scholarly journals Composition and Characteristics of Blended Kentucky Bluegrass Stands

HortScience ◽  
2002 ◽  
Vol 37 (7) ◽  
pp. 1124-1126 ◽  
Author(s):  
Darin W. Lickfeldt ◽  
Thomas B. Voigt ◽  
Andrew M. Hamblin

Kentucky bluegrass (Poa pratensis L.) cultivars are often blended to incorporate diverse characteristics. Factors that may contribute to the actual cultivar composition have not been evaluated. Through the use of DNA markers, individual plants in blended stands can be identified. This study evaluated changes in cultivar composition of `Blacksburg', `Midnight', and `Unique' Kentucky bluegrass blends. Characteristics such as seed size, seed moisture content, percent germination, and seedling development did not affect the initial composition of blends at time of seeding. DNA markers were used to demonstrate how the composition of a blended `Blacksburg', `Midnight', and `Unique' turf changed during the first growing season following establishment. The composition of blends did not significantly change from time of seeding in Sept. 1999 to Apr. 2000 or from Apr. 2000 to Oct. 2000. Two of the three blends were significantly different by Oct. 2000 relative to the percentages seeded in Sept. 1999.

2017 ◽  
Vol 39 (4) ◽  
pp. 393-400 ◽  
Author(s):  
Erica Fernandes Leão-Araújo ◽  
Juliana Faria dos Santos ◽  
Clíssia Barboza da Silva ◽  
Júlio Marcos-Filho ◽  
Roberval Daiton Vieira

Abstract: Vigor tests are important tools for verifying the physiological potential of seed lots; however, various aspects can interfere in the consistency of the test results. The search for less subjective procedures has drawn the interest of researchers. The aim of this study was to adapt the methodology of the controlled deterioration test and verify the efficiency of the Seed Vigor Imaging System (SVIS ® ) to evaluate the vigor of crambe seeds. Initially, seed moisture content was determined and germination and vigor were evaluated in five seed lots. For the controlled deterioration test, the seed moisture content was adjusted to 18%, 20%, and 22%, and the results were interpreted at four and five days after sowing. The controlled deterioration test should be performed with initial adjustment of seed moisture content to 18%, and the germination test should be evaluated on the fifth day after sowing. SVIS ® provided information on the vigor index and the length and uniformity of seedling development. Computerized image analysis is effective in evaluating the vigor of crambe seeds, and the uniformity of seedling development parameter offers the most consistent data.


2005 ◽  
Vol 23 (1) ◽  
pp. 29-32
Author(s):  
Sandra M. Reed

Abstract Dogwood producers occasionally face a shortage of flowering dogwood seed. Storing excess seed during years when seed are abundant would allow growers to stabilize their seed supply. This study was conducted to evaluate the effects of seed moisture and storage temperature on the viability of stored flowering dogwood seed. Seed were collected in Fall 1999 and 2000, dried to 6, 10 and 14% moisture content, and stored at 22, 5 and −20C (72, 41 and −4F) for 1, 2 and 3 years. Following storage, seed were cold stratified and sown in a greenhouse. Percent germination and seedling dry weight were recorded. Seed stored at 22C (72F) quickly lost viability. At 5C (41F), seed moisture content was critical, with seed dried to 14% moisture content germinating poorly after 2 years and failing to germinate after 3 years in storage. In general, storage at −20C (−4F) was superior to storage at 5C (41F). Seed moisture content was not as critical at −20C (−4F) as it was at 5C (41F), but may become more important if length of storage is extended past 3 years. Based on the results of this study, it is recommended that seed be dried to 6 to 10% moisture prior to storage, stored in air-tight containers, and stored in a −20C (−4F) freezer.


