INTERACTION BETWEEN DIURNAL TEMPERATURE FLUCTUATIONS AND GIBBERELLINS ON LYCOPERSlCUM STEM ELONGATION AND CHLOROPHYLL CONTENT.

Lypcopersicum esculentum cv `Money Maker' seeds were germinated at constant 20C. Three days after germination seedlings were randomly divided into 3 groups and placed into 3 growth chambers maintained at 23/17, 20/20, or 17/23C (day/night temperature) (DT/NT). Irradiance and photoperiod were maintained at 250 μmol s-1 m-2 and 12 hrs, respectively. At the 2 leaf stage, plants in each chamber were divided into 3 groups of 3 plants each to receive a growth regulator treatment. Growth regulator treatments consisted of spray applications of either ancymidol (52ppm), GA3 (12ppm), or water applied every 3 days for 21 days. Measurements were taken on internode length and chlorophyll content after 21 days. Internode length increased as the difference (DIF) between DT and NT increased (DT-NT). Exogenous applications of GA3 overcame inhibition of stem elongation resulting from a -DIF environment. Application of ancymidol did not significantly decrease stem elongation in a -DIF environment. Temperature regime had a significant impact on chlorophyll content per mg dry weight. In contrast, growth regulator applications had a significant impact on chlorophyll content cm-2. There was no significant impact of either temperature regime or growth regulator treatment on the chlorophyll a/b ratio.

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Effect of a plant growth regulator regime on internode length and weight of tillers in conventional and hybrid rye and the impact of nitrogen on crop performance

The Journal of Agricultural Science ◽

10.1017/s0021859696004029 ◽

1997 ◽

Vol 128 (2) ◽

pp. 143-154 ◽

Cited By ~ 1

Author(s):

M. A. FROMENT ◽

H. G. McDONALD

Keyword(s):

Plant Growth ◽

Growth Regulator ◽

Plant Growth Regulator ◽

Unit Length ◽

Dry Weight ◽

Internode Length ◽

Stem Length ◽

Winter Rye ◽

Crop Performance ◽

Growth Regulator Treatment

The effect of nitrogen and a plant growth regulator regime (chlormequat chloride followed by 2-chloroethylphosphonic acid) on the crop performance of a hybrid (cv. Luchs) and a conventionally bred winter rye (cv. Sentinel) were investigated in two field experiments each year between 1993 and 1995 at Winchester, UK. Internode length and dry weight/unit length of internodes was measured in order to assess the effect of the growth regulator regime on stem structure. Grain yields were 15% higher in the hybrid Luchs than in Sentinel. With high levels of applied nitrogen, both cultivars lodged in all seasons and this was most severe in 1994 when 88% of the crop lodged in Sentinel and 52% in Luchs. Plant growth regulator treatment consistently reduced lodging but did not eliminate it. Reductions in lodging were not always associated with an increase in grain yield. In the hybrid cultivar, the growth regulator treatment reduced yield in 1993 and 1995 when 2-chloroethyl-phosphonic acid was applied at GS49 and GS39 respectively, but increased yield in 1994 when applied at GS37. Growth regulator consistently reduced stem length, and the percentage reduction in length of the individual internodes within the stem was strongly influenced by the timing of the 2-chloroethylphosphonic acid component of the PGR treatment. Growth regulator reduced internode lengths by up to 25% in Sentinel and 35% in Luchs, and this was associated with reductions in the dry weight of internodes by up to 32% in Sentinel and 38% in Luchs. Consequently, dry weight/unit length of the stem was not increased by growth regulator treatment. Yield reductions in Luchs following growth regulator treatment may have been due to reduced stem reserves which have been associated with tolerance of stress in rye. Both cultivars were highly responsive to nitrogen. Economic optima varied from season to season, but they ranged over three years, from 175–273 kg/ha nitrogen, and were greater than the currently recommended application rates. Crop lodging increased with increasing nitrogen rate even when plant growth regulator was applied and yield penalties from lodging would have been high, if weather conditions during grain maturity had been unfavourable.

