Jojoba flower buds: temperature and photoperiod effects in breaking dormancy

1980 ◽  
Vol 31 (4) ◽  
pp. 727 ◽  
Author(s):  
RL Dunstone
Keyword(s):  
Seed Weight ◽  
Diurnal Temperature Range ◽  
Night Temperature ◽  
Flower Buds ◽  
Flower Bud ◽  
Desert Shrub ◽  
Breaking Dormancy ◽  
Controlled Environments ◽  
Effects Of Temperature ◽  
Lower Temperature

Jojoba (Simmondsia chinensis [Link] Schneid.) is a long-lived desert shrub, valued for the liquid wax which makes up 50% of the seed weight. As attempts are being made to domesticate the species, it is important to understand the environmental factors controlling the reproductive cycle and governing seed yield. The effects of temperature and photoperiod in breaking flower bud dormancy were studied on plants growing under well-watered conditions in controlled environments. Plants 42-48 months old produced only dormant flower buds when growing in 27/22� to 36/31�C day/night temperature. When the plants were moved to lower temperatures of 24/19� or 18/13�, every plant produced a flowering flush. In two experiments, clonal material was grown at either 30/25� or 36/3l�C, then moved to lower temperature treatments. Down to the lowest temperature used (18/13�), the greater the drop in temperature, the greater the number of flowers which opened. Flowering occurred under both short (8 h) or long (16 h) photoperiods. There was a critical temperature in the region of 27/22� to 30/25�, above which no flowering occurred. Flowering was not dependent on a large diurnal temperature range, but occurred only if the plants were subjected to a low temperature for at least 21 days.

scholarly journals Flowering Responses of Easter Cactus Clones at Optimal and Supraoptimal Temperatures

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 613-616
Author(s):  
Thomas H. Boyle
Keyword(s):  
Night Temperature ◽  
Flower Buds ◽  
Days To Flowering ◽  
Supraoptimal Temperatures ◽  
Effects Of Temperature ◽  
Short Days

The effects of temperature and clonal genotype on flowering of Easter cactus (Rhipsalidopsis Britton & Rose) were investigated in two experiments. Plants of `Crimson Giant', `Evita', `Purple Pride', and `Red Pride' were exposed to 6 weeks of either 10C or 18C night temperature (NT) under 9- to 9.5-hour natural daylengths (ND), and afterwards were forced at 18C NT and long days (LD). All clones produced fewer flowers when exposed to 18C and ND as compared with 10C and ND; however, the clones varied significantly in their flowering responses. Relative to 10C NT and ND, exposure to 18C NT and ND resulted in an 84% to 95% decrease in the number of flower buds for `Evita', `Purple Pride', and `Red Pride', but only a 50% decrease in the number of flower buds for `Crimson Giant'. In another experiment, 23 clones were exposed to 18C NT and 8-hour short days for 6 weeks, then forced at 18C NT and LD. The clones exhibited differences in percentage of plants flowering, days to flowering, percentage of apical phylloclades flowering, and number of flower buds. `Crimson Giant' outperformed all other clones. Further breeding and selection may yield genotypes that flower more prolifically at 18C minimum than current cultivars.

scholarly journals Management Of Thrips Infesting Mung Bean Using Pesticides

2020 ◽  
Vol 17 (2) ◽  
pp. 43-52
Author(s):  
S Yasmin ◽  
MA Latif ◽  
M Ali ◽  
MM Rahman
Keyword(s):  
Mung Bean ◽  
Untreated Control ◽  
Seed Weight ◽  
Growth Stages ◽  
Flower Buds ◽  
Flower Bud ◽  
Thrips Palmi ◽  
Thrips Species ◽  
Vegetative And Reproductive Growth ◽  
Thrips Population

The study was conducted to evaluate the effect of bio-pesticides and chemical insecticides namely Novastar 56EC, Stargate 48SC, Confidor 70WG, Actara 25aWG, Tracer 45SC, Ecomec 1.8EC, Bioneem plus 1EC to control thrips infesting mung bean in the experimental field of Sher-e- Bangla Agricultural University during November 2017 to February 2018. An untreated control observation was also evaluated. Efficacy of the treatments differed significantly and showed effective results in reduction of thrips population and infestation on mung bean at vegetative and reproductive growth stages of the plant. Stargate 48SC (clothianidin) was the most effective insecticide against the thrips species Megalurothrips usitatus and Thrips palmi with the highest reduction of population on top trifoliate leaves and terminal shoots (100.00 and 89.40%, respectively) at vegetative stage and reduction on flower buds and flowers (86.04 and 85.95%, respectively) at reproductive stage of mung bean. The lowest flower bud and flower infestation (7.22 and 3.41%, respectively) and shedding (4.21 and 1.06%, respectively) by thrips with the highest number of pod (23.80 plant-1), seed (10.20 pod-1), 1000 seed weight (48.40 g) and yield (1026.91 kg ha-1) were also found in Stargate 48SC treated plots followed by Confidor 70WG and Actara 25WG treatments. SAARC J. Agri., 17(2): 43-52 (2019)

scholarly journals Low Night Temperature Increases Ovary Size in Sweet Pepper Cultivars

