Germination, Emergence, Vegetative Growth and Flowering of Two Silvergrasses, Vulpia bromoides (L.) S.F. Gray and V. myuros (L.) C.C. Gmel

1984 ◽  
Vol 32 (2) ◽  
pp. 165 ◽  
Author(s):  
SP Dillon ◽  
F Forcella
Keyword(s):  
Vegetative Growth ◽  
Low Temperatures ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Germination Percentage ◽  
Effect Of Temperature ◽  
Optimum Temperature ◽  
Measured Characteristic ◽  
Rates Of Growth ◽  
Depth Of Burial

Effect of temperature and light on seed germination percentage and rate, depth of burial and seasonality on seedling emergence, and temperature and photoperiod on both vegetative growth and flowering were examined for two species of silvergrass in Australia. Maximum germination percentage was high for both taxa and occurred over a broad range of temperatures. In darkness, both optimum temperature for germination and germination rate were higher for V. myuros than for V. bromoides. In light, optimum temperature was similar for both species, although V. myuros maintained its higher rate. In addition, light doubled the range of temperatures over which the two species were able to germinate. Emergence of both taxa was retarded if seeds were buried below surficial depths but was consistently higher for V. myuros than for V. bromoides at all depths. Upon fulfilling an after-ripening requirement of 2-3 months, fresh seed could germinate and emerge in the field at any season but most seed germinated with the first substantial summer or early autumn rain. Vegetative growth of both species was stimulated initially by high temperatures and long photoperiods but, subsequently, growth was much greater at low temperatures and short photoperiods. This changing response with age to temperature and photoperiod corresponds to expected changes in field environments as plants age naturally V. rnyuros usually maintained higher rates of growth than V. bromoides. Low temperatures and short photoperiods also were required for flowering, particularly for V. myuros. Flowering was the only measured characteristic for which V. bromoldes had greater environmental tolerance than V. myuros. These characteristics of silvergrass relate to their incidence in direct drilled crops in the higher rainfall zones of southern Australia, compared to their relative absence in conventionally sown crops.

The effect of temperature on the consumption of fat during pupal development inGlossina.

1960 ◽  
Vol 51 (3) ◽  
pp. 583-598 ◽  
Author(s):  
E. Bursell
Keyword(s):  
Low Temperatures ◽  
Fat Content ◽  
Effect Of Temperature ◽  
Tsetse Flies ◽  
Optimum Temperature ◽  
Glossina Morsitans ◽  
Pupal Development ◽  
Pupal Period ◽  
Fat Consumption ◽  
Different Temperatures

The size-specific fat content of tsetse flies recently emerged from their puparia was determined and by comparison with the size-specific fat content of newly deposited larvae an estimate was obtained of the consumption of fat during pupal development. Experiments withGlossina morsitansWestw. were carried out at a number of different temperatures and it was found that the amount of fat consumed was least at temperatures between 22 and 24°C.Knowing the duration of the pupal period at different temperatures, the rate of fat consumption could be calculated and the logarithm of this rate was found to be linearly related to temperature. The occurrence of an optimum temperature in respect of fat consumption thus reflects the fact that at high temperatures the rate of fat consumption is greatly increased without a corresponding reduction in the duration of the pupal period, whereas at low temperatures the pupal period is very greatly lengthened without a corresponding decrease in the rate of fat consumption.

scholarly journals Effect of Seed Priming on Germination Properties and Seedling Establishment of Cowpea (Vigna sinensis)

2011 ◽  
Vol 3 (4) ◽  
pp. 113-116 ◽  
Author(s):  
Hamdollah ESKANDARI ◽  
Kamyar KAZEMI
Keyword(s):  
Laboratory Tests ◽  
Low Cost ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Laboratory Data ◽  
Seed Priming ◽  
Germination Percentage ◽  
Seed Vigor ◽  
Seedling Vigor ◽  
Contributing Factors

