Fungicide Treatments for Improved Germination of Switchgrass Seed.

Switchgrass is a major cellulosic biofuel crop that has significant potential for contributing to the production of biofuels in the USA and throughout the world. Given the expectation, significant acreage must be planted. However, seed quality can be a major concern of growers with regards to a high level of dormancy and losses from fungal contaminations. In this paper four common fungicides (Captan, Daconil, Heritage, and Maneb) were screened for effectiveness against fungal infection of germinating seed in three varieties: Alamo, Kanlo and Cimarron. Seed was placed on top of a germination paper saturated with each fungicide and 0.2% KNO3. The germination paper was placed atop a blotter saturated in KNO3 within a plastic box covered with lid to maintain moisture. Germination boxes were placed in an environmental control chamber set at 30o/15o C and 8h/16h Day/Night thermo- and photoperiod, respectively. Controls were treated with KNO3, without fungicide. Percent of seed germinating and numbers of fungal infected seed were determined after a 14 day period. Across all three varieties, germination was 40% (Alamo (54%), Kanlo (34%), and Cimarron (31%)). Germination did not significantly differ from the KNO3 control with each fungicide treatment except for variety Kanlo treated with Daconil (25%). Overall, an average of 26% of the seed was fungal contaminated indicating that fungal growth is a concern for the above varieties. All four fungicides significantly reduced the percent of fungal contaminated seeds overall 3.9 fold to 6.7% compared to 26% for KNO3 controls (p< 0.001). The fungicides that gave the most control was Maneb > Captan > Daconil > Heritage. Infecting fungi for each treatment were collected and are currently being identified via their 18s rRNA gene sequence.