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Influence of Day and Night Temperatures on Sweet Pepper Seedling Development

Journal of the American Society for Horticultural Science ◽

10.21273/jashs.121.4.699 ◽

1996 ◽

Vol 121 (4) ◽

pp. 699-704 ◽

Cited By ~ 4

Author(s):

Yaping Si ◽

Royal D. Heins

Keyword(s):

Leaf Area ◽

Dry Weight ◽

Sweet Pepper ◽

Internode Length ◽

Stem Diameter ◽

Stem Length ◽

Shoot Dry Weight ◽

Shoot Ratio ◽

Root Shoot Ratio ◽

The Difference

Sweet pepper (Capsicum annuum `Resistant Giant no. 4') seedlings were grown for 6 weeks in 128-cell plug trays under 16 day/night temperature (DT/NT) regimes from 14 to 26 °C. Seedling stem length, internode length, stem diameter, leaf area, internode and leaf count, plant volume, shoot dry weight (DW), seedling index, and leaf unfolding rate (LUR) were primarily functions of average daily temperature (ADT); i.e., DT and NT had similar effects on each growth or development parameter. Compared to ADT, the difference (DIF, where DIF = DT - NT) between DT and NT had a smaller but still statistically significant effect on stem and internode length, leaf area, plant volume, stem diameter, and seedling index. DIF had no effect on internode and leaf count, shoot DW, and LUR. The root: shoot ratio and leaf reflectance were affected by DT and DIF. Positive DIF (DT higher than NT) caused darker-green leaf color than negative DIF. The node at which the first flower initiated was related to NT. The number of nodes to the first flower on pepper plugs grown at 26 C NT was 1.2 fewer than those of plants grown at 14 °C NT.

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Pengaruh Asal Bahan Stek dan Jenis Zat Pengatur Tumbuh (Zpt) pada Pertumbuhan Stek Daun Lidah Mertua (Sansevieria Trifasciata)

Daun Jurnal Ilmiah Pertanian dan Kehutanan ◽

10.33084/daun.v3i2.150 ◽

2016 ◽

Vol 3 (2) ◽

pp. 90-98

Author(s):

Pienyani Rosawanti

Keyword(s):

Plant Growth ◽

Growth Regulator ◽

Root Length ◽

Plant Growth Regulator ◽

Block Design ◽

Dry Weight ◽

Root Dry Weight ◽

Wet Weight ◽

Treatment Research ◽

Growth Regulator Treatment

This research aims to study the growth response of plant leaf cuttings mother in-law�s tongue (Sansevieria parva) origin of cuttings and various plant growth regulator treatment. Research was using complete randomized block design (RAKL) with 6 replications. The first factor was the origin of cuttings, i.e. the top/tip leaves, the middle leave, and the bottom/leaves base. The second factor was the various plant growth regulator (PGR) treatment i.e. onion extracts, water coconut and Rootone-F. Parameters observed and measured is the experiment root length, number of roots, root wet weight and root dry weight. The results showed that plant growth regulator treatment significant effect on root length, number of roots, root wet weight, and root dry weight. The treatment combination of origin of cuttings and synthetic plant growth regulator by cutting material from the middle to give the best results on the number of root and root wet weight.

