Dormancy and hard-seededness in Western Australian serradella (Ornithopus compressus L.)

1964 ◽  
Vol 15 (6) ◽  
pp. 895 ◽  
Author(s):  
RA Barrett-Lennard ◽  
JS Gladstones
Keyword(s):  
Constant Temperature ◽  
Soil Surface ◽  
Water Soluble ◽  
Appreciable Effect ◽  
Seed Moisture Content ◽  
Seed Moisture ◽  
Physiological Dormancy ◽  
Ornithopus Compressus ◽  
High And Low Temperatures ◽  
Western Australian

Experiments were carried out to test the effects of harvesting date, relative humidity in storage, alternating high and low storage temperatures, and hulling and scarification on seed permeability, dormancy, and viability in Western Australian serradella (Ornithopus compressus L.). Hard-seededness (permeability) was found to be governed by seed moisture content. At storage humidities of 76% R.H. and more, all initially soft seeds remained soft, while at 44% R.H. or less and in the open laboratory, all seeds became fully hard. Storage at 52 and 66% R.H. resulted in semi-hardness and delayed germination. Seed maturity did not influence the degree of hardness attained. Seeds in the field became impermeable as soon as they were mature. Breakdown of impermeability occurred either naturally in the field or in storage under alternating temperatures simulating the summer temperature range at the soil surface, but not in storage at a constant temperature of 20°C. The presence of husks surrounding the seeds had no appreciable effect on permeability. The viability of soft seeds was impaired after 7 months' storage at R.H. levels of 76% and over and a constant temperature of 20°C. Hard-seededness gave complete protection against the injurious effects of these conditions. Loss of viability of the soft seeds was not related to their maturity within the range of maturities tested. No physiological dormancy was observed in the seeds themselves, but unhulled seeds (i.e. those not threshed out of the pod segments) tended to remain dormant, which suggested the presence of a water-soluble germination-inhibiting substance in the husks. This dormancy broke down in mature pod segments under alternating high and low temperatures, but not in immature segments or at a constant temperature of 20°C. Recommendations are made for improving the germination of commercial Western Australian serradella seed.

Seed development in Malva parviflora: onset of germinability, dormancy and desiccation tolerance

2007 ◽  
Vol 47 (6) ◽  
pp. 683 ◽  
Author(s):  
Pippa J. Michael ◽  
Kathryn J. Steadman ◽  
Julie A. Plummer
Keyword(s):  
Moisture Content ◽  
Seed Development ◽  
Desiccation Tolerance ◽  
Dry Weight ◽  
Physical Dormancy ◽  
Seed Moisture Content ◽  
Physiological Maturity ◽  
Seed Moisture ◽  
Physiological Dormancy ◽  
Malva Parviflora

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.

scholarly journals The Imbibition, Viability, and Germination of Caper Seeds (Capparisspinosa L.) in the First Year of Storage

Plants ◽  
2022 ◽  
Vol 11 (2) ◽  
pp. 202
Author(s):  
María Laura Foschi ◽  
Mariano Juan ◽  
Bernardo Pascual ◽  
Nuria Pascual-Seva
Keyword(s):  
Gibberellic Acid ◽  
Harsh Environments ◽  
First Year ◽  
Slow Process ◽  
Seed Moisture Content ◽  
Seed Moisture ◽  
High Germination ◽  
Physiological Dormancy ◽  
Viable Seeds ◽  
One Year

The caper is a shrub that adapts to harsh environments when it is established, but it presents serious difficulties in its propagation, both by cuttings and by seeds. Its seeds have low germination percentages, and germination is a very slow process. Significant increases in germination have been obtained with scarification and with the addition of gibberellic acid (GA3) to the substrate, leading to the hypothesis that they have possible physical and physiological dormancy. However, the only way to examine the water-impermeability of the cover is through imbibition analysis. This study analyzes the imbibition, viability, and germination of two seed lots, obtained in different years and evaluated immediately after their collection (FS) and after being stored (7 °C) for one month (DS) and one year (SS). The seed moisture content stabilizes from the fourth day, exceeding in all cases 31% in all three seed states tested (FS, DS and SS). This allows the germination of all viable seeds, only with the addition of GA3 to the germination substrate, without the need for scarification, so that caper seeds exclusively appear to present a physiological latency. Germination decreased in storage, even with just one month. With the GA3 addition, high germination values were obtained (up to 95% in FS).

