Managing Global Resources for a Secure Future

2017 Annual Meeting | Oct. 22-25 | Tampa, FL

38-11 Composition and Morphology As Predictors of Stalk Strength.

See more from this Division: ASA Section: Agronomic Production Systems
See more from this Session: General Bioenergy Systems Oral

Monday, October 23, 2017: 10:45 AM
Marriott Tampa Waterside, Grand Ballroom B

Pearl Rwauya1, Ushna Usman1, Zachary W Brenton2, Stephen Kresovich3, Daniel Robertson1 and Douglas Cook4, (1)Engineering, New York University Abu Dhabi, New York, NY
(2)Clemson University, Sandy Springs, SC
(3)Clemson University, Clemson University, Clemson, SC
(4)New York University, New York, NY
Abstract:
For many years, researchers have observed that the stalks of bioenergy stalks become more susceptible to lodging as lignin content is decreased. Stalks that are readily digestible are therefore prone to lodging failure, while stalks that are resistant to lodging exhibit poor digestibility. An engineering analysis of the structural integrity of maize stalks indicated that stalk morphology has a larger influence on strength than composition. If this is true, the structural weakness caused by a decrease in lignin could potentially be offset by changes to stalk morphology, thus achieving stalks that are both digestible and lodging resistant. The purpose of this study was to experimentally assess the relative influence of morphology and composition. This study involved assessment of composition, morphology, and mechanical strength of three crops: dent maize, grain sorghum, and bioenergy sorghum. Composition was assessed via near infra-red (NIR) spectroscopy. Maize stalk morphology was assessed via x-ray computed tomography (CT scanning). Scan data was analyzed using a customized computer code which used image processing techniques to identify morphological features of maize stalk cross-sections. The morphology of sorghum stalks was assessed by measuring the major and minor diameters of each stalk with digital calipers. Three-point bending tests were used to measure the bending strength of all stalks. Multiple regression techniques were used to assess the contribution of morphological and compositional factors, both individually, and as groups. Morphological features were found to be stronger and more reliable predictors of stalk strength than chemical composition. These findings support the notion that a reduction in strength associated with changes in stalk composition can be compensated by changes in stalk morphology, thus suggesting new avenues for the development of robust bioenergy crops.

See more from this Division: ASA Section: Agronomic Production Systems
See more from this Session: General Bioenergy Systems Oral