HortScience ◽  
2011 ◽  
Vol 46 (3) ◽  
pp. 396-401 ◽  
Author(s):  
Nicacio Cruz-Huerta ◽  
Jeffrey G. Williamson ◽  
Rebecca L. Darnell
Keyword(s):  
Production Systems ◽  
Sweet Pepper ◽  
Bell Pepper ◽  
Fresh Weight ◽  
Night Temperature ◽  
Flower Buds ◽  
Flower Bud ◽  
Bud Initiation ◽  
Cool Night

Cool night temperatures have been reported to induce ovary swelling and consequent fruit deformation in bell pepper (Capsicum annuum L.), resulting in unmarketable fruit. This response is a serious limitation to the success of winter production systems for bell pepper. Limited work has been done with other types of sweet pepper, so it is unknown how universal this response is. Furthermore, most prior work has examined effects on ovary diameter only, and there is limited characterization of other ovary traits in response to cool night temperature. The objectives of the present study were to determine the effects of low night temperature on ovary characteristics in different sweet pepper cultivars and to determine the parts of the ovary that are most affected by these factors. Three types of sweet pepper (bell, long-fruited, and cherry) were exposed to 22/20 or 22/12 °C day:night temperatures and flowers at anthesis were continuously harvested throughout the experiments. Ovary fresh weight (FW), diameter, and length across all types (and cultivars within type) were greater under 22/12 °C compared with 22/20 °C. The increase in ovary FW was the result of increases in both ovary wall and placenta FW. In general, all cultivars exhibited increases in ovary size under 12 °C compared with 20 °C night temperature. Differences in ovary FW resulting from night temperature became more pronounced with time. These results indicate that low night temperature effects on ovary swelling may be a universal response among sweet pepper types. Three to 4 weeks are required for maximum swelling response, suggesting that flower buds must be exposed to low night temperatures within the first week after flower bud initiation, because previous work found that flower bud initiation in bell pepper takes ≈4 weeks. However, the duration of low night temperatures necessary for this response remains unknown.

scholarly journals Interactions of Ethephon, Whitewashing, and Dormant Oil on Peach Pistil Growth, Hardiness, and Yield

HortScience ◽  
1992 ◽  
Vol 27 (2) ◽  
pp. 104-105 ◽  
Author(s):  
Edward F. Durner ◽  
Thomas J. Gianfagna
Keyword(s):  
Prunus Persica ◽  
Interactive Effects ◽  
Growth Time ◽  
Flower Buds ◽  
Flower Bud ◽  
Bud Development ◽  
Main Effect ◽  
Lower Temperature ◽  
Peach Trees ◽  
Main Effects

Six-year-old peach trees [Prunus persica (L.) Batsch] were sprayed with ethephon (100 mg·liter–1) in Oct. 1989, whitewashed in Jan. 1990, and sprayed with dormant oil on one or two dates in Mar. 1990 to study possible interactive effects on flower bud hardiness, pistil growth, time of bloom, and yield. Flower buds from ethephon-treated trees supercooled to a lower temperature [mean low temperature exotherm (MLTE) of –18.5C] than buds from nontreated trees (MLTE of –17.7C) in February; there was no main effect of whitewashing or any interaction with ethephon. No treatment effects on hardiness were detected in March. Ethephon-treated pistils were smaller than nontreated pistils, and pistils from buds on whitewashed trees were smaller than those on nonwhitewashed trees. No main effects or interactions of dormant oil on pistil size were detected. Ethephon and whitewashing delayed bud development during bloom, but prebloom oil application(s) had no effect. Buds from ethephon-treated and whitewashed trees were more tolerant of freezes during bloom than buds from oil-sprayed trees, and yield was enhanced by ethephon and whitewashing. Prebloom oil sprays reduced yield compared with controls. Chemical name used: 2-chloroethylphosphonic acid (ethephon).

scholarly journals Physiology of Sugar-Cane VII. Effects of Temperature, Photoperiod Duration, and Diurnal and Seasonal Temperature Changes on Growth and Ripening

1965 ◽  
Vol 18 (1) ◽  
pp. 53 ◽  
Author(s):  
KT Glasziou ◽  
TA Bull ◽  
MD Hatch ◽  
PC Whiteman
Keyword(s):  
Sugar Cane ◽  
Temperature Effects ◽  
Interaction Effects ◽  
Seasonal Temperature ◽  
Night Temperature ◽  
Temperature Changes ◽  
Temperature Regimes ◽  
Controlled Environments ◽  
Effects Of Temperature ◽  
Period Duration

Independent and interaction effects of day and night temperature, photo-period duration, and diurnal thermoperiodicity were studied on sugar-cane grown under controlled environments. During the first 3 months of growth, day and night temperature effects were mainly additive, but at 6 months the interaction effects of all variables were numerous and complex. Many of the interaction effects could be attributed to increased responses to constant-temperature regimes with a 12-hr photoperiod. No evidence for thermoperiodicity requirements was found.

