Hard Seed

Hard Seed

 

a seed that does not swell or germinate within its established period of viability. A hard seed has a tough impermeable coat, or testa, that does not allow water or air to reach the embryo.

Hard seeds are encountered most often in seed lots of leguminous herbs (clover, alfalfa, sweet clover), small-seeded vetch, and lupine. Their quantity depends on the conditions that existed during their formation and maturation. For example, in years of drought up to 60–65 percent of the seeds produced by red clover and alfalfa are hard. The number of hard seeds decreases after storage, which varies in time for different crops from several weeks to several years. The sowing of hard seeds results in non-uniform germination and sparse plantings. The impervious seed coats may be scarified before sowing to facilitate germination.

References in periodicals archive ?
flavicarpa is a specie that presents seeds involved by aril and hard seed coat with a semi-permeable inner layer (Delanoy et al., 2006), which confers a combination of physical and physiological dormancy (Alexandre et al., 2004).
Soaking the seeds or chipping the hard seed coats with a sharp knife will speed up the germination process.
To correct for non-normality the statistical analysis was done on arcsine transformed values for germination rate and hard seed. For data analysis the SPSS version 11.0 (SPSS inc., USA) and STATISTICA version 8 (StatSoft, Inc.
Once dragged back to the colony, the energy-laden accessory is removed for consumption, and the hard seed body is dumped in a waste pit where it may ultimately sprout.
Although hard seed coat improves the survival of seeds in the soil especially in adverse environmental conditions and helps to avoid extinction of species in nature, it may prevent use of plant cultivars or wild-type relatives for agricultural or breeding purposes [20,21].
The African oil bean seed is normally boiled for up to 12 hours or more to remove the hard seed coat.
The risk of seed escape is heightened by the fact that harvested alfalfa seed often contains some "hard seed," which is unable to absorb water due to its hard seed coat.
Exogenous dormancy, originated from a chemical inhibitor is present in the seed coat and hard seed coat.
nummularia is not easy because of hard seed coat and in nature conditions the seeds are able to germinate by aging and weathering in soil during months to one year [10,6, 9,4].
Persistent-seeded species, including species with hard seed coats or other enforced dormancy, remain as dormant individuals until exposed to the proper germination cues (Baskin and Baskin, 1989).
This seed will not germinate and is called hard seed. These seed coatings must be abraded or scratched (scarified) to enable germination.