Early emergence and stand establishment of cowpea are considered to be the most important yield-contributing factors in rainfed areas. Laboratory tests and afield experiment were conducted in RCB design in 2011 at a research farm in Ramhormoz, Iran, to evaluate the effects of hydropriming (8, 12 and 16 hours duration) and halo priming (solutions of 1.5% KNO3 and 0.8% NaCl) on seedling vigor and field establishment of cowpea. Analysis of variance of laboratory data showed that hydropriming significantly improved germination rate, seed vigor index, and seedling dry weights. However, germination percentage for seeds primed with KNO3 and non-primed seeds were statistically similar, but higher than those for NaCl priming. Overall, hydropriming treatment was comparatively superior in the laboratory tests. Invigoration of cowpea seeds by hydropriming and NaCl priming resulted in higher seedling emergence and establishment in the field, compared to control and seed priming with KNO3. Seedling emergence rate was also enhanced by priming seeds with water, suggesting that hydropriming is a simple, low cost and environmentally friendly technique for improving seed and seedling vigor of cowpea.

scholarly journals GIBBERELLIC ACID DURING PRIMING OF PURPLE CONEFLOWER [ECHINACEA PURPUREA (L) MOENCH.] SEEDS IMPROVES GERMINATION AND SEEDLING EMERGENCE

HortScience ◽  
1995 ◽  
Vol 30 (2) ◽  
pp. 186c-186
Author(s):  
Janine O. Haynes ◽  
Wallace G. Pill
Keyword(s):  
Gibberellic Acid ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Dry Weight ◽  
Echinacea Purpurea ◽  
Germination Percentage ◽  
Shoot Dry Weight ◽  
Greenhouse Study ◽  
Purple Coneflower ◽  
Percentage Points

Purple coneflower seeds following priming (-0.04 MPa, 10 days, 15C, darkness) osmotically in polyethylene glycol 8000 (PEG) or matrically in expanded no. 5 vermiculite had greater germination rate and synchrony at continuous 20C or 30C than untreated seeds, but germination percentage was unaffected. Inclusion of 5.5 × 10-2 M gibberellic acid (GA3 as ProGibb Plus 2X, Abbott Laboratories, N. Chicago, Ill.) further improved germination rate and synchrony at 20C, but not at 30C. In a greenhouse study (30C day/27C night, July-August natural light), seeds primed in PEG or vermiculite containing G A3 compared to untreated seeds had 6 percentage points higher maximum emergence (ME), 3.3 fewer days to 50% ME, 1.9 fewer days between 10% and 90% ME, 116% greater shoot dry weight, and 125% longer leaves at 16 days after planting in peat-lite. Inclusion of ethephon (0.01 m, as Florel) either alone or with GA3 during priming provided no benefit to seed germination or seedling emergence. Moistened vermiculite substituted for PEG solution as a priming medium for purple coneflower seeds, the priming benefit on seedling emergence and growth being enhanced by 5.5 × 10-2m G A3 inclusion in the priming media.

scholarly journals Seed Germination and Early Growth Responses of Hyssop, Sweet Basil and Oregano to Temperature Levels

2013 ◽  
Vol 5 (4) ◽  
pp. 462-467 ◽  
Author(s):  
Sajad MIJANI ◽  
Samieh ESKANDARI NASRABADI ◽  
Hadi ZARGHANI ◽  
Mohhamad GHIAS ABADI
Keyword(s):  
Germination Rate ◽  
Germination Percentage ◽  
Effect Of Temperature ◽  
Base Temperature ◽  
Growth Responses ◽  
Model Base ◽  
Sweet Basil ◽  
The Difference ◽  
Maximum Temperatures ◽  
Temperature Levels