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Influence of Day and Night Temperature on Development of Sweet Pepper Seedlings

HortScience ◽

10.21273/hortsci.30.4.862b ◽

1995 ◽

Vol 30 (4) ◽

pp. 862B-862

Author(s):

Yaping Si ◽

Royal D. Heins

Keyword(s):

Dry Weight ◽

Sweet Pepper ◽

Internode Length ◽

Stem Diameter ◽

Stem Height ◽

Night Temperature ◽

Shoot Dry Weight ◽

Temperature Regimes ◽

Plant Stem ◽

The Difference

Sweet pepper (Capsicum annuum `Resistant Giant #4') seedlings were grown in 128-cell plug trays under 16 day/night temperature (DT/NT) regimes from 14 to 26C. In this temperature range, plant stem height, leaf unfolding rate, plant volume, internode length, stem diameter, leaf area, and shoot dry weight were primarily functions of average daily temperature (ADT). Internode length increased as ADT or the difference between day and night temperature (DIF) increased. The root-to-shoot ratio decreased linearly as DT increased and was not significantly affected by NT. Leaves were darker green under positive DIF than negative DIF temperature regimes. Increasing NT from 14 to 26C reduced the node at which the first flower appeared by an average of 1.2 nodes. Percent abortion of the first flower increased as DT increased. Plant quality, as defined by seedling index [(dry weight × stem diameter)/internode length], increased as DIF became more negative.

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UTILITY OF DIF TO REGULATE VEGETABLE TRANSPLANT STEM ELONGATION

HortScience ◽

10.21273/hortsci.27.6.615g ◽

1992 ◽

Vol 27 (6) ◽

pp. 615g-616

Author(s):

John T. Erwin

Keyword(s):

Sweet Corn ◽

Stem Elongation ◽

Internode Length ◽

Snap Bean ◽

Light Quantity ◽

The Difference ◽

Male To Female ◽

Bulb Crops

Seedling stem elongation increased as the difference (DIF) between day (DT) and night (NT) temperatures increased from 10 to 26C (DIF=DT-NT). Stem elongation was primarily dependent on DIF on all crops studied except spring bulb crops. Internode lengths decreased in tomato (68%), watermelon (80%), squash (32%), sweet corn (68%) and snap bean (26%) as the difference between day and night temperatures decreased 12 degrees (C). Cucumber internode length decreased by 84% as DIF decreased 16 degrees (C). The ratio of male to female cucumber flowers decreased from 14 to 1, as DIF decreased 12 degrees (C) from 23 DT/17 NT to 17 DT/26 NT. Stem elongation was very sensitive to cool temperatures during the first 3 hours of the morning. Stem elongation was almost the same if the seedlings were cooled for the first 3 hours of the day versus cooling the plants all day. The interactions between temperature on stem elongation and light quantity and quality, and photoperiod will be discussed. Application of DIF in both northern and southern greenhouses will also be discussed.

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Effect of gibberellin, auxin and kinetin treatments combined with foliar applied NPK on the yield of Capsicum annuum L. fruits and their capsaicin content

Acta Agrobotanica ◽

10.5586/aa.1980.007 ◽

2013 ◽

Vol 33 (1) ◽

pp. 81-92 ◽

Cited By ~ 3

Author(s):

Tomasz J. Nowak

Keyword(s):

Gibberellic Acid ◽

Capsicum Annuum ◽

Growth Regulators ◽

Growth Regulator ◽

Foliar Application ◽

Dry Weight ◽

Hydroponic Culture ◽

Optimal Conditions ◽

Capsicum Annuum L ◽

Growth Regulator Treatment

The Wrocław version of hydroponic culture was applied. Under optimal conditions of root fertilization the plants were sprayed with growth regulators sueh as gibberellins, auxins and kinetins, and .their mixtures. Each growth regulator treatment was applied with or without NPK added. The influence of these treatments on the fresh and dry weight of the fruit, percentage of ripe fruits and content and yield of capsaicin was studied. The highest yield of fruits and capsaicin. was obtained from plants sprayed with gibberellic acid and kinetin (in concentrations of 10 and 5 mg/l, respectively) together with NPK foliar application. No influence of ,growth regulators and foliar-applied NPK was noted on capsaicin content and dry weight of fruits.

