Submitted to: Biofuels
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 8/28/2012
Publication Date: 10/24/2012
Citation: Mitchell, R., Vogel, K.P., Sarath, G. 2012. Predicting the field establishment of perennial grass feedstocks: progress made and challenges ahead. Biofuels. 3:653-656.
Interpretive Summary: Field establishment of perennial grasses for bioenergy is difficult to predict with currently-available seed lot information. Although establishment of perennial bioenergy grasses like switchgrass has inherent risks, risk can be moderated with good management and can provide rapid, complete, and inexpensive establishment. Poor seed quality such as low germination, high seed dormancy, and low seedling vigor affects the economics of growing perennial grasses for bioenergy. Two simple changes in the seed testing and reporting process would help producers establish productive stands more consistently. Reporting the number of seeds per pound on the seed bag label and reporting the number of germinable seeds per pound without any dormancy breaking treatments on the seed bag label could benefit farmers, seed producers, and seed companies. More research on seed quality and seed quality testing methods is needed for grasses like switchgrass, big bluestem, and indiangrass to improve our ability to predict field establishment from the information reported on the seed bag label.
Technical Abstract: The goal of perennial grass feedstock planting is to establish the feedstock as rapidly, completely, and inexpensively as possible. The economic viability of growing perennial grass feedstocks for bioenergy is impacted significantly by the success of stand establishment in the seeding year. Establishment risks for perennial feedstocks such as switchgrass (Panicum virgatum L.) can be moderated with good management. Poor seed quality such as low germination, high seed dormancy, and low seedling vigor is a major impediment to perennial feedstock establishment. Two simple changes in the seed testing and reporting process would enable producers to establish productive stands more consistently. Reporting the number of seeds kg-1 on the seed bag label and reporting the number of germinable seeds per kg without any dormancy breaking or pre-chill treatments on the seed bag label would require no rule changes for seed testing and could be used by seed producers and seed companies to identify and market higher-quality seed lots. Additional research on seed quality and seed quality testing methods is needed for grasses such as switchgrass, big bluestem, and indiangrass including the development of laboratory tests for estimating seed vigor. These advancements in seed quality would reduce risk and improve the predictive ability of field establishment from reported seed lot information.