2004 ◽  
Vol 22 (1) ◽  
pp. 62
Author(s):  
A P Tyagi ◽  
M Taylor ◽  
P C Deo

Two taro (Colocasia esculenta (L.) Schott var. esculenta) cultivars from Fiji and Papua New Guinea were grown at the University of the South Pacific, Laucala Campus, Fiji to produce seeds for seed storage experiments. Gibberellic acid at a 500ppm concentration was used to induce flowering. Very few flowering shoots (inflorescence) were observed in the Fiji cultivar and all pollinations were unsuccessful. However the PNG cultivar flowered well and was used to obtain seed after hand pollination. Hand pollination was carried out to ensure seed setting in developing fruits in the inflorescence. Seeds were extracted in the laboratory after harvesting mature inflorescences. Experiments were conducted on seed moisture content, desiccation, germination, seedling development and seed storage behaviour of taro (Colocasia esculenta) seeds. Seed moisture content was determined using oven methods and air-drying. Results demonstrated that taro seeds have a moisture content of 12-13% after air-drying for three to four weeks. Seeds were dried to desired moisture contents in a desiccator over silica gel. After drying to 5% moisture content seed viability was tested by germinating seeds on moist filter paper at room temperature with 65% relative humidity and seven to eight hours day length. Preliminary seed germination tests demonstrated up to 83% germination for seeds with 13% moisture content. Germination occurred within five to seven days. Maximum germination was achieved within 21 days. The highest germination (80%) was achieved with seeds with 12% moisture content. Results indicated there was no relationship between moisture content and seed germination. Normal seedling development and growth was recorded after germination.


2001 ◽  
Vol 1 (2) ◽  
pp. 119 ◽  
Author(s):  
S.O. Nelson ◽  
S. Trabelsi ◽  
A.W. Kraszewski

2007 ◽  
Vol 47 (6) ◽  
pp. 683 ◽  
Author(s):  
Pippa J. Michael ◽  
Kathryn J. Steadman ◽  
Julie A. Plummer

Seed development was examined in Malva parviflora. The first flower opened 51 days after germination; flowers were tagged on the day that they opened and monitored for 33 days. Seeds were collected at 12 stages during this period and used to determine moisture content, germination of fresh seeds and desiccation tolerance (seeds dried to 10% moisture content followed by germination testing). Seed moisture content decreased as seeds developed, whereas fresh (max. 296 mg) and dry weight (max. 212 mg) increased to peak at 12–15 and ~21 days after flowering (DAF), respectively. Therefore, physiological maturity occurred at 21 DAF, when seed moisture content was 16–21%. Seeds were capable of germinating early in development, reaching a maximum of 63% at 9 DAF, but germination declined as development continued, presumably due to the imposition of physiological dormancy. Physical dormancy developed at or after physiological maturity, once seed moisture content declined below 20%. Seeds were able to tolerate desiccation from 18 DAF; desiccation hastened development of physical dormancy and improved germination. These results provide important information regarding M. parviflora seed development, which will ultimately improve weed control techniques aimed at preventing seed set and further additions to the seed bank.


1987 ◽  
Vol 27 (1) ◽  
pp. 179 ◽  
Author(s):  
MA Siddique ◽  
G Somerset ◽  
PB Goodwin

Trials on the cultivars Canyon and Gallatin 50 in 1978 and Cascade in 1979 were run in North Queensland to examine ways of improving seed quality of snap beans. The trials concentrated on the maturation period, since this is a critical period for the development of seed quality. We found that seed quality was poor when the crop was cut at the stage when the leaves had fallen and all the pods were dry, or if the plants were cut at any stage and allowed to dry on the ground in single rows. This poor seed quality was associated with high pod temperatures during seed maturation. Cutting the crop before leaf fall, at a seed moisture content close to 50% (20-40% of pods dry) and windrowing immediately in 5 or 10 rows to 1 windrow gave low pod temperatures during seed maturation and high seed quality. Seed harvested and threshed directly off the crop was of good quality provided the seed moisture content in the crop had fallen to less than 25%.