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 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 Lower Temperatures Exacerbate NLRP3 Inflammasome Activation by Promoting Monosodium Urate Crystallization, Causing Gout

Cells ◽  
2021 ◽  
Vol 10 (8) ◽  
pp. 1919
Author(s):  
Huijeong Ahn ◽  
Gilyoung Lee ◽  
Geun-Shik Lee
Keyword(s):  
Environmental Factor ◽  
Nlrp3 Inflammasome ◽  
Inflammasome Activation ◽  
Optimal Temperature ◽  
Monosodium Urate ◽  
Nlrp3 Inflammasome Activation ◽  
Hyperthermia Therapy ◽  
Effects Of Temperature ◽  
Lower Temperature ◽  
Msu Crystals

Gout is a recurrent and chronic form of arthritis caused by the deposition of monosodium urate (MSU) crystals in the joints. Macrophages intake MSU crystals, the trigger for NLRP3 inflammasome activation, which leads to the release of interleukin (IL)-1β and results in the flaring of gout. The effects of temperature, an environmental factor for MSU crystallization, on IL-1β secretion have not been well studied. This study examined the effects of temperature on inflammasome activation. Specific triggers activated canonical inflammasomes (NLRP3, NLRC4, and AIM2) in murine macrophages at various temperatures (25, 33, 37, 39, and 42 °C). The maturation of IL-1β and caspase-1 was measured as an indicator for inflammasome activation. As expected, the optimal temperature of inflammasome activation was 37 °C. The MSU crystal-mediated activation of inflammasome increased at temperatures lower than 37 °C and decreased at higher temperatures. MSU crystals at lower temperatures enhanced IL-1β secretion via the NLRP3 inflammasome pathway. A lower temperature promoted the formation of MSU crystals without changing phagocytosis. Overall, lower temperatures form more MSU crystals and enhance NLRP3 inflammasome activation. In light of these findings, it is possible that hyperthermia therapy may reduce gout flaring.

SEVERAL SOIL MANAGEMENT PRACTICES INFLUENCING THE GROWTH AND RHIZOME DEVELOPMENT OF THE LOWBUSH BLUEBERRY

1966 ◽  
Vol 46 (2) ◽  
pp. 141-149 ◽  
Author(s):  
Walter J. Kender ◽  
Franklin P. Eggert
Keyword(s):  
Management Practices ◽  
Soil Moisture Content ◽  
Effective Means ◽  
Soil Management ◽  
Flower Buds ◽  
Flower Bud ◽  
Undisturbed Soil ◽  
Rhizome Growth ◽  
Lowbush Blueberry ◽  
Rhizome Development

A field experiment using various soil management practices showed that the most effective means to increase blueberry plant spread was through the use of a surface mulch. Peat and sawdust were of equal suitability as a mulching material influencing vegetative growth, although sawdust did result in a reduction in the number of flower buds produced when compared with peat. Mulching was associated with a higher soil moisture content than non-mulched plots.Blueberry plants growing in nitrogen-treated plots had an increased flower bud number and rhizome growth in contrast with those growing in unfertilized plots. Nitrogen fertilization was of particular benefit when applied in association with surface organic mulches.Plants growing in an undisturbed soil were more vigorous than in a homogenized or tilled soil. Sawdust was found to be detrimental to the growth of lowbush blueberry plants when incorporated into a homogenized soil.

The Self-Decay Characteristics of Chlorine Dioxide in Water

2012 ◽  
Vol 610-613 ◽  
pp. 296-299
Author(s):  
Xin Jie Li ◽  
Dan Nan Jiang ◽  
Yue Jun Zhang
Keyword(s):  
Rate Constants ◽  
Tap Water ◽  
Pure Water ◽  
Decay Behaviour ◽  
Increase With Increase ◽  
Higher Temperature ◽  
Effects Of Temperature ◽  
Lower Temperature ◽  
Kinetics Of ◽  
Temperature Water

In order to learn the ClO2 decay behaviour in tap water, the kinetics of ClO2 decay in pure water was studied. Under the conditions of tap water treatment and keeping away from light, the effects of temperature and pH on ClO2 degradation were investigated. The results show that the ClO2 decay reaction in pure water is the first-order with respect to ClO2, the decay rate constants increase with increase in temperature or pH. At pH=6.87, the rate constants are 0.012h-1(15°C), 0.017h-1(25°C), 0.023h-1(35°C), and 0.029h-1(45°C), respectively. At 25°C, the rate constants are 0.0083h-1(pH=4.5), 0.0111h-1(pH=5.5), 0.0143h-1(pH=6.5), 0.0222h-1(pH=7.5), and 0.0351h-1(pH=8.5), respectively. The experimental data prove that ClO2 is more stable in acidic or lower temperature water than in neutral, alkalescent, or higher temperature water.

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