traducción al inglés y la traducción, el inglés prevalece.
Al hacer clic en el enlace de traducción se activa un servicio de traducción gratuito para convertir la página al español. Al igual que con cualquier traducción por Internet, la conversión no es sensible al contexto y puede que no traduzca el texto en su significado original. NC State Extension no garantiza la exactitud del texto traducido. Por favor, tenga en cuenta que algunas aplicaciones y/o servicios pueden no funcionar como se espera cuando se traducen.
English is the controlling language of this page. To the extent there is any conflict between the English text and the translation, English controls.
Clicking on the translation link activates a free translation service to convert the page to Spanish. As with any Internet translation, the conversion is not context-sensitive and may not translate the text to its original meaning. NC State Extension does not guarantee the accuracy of the translated text. Please note that some applications and/or services may not function as expected when translated.Collapse ▲
It’s no secret that there have been cool temperatures this week. Stokes County has seen freeze watches during the beginning of this week, and experienced a freeze on October 19th. While it’s not uncharacteristically early for the first hard freeze, there are implications on forage production to keep in mind.
Sorghum-sudangrass hybrids, sudangrass, forage sorghum, and johnsongrass are all in the sorghum plant family. As such, they are susceptible to accumulations of cyanide, more commonly referred to in forages as prussic acid. Prussic acid accumulations are especially common during periods of drought stress and immediately following frost.
As described by Alabama Cooperative Extension, nitrogen application history and plant factors can also impact prussic acid accumulation. If nitrogen has been applied at higher than 70lbs/acre, there is an increased probability of prussic acid accumulation following stress events. Concentrations of prussic acid will be higher in young plants rather than mature plants, and increased in plant leaves as compared to stems.
Prussic acid can be deadly to ruminant livestock in relatively small doses. For example a 1,200 lb. cow would need to consume only 2 – 14 lb. of frost-damaged forage sorghum for it to be lethal. Despite this, prussic acid will dissipate from forages in about 5-7 days following a stress event. If you have one of the forage species listed above, it will be safe to graze them again in about one week, if there are no more freeze events during that time. Alternatively, these forages can be harvested for hay or silage immediately, but it is advised to wait 3-4 weeks before feeding the harvested forages to allow prussic acid levels to decrease.
If you have concerns about prussic acid levels in your forages, please contact your local Extension office.