scholarly journals EFEITOS DA TEMPERATURA NA GERMINAÇÃO DE SEMENTES E NA FORMAÇÃO DE PLÂNTULAS DE Cedrela fissilis

FLORESTA ◽  
2014 ◽  
Vol 44 (3) ◽  
pp. 441 ◽  
Author(s):  
Ademir Kleber Morbeck Oliveira ◽  
Luciene Andrade Barbosa
Keyword(s):  
Constant Temperature ◽  
Dry Matter ◽  
Seed Moisture Content ◽  
Mato Grosso ◽  
Natural Medicine ◽  
Randomized Design ◽  
Seed Moisture ◽  
Different Temperatures ◽  
Completely Randomized Design ◽  
Mato Grosso Do Sul

O cedro-rosa é uma espécie que ocorre em diversas formações florestais brasileiras, incluindo o Pantanal. As espécies dessa família possuem importante papel na medicina tradicional, além de sua utilização como madeira, empregadaem compensados. Opresente trabalho tem como objetivo avaliar os efeitos de diferentes temperaturas sobre a germinação e formação de plântulas de cedro-rosa, com frutos coletados no Pantanal do Negro, Mato Grosso do Sul, Brasil. Foi determinado o teor de água e avaliaram-se os efeitos das temperaturas constantes de 20, 25, 30 e 35 ºC e alternadas de 20-30 e 25-35 °C, sob fotoperíodo de doze horas de luz branca, com delineamento experimental inteiramente casualizado. O grau de umidade nas sementes foi de 50,5%, com as temperaturas constantes de 20 e 25 °C e alternada de 20-30 °C apresentando os maiores valores médios de germinação, 91, 85 e 87%, respectivamente. O índice de velocidade de germinação foi maior nas temperaturas de 25 e30 °C(8,2), com melhor tempo médio de germinação na temperatura de 30 °C (5,8 dias). A temperatura constante de 25 °C apresentou a melhor média de crescimento e produção de matéria seca e foi a mais adequada.Palavras-chave: Pantanal; sementes florestais; plântulas; Meliaceae; cedro-rosa. AbstractEffect of temperature on seed germination and seedling formation of Cedrela fissilis. The Cedrela fissilis Vell is a wide dispersion species that occurs in several Brazilian forest formations, even in Pantanal. The species of this family have an important role in natural medicine and its wood is used to plywood. This work aims to evaluate the germination and seedling production of Cedrela fissilis Vell under different temperatures. We used fruits collected from Pantanal of Negro, Mato Grosso do Sul, Brazil. It was quantified the water content and evaluated the effects of constant 20, 25 and 30ºC and alternated 20-30 and 25-35°C temperature,  twelve photoperiod under white light. For statistical analysis, the experimental design was completely randomized design. The seed moisture content was 50.5% and constant temperature of 20 and 25 °C and alternated, 20-30 °C, the best treatments for germination, 91, 85 and 87%, respectively. The germination speed was higher at temperatures of 25 and 30 °C (8.2), with the best time of germination at 30 °C (5.8 days). The constant temperature of 25 °C had been the best for the production of dry matter and growth. Taking into account all parameters, the temperature of 25 °C was the most suitable.Keywords: Pantanal; forest seeds; seedlings; Meliaceae; Cedro-rosa.

scholarly journals PENGEMBANGAN METODE PENETAPAN KADAR AIR BENIH SAGA POHON (Adenanthera pavoninaL) DENGAN METODE OVEN SUHU RENDAH DAN TINGGI

Agrin ◽  
2017 ◽  
Vol 21 (1) ◽  
Author(s):  
Heny Agustin ◽  
Yudha Prananda
Keyword(s):  
Moisture Content ◽  
Constant Temperature ◽  
Seed Treatment ◽  
Oven Method ◽  
Seed Moisture Content ◽  
Ground Seed ◽  
Seed Moisture ◽  
Half Seed ◽  
Whole Seed ◽  
High Constant Temperature

