scholarly journals Effect of Cold Storage on the Germination Success of Four Stonecrop Species

2017 ◽  
Vol 27 (3) ◽  
pp. 354-357
Author(s):  
Kathryn L. McDavid ◽  
David L. Sanford ◽  
Robert D. Berghage

Green roof construction is constrained by cost of labor to install the plant material. Optimizing seed germination and establishment could significantly reduce installation costs but would require specific growing conditions that are difficult to provide during installation. Plants of the stonecrop (Sedum) genus are commonly used for the roof top because they will tolerate the high temperatures. This study compared the germination rates of four stonecrop species {goldmoss sedum (Sedum acre), ‘Oracle’ sedum (Sedum forsterianum), blue spruce sedum (Sedum reflexum), and amur sedum [Sedum selskianum (synonm Phedimus selskianum)]} at two temperatures, 70 and 90 °F, following storage of seed in dry, cool (40 °F) conditions of different durations (54, 98, 157, 197, 255, or 343 days). At 70 °F seed of goldmoss sedum, ‘Oracle’ sedum, and blue spruce sedum produced minimum germination rates of 60% at 21 days in seed stored for 54, 98, 157, 197, 255, or 343 days. Goldmoss sedum, ‘Oracle’ sedum, and blue spruce sedum showed reduced germination in 90 °F, probably due to temperature-induced dormancy. Amur sedum had germination of at least 83% at 21 days in both temperatures tested. As amur sedum germination rates appear to be unaffected in the temperatures tested, it could provide an excellent seed for use on green roofs where ideal temperatures are rarely available.

1992 ◽  
Vol 2 (1) ◽  
pp. 15 ◽  
Author(s):  
L Valbuena ◽  
R Tarrega ◽  
E Luis

The influence of high temperatures on germination of Cistus laurifolius and Cistus ladanifer seeds was analyzed. Seeds were subjected to different temperatures for different times, afterwards they were sowed in plastic petri dishes and monitored for germinated seeds over two months.The germination rate observed in Cistus ldanifer was greater than in Cistus laurifolius. In both species, heat increased germination percentages. For Cistus laurifolius higher temperatures or longer exposure times were needed. Germination percentages of Cistus ladanifer were lower when heat exposure time was 15 minutes.It must be emphasized that germination occurred when seeds were not treated, while seeds exposed to 150�C for 5 minutes or more did not germinate.


2003 ◽  
Vol 60 (3) ◽  
pp. 477-480 ◽  
Author(s):  
Warley Marcos Nascimento

Lettuce (Lactuca sativa L.) seed germination is strongly temperature dependent and under high temperatures, germination of most of genotypes can be erratic or completely inhibited. Lettuce seeds of 'Dark Green Boston' (DGB) were incubated at temperatures ranging from 15° to 35°C at light and dark conditions. Other seeds were imbibed in dark at 20°; 25°; 30°; and 35°C for 8 and 16 hours and then transferred to 20 or 35°C, in dark. Seeds were also incubated at constant temperature of 20° and 35 °C, in the dark, as control. In another treatment, seeds were primed for 3 days at 15°C with constant light. DGB lettuce seeds required light to germinate adequately at temperatures above 25°C. Seeds incubated at 20°C had 97% germination, whereas seeds incubated at 35°C did not germinate. Seeds imbibed at 20°C for 8 and 16 hours had germination. At 35°C, seeds imbibed initially at 20°C for 8 and 16 hours, had 89 and 97% germination, respectively. Seeds imbibed at 25°C for 16 hours, germinated satisfactory at 35°C. High temperatures of imbibition led to no germination. Primed and non-primed seeds had 100% germination at 20°C. Primed seeds had 100% germination at 35°C, whereas non-primed seeds germinate only 4%. The first hours of imbibition are very critical for lettuce seed germination at high temperatures.


2001 ◽  
Vol 44 (4) ◽  
pp. 401-404 ◽  
Author(s):  
Fernanda G. A. Ferraz-Grande ◽  
Massanori Takaki

The germination of endangered species Dalbergia nigra was studied and 30.5° C was found as optimum temperature, although the species presented a broad temperature range where germination occurs and light had no effect. The analysis of kinetics of seed germination confirmed the asynchronized germination below and above the optimum temperature. The light insensitive seed and germination also at high temperatures indicated that D. nigra could occur both in understories and gaps where the mean temperature was high.


2008 ◽  
Vol 2008 ◽  
pp. 1-12 ◽  
Author(s):  
Joaquin Aguilar-Santillan

The effects ofBaSO4additions on the wetting of alumina by molten aluminum were studied by the sessile drop technique. To study the effect ofBaSO4decomposition(1100–1150∘C), the additions were treated at two temperatures700∘C(973 K) and1450∘C(1723 K), respectively.BaSO4additions at low and high temperatures did not improve the nonwetting character of these compositions. However, at higher firing temperature, the formation ofBA6 (BaO•6Al2O3)has a nonwetting trend with increasing its content. To address theBA6specifically a pureBaO•6Al2O3was produced and tested. It was more nonwetting than the pure alumina. After the analysis of the contact angles for theBaSO4and theBA6 (BaO•6Al2O3), it was concluded that these additions to alumina do not inhibit wetting by molten aluminum. In fact, at the addition levels common for refractories, the wetting tendency of molten aluminum is enhanced. Alternative explanations for the effectiveness ofBaSO4additions to alumina refractories are discussed.


1986 ◽  
Vol 26 (4) ◽  
pp. 501
Author(s):  
BM El-Zeftawi ◽  
FH Goubran ◽  
JG Richards

Parent canes of Willamette raspberry produced more vigorous canes than those of Glen Clova although the latter was less prone to bud failure in the first year. Reducing the length of the parent canes encouraged cane production and lowered the incidence of bud failure. Freshly dug plant material had more canes and less bud failure than those stored at 2�C, particularly when planted during June-July. For all treatments, the percentage of fruiting canes was 2-3 times higher in the second growing season than in the first, despite the total number of canes being less.


2019 ◽  
Vol 32 (2) ◽  
pp. 411-418
Author(s):  
CLAUDIA KELY PIRES DE MATTOS SORANA ◽  
CARLOS HENRIQUE QUEIROZ REGO ◽  
FERNANDA BRITO CARDOSO ◽  
TIAGO ROQUE BENETOLI DA SILVA ◽  
ANA CARINA DA SILVA CÂNDIDO ◽  
...  

ABSTRACT The aim of the present study was to evaluate the effects of temperature, substrate, and luminosity on chia seeds in order to determine adequate conditions for a germination test. The experiment consisted of a completely randomized design, in a 4 × 5 × 2 factorial scheme (four substrates × five temperatures × two luminosity conditions), with four replications. The following variables were analyzed: first germination count, germination, germination speed index, and mean germination time. Germination was best at 15, 20, 25, and 30 °C for the on-paper, paper roll, and sand substrates. However, in the presence of luminosity and at 25 °C, the on-paper substrate had the highest mean. For all substrates, the lowest germination was achieved at 35 °C, proving that high temperatures reduce chia seed germination. Germination speed index was highest at 25 and 30 °C for on-paper, paper roll, and sand substrates, in both the presence and absence of luminosity. Chia seeds are considered to be neutral photoblasts. Germination tests should be performed with the on-paper substrate, at 25 °C, and with a duration of seven days. The first count should be carried out four days after establishment of the test.


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