Temperature Requirements for Afterripening of Seeds of a Winter Annual Induced into Secondary Dormancy by Low Winter Temperatures

1978 ◽  
Vol 105 (2) ◽  
pp. 104 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Secondary Dormancy ◽  
Winter Temperatures ◽  
Temperature Requirements ◽  
Winter Annual

Delayed germination in seeds of Phacelia dubia var. dubia

1973 ◽  
Vol 51 (12) ◽  
pp. 2481-2486 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Life Cycle ◽  
Seedling Establishment ◽  
Winter Temperature ◽  
Seed Crop ◽  
Temperature Conditions ◽  
Secondary Dormancy ◽  
Winter Temperatures ◽  
Winter Annual ◽  
Delayed Germination ◽  
Germinating Seeds

Not all seeds of a particular seed crop of the winter annual Phacelia dubia var. dubia germinate the first autumn after their dispersal in spring, and germination of a given seed crop is spread over several years. Nondormant seeds that do not germinate in autumn are induced into secondary dormancy by low winter temperatures and must afterripen again during summer before they are capable of germinating. Seeds that do not afterripen the first summer after dispersal are prevented from doing so until at least the next summer because winter temperature conditions prevent afterripening. These responses of the seeds to the environment insure that germination will occur only in autumn, the only season of the year that is suitable for seedling establishment and eventual completion of the life cycle.

Germination response patterns to temperature during afterripening of achenes of four Texas winter annual Asteraceae

1992 ◽  
Vol 70 (12) ◽  
pp. 2354-2358 ◽  
Author(s):  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
O. W. Van Auken
Keyword(s):  
Response Pattern ◽  
Maximum Temperature ◽  
Response Patterns ◽  
Temperature Requirements ◽  
Winter Annuals ◽  
Winter Annual ◽  
Plant Families ◽  
Type 3

Patterns of change in temperature requirements for germination of achenes of four Texas winter annual Asteraceae were investigated as they afterripened at simulated summer habitat temperatures. In addition, temperature requirements for after-ripening were determined. In Gaillardia pulchella, Krigia gracilis, and Pyrrhopappus multicaulis, the maximum temperature for germination increased during afterripening (type 1 response pattern). This is the first report of a type 1 pattern in the Asteraceae. In Hymenoxys linearifolia, the maximum and minimum temperatures for germination increased and decreased, respectively, increasing to two the number of winter annuals with a type 3 response pattern. As in winter annuals in other plant families, achenes of the four species required exposure to moderately high temperatures (25:15, 30:15 °C) to gain the ability to germinate to high percentages at autumn temperatures in autumn. Of the 32 species of Asteraceae whose afterripening pattern has been investigated, 3 have type 1, 22 have type 2, and 7 have type 3. Evidence suggests that types 1 and 3 and types 2 and 3 are more closely related physiologically than are types 1 and 2. Key words: winter annuals, Asteraceae, achenes, seed germination, afterripening.

scholarly journals A quantitative analysis of seed dormancy and germination in the winter annual weed Sinapis arvensis (Brassicaceae)

Botany ◽  
2016 ◽  
Vol 94 (4) ◽  
pp. 289-300 ◽  
Author(s):  
Elias Soltani ◽  
Carol C. Baskin ◽  
Jerry M. Baskin ◽  
Afshin Soltani ◽  
Serolla Galeshi ◽  
...  
Keyword(s):  
Water Stress ◽  
Water Potential ◽  
Soil Seed Bank ◽  
Threshold Temperature ◽  
Burial Depth ◽  
Sinapis Arvensis ◽  
Secondary Dormancy ◽  
Winter Annual ◽  
Persistent Soil Seed Bank ◽  
Dormancy Induction

The aims of this study were to determine the effects of burial on germination and longevity, and of water stress and temperature on germination and dormancy induction of the weed Sinapis arvensis L. During exposure to the high temperatures of summer, seeds buried in the field became nondormant, but low water potential and supra-optimal temperatures (constant not alternating) induced them into secondary dormancy. The threshold temperature for dormancy induction (TTDI) was about 19 °C when water was not limiting germination, and it decreased with a slope of 10 °C per MPa as water potential decreased. Seeds had minimum dormancy (Dmin) when T < TTDI, and Dmin decreased by 81.5% per MPa increase in water potential. Dormancy induction increased linearly with a slope of 13.23% for each additional centimetre of burial depth from 1.0 to 5.19 cm. Dormancy was induced to its highest level (96%) in seeds buried at a depth of ≥5.19 cm; the remaining seeds were dead or were presumed to be dead Sinapis arvensis can form a persistent soil seed bank, and either water stress or conditions associated with increased burial depth can promote induction of secondary dormancy in the seeds.

EVALUATION OF CLOVERS ON SANDY COASTAL SOIL

1977 ◽  
pp. 130-138 ◽  
Author(s):  
W.M. Williams ◽  
L.B. Anderson ◽  
B.M. Cooper
Keyword(s):  
New Zealand ◽  
Drought Stress ◽  
Sandy Soil ◽  
White Clover ◽  
Plant Material ◽  
Red Clover ◽  
Early Spring ◽  
Commercial Cultivars ◽  
Mediterranean Origin ◽  
Winter Annual

In evaluations of clover performances on summer-dry Himatangi sandy soil, it was found that none could match lucerne over summer. Emphasis was therefore placed on production in autumn-winter- early spring when lucerne growth was slow. Evaluations of some winter annual clover species suggested that Trifolium spumosum, T. pallidum, T. resupinatum, and T. vesiculosum would justify further investigation, along with T. subterraneum which is already used in pastures on this soil type. Among the perennial clover species, Kenya white clover (7'. semipilosum) showed outstanding recovery from drought and was the only species to produce significantly in autumn. However, it failed to grow in winter-early spring. Within red clover, materials of New Zealand x Moroccan origin substantially outproduced the commercial cultivars. Within white clover, material from Israel, Italy and Lebanon, as well as progeny of a selected New Zealand plant, showed more rapid recovery from drought stress and subsequently better winter growth than New Zealand commercial material ('Grasslands Huia'). The wider use of plant material of Mediterranean origin and of plants collected in New Zealand dryland pastures is advocated in development of clover cultivars for New Zealand dryland situations.

