the most tolerant grasses to salinity, whereas bahiagrass ( Paspalum notatum Flüggé) is highly sensitive to increases in salinity at the germination stage ( Peacock and Dudeck, 1989 ). Commercially available turfgrass seeds can be coated with
Matteo Serena, Bernd Leinauer, Rossana Sallenave, Marco Schiavon, and Bernd Maier
Arianna Bozzolo and Michael R. Evans
weight, and average dry root weight occurred between seeds germinated with a cork granulate or vermiculite top coat. Results and discussion Physical properties of vermiculite and cork granulates. The bulk density of cork granulates was 0.16 g·cm −3 and
James T. Watkins
Sakata Seed America investigated the possibility of marketing a film-coated broccoli seed product. Film coating is the process of applying a colored polymer film material onto the seed surface that completely covers the seed and any seed pesticide. Film-coated seed has the benefit of providing uniform and precise pesticide placement, is dust free, safe to handle, can be highly visible in the soil, and has increased flowability in seed planters. The drawbacks arc the cost of the film-coating machinery and the film product as well as the slower application rate. The basic application procedure of film products to broccoli seed and the effects of film products on seed viability and seed storage will be discussed.
J. E. Wyatt
Differences in water absorption by intact seeds and in osmotic properties of excised seed coats were measured in 4 near-isogenic breeding lines of snap bean, Phaseolus vulgaris L. White seeds absorbed water more rapidly than colored seeds. Excised white seed coats were more permeable to water than colored seed coats in response to an osmotic gradient. Seed coat thickness and seed coat dry weight were negatively correlated with rate of osmosis through the seed coats. Colored seeds had greater seed coat dry weight and thickness than white-seeded isolines.
Mark J. Bassett and Phillip N. Miklas
Bassett (2007) wrote a comprehensive review of the genetics of seed-coat color and pattern in common bean ( Phaseolus vulgaris ). The gene loci T , P , and V have multiple alleles, which express pleiotropic effects on color and pattern in
Veronica M. Valdes, Kent J. Bradford, and Keith S. Mayberry
Lettuce (Lactuca sativa L. ‘Empire’) seeds (achenes) were given an osmotic priming treatment (24 hr in aerated —1.5 MPa polyethylene glycol (PEG 8000) solution at 18°C in the light) which alleviated thermodormancy in laboratory tests. The seeds then were coated commercially for precision planting. Additional seeds also received a proprietary treatment for enhancing high temperature germination (Royal Sluis Split-kote D). In field trials in the Imperial Valley of California, where the soil temperature exceeded 35°C for the first 11 hr of imbibition under sprinkler irrigation, total emergence of untreated seeds after 6 days was between 18% and 21%, whereas that of primed and Splitkote D seeds ranged from 46% to 69%. Uniformity and rate of emergence were also greater for the primed seeds, with 91 % of the final emergence occurring by the 3rd day, as compared to only 70% for the control. Seed priming prior to coating can be an effective method of improving lettuce stand establishment under high temperature conditions.
M. Sachs, D. J. Cantliffe, and T. A. Nell
Germination rate of sand-coated pepper (Capsicum annum L.) seed (sand grain size < 75μm for an inner coat and 75–105 μm for an outer coat layer) was faster than clay-coated seed but was slower than raw seed. Part of the germination reduction in sand-coated seeds was caused by the water-soluble Gelvatol binder used. High oxygen (O2) levels promoted the germination of sand-coated seed to a rate comparable to that of raw seed. This suggests that even with a porous sand-coating material, O2 may be limiting for the germinating seed. When inorganic O2-releasing compounds (BaO2 or NaBO3) were incorporated into the sand material, the germination of pepper seed was further inhibited.
M. Sachs, D. J. Cantliffe, and T. A. Nell
Seed germination of sweet pepper (Capsicum annuum L.) is inhibited after the seed is coated. The inhibitory effect of pellet-coating of ‘Early Calwonder’ pepper seed was caused by the physical properties of the coating materials. Clay coating limited part of the oxygen (O2) from reaching the germinating seed and provided a mechanical barrier to protrusion of the radicle. Clay-coated pepper seed germinated satisfactorily on filter paper in a high O2 environment or with minimum moisture on agar. Pellet coating formulations which would provide more O2 to the imbibing seed would assure comparable germination of raw and coated sweet pepper seed.
L. H. Halsey and J. M. White
Raw and coated seed of carrot (Daucus carota L. cv Danvers 126) were planted with Stanhay, Earthway and Planet Jr. seeders on October 1, 1976 at Sanford and Zellwood, Florida, and on October 8 and November 16 at Gainesville, Florida. Carrot roots were harvested and graded in February, April, and May, 1977. Differences in weight of marketable carrot roots occurred between planters at 3 of the 4 locations, whereas response to seed coating was independent of locations. The effect of planters on numbers of marketable carrots varied significantly at 2 of the locations, with no effect of seed coating related to location. No difference was found in response to raw or coated seed in number or weight of marketable carrots, whereas carrots from coated seed were slightly larger than from uncoated seed.
P.C. Lee, A.G. Taylor, and T.G. Min
Sinapine leakage to detect seed germination potential on a single-seed basis in Brassica has been developed as a rapid test. In this test, sinapine leakage predicts that a seed is non-germinable; however, the major source of errors in this method are false-negative (F–)—i.e., the method predicted a seed was germinable because the seed did not leak, and it did not germinate. The sinapine leakage index (SLI) was used to asses the F– for any seed lot by dividing the number of non-germinable seeds that leaked sinapine by the total number of non-germinable seeds. Seed lots including cabbage, cauliflower, and broccoli (B. oleracea L., Captitata, Botrytis, and Italica groups, respectively) were used to examine the F–. The leakage rate as measured by T50, the time for 50% of heat-killed seeds to leak, was linearly correlated to SLI. Cabbage seeds were viewed by scanning electronic microscopy and leaking non-germinable seeds either had cracks or were shrunken. NaOCl pretreatment has been found to increase the rate of sinapine leakage and SLI. The mode of NaOCl was due to high pH altering the seed coat permeability. Chemical analysis was conducted on isolated seed coats for pectin, tannins, hemicellulose, cellulose, phenolic lignin, and cutin. It was found that the higher SLI (more permeable) lots contained lower amounts of cutin, suggesting that cutin may restrict the diffusion of sinapine through the testa.