Polymer film coatings decrease water uptake and water vapour movement into seeds and reduce imbititional chilling injury

摘要

Polymer film coatings were explored to alter water movement and alleviate imbibitional chilling injury in Phaseolus vulgaris. Our earlier work (Taylor et al., 1992) illustrated that experimental hydrophobic seed coatings could retard water uptake and enhance germination and stand establishment in cold, wet soils. A commercial film coating formulation was developed recently by Seedbiotics, Caldwell, ID and laboratory investigations were performed at Cornell. A stress test was developed by germinating seeds in saturated rolled towels for 1 d at 5 deg C, then transferring to 25 deg C for an additional 7 d. A single lot of 'Nicelo' snap beans was used for all studies. Seeds were coated with the film-coating formulation, 'SB2000', at 0 to 4 percent weight gains. A weight gain or build-up of 0.5 percent and greater was found to enhance germination in the stress test. Both hydration rates and sucrose leakage decreased as coating weight gain increased. The coating acted as a physical barrier to both water uptake and water vapour movement into the seeds. When the polymer was applied onto inert polystyrene spheres, the coating showed hydrophilic and hygroscopic characteristics.