scholarly journals Arctic Plants Produce Vastly Different Numbers of Flowers in Three Contrasting Years at Lake Hazen, Quttinirpaaq National Park, Ellesmere Island, Nunavut, Canada

2016 ◽  
Vol 130 (1) ◽  
pp. 56 ◽  
Author(s):  
Zoe A. Panchen
Keyword(s):  
Reproductive Success ◽  
National Park ◽  
Growing Season ◽  
Ellesmere Island ◽  
Flower Buds ◽  
Flower Bud ◽  
Ambient Temperatures ◽  
Arctic Plants ◽  
Growing Seasons ◽  
Warming Climate

To maximise reproductive success in the short Arctic growing season, plants pre-form flower buds the year prior to flowering. Flower bud production depends on warm ambient temperatures. Thus, although currently Arctic plants have low rates of sexual reproductive success, the warming climate may increase reproductive success. Following the long, warm growing season in 2012, plants at Lake Hazen, Ellesmere Island, produced many flowers in the short, cold growing season of 2013. Conversely, few flowers were produced in 2014, a long, warm growing season, but many flowers were produced in 2015, another long, warm growing season. Potentially higher rates of reproductive success in a warming climate could be compromised if consecutive years do not have long, warm growing seasons.

scholarly journals The onset in spring and the end in autumn of the thermal and vegetative growing season affect calving time and reproductive success in reindeer

2019 ◽  
Vol 66 (2) ◽  
pp. 123-134 ◽  
Author(s):  
Amélie Paoli ◽  
Robert B Weladji ◽  
Øystein Holand ◽  
Jouko Kumpula
Keyword(s):  
Reproductive Success ◽  
Time Lag ◽  
Growing Season ◽  
Plant Phenology ◽  
Negative Effects ◽  
Main Hypothesis ◽  
Vegetation Growth ◽  
Growing Seasons ◽  
Finnish Lapland ◽  
Reindeer Population

Abstract A developing trophic mismatch between the peak of energy demands by reproducing animals and the peak of forage availability has caused many species’ reproductive success to decrease. The match–mismatch hypothesis (MMH) is an appealing concept that can be used to assess such fitness consequences. However, concerns have been raised on applying the MMH on capital breeders such as reindeer because the reliance on maternal capita rather than dietary income may mitigate negative effects of changing phenologies. Using a long-term dataset of reindeer calving dates recorded since 1970 in a semidomesticated reindeer population in Finnish Lapland and proxies of plant phenology; we tested the main hypothesis that the time lag between calving date and the plant phenology in autumn when females store nutrient reserves to finance reproduction would lead to consequences on reproductive success, as the time lag with spring conditions would. As predicted, the reproductive success of females of the Kutuharju reindeer population was affected by both the onset of spring green-up and vegetative senescence in autumn as calves were born heavier and with a higher first-summer survival when the onset of the vegetation growth was earlier and the end of the thermal growing season the previous year was earlier as well. Our results demonstrated that longer plant growing seasons might be detrimental to reindeer’s reproductive success if a later end is accompanied by a reduced abundance of mushrooms.

Effect of paclobutrazol on flower-bud production and vegetative growth in two species of Eucalyptus

1993 ◽  
Vol 23 (4) ◽  
pp. 640-647 ◽  
Author(s):  
A.R. Griffin ◽  
P. Whiteman ◽  
T. Rudge ◽  
I.P. Burgess ◽  
M. Moncur
Keyword(s):  
Vegetative Growth ◽  
Foliar Spray ◽  
Weather Conditions ◽  
Growing Season ◽  
Seed Orchard ◽  
Response Assessment ◽  
Growth Responses ◽  
Flower Bud ◽  
Growing Seasons ◽  
Quality Choice

A series of experiments on field-grown seed-derived trees between 2 and 17 years old demonstrated that the growth regulator paclobutrazol could be used to reduce vegetative growth and enhance flower-bud production in Eucalyptusglobulus Labill. and Eucalyptusnitens (Dean & Maid.) ex Maid. Responses to high levels of trunk injection and collar drenching persisted for up to six growing seasons, yielding both increases in frequency of flowering and heaviness of bud crop. Growth responses were expressed in the immediate growing season, but flowering responses were not evident for another year. Foliar spray treatments reduced vegetative growth in young trees of both species for one growing season, but only the E. globulus showed an associated flowering response. Assessment of seed yield per capsule and subsequent germination tests showed no deleterious effects on seed development or quality. Choice of application method will vary with objective and size of tree. Collar drenching shows the most promise for treating large numbers of seed orchard trees because application time is substantially independent of tree size and weather conditions.