Agricultural practices of improve hardiness a winter-annual rape

2016 ◽  
Vol 2 (91) ◽  
pp. 57-62
Author(s):  
O.L. Kyrylesko
Keyword(s):  
Dry Matter ◽  
Agricultural Practices ◽  
Mineral Fertilizers ◽  
Farming Practices ◽  
Winter Rape ◽  
Output Capacity ◽  
Careful Preparation ◽  
Digestible Protein ◽  
Winter Annual ◽  
Selection Of

Influence of top-dressing is considered in the article, norms and terms of sowing on of winter-annual rape. The assessment conducted by the yield of green mass and seeds, output capacity by about 1 hectare of dry matter, feed units and digestible protein, the number of dead plants and density of herbage. Established that hardiness and productivity of winter rape can be enhanced through the use of farming practices as: by creating a moderate density of herbage, using optimal terms of planting and doses of mineral fertilizers, selection of predecessors and careful preparation of the soil ect. The mechanism of influence of agrotechnical receptions is exposed on of winter-annual rape through determination in roots before the offensive of the winter of separate biochemical indexes (sugar, starch, to protein).

Temperature Requirements for Growth of Grass‐clump Dwarf Wheats and the Inheritance of the Trait 1

Crop Science ◽  
1976 ◽  
Vol 16 (5) ◽  
pp. 643-647 ◽  
Author(s):  
P. B. E. McVetty ◽  
David T. Canvin ◽  
C. H. Hood
Keyword(s):  
Temperature Requirements

scholarly journals Detecting Climate Driven Changes in Chlorophyll-a in Deep Subalpine Lakes Using Long Term Satellite Data

Water ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 866
Author(s):  
Gary Free ◽  
Mariano Bresciani ◽  
Monica Pinardi ◽  
Nicola Ghirardi ◽  
Giulia Luciani ◽  
...  
Keyword(s):  
Climate Change ◽  
Chlorophyll A ◽  
Nutrient Dynamics ◽  
Cascading Effects ◽  
The North ◽  
Subalpine Lakes ◽  
Winter Temperatures ◽  
Decadal Climate ◽  
The North Atlantic Oscillation ◽  
Traditional Pattern

Climate change has increased the temperature and altered the mixing regime of high-value lakes in the subalpine region of Northern Italy. Remote sensing of chlorophyll-a can help provide a time series to allow an assessment of the ecological implications of this. Non-parametric multiplicative regression (NPMR) was used to visualize and understand the changes that have occurred between 2003–2018 in Lakes Garda, Como, Iseo, and Maggiore. In all four deep subalpine lakes, there has been a disruption from a traditional pattern of a significant spring chlorophyll-a peak followed by a clear water phase and summer/autumn peaks. This was replaced after 2010–2012, with lower spring peaks and a tendency for annual maxima to occur in summer. There was a tendency for this switch to be interspersed by a two-year period of low chlorophyll-a. Variables that were significant in NPMR included time, air temperature, total phosphorus, winter temperature, and winter values for the North Atlantic Oscillation. The change from spring to summer chlorophyll-a maxima, relatively sudden in an ecological context, could be interpreted as a regime shift. The cause was probably cascading effects from increased winter temperatures, reduced winter mixing, and altered nutrient dynamics. Future trends will depend on climate change and inter-decadal climate drivers.

scholarly journals Environmental cues affecting horseweed (Conyza canadensis) growth type and their sensitivity to glyphosate

Weed Science ◽  
2021 ◽  
pp. 1-35
Author(s):  
John A. Schramski ◽  
Christy L. Sprague ◽  
Eric L. Patterson
Keyword(s):  
Soil Moisture ◽  
Glyphosate Resistance ◽  
Single Parent ◽  
Environmental Cues ◽  
Conyza Canadensis ◽  
Growth Type ◽  
Susceptible Population ◽  
Water Imbibition ◽  
Growth Types ◽  
Winter Annual

Abstract Horseweed [Conyza canadensis (L.) Cronquist] is a facultative winter annual weed that can emerge from March to November in Michigan. Fall emerging C. canadensis overwinters as a rosette, while spring emerging C. canadensis skips the rosette stage and immediately grows upright upon emergence. In Michigan, primary emergence recently shifted from fall to spring/summer and therefore from a rosette to an upright growth type. Growth chamber experiments were conducted to determine 1) whether both C. canadensis growth types could originate from a single parent and 2) if common environmental cues can influence growth type. Variations in temperature, photoperiod, competition, shading, and soil moisture only resulted in the rosette growth type in four C. canadensis populations originating from seed collected from a single parent of the upright growth type. However, a vernalization period of four weeks following water imbibition, but prior to germination, resulted in the upright growth type. Dose-response experiments were conducted to determine whether glyphosate sensitivity differed between C. canadensis growth types generated from a single parent of the upright growth type. Upright type C. canadensis from known glyphosate-resistant populations ISB-18 and MSU-18 were four and three-fold less sensitive to glyphosate than their rosette siblings, respectively. Interestingly, differences in glyphosate sensitivity was not observed between growth types from the susceptible population. These results suggest that while C. canadensis populations shift from winter to summer annual lifecycles, concurrent increases in glyphosate resistance could occur.

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