Pengujian kadar air benih secara umum telah diatur oleh International Seed Testing Association untukberbagai keperluan, namun beberapa komoditi belum diatur secara jelas termasuk benih saga pohon. Oleh karenaitu pengembangan uji kadar air pada benih saga pohon dirasa perlu untuk dilakukan. Penelitian ini bertujuan untukmengembangkan uji kadar air benih saga pohon dengan dua metode oven yaitu suhu rendah dan tinggi. Penelitiandilaksanan di Lab. Agroekoteknologi, Universitas Trilogi sejak September-Desember 2016. Penelitian terdiri atasdua percobaan yaitu dengan metode oven suhu rendah (103±2)oC dan suhu tinggi (133±2)oC yang keduanyamenggunakan Rancangan Acak Kelompok dua faktor yaitu perlakuan benih saat di oven dan lamanya pengovenan.Untuk metode oven suhu rendah, faktor perlakuan benih saat di oven terdiri atas tiga taraf yaitu benih utuh, benihdibelah dua, benih dihaluskan dan lamanya pengovenan terdiri atas empat taraf yaitu 17 jam, 19 jam, 21 jam, dan23 jam. Untuk metode oven suhu tinggi, faktor perlakuan benih saat dioven terdiri atas tiga taraf yaitu benih utuh,benih dibelah dua, benih dihaluskan dan faktor lamanya pengovenan terdiri atas lima taraf yaitu 1 jam, 2 jam, 3jam, 4 jam, dan 5 jam. Hasil percobaan menunjukkan bahwa kadar air benih saga pohon dapat dilakukan denganmetode oven suhu rendah selama 17 jam dengan perlakuan benih dibelah dua atau selama 19-23 jam denganperlakuan benih utuh. Pengujian kadar air dengan metode suhu tinggi untuk perlakuan lamanya pengovenan dapatdilakukan selama 1 jam dan untuk perlakuan benih saat di oven dapat dilakukan dalam keadaan benih utuh.Kata kunci: benih utuh, benih dibelah dua, benih dihaluskan, lamanya pengovenan.ABSTRACTInternational Seed Testing Association generally rules the testing method of seed moisture content forvarious purposes. However, some commodities have not been clearly regulated including saga seeds. Therefore,the development of seed moisture content testing for saga seeds is considered necessary. The objective of the studywas to develop seed moisture content testing using two oven methods, namely low and high constant temperature.It was conducted at Integrated Lab. of Agroecotechnology, Department of Agroecotecnology, Trilogi Universitystarting from September to December 2016. Two experiments which were low constant temperature oven method(103±2) oC and high constant temperature oven method (133±2) oC were tested using two factors randomizedgroup design. The factors were seed treatment in the oven and period of seed drying. Low constant temperaturemethod used 3 levels of seed treatment (whole seed, half seed, and ground seed, respectively) and 4 levels of dryingperiod (17, 19, 21, and 23 hours, respectively). While high constant temperature method used 3 levels of seedtreatment (whole seed, half seed, and ground seed, respectively) and 5 levels of drying period (1, 2, 3, 4, and 5hours, respectively). The results showed that saga moisture content could be determined using low temperaturemethod with 17-hour drying period for half seeds or 19-23 hours of drying period for whole seeds. As for hightemperature method, seed moisture content testing could be done when seeds were dried for 1 hour, while for seedtreatment in the oven conducted for whole seeds.Key words: whole seed, half seed, ground seed, period of seed drying.

scholarly journals Breaking Seed Dormancy during Dry Storage: A Useful Tool or Major Problem for Successful Restoration via Direct Seeding?

Plants ◽  
2020 ◽  
Vol 9 (5) ◽  
pp. 636 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin
Keyword(s):  
Seed Dormancy ◽  
Research Effort ◽  
Storage Period ◽  
Cost Effective ◽  
Seed Moisture Content ◽  
Dry Storage ◽  
Seed Moisture ◽  
Physiological Dormancy ◽  
Breaking Seed Dormancy ◽  
Time Required