scholarly journals Rapid Flowering of Microcultured Cranberry Plants

HortScience ◽  
1994 ◽  
Vol 29 (3) ◽  
pp. 159-161 ◽  
Author(s):  
Rodney Serres ◽  
Brent McCown
Keyword(s):  
Woody Plant ◽  
Cold Treatment ◽  
Growing Season ◽  
Flowering Plants ◽  
Vaccinium Macrocarpon ◽  
Flower Buds ◽  
Flower Bud ◽  
Air Temperatures ◽  
Bud Set ◽  
Potted Plant

The capability to uniformlyinduce flowering in cranberry (Vaccinium macrocarpon Ait. `Stevens') in < 1 year from microculture was investigated to accelerate cranberry breeding and to study woody plant reproductive biotechnology. Flower buds were induced on newly micropropagated cranberry plants during the first growing season. A treatment of 2.5 mg of paclobutrazol applied as a soil drench per 2- to 3-month-old potted plant in midsummer, when the plants were grown in coldframes under natural daylength and air temperatures, resulted in 70% of the plants flowering. Plants not treated with paclobutrazol did not flower. Reduced but significant flower bud set was observed on plants treated with paclobutrazol but grown in the greenhouse under natural daylength. Flowering was stimulated by cold treatment coupled with gibberellin sprays and/or repotting to nonpaclobutrazol-treated medium. Chemical name used: β -[(4-chlorophenyl)methyl]-ct-(1,1-dimethylethyl)-1H-1,2,4-triazole-1-ethanol (paclobutrazol).

Effects of pollinators and flower bud herbivores on reproductive success of two ericaceous woody species differing in flowering season

2006 ◽  
Vol 84 (1) ◽  
pp. 112-119 ◽  
Author(s):  
Noriyuki Osada ◽  
Shinji Sugiura
Keyword(s):  
Reproductive Success ◽  
Fruit Set ◽  
Woody Species ◽  
Early Spring ◽  
Relative Importance ◽  
Flower Buds ◽  
Flower Bud ◽  
Flowering Duration ◽  
Floral Longevity ◽  
Flowering Season

To investigate the relative importance of pollinators and flower bud herbivores on final fruit set, the ratios of flower to flower bud (flower/bud), fruit to flower (fruit/flower), and fruit to flower bud (fruit/bud) were examined for the two bumble-bee-pollinated ericaceous species that have different flowering seasons: Pieris japonica (Thunb.) D. Don produces flower buds in autumn and blooms in early spring, whereas Lyonia ovalifolia (Wall.) Drude produces flower buds and blooms in late spring. Floral longevity was longer in P. japonica than in L. ovalifolia, and bagged flowers had an even longer floral longevity. The fruit/flower ratio was similar between the cross-pollinated and control flowers in P. japonica, but was smaller in control flowers than in cross-pollinated flowers in L. ovalifolia. Despite unpredictable pollinator activity in early spring, long flowering duration and no competition for pollinators facilitated reproductive success of P. japonica. In contrast, short flowering duration and severe competition for pollinators limited the reproductive success of L. ovalifolia. Flower bud herbivory was more severe in P. japonica than in L. ovalifolia. In both species, predispersal seed herbivores were negligible. Consequently, the fruit/bud ratio was mainly affected by the flower/bud ratio in P. japonica and by the fruit/flower ratio in L. ovalifolia. Our results suggest that despite intense herbivory of flower buds, early spring flowering of P. japonica facilitates pollination because of less competition for pollinators in comparison to L. ovalifolia. Thus, the relative importance of pollinators and herbivores on fruit set differs between the two studied species that differ in flowering periods.

INTERACTION OF METHOD AND DATE OF PRUNING ON GROWTH AND PRODUCTIVITY OF THE LOWBUSH BLUEBERRY

1982 ◽  
Vol 62 (3) ◽  
pp. 677-682 ◽  
Author(s):  
AMR A. ISMAIL ◽  
ERIC J. HANSON
Keyword(s):  
Plant Growth ◽  
Growth Pattern ◽  
Growth Habit ◽  
Growing Season ◽  
Flower Buds ◽  
Flower Bud ◽  
Vaccinium Angustifolium ◽  
Flower Primordia ◽  
Lowbush Blueberry ◽  
Number Of Stems

Lowbush blueberry plants (Vaccinium angustifolium Ait.) were pruned mechanically by flail mowing or thermally by oil burning in the spring and fall. Plant growth pattern, vigor, and flower bud production were determined after one growing season. The incidence of winter injury to flower primordia and berry yields was also determined. The total number of stems produced was not affected by the pruning treatments, but the growth habit of stems was influenced by the method and time of pruning. The pruning treatments had no influence on the incidence of winter injury to flower primordia. Burning resulted in more flower buds per 0.1 m2 than mowing. Yields were not influenced by the method or time of pruning.