The objectives of this survey were to determine the effect of temperature on germination and seedling growth of Hyssop (Hyssopus officinalis L.), Sweet basil (Ocimum basilicum L.) and Oregano (Origanum vulgare L.) (Lamiaceae family) as well as comparing species regarding germination behavior and growth characteristics. Seeds were germinated on a temperature-gradient bar varying between 5 and 40 °C (with 5 °C intervals). Results indicated that the highest germination percentage of hyssop (92-98%), sweet basil (86-90%) and oregano (74-77%) occurred at 20-30 °C, 25-30 °C and 20-30 °C, respectively; therefore, moderate and warm temperatures are proper for germination of all species. In all species the maximum germination rate obtained at 30 °C. Among all species, Day 10 % of Sweet basil Germination had the lowest value, which indicates faster germination. The cardinal temperatures (base, optimum and ceiling or maximum) were estimated by the segmented model. Base temperature (Tb) was calculated for hyssop, sweet basil and oregano as 3.42, 5.70 and 5.46 °C, respectively. Optimal temperature (To) calculated for all species was approximately 30°C, So warmer temperatures are much more proper for them. The species showed different maximum temperatures (Tm) from 42.91 (Oregano) to 48.05 °C (Hyssop). In Hyssop and Sweet basil optimum growth of seedlings were observed at 30°C while Oregano reached its best growth at 25°C. The difference between maximum and minimum temperatures of germination knowing as temperature range (TR) index could show adaptation capability to broad sites for planting and domestication. Regarding this index Hyssop stood in the first place.

scholarly journals Seed quality of Amburana cearensis (Allemão) A.C. Sm. (Fabaceae) is influenced by storage condition

2017 ◽  
Vol 39 (4) ◽  
pp. 401-409 ◽  
Author(s):  
Marcelo do Nascimento Araujo ◽  
Marisol Ferraz ◽  
Fabiana Karla Araújo Américo ◽  
Fabrício Francisco Santos Silva ◽  
Bárbara França Dantas ◽  
...  
Keyword(s):  
Low Temperatures ◽  
Reducing Sugars ◽  
Seed Quality ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Soluble Sugars ◽  
Storage Condition ◽  
Storage Conditions ◽  
Total Soluble Sugars

Abstract: The aim of this study was to evaluate the effects of storage conditions on the germination of A. cearensis seeds. The experimental design was completely randomized into split plots over time with four replicates. The storage conditions of the airtight containers in the refrigerator and laboratory, paper bags in the laboratory and liquid nitrogen were assessed for 27 months. In the laboratory, we evaluated the germination, the germination rate, uniformity of germination, and total soluble and reducing sugars in the radicle. In the greenhouse, we evaluated seedling emergence, emergence rate and height of 30-day-old seedlings. Seeds stored in the refrigerator maintained a high initial germination rate, which decreased from the 21st month. Seeds stored in paper bags in the laboratory showed low emergence and small seedlings. Total soluble sugars and reducing sugars were mobilized when the seeds were stored at low temperatures. Thus, it is not advisable to store A. cearensis seeds in a laboratory environment without airtight containers. A. cearensis seeds kept in a refrigerated environment maintained their viability for at least two years.

An experimental comparison of germination ecology and its implication for conservation of selected rare and endangered species of Dianthus (Caryophyllaceae)

Botany ◽  
2018 ◽  
Vol 96 (5) ◽  
pp. 319-328 ◽  
Author(s):  
Jeremi Kołodziejek ◽  
Jacek Patykowski ◽  
Mateusz Wala
Keyword(s):  
Germination Rate ◽  
Seedling Emergence ◽  
Storage Period ◽  
Soil Surface ◽  
Potassium Nitrate ◽  
Germination Percentage ◽  
Experimental Comparison ◽  
Cold Stratification ◽  
Sowing Depth ◽  
Rare And Endangered Species

