Priming and Pelleting to Overcome Abiotic Stresses and Improve Stand Establishment.

Seed enhancement technologies have improved over the last 10 years mainly due to an increase in diversity and demand for fresh vegetables. Precision seeding technologies such as pelleting and encrusting reduces planting costs and improves stand uniformity by stabilizing seed placement, increasing singulation, and regulating water uptake. Pelleting can also be used to improve ballistics for aerial seeding. An example of seed pelleting for a BAER (Burned Area Emergency Response team) project will be discussed. Small seed size is not a limitation for pelleting. Even very small seeds such as Begonia spp. (88 x10³ seed g^-1) can be successfully pelleted for mechanical planting (a 100-fold weight increase) without negatively affecting germination. Seed pellets have been used as a carrier for pesticides and beneficial organisms such as mycorrihiza. Pelleting reduces toxicity of some common pesticides by spatial separation and increased dosage uniformity. Physiological enhancement of vegetable seeds to eliminate secondary dormancy and/or improve speed of emergence has been used extensively for many years. Improvement and refinement of priming has increased lettuce production by enabling very environmentally-sensitive seeds to be planted in areas and at times that were once considered too harsh for stand establishment. Vegetable priming technology has also been commercially used on relatively non-domesticated crop species as diverse as saltgrass and rosemary and to eliminate seed-borne organisms such as: Xanthromonas, Septoria, and Corynebacterium. Although not yet used commercially, priming has been demonstrated to vastly improve germination and thus lessen negative environmental effects of species such as Indian ricegrass and Douglas fir that are severly affected by primary dormancy. Specific examples of how  priming and pelleting technology provides improved stand establishment by allowing seeds to germinate over a wider range of moistures, temperatures, and salty conditions will be shown. with increased longevity (as compared to older technology) . Other specific examples of how newer priming and pelleting productions allows for better seed longeveity will be given.