Cyclamen Leaf Unfolding Rate in Response to Temperature

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 447d-447
Author(s):  
Meriam Karlsson ◽  
Jeffrey Werner
Keyword(s):  
Day Length ◽  
Leaf Number ◽  
Cyclamen Persicum ◽  
Flower Buds ◽  
Flower Bud ◽  
Leaf Unfolding ◽  
Significant Difference ◽  
Number Of Leaves ◽  
Growth Chambers ◽  
Response To Temperature

Nine-week-old plants of Cyclamen persicum `Miracle Salmon' were transplanted into 10-cm pots and placed in growth chambers at 8, 12, 16, 20, or 24 °C. The irradiance was 10 mol/day per m2 during a 16-h day length. After 8 weeks, the temperature was changed to 16 °C for all plants. Expanded leaves (1 cm or larger) were counted at weekly intervals for each plant. The rate of leaf unfolding increased with temperature to 20 °C. The fastest rate at 20 °C was 0.34 ± 0.05 leaf/day. Flower buds were visible 55 ± 7 days from start of temperature treatments (118 days from seeding) for the plants grown at 12, 16, or 20 °C. Flower buds appeared 60 ± 6.9 days from initiation of treatments for plants grown at 24 °C and 93 ± 8.9 days for cyclamens grown at 8 °C. Although there was no significant difference in rate of flower bud appearance for cyclamens grown at 12, 16, or 20 °C, the number of leaves, flowers, and flower buds varied significantly among all temperature treatments. Leaf number at flowering increased from 38 ± 4.7 for plants at 12 °C to 77 ± 8.3 at 24 °C. Flowers and flower buds increased from 18 ± 2.9 to 52 ± 11.0 as temperature increased from 12 to 24 °C. Plants grown at 8 °C had on average 6 ± 2 visible flower buds, but no open flowers at termination of the study (128 days from start of treatments).

scholarly journals Growth Responses of Boreal Scots Pine, Norway Spruce and Silver Birch Seedlings to Simulated Climate Warming over Three Growing Seasons in a Controlled Field Experiment

Forests ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 943
Author(s):  
Katri Nissinen ◽  
Virpi Virjamo ◽  
Antti Kilpeläinen ◽  
Veli-Pekka Ikonen ◽  
Laura Pikkarainen ◽  
...  
Keyword(s):  
Norway Spruce ◽  
Scots Pine ◽  
Root Biomass ◽  
Growing Season ◽  
Silver Birch ◽  
Shoot Biomass ◽  
Growth Responses ◽  
Growing Seasons ◽  
Simulated Climate ◽  
Shoot And Root Biomass

We studied the growth responses of boreal Scots pine (Pinus sylvestris L.), Norway spruce (Picea abies L. Karst.) and silver birch (Betula pendula Roth) seedlings to simulated climate warming of an average of 1.3 °C over the growing season in a controlled field experiment in central Finland. We had six replicate plots for elevated and ambient temperature for each tree species. The warming treatment lasted for the conifers for three growing seasons and for the birch two growing seasons. We measured the height and diameter growth of all the seedlings weekly during the growing season. The shoot and root biomass and their ratios were measured annually in one-third of seedlings harvested from each plot in autumn. After two growing seasons, the height, diameter and shoot biomass were 45%, 19% and 41% larger in silver birch seedlings under the warming treatment, but the root biomass was clearly less affected. After three growing seasons, the height, diameter, shoot and root biomass were under a warming treatment 39, 47, 189 and 113% greater in Scots pine, but the root:shoot ratio 29% lower, respectively. The corresponding responses of Norway spruce to warming were clearly smaller (e.g., shoot biomass 46% higher under a warming treatment). As a comparison, the relative response of height growth in silver birch was after two growing seasons equal to that measured in Scots pine after three growing seasons. Based on our findings, especially silver birch seedlings, but also Scots pine seedlings benefitted from warming, which should be taken into account in forest regeneration in the future.

Smallseed Falseflax (Camelina microcarpa) Management in Oklahoma Winter Wheat

2021 ◽  
pp. 1-14
Author(s):  
Jodie A. Crose ◽  
Misha R. Manuchehri ◽  
Todd A. Baughman
Keyword(s):  
Winter Wheat ◽  
Weed Control ◽  
Herbicide Resistance ◽  
Wheat Yield ◽  
Acetolactate Synthase ◽  
Growing Season ◽  
Time Of Application ◽  
Adequate Control ◽  
Growing Seasons