The germination requirements of four taxonomically related taxa of Dianthus (D. arenarius L. subsp. borussicus Vierh., D. carthusianorum L., D. gratianopolitanus Vill., and D. deltoides L.) were studied under controlled conditions in a laboratory. A set of experiments were conducted to evaluate seed germination responses to storage period and cold stratification, different hydrogen ion concentrations (pH), potassium nitrate ([Formula: see text]), temperatures, and light conditions. Experiments were also performed to study the effects of sowing depth and water supply on seedling emergence. There were no differences in germination between seeds incubated under light or dark conditions for any of the taxa we studied. Germination percentages increased significantly with increases in temperature. The taxa of Dianthus we studied showed similar responses to sand burial, i.e., seeds placed on or near the soil surface had maximum emergence, and emergence declined with increasing depth of seed burial. In the studied taxa, germination was reduced by declining osmotic potentials. Cold stratification increased the germination rate, but did not affect final germination percentage of Dianthus seeds. A higher concentration of nutritious solutions (KNO3) negatively affected the germination percentage. The results show that seeds of the studied taxa are potentially germinable in the species’ habitat at any time between April and October.

scholarly journals Seed priming effects on germination and first growth of the medicinal plant Achillea millefolium L.

2020 ◽  
pp. 20-23
Author(s):  
Panagiotis Kanatas ◽  
Vyronas Dellaportas ◽  
Ioanna Kakabouki ◽  
Panayiota Papastylianou
Keyword(s):  
Control Experiment ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Seed Priming ◽  
Potassium Nitrate ◽  
Potential Effect ◽  
Germination Percentage ◽  
Priming Effects ◽  
Positive Effects ◽  
Germination And Growth

This study evaluated the effects of seed priming on germination and growth of A. millefolium by means of laboratory and greenhouse experiments conducted during 2018 in the Agricultural University of Athens. Treatments were GA3 (400 and 800 ppm), potassium nitrate (2% and 4%), polyethylene-glycol (soaking for 12 and 24h) besides an untreated control. Experiment in Petri dishes revealed that GA3 at 400 ppm, potassium nitrate (at concentration 2 and 4%) and PEG significantly increased germination percentage of A. millefolium, while germination rate was also significantly improved as a result of all seed priming techniques. In addition, due to the soil experiment, seedling emergence was significantly increased by GA3 at 400 ppm, potassium nitrate (at both concentrations) and PEG compared with the untreated seeds. Dry biomass of the young seedlings was significantly enhanced by means of GA3 (at 400 and 800 ppm), KNO3 (4%) and PEG for 24 h, indicating the potential effect of seed priming on first growth as well. The results of the present study revealed the significant positive effects of seed priming on A. millefolium seed germination, seedling emergence and early growth.

scholarly journals Soaking, Temperature, and Seed Placement Affect Seed Germination and Seedling Emergence of Litchi chinensis

HortScience ◽  
2015 ◽  
Vol 50 (4) ◽  
pp. 628-632 ◽  
Author(s):  
Chunyang Zhang ◽  
Jiefang Wu ◽  
Danwen Fu ◽  
Limin Wang ◽  
Jiezhen Chen ◽  
...  
Keyword(s):  
Seed Germination ◽  
High Temperatures ◽  
Seedling Recruitment ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Germination Percentage ◽  
Burial Depth ◽  
Litchi Chinensis ◽  
Average Percentage ◽  
Seed Placement

To find efficient ways to increase the percentage of seed germination and seedling emergence in litchi (Litchi chinensis Sonn.), we investigated the effects of soaking and high temperature on seed germination, as well as the influence of seed placement (orientation and burial depth) on seedling emergence. Seeds of most tested litchi cultivars soaked in water had a better germination performance than seeds without soaking. More than 90% germination of tested litchi seeds was obtained when the soaking times were 26–54 hours. During presprouting, short-term high temperatures (37–44 °C) exerted a negative effect on seed germination rate, but did not influence the germination percentage. In addition, high temperatures (>42 °C) compromised the further growth of sprouted litchi seeds. Burial depth and seed orientation both significantly influenced the seedling recruitment. There was a reduction in seedling emergence with an increase in burial depth. Seeds at the depth of 2 cm showed the best seedling emergence with an average percentage of 90%. Litchi seedling emergence was greatest and most rapid when seeds were sown 2 cm deep, positioned flat, on their sides, and with the radicle oriented downward.