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The Effects of a Caffeine Placebo and Experimenter Expectation on Blood Pressure, Heart Rate, Well-Being, and Cognitive Performance

European Psychologist ◽

10.1027//1016-9040.6.1.15 ◽

2001 ◽

Vol 6 (1) ◽

pp. 15-25 ◽

Cited By ~ 18

Author(s):

Harald Walach ◽

Stefan Schmidt ◽

Yvonne-Michelle Bihr ◽

Susanne Wiesch

Keyword(s):

Blood Pressure ◽

Heart Rate ◽

Cognitive Task ◽

Well Being ◽

Control Group ◽

Double Blind ◽

Main Effect ◽

The Difference ◽

Being There ◽

To Receive

We studied the effect of experimenter expectations and different instructions in a balanced placebo design. 157 subjects were randomized into a 2 × 4 factorial design. Two experimenters were led to expect placebos either to produce physiological effects or not (pro- vs. antiplacebo). All subjects except a control group received a caffeine placebo. They were either made to expect coffee, no coffee, or were in a double-blind condition. Dependent measures were blood pressure, heart rate, well-being, and a cognitive task. There was one main effect on the instruction factor (p = 0.03) with the group “told no caffeine” reporting significantly better well-being. There was one main effect on the experimenter factor with subjects instructed by experimenter “proplacebo” having higher systolic blood pressure (p = 0.008). There was one interaction with subjects instructed by experimenter “proplacebo” to receive coffee doing worse in the cognitive task than the rest. Subjects instructed by experimenter “antiplacebo” were significantly less likely to believe the experimental instruction, and that mostly if they had been instructed to receive coffee. Contrary to the literature we could not show an effect of instruction, but there was an effect of experimenters. It is likely, however, that these experimenter effects were not due to experimental manipulations, but to the difference in personalities.

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Long-term Effects of Triazol Growth Regulators on Stem Elongation of Rhododendron and Kalmia

HortScience ◽

10.21273/hortsci.32.3.436e ◽

1997 ◽

Vol 32 (3) ◽

pp. 436E-436

Author(s):

Martin P.N. Gent

Keyword(s):

Dose Response ◽

Growth Regulator ◽

Stem Elongation ◽

Spray Application ◽

Long Term Effects ◽

Potted Plants ◽

Response Coefficient ◽

Wide Range ◽

Second Year

The persistence of effects of paclobutrazol or uniconazol on stem elongation was determined for several years after large-leaf Rhododendron and Kalmia latifolia were treated with a single-spray application of these triazol growth-regulator chemicals. Potted plants were treated in the second year from propagation, and transplanted into the field in the following spring. The elongation of stems was measured in the year of application and in the following 2 to 4 years. Treatments with a wide range of doses were applied in 1991, 1992, or 1995. For all except the most-dilute applications, stem elongation was retarded in the year following application. At the highest doses, stem growth was inhibited 2 years following application. The results could be explained by a model of growth regulator action that assumed stem elongation was inversely related to amount of growth regulator applied. The dose response coefficient for paclobutrazol was less than that for uniconazol. The dose that inhibited stem elongation one-half as much as a saturating dose was about 0.5 and 0.05 mg/plant, for paclobutrazol and uniconazol, respectively. The dose response coefficient decreased exponentially with time after application, with an exponential time constant of about 2/year. The model predicted a dose of growth regulator that inhibited 0.9 of stem elongation immediately after application would continue to inhibit 0.5 of stem elongation in the following year.

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Functional ecology of the biological soil crust in semiarid SE Spain: sun and shade populations of Diploschistes diacapsis (Ach.) Lumbsch.

