Forage sorghum silage in the Texas High Plains is a viable option with sugarcane aphid control, according to a Texas A&M AgriLife Extension Service study.
Texas High Plains feedlots and dairies demand large quantities of quality silages. While corn is the predominant silage crop, declining well capacities and pumping restrictions are prompting interest in forage sorghum silage.
The concern, however, is with sugarcane aphids, or SCAs, and whether heavy infestations will allow proper ensiling, said Dr. Jourdan Bell, AgriLife Extension agronomist in Amarillo. Also, producers question if damage to the forage will degrade further during the fermentation process.
The Bottom Line
In 2017, Dr. Ed Bynum, AgriLife Extension entomologist in Amarillo, and Bell conducted a field trial to evaluate damage potential of SCAs to forage sorghum yield and silage quality. The research funding came from the Texas Grain Sorghum Board. Find the full study outline at https://tinyurl.com/sorghforageSCAdamages.
Ultimately, Bell said, the quality of the silage is only as good as the quality of the harvested forage. So, when managing forage sorghums, timely SCA management is necessary to maintain fresh and ensiled quality.
Managing the Infestation
Using a commercial forage sorghum hybrid commonly grown for silage in his study, Bynum said he expects this data to apply equally to other hybrids.
SCA density levels start causing significant increases in damages by Sept. 1 when sorghum is in the beginning milk stage in the untreated and Warrior plots, he said. Damage levels in these two treatments continue to increase and remain significantly higher than the other treatments from Sept. 8-20.
Monitoring Forage Damage
Crude protein, lignin, starch, acid detergent fiber and in-vitro dry matter digestibility were all negatively affected by the damage in the untreated and Warrior treatments, she said. There is no statistical difference between other insecticide treatments for the fresh forage.
Depending on the end-user needs, crude protein and starch are also important parameters, she said. These levels decrease with increased SCA damage, due to a lack of grain development.
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