Abstract Three herbicide premixes have recently been introduced for weed control in wheat. These include: halauxifen + florasulam, thifensulfuron + fluroxypyr, and bromoxynil + bicyclopyrone. The objective of this study was to evaluate these herbicides along with older products for their control of smallseed falseflax in winter wheat in Oklahoma. Studies took place during the 2017, 2018, and 2020 winter wheat growing seasons. Weed control was visually estimated every two weeks throughout the growing season and wheat yield was collected in all three years. Smallseed falseflax size was approximately six cm in diameter at time of application in all years. Control ranged from 96 to 99% following all treatments with the exception of bicyclopyrone + bromoxynil and dicamba alone, which controlled falseflax 90%. All treatments containing an acetolactate synthase (ALS)-inhibiting herbicide achieved adequate control; therefore, resistance is not suspected in this population. Halauxifen + florasulam and thifensulfuron + fluroxypyr effectively controlled smallseed falseflax similarly to other standards recommended for broadleaf weed control in wheat in Oklahoma. Rotational use of these products allows producers flexibility in controlling smallseed falseflax and reduces the potential for development of herbicide resistance in this species.

scholarly journals Regulation of Flowering Timing by ABA-NnSnRK1 Signaling Pathway in Lotus

2021 ◽  
Vol 22 (8) ◽  
pp. 3932
Author(s):  
Jing Cao ◽  
Qijiang Jin ◽  
Jiaying Kuang ◽  
Yanjie Wang ◽  
Yingchun Xu
Keyword(s):  
Protein Kinase ◽  
Environmental Changes ◽  
Molecular Genetic ◽  
Maximal Response ◽  
Protein Kinase Activity ◽  
Hormonal Changes ◽  
Flower Buds ◽  
Flower Bud ◽  
Aba Content ◽  
Flower Bud Abortion

The lotus produces flower buds at each node, yet most of them are aborted because of unfavorable environmental changes and the mechanism remains unclear. In this work, we proposed a potential novel pathway for ABA-mediated flower timing control in the lotus, which was explored by combining molecular, genetic, transcriptomic, biochemical, and pharmacologic approaches. We found that the aborting flower buds experienced extensive programmed cell death (PCD). The hormonal changes between the normal and aborting flower buds were dominated by abscisic acid (ABA). Seedlings treated with increasing concentrations of ABA exhibited a differential alleviating effect on flower bud abortion, with a maximal response at 80 μM. Transcriptome analysis further confirmed the changes of ABA content and the occurrence of PCD, and indicated the importance of PCD-related SNF1-related protein kinase 1 (NnSnRK1). The NnSnRK1-silenced lotus seedlings showed stronger flowering ability, with their flower:leaf ratio increased by 40%. When seedlings were treated with ABA, the expression level and protein kinase activity of NnSnRK1 significantly decreased. The phenotype of NnSnRK1-silenced seedlings could also be enhanced by ABA treatment and reversed by tungstate treatment. These results suggested that the decline of ABA content in lotus flower buds released its repression of NnSnRK1, which then initiated flower bud abortion.

scholarly journals Rattail fescue (Vulpia myuros) interference and seed production as affected by sowing time and crop density in winter wheat

Weed Science ◽  
2020 ◽  
pp. 1-10
Author(s):  
Muhammad Javaid Akhter ◽  
Per Kudsk ◽  
Solvejg Kopp Mathiassen ◽  
Bo Melander
Keyword(s):  
Winter Wheat ◽  
Grain Yield ◽  
Seed Production ◽  
Yield Components ◽  
Field Experiments ◽  
Growing Season ◽  
Sowing Time ◽  
Growing Seasons ◽  
Crop Density ◽  
Wide Range

Abstract Field experiments were conducted in the growing seasons of 2017 to 2018 and 2018 to 2019 to evaluate the competitive effects of rattail fescue [Vulpia myuros (L.) C.C. Gmel.] in winter wheat (Triticum aestivum L.) and to assess whether delayed crop sowing and increased crop density influence the emergence, competitiveness, and fecundity of V. myuros. Cumulative emergence showed the potential of V. myuros to emerge rapidly and under a wide range of climatic conditions with no effect of crop density and variable effects of sowing time between the two experiments. Grain yield and yield components were negatively affected by increasing V. myuros density. The relationship between grain yield and V. myuros density was not influenced by sowing time or by crop density, but crop–weed competition was strongly influenced by growing conditions. Due to very different weather conditions, grain yield reductions were lower in the growing season of 2017 to 2018 than in 2018 to 2019, with maximum grain yield losses of 22% and 50% in the two growing seasons, respectively. The yield components, number of crop ears per square meter, and 1,000-kernel weight were affected almost equally, reflecting that V. myuros’s competition with winter wheat occurred both early and late in the growing season. Seed production of V. myuros was suppressed by delaying sowing and increasing crop density. The impacts of delayed sowing and increasing crop density on seed production of V. myuros highlight the potential of these cultural weed control tactics in the long-term management programs of this species.

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