Chilling-tolerant forage sorghum as a potential bioenergy feedstock in North Central USA

Authors: BERTI, MARISOL - North Dakota State University; PODDER, SWARUP - North Dakota State University; CABELLO, SERGIO - North Dakota State University; ANDERSEN, BRYCE - North Dakota State University; SAMARAPPULI, DULAN - North Dakota State University; PETERSON, ALAN - North Dakota State University; Anderson, James

Submitted to: Meeting Abstract
Publication Type: Proceedings
Publication Acceptance Date: 5/14/2018
Publication Date: 7/6/2018
Citation: Berti, M.T., Podder, S., Cabello, S., Andersen, B., Samarappuli, D., Peterson, A., Anderson, J.V. 2018. Chilling-tolerant forage sorghum as a potential bioenergy feedstock in North Central USA. In: 26th European Biomass Conference and Exhibition Proceedings, May 14-17, 2018, Copenhagen, Denmark. https://doi.org/10.5071/26thEUBCE2018-1CO.5.2 .
DOI: https://doi.org/10.5071/26thEUBCE2018-1CO.5.2

Interpretive Summary: Forage sorghum [Sorghum bicolor (L.) Moench] is a warm-season annual grass used mainly as a silage or hay crop in the USA with the potential to become a bioenergy feedstock. Chilling-tolerant forage sorghum genotypes would allow an earlier planting for more optimum use of the growing season. This will likely lead to an increase in productivity of forage sorghum in North Central Regions of the USA. The objective of this study was to screen and select potential chilling-tolerant forage sorghum genotypes with the hypothesis that chilling-tolerant genotypes would produce greater or similar dry matter yield when sown earlier than normal into field plots in Fargo and Hickson, ND. In the field, cv. SPX-901 was among the highest yielding genotypes (16.4 Mg ha-1), which produced similar yields between early (10 May) and more normal (27 May) sowing dates. These results indicate that early planting did not affect crop performance and yield. Preliminary conclusions indicate chilling tolerance exists among commercial cultivars, which can produce greater biomass yield when planted earlier than normal in the North Central US.

Technical Abstract: Forage sorghum [Sorghum bicolor (L.) Moench] is a warm-season annual grass used mainly as a silage or hay crop in the USA with the potential to become a bioenergy feedstock. Its minimum temperature for growth is 15'C, limiting its planting early in the growing season. Cold-tolerant forage sorghum genotypes would allow an earlier planting and optimum use of the growing season, which should lead to an increase in productivity of forage sorghum in the North Central Region. The objective of this study was to screen and select potential cold-tolerant forage sorghum genotypes with the hypothesis that cold tolerant genotypes produce greater or similar dry matter yield when seeded early in the field in Fargo and Hickson, ND. First, 74 commercial cultivars of forage sorghum and 10 cold-tolerant genotypes of grain sorghum were tested at 24'C and 12'C in environmental chambers. Fifty seeds of each cultivar were germinated in Petri dishes using a completely randomized design with three replicates and seed germination rate, vigor index, and dry weight of seedlings were recorded. The genotypes were ranked from high to low cold-tolerance and cluster analysis was used to select the eight highest ranked and two lowest ranked cultivars, and two cold-tolerant grain sorghum genotypes (BTx 623, SC 265) for planting on two seeding dates: normal (27 May 2017) and early (10 May 2017). The experimental design was a randomized complete block design with four replicates and evaluations included: emergence index, normalized difference vegetation index (NDVI), intercepted photosynthetically active radiation (PAR) light under the canopy, leaf area index (LAI) and biomass yield at two harvest dates. Under field conditions, biomass dry matter yield was only significant for genotypes in the first harvest date. In the second harvest, total dry matter yield (sum of both harvests) was significantly different for the seeding date, genotype, and the interaction genotype by seeding date. Although genotype SPX-901 was among the highest yielding genotypes when averaging both dates (16.4 Mg ha-1), its similar yield between both dates indicating planting it earlier did not affect crop performance and yield. Other genotypes with above average and similar yield in both dates were Forage King, Hay King, 1990, and Pampa Triunfo XL. A genotype with the ability of having greater yield planted in the early seeding date is assumed to have greater cold tolerance. This was observed for BTX 623, a known cold-tolerant check in the experiment; although a low yielding genotype, it had significantly greater yield when planted earlier. Oppositely, genotypes having significantly higher yield when seeded on the second date are assumed to not have greater cold tolerance than the average forage sorghum population. These results indicate cold tolerant genotypes selected in growth chamber also showed cold tolerance in the field. These selected genotypes can be utilized to improve cold tolerance in forage sorghum with the aim of breeding cultivars adapted to grow in northern regions as forage or feedstock for bioenergy.