Seed Production Research Update

Jeffrey G. Norcini
North Florida Research & Education Center
University of Florida/IFAS
(850) 342-0988
jgn@mail.ifas.ufl.edu

Large-scale production of native wildflower seed in the Southeast is extremely limited by the lack of technical information for potential growers in this section of the country and the very limited availability of regionally adapted seed. Two projects that support Florida's emerging native wildflower seed production industry are summarized below.

Establishment of Sustainable Populations of Native Wildflowers on Florida's Roadsides: Ecosystem Management Approaches to the Statewide Application of FDOT's Roadside Wildflower Program
(funding provided by the Florida DOT's Environmental Mgmt. Office)

Species. Argemone mexicana (Mexican Pricklypoppy)*, Coreopsis basalis (Dye Flower), Coreopsis gladiata (Coastalplain Tickseed), Coreopsis lanceolata (Lanceleaf Coreopsis), Coreopsis leavenworthii (Leavenworth's Coreopsis), Flaveria linearis (Yellowtop), Gaillardia pulchella (Blanketflower), Lupinus diffusus (Sky-blue Lupine), Mimosa strigillosa (Powderpuff), Phlox drummondii (Annual Phlox), Rudbeckia hirta (Black-eyed Susan), Trifolium reflexum (Buffalo Clover)

*For demos only; see below

Germination. Understanding germination characteristics is crucial to successfully establishing native wildflower stands, whether in a production field or on the roadside. Extensive seed ecology work is being conducted on a few key species, with basic germination characteristics being determined for the other species.

Seed increasing. Florida wildflower seed growers and the USDA Plant Materials Center in Brooksville are increasing seed derived from native Florida populations of the species listed above.

Interstate demo sites. In cooperation with local FDOT and subcontractor roadside vegetation managers, 10 native (Florida ecotype) wildflower plantings have been established across Florida. The sites were established by seeding or by designation of existing populations for preservation and enhancement. Master Gardeners are assisting with some evaluations.

Use of Plateau Herbicide for Weed Management in Native Wildflower Stands

Plateau (imazapic; BASF) is an imidazolinone herbicide to which many native wildflowers are relatively tolerant. Many broadleaf weeds, grasses, and sedges are controlled or suppressed by Plateau. It can be broadcast prior to germination and emergence of wildflowers as well as to established stands. However, tolerance to Plateau can vary considerably with seed source, genotype, variety, stage of growth, and environmental conditions. Plateau is labelled for use on noncrop sites such as roadsides but is not yet labelled for use on any crop.

Plateau 2AS at up to 12 oz product per acre was applied to established stands of Florida ecotypes of blanketflower, dye flower, black-eyed susan, and lanceleaf coreopsis. We concluded that under our environmental conditions and for these ecotypes, 1 to 2 oz product per acre (0.016 to 0.031 lb ai/A) would usually reduce weed competition (depending on the weed species) and cause minimal to no injury.