The Lichenologist ◽

10.1017/s0024282905015021 ◽

2005 ◽

Vol 37 (5) ◽

pp. 425-432 ◽

Cited By ~ 38

Author(s):

Ana PINTADO ◽

Leopoldo G. SANCHO ◽

T. G. Allan GREEN ◽

José Manuel BLANQUER ◽

Roberto LÁZARO

Keyword(s):

Water Content ◽

Chlorophyll Content ◽

Unit Area ◽

Biological Soil Crust ◽

Dry Weight ◽

Mean Annual Precipitation ◽

Plant Colonization ◽

Soil Crust ◽

Active Time ◽

Exposed Population

The Tabernas badlands in semiarid south-east Spain is one of the driest regions in Europe with a mean annual precipitation of c. 240 mm. The landscape is deeply dissected, with canyons, ramblas and sparsely vegetated eroded badland slopes. The vegetation is predominantly a biological soil crust consisting of different types of lichen-rich communities, one of the more conspicuous being dominated by Diploschistes diacapsis (Ach.) Lumbsch. This lichen is mainly restricted to the north- facing slopes, where it forms extensive whitish carpets and probably plays an important role in preventing erosion of the slopes and allowing plant colonization. South-facing slopes are much more eroded and generally lack vegetation. %The photosynthetic performance of north (shade) and south-facing (sun) populations of D. diacapsis was studied to determine if these different populations showed any adaptations to the microclimatic conditions of their individual habitats. The response of CO2 exchange to light intensity, temperature and water content was measured under controlled conditions in the laboratory. Dry weight-based net photosynthetic rates were higher in the southern-exposed population but quantum efficiency, and light compensation points were similar. Thallus weight per unit area (LMA) was considerably higher for shade specimens but maximum water content and optimal water content were very similar and chlorophyll content on a dry weight basis was also similar. Chlorophyll content on an area basis was higher in the northern-exposed population and always much larger than those reported in other studies on the same species (up to 8 times larger) with the result that NP values on a chlorophyll basis were relatively low. The larger LMA meant that shade thalli stored more water per unit area which should ensure longer active periods than sun thalli. The results support a strategy pair of high NP and short active time versus low NP and long active time, both having been reported for other soil crust species. However, the visibly larger biomass of the shade D. diacapsis suggests that the lichen is at the limit of its adaptability in these habitats.

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Gibberellic acid and nitrogen efficiently protect early seedlings growth stage from salt stress damage in Sorghum

Scientific Reports ◽

10.1038/s41598-021-84713-9 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Adam Yousif Adam Ali ◽

Muhi Eldeen Hussien Ibrahim ◽

Guisheng Zhou ◽

Nimir Eltyb Ahmed Nimir ◽

Aboagla Mohammed Ibrahim Elsiddig ◽

...

Keyword(s):

Chlorophyll Content ◽

Seedling Growth ◽

Soluble Protein ◽

Dry Weight ◽

Sod Activity ◽

Seedling Length ◽

Relative Water ◽

Emergence Percentage ◽

Negative Impacts ◽

Stress Damage

AbstractSalinity one of environmental factor that limits the growth and productivity of crops. This research was done to investigate whether GA3 (0, 144.3, 288.7 and 577.5 μM) and nitrogen fertilizer (0, 90 and 135 kg N ha−1) could mitigate the negative impacts of NaCl (0, 100, and 200 mM NaCl) on emergence percentage, seedling growth and some biochemical parameters. The results showed that high salinity level decreased emergence percentage, seedling growth, relative water content, chlorophyll content (SPAD reading), catalase (CAT) and peroxide (POD), but increased soluble protein content, superoxide dismutase (SOD) activity and malondialdehyde (MDA) content. The SOD activity was decreased by nitrogen. However, the other measurements were increased by nitrogen. The interactive impact between nitrogen and salinity was significant in most parameters except EP, CAT and POD. The seedling length, dry weight, fresh weight, emergence percentage, POD, soluble protein and chlorophyll content were significantly affected by the interaction between GA3 and salinity. The GA3 and nitrogen application was successful mitigating the adverse effects of salinity. The level of 144.3 and 288.7 μm GA3 and the rate of 90 and 135 kg N ha−1 were most effective on many of the attributes studied. Our study suggested that GA3 and nitrogen could efficiently protect early seedlings growth from salinity damage.

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