To facilitate the restoration of disturbed vegetation, seeds of wild species are collected and held in dry storage, but often there is a shortage of seeds for this purpose. Thus, much research effort is expended to maximize the use of the available seeds and to ensure that they are nondormant when sown. Sowing nondormant (versus dormant) seeds in the field should increase the success of the restoration. Of the various treatments available to break seed dormancy, afterripening, that is, dormancy break during dry storage, is the most cost-effective. Seeds that can undergo afterripening have nondeep physiological dormancy, and this includes members of common families such as Asteraceae and Poaceae. In this review, we consider differences between species in terms of seed moisture content, temperature and time required for afterripening and discuss the conditions in which afterripening is rapid but could lead to seed aging and death if storage is too long. Attention is given to the induction of secondary dormancy in seeds that have become nondormant via afterripening and to the biochemical and molecular changes occurring in seeds during dry storage. Some recommendations are made for managing afterripening so that seeds are nondormant at the time for sowing. The most important recommendation probably is that germination responses of the seeds need to be monitored for germinability/viability during the storage period.

Phytotoxic Effect of Decaying Quackgrass (Agropyron repens) Residues

Weed Science ◽  
1979 ◽  
Vol 27 (6) ◽  
pp. 595-598 ◽  
Author(s):  
T. V. Toai ◽  
D. L. Linscott
Keyword(s):  
Incubation Temperature ◽  
Soil Surface ◽  
Water Soluble ◽  
Water Extracts ◽  
Phytotoxic Activity ◽  
Phytotoxic Effect ◽  
Effects Of Temperature ◽  
Incubation Temperatures ◽  
Toxin Formation ◽  
Agropyron Repens

We studied the effects of temperature (5, 10, 20, and 30 C) on the phytotoxic activity of decaying quackgrass [Agropyron repens (L.) Beauv.] leaves and rhizomes that were incubated in soils for 0, 1, 2, 4, and 6 weeks. Alfalfa (Medicago sativa L.) seeds were grown for 96 h in water, water extracts of control soils, and water extracts of soil with quackgrass rhizomes or leaves. Dried quackgrass rhizomes and leaves contained water-soluble toxins that inhibited alfalfa seedling development and growth. There was a strong interaction between incubation time and temperature on the development of additional toxins by decomposing quackgrass. High incubation temperature (30 C) accelerated toxin formation and ultimate decay. Intermediate temperature (20 C) delayed toxin formation and decay. Low incubation temperatures (5 C and 10 C) prevented formation of additional toxin. In all extracts of quackgrass and soil that had been incubated for 6 weeks, normal alfalfa seedling number equaled that in water. However, seedling growth varied with incubation temperatures.Treatment of quackgrass with glyphosate [N-(phosphonomethyl) glycine] in the greenhouse did not influence the toxicity of decaying quackgrass leaves. The highest toxic effect was noted after 1 week of decay on the soil surface.

scholarly journals Assessing the storage potential of Australian rainforest seeds: a decision-making key to aid rapid conservation

2021 ◽  
Author(s):  
K. D. Sommerville ◽  
G. Errington ◽  
Z-J. Newby ◽  
G. S. Liyanage ◽  
C. A. Offord
Keyword(s):  
Decision Making ◽  
Logistic Regression ◽  
Dry Weight ◽  
Germination Percentage ◽  
Fleshy Fruit ◽  
Seed Moisture Content ◽  
Fresh Seed ◽  
Desiccation Sensitivity ◽  
Seed Moisture ◽  
Seed Characteristics

AbstractSeed banking of rainforest species is hindered by lack of knowledge as to which species are tolerant of desiccation and freezing. We assessed 313 Australian rainforest species for seed banking suitability by comparing the germination percentage of fresh seeds to seeds dried at 15% RH and seeds stored at −20 °C after drying. We then compared desiccation responses to environmental, habit, fruit and seed characteristics to identify the most useful predictors of desiccation sensitivity. Of 162 species with ≥ 50% initial germination, 22% were sensitive to desiccation, 64% were tolerant and 10% were partially tolerant; the responses of 4% were uncertain. Of 107 desiccation tolerant species tested for response to freezing, 24% were freezing sensitive or short-lived in storage at −20 °C. Median values for fresh seed moisture content (SMC), oven dry weight (DW) and the likelihood of desiccation sensitivity (PD-S) were significantly greater for desiccation sensitive than desiccation tolerant seeds. Ninety-four to 97% of seeds with SMC < 29%, DW < 20 mg or PD-S < 0.01 were desiccation tolerant. Ordinal logistic regression of desiccation response against environmental, habit, fruit and seed characteristics indicated that the likelihood of desiccation sensitivity was significantly increased by a tree habit, fleshy fruit, increasing fresh SMC and increasing PD-S. The responses observed in this study were combined with earlier studies to develop a simple decision key to aid prediction of desiccation responses in untested rainforest species.

