Developmental Morphology and Biomass Yield of Upland and Lowland Switchgrass Ecotypes Grown in Iowa

作者：Aurangzaib Muhammad^*; Moore Kenneth J; Lenssen Andrew W; Archontoulis Sotirios V; Heaton Emily A; Fei Shuizhang

来源：Agronomy-Basel, 2018, 8(5): 61.

DOI：10.3390/agronomy8050061

• Panicum virgatum L
• biomass yield
• biomass harvest
• grass staging
• grass morphology
• switchgrass development
• leaf area index

Sustainable development of the bioenergy industry will depend upon the amount and quality of bioenergy feedstock produced. Switchgrass (Panicum virgatum L.) is a model lignocellulosic bioenergy crop but critical information is lacking for improved management, growth, and development simulation model calibration. A field study was conducted near Ames, IA during 2012-2013 with the objective to evaluate upland ("Cave-in-Rock", 'Trailblazer' and 'Blackwell') and lowland ("Kanlow" and "Alamo") switchgrass ecotypes for harvest timing on morphology (i.e., phenology, leaf area index (LAI), and biomass yield). The experiment used a randomized complete block design, with three upland and two lowland varieties harvested at six dates annually. In both years, delaying harvest to later maturity increased biomass yield; lowland cultivars produced greater biomass yield (6.15 tons ha(-1)) than upland ecotypes (5.10 tons ha(-1)). Lowland ecotypes had delayed reproductive development compared with upland ecotypes. At the end of both growing seasons, upland ecotypes had greater mean stage count (MSC) than lowland ecotypes. "Cave-in-Rock" had greatest MSC and LAI, but did not produce the greatest biomass. Relationships were nonlinear between MSC and biomass yield, with significant cultivar-year interaction. The relationship between biomass yield and MSC will be useful for improving switchgrass, including cultivar selection, fertilizer application, and optimum harvest time.

• 出版日期2018-5