Improving sea oats seedling production from seed with fungicides

In Louisiana, sea oats (Uniola paniculata) are incorporated into beach restoration projects to build and stabilize sand dunes. Unfortunately, sea oats seed yield, germination, and seedling survival are poor. The objectives of this study were to assess the impact of commercial fungicide(s) on sea oats germination, seedling survival, and seedling quality. Sea oats seed were planted into soilless media and grown in greenhouse conditions in Baton Rouge, LA. Four fungicide treatments at two rates were applied to seeded trays: mefenoxam, thiophanate-methyl, azoxystrobin, and iprodione. Two control treatments were included: a 15-minute seed soak in water before seeding and dry seed. Percentage germination, percentage survival, shoot height, and fresh weight were measured. Sea oats seed treated with thiophanate-methyl at twice the fungicide label’s recommended rate [2× (23.0 oz/1000 ft² a.i.)] had the greatest mean germination and survival and were the tallest seedlings 8 weeks after seeding. These results strongly suggest that treating seed with thiophanate-methyl 2× increased sea oats germination, survival, seedling quality, and profitability of sea oats production. The cost to apply thiophanate-methyl 2× to 1000 sea oats seed was $1.74. The additional revenue generated from greater germination, survival, and seedling quality when growing media was treated with thiophanate-methyl 2× was $37.72 per 1000 sea oats seeds. Therefore, the fungicide thiophanate-methyl was identified to be a practical and economical method to rapidly produce a large number of genetically diverse sea oats plants.