Metabolism of a Pyrrolidine Urea Herbicide in Corn and Weeds

Weed Science ◽  
1974 ◽  
Vol 22 (1) ◽  
pp. 10-14 ◽  
Author(s):  
R. E. Holm ◽  
D. E. Stallard
Keyword(s):  
Adventitious Roots ◽  
Parent Compound ◽  
Soil Surface ◽  
Abutilon Theophrasti ◽  
Water Soluble ◽  
Hill Reaction ◽  
Panicum Miliaceum ◽  
Proso Millet ◽  
Ipomoea Purpurea ◽  
The Hill

Five 2,5-dimethyl-1-pyrrolidinecarboxanilides were effective inhibitors of the Hill reaction. However, only thecisisomers were active; thetransisomers were totally inactive. Experiments were conducted using14C-5328 (cis-2,5-dimethyl-1-pyrrolidinecarboxanilide). A correlation existed between resistance of various plants to 5328 and their ability to metabolize it to water soluble metabolites. Velvetleaf (Abutilon theophrastiMedic.) and proso millet (Panicum miliaceumL.) seedlings were very susceptible to 5328 and were unable to metabolize it. Tall morningglory [Ipomoea purpurea(L.) Roth] seedlings were highly tolerant to 5328 and converted it completely to its metabolites. Corn (Zea maysL. ‘DeKalb variety XL-45′) seedlings which were slightly susceptible to 5328 injury were able to metabolize up to 90% of the parent compound. Corn foliage uptake of14C-5328 applied to the soil surface occurred through the adventitious roots.

RF sensing of grain and seed moisture content

2001 ◽  
Vol 1 (2) ◽  
pp. 119 ◽  
Author(s):  
S.O. Nelson ◽  
S. Trabelsi ◽  
A.W. Kraszewski
Keyword(s):  
Moisture Content ◽  
Seed Moisture Content ◽  
Seed Moisture ◽  
Rf Sensing

scholarly journals Relationship of Hull Mesocarp Color to Seed Germination and Vigor in Large-Seeded Virginia-Type Peanuts

1995 ◽  
Vol 22 (1) ◽  
pp. 22-26 ◽  
Author(s):  
J. F. Spears ◽  
G. A. Sullivan
Keyword(s):  
Accelerated Aging ◽  
Dry Weight ◽  
Seed Moisture Content ◽  
Physiological Maturity ◽  
Seed Maturity ◽  
Seed Moisture ◽  
Arachis Hypogaea L ◽  
Maturity Class ◽  
Relationship Of

Abstract Classification of peanuts (Arachis hypogaea L.) based on pod mesocarp color has become a popular means of estimating maturity of runner peanuts. This study was initiated to determine if the hull mesocarp color is related to seed maturity of virginia-type peanuts and to evaluate changes in quality as seed mature. Cultivars NC 7 and NC 9 peanuts were harvested by hand in 1990, 1991, and 1992. Pods were separated according to mesocarp color. Seed moisture content and dry weight within a maturity class varied with cultivar and production year. Germination of NC 7 seed grown in 1990 and 1992 increased as seed approached maturity. Immature NC 9 seed grown in 1991 and 1992 had substantially lower germination than seed from mature pods. There was no increase in germination during maturation of NC 7 seed harvested in 1991 or NC 9 from 1990. Seed leakage during imbibition, measured by electrical conductivity, decreased as seed matured. The lowest leakage levels occurred when seed had reached physiological maturity. Germination following accelerated aging (AA) increased as seed matured. Maximum AA germination of NC 7 occurred when seed had reached 77, 84, and 100% of their final dry weight in 1990, 1991, and 1992, respectively. NC 9 seed achieved maximum germination following AA after the seed amassed at least 90% of their final dry weight.

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