scholarly journals SEED QUALITY EFFECTS ON HYDROPONIC LETTUCE

HortScience ◽  
1996 ◽  
Vol 31 (6) ◽  
pp. 912D-912
Author(s):  
Ahmet Korkmaz ◽  
Wallace Pill
Keyword(s):  
Seed Quality ◽  
Germination Rate ◽  
Seedling Emergence ◽  
Seed Priming ◽  
Germination Percentage ◽  
Fresh Weight ◽  
Seedling Length ◽  
Size Uniformity ◽  
Initial Seed ◽  
Final Harvest

Achievement of head size uniformity at final harvest reduces loss and increases profitability for the hydroponic lettuce grower. Shoot fresh weight of `Cortina' lettuce (Lactuca sativa L.) at 7 or 21 days after planting (DAP) was inversely proportional to the number of days required for seedling emergence, and was greater for raw than for pelleted seeds. Head fresh weight at final harvest (61 DAP) was directly proportional to seedling length at 21 DAP, but raw and pelleted seeds produced equal head weights. Thus, initial seed (seedling) vigor differences were maintained to final harvest. Osmotic seed priming (–1.5 MPa KH2PO4, 20 h, dark) led to increased germination rate at 15, 25, and 35C; had no effect on germination synchrony; and increased germination percentage only at 35C. Covering raw or pelleted seeds sown in depressions of the phenolic foam trays with fine (No. 5) vermiculite compared to leaving the seeds uncovered, and soaking the trays in hydroponic solution rather than water, increased seedling shoot fresh weights. Seeds sown on their first day of germination or primed seeds gave greater seedling shoot fresh weights than pelleted seeds. However, the more uniform seedling shoot fresh weights from germinated seeds than from primed seeds was associated with more rapid and synchronous seedling emergence.

scholarly journals Effect of different constant and alternative temperatures and light situations on germination behavior of two Purslane (Protulaca oleracea L.) populations

2016 ◽  
Vol 4 (2) ◽  
pp. 13-21
Author(s):  
F Golzardi ◽  
Y Vaziritabar ◽  
K Sadat Asilan ◽  
M Ashraf ◽  
SZ Ebadi ◽  
...  
Keyword(s):  
Germination Rate ◽  
Germination Percentage ◽  
Shoot Length ◽  
Constant Darkness ◽  
Optimum Temperature ◽  
Fresh Weight ◽  
Continuous Darkness ◽  
Light Regimes ◽  
Light Darkness ◽  
Alternating Temperature

This study was carried out to investigate the germination behavior of two purslane populations (Karaj and Ahvaz), the effect of constant temperatures under two light regimes (12 hrs light/dark and continuous dark), alternative temperatures (day/night) and the lighting/darkness periods on purslane germination. The study was conducted in a randomized complete blocks design with four replications. The results showed that the highest percentage and germination rate in constant temperatures under two light regimes in Karaj mass (continuous darkness) and Ahvaz (12/12 hrs light/darkness), respectively at 25 and 30 °C (Optimum temperature) was observed. Purslane percentage and germination rate changes in alternating temperature (day/night) showed, the maximum values of both masses achieved at 30/20°C alternative temperature. According to result, by getting away from the optimum temperature, the germination percentage and its rate tends to have a descending process in both thermal experiments (alternative and constant temperature tests). Also the effect of different darkness/light periods on purslane percentage and germination rate showed, at (0/24) constant darkness treatment these traits got to the lowest point. The highest percentage and germination rates in Karaj and Ahvaz populations, respectively observed at 0/24, 12/12, 10/14 and 8/16 treatments; which had no statistical difference. Radicle length, shoot length and fresh weight of seedlings in both populations at constant temperatures under both light regimes at 20 to 30 °C and alternative temperatures (light/dark) at 30/20 °C had the highest values.International Journal of Natural Sciences (2014), 4(2) 13-21

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