Burning sugarcane residue: an integrated approach for managing surface deposited divine nightshade and itchgrass seed

Authors: Spaunhorst, Douglas

Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 2/6/2019
Publication Date: 2/12/2019
Citation: Spaunhorst, D.J. 2019. Burning sugarcane residue: an integrated approach for managing surface deposited divine nightshade and itchgrass seed [abstract]. Weed Science Society of America Meeting Abstracts, February 11-14, 2019, New Orleans, Louisiana. 2019:168. http://wssaabstracts.com/public/59/Presentations-sorted-by-title.html

Interpretive Summary:

Technical Abstract: In Louisiana, growers remove sugarcane residue following green-cane harvesting by prescribed burning. Divine nightshade [Solanum nigrescens (Mart. & Gal)] and itchgrass [Rottboellia cochinchinensis (Lour.) Clayton] are problematic weeds in Louisiana sugarcane production. The objective of this study was to determine the effects of dry heat and exposure duration on divine nightshade and itchgrass emergence. Divine nightshade and itchgrass seeds were exposed to three temperature levels (100, 150, and 200°C) for seven exposure timings (0, 5, 10, 20, 40, 80, and 160 s). Divine nightshade emergence was not completely inhibited at 200°C for 160 s. However, itchgrass exposed to 150°C for 40 s or longer failed to emerge. Exposure to 150°C for 5 to 20 s and 200°C for 5 to 10 s resulted in more than 100% divine nightshade emergence, presumably short periods of heat exposure alleviated seed dormancy. Results from this study showed itchgrass seed could be controlled with dry heat, but prescribed burns that produced temperatures below 100°C or temperatures greater than 150°C for short durations may not control all divine nightshade seeds. The aforementioned temperature and exposure time that allowed divine nightshade to survive, introduced the potential for divine nightshade to become more abundant. The fluid-filled fruit capsule that contained divine nightshade seed likely insulated the seed from being exposed to extreme temperatures.