2020 ◽  
Vol 11 (3) ◽  
pp. 199-205
Author(s):  
Arum Sekar Wulandari ◽  
Afrida Rizka Farzana

The presence of Pericopsis mooniana (Thw.) Thw. in nature is endangered. Meanwhile, Pericopsis mooniana plants have its obstacles in generative propagation because the seeds have mechanical dormancy. Studies carried out to: (1) observe the morphology of pods, seeds and sprouts of Pericopsis mooniana; (2) determine the physical quality of Pericopsis mooniana seeds, and (3) analyze the proper dormancy breaking treatment for Pericopsis mooniana seeds. Research is conducted in laboratories and in greenhouses. The physical quality of the seeds measured was the weight of 1,000 seeds and the moisture content. The treatment for breaking the dormancy of the Pericopsis mooniana seeds were control, scarification of the seeds using nail clippers and soaking in hot to cold water for 48 hours. Morphologically, the fruit of Pericopsis mooniana is pod-shaped, with orange seeds, oval-shaped and curved edges. Pericopsis mooniana sprouts include in the epigeal type. In 1 kg of weight there are ± 4,000 Pericopsis mooniana seeds, with the post harvest seed moisture content amounting to 7.62%. The dormancy breaking treatment of Pericopsis mooniana seeds increased seeds germination by 60% compared to controls. The scarification of Pericopsis mooniana seeds using nail clippers for breaking mechanical dormancy is the best treatment because it can increase the number of seeds germinating in a short time and simultaneously. Key words: breaking seed dormancy, morphology, Pericopsis mooniana, physical quality, seed scarificatio


2011 ◽  
Vol 79 (1) ◽  
pp. 21-25
Author(s):  
Agnieszka I. Piotrowicz-Cieślak ◽  
Maciej Niedzielski ◽  
Dariusz J. Michalczyk ◽  
Wiesław Łuczak ◽  
Barbara Adomas

Germinability and the content of soluble carbohydrates were analysed in cereal seed (winter rye, cv. Warko; spring wheat, cv. Santa; hexaploid winter triticale, cv. Fidelio and cv. Woltario). Seed moisture content (mc) was equilibrated over silica gel to 0.08 g H<sub>2</sub>O/g dry mass and stored in a desiccator at 20<sup>o</sup>C for up to 205 weeks or were equilibrated to mc 0.06, 0.08 or 0.10 g H<sub>2</sub>O/g dm and subjected to artificial aging at 35<sup>o</sup>C in air-tight laminated aluminium foil packages for 205 weeks. It was shown that the rate of seed aging depended on the species and seed moisture content. The fastest decrease of germinability upon storage was observed in seed with the highest moisture level. Complete germinability loss for winter rye, winter triticale cv. Fidelio, winter triticale cv. Woltario and spring wheat seed with mc 0.10 g H<sub>2</sub>O/g dm<sup>3</sup> occurred after 81, 81, 101 and 133 weeks, respectively. Fructose, glucose, galactose, myo-inositol, sucrose, galactinol, raffinose, stachyose and verbascose were the main soluble carbohydrates found in the seed. The obtained data on the contents of specific sugars and the composition of soluble sugars fraction in seed of rye, wheat and triticale did not corroborate any profound effect of reducing sugars, sucrose and oligosaccharides on seed longevity.


2017 ◽  
Vol 50 (4) ◽  
pp. 5-16
Author(s):  
F. Shahbazi

AbstractMechanical damage of seeds due to harvest, handling and other process is an important factor that affects the quality and quaintly of seeds. The objective of this research was to determine the effects of moisture content and the impact energy on the breakage susceptibility of vetch seeds. The experiments were conducted at moisture contents of 7.57 to 25% (wet basis) and at the impact energies of 0.1, 0.2 and 0.3 J, using an impact damage assessment device. The results showed that impact energy, moisture content, and the interaction effects of these two variables significantly influenced the percentage breakage in vetch seeds (p<0.01). Increasing the impact energy from 0.1 to 0.3 J caused a significant increase in the mean values of seeds breakage from 41.69 to 78.67%. It was found that the relation between vetch seeds moisture content and seeds breakage was non-linear, and the extent of damaged seeds decreased significantlyas a polynomial (from 92.47 to 33.56%) with increasing moisture (from 7.57 to 17.5%) and reached a minimum at moisture level of about 17.5%. Further increase in seed moisture, however, caused an increase in the amount of seeds breakage. Mathematical relationships composed of seed moisture content and impact energy, were developed for accurately description the percentage breakage of vetch seeds under impact loading. It was found that the models have provided satisfactory results over the whole set of values for the dependent variable.


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