Photosynthetic characteristics in leaves of ‘Valencia’ orange (Citrus sinensis (L.) Osbeck) grown under high and low temperature regimes

1987 ◽  
Vol 27 (3) ◽  
pp. 279-287 ◽  
Author(s):  
J.C.V. Vu ◽  
G. Yelenosky
Keyword(s):  
Low Temperature ◽  
Citrus Sinensis ◽  
Photosynthetic Characteristics ◽  
Temperature Regimes ◽  
Valencia Orange

scholarly journals Temperature Factor Affecting the Abscission Response of Mature Fruit and Leaves to CMN-Pyrazole and Ethephon in `Hamlin' Oranges

2004 ◽  
Vol 129 (3) ◽  
pp. 287-293 ◽  
Author(s):  
Rongcai Yuan ◽  
Jacqueline K. Burns
Keyword(s):  
Low Temperature ◽  
Citrus Sinensis ◽  
Leaf Abscission ◽  
Effect Of Temperature ◽  
Night Temperature ◽  
Temperature Dependent ◽  
Ethylene Evolution ◽  
Mature Fruit ◽  
Temperature Regimes ◽  
Ethephon Treatment

The effect of temperature on the ability of 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP) and ethephon to induce ethylene evolution and abscission of mature fruit and leaves was determined using 3-year-old potted `Hamlin' orange [Citrus sinensis (L.) Osb.] trees in environment-controlled growth rooms in seasons 2001-02 and 2002-03. Ethylene evolution and abscission of CMNP or ethephon-treated fruit and ethephon-treated leaves were highly temperature dependent. Fruit detachment force (FDF) and fruit ethylene evolution were not affected by application of ethephon at 200 mg·L-1 or CMNP at 200 mg·L-1 when air temperature was 10 °C for ethephon treatment or ≤15.6 °C for CMNP treatment. However, ethylene evolution of CMNP or ethephon-treated fruit increased sharply, and FDF decreased drastically as temperature increased from 10 to 26.7 °C for ethephon treatment or from 15.6 to 26.7 °C for CMNP treatment. Several 10 hour day/14 hour night temperature regimes were explored to determine the effect of varying daily and nightly temperatures on efficacy and ethylene evolution. At least 3 days of exposure to 21/10 °C were required for CMNP to effectively loosen fruit, whereas only one day of exposure to 26.7/15.6 °C was enough to induce similar changes. At 21/10 °C, CMNP significantly reduced FDF to<25 N and markedly enhanced fruit ethylene evolution, regardless of interruption by 1 day of low temperature at 10/10 °C in the first 5 d after application. Ethephon had no significant effect on leaf ethylene evolution and leaf abscission when temperature was 10 °C, but caused a marked increase in both leaf ethylene evolution and leaf abscission as temperature increased from 10 to 26.7 °C. CMNP did not stimulate leaf ethylene evolution and leaf abscission regardless of temperature. Chemical names used: 5-chloro-3-methyl-4-nitro-1 H-Pyrazole (CMNP); 2-chloroethylphosphonic acid (ethephon).

scholarly journals Guanfacine and Clonidine Reduce Defoliation and Phytotoxicity Associated with Abscission Agents

2003 ◽  
Vol 128 (1) ◽  
pp. 42-47 ◽  
Author(s):  
Jacqueline K. Burns ◽  
Luis V. Pozo ◽  
Rongcai Yuan ◽  
Brandon Hockema
Keyword(s):  
Butyric Acid ◽  
Phosphonic Acid ◽  
Tree Species ◽  
Citrus Sinensis ◽  
Prunus Persica ◽  
Continuous Exposure ◽  
Immature Fruit ◽  
Metsulfuron Methyl ◽  
Valencia Orange ◽  
Vegetative Cuttings

Guanfacine and clonidine were combined with ethephon or metsulfuron-methyl in the spray tank and applied as foliar sprays to Citrus sinensis L. Osb. `Valencia', Citrus madurensis Loureiro (calamondin), and Prunus persica `Elberta' to determine their effects on leaf loss, fruit detachment force (FDF), immature fruit loss, and twig dieback. In `Valencia' orange, `Elberta' peach and calamondin, guanfacine and clonidine effectively reduced ethephon-induced defoliation in all three tree species, whereas only guanfacine was effective with metsulfuron-methyl applications in `Valencia'. The ability of ethephon to reduce FDF in `Valencia' was only minimally impaired by guanfacine but not impaired by clonidine. Both guanfacine and clonidine diminished the capacity of metsulfuron-methyl to reduce FDF. Guanfacine reduced immature fruit loss of `Valencia' caused by metsulfuron-methyl and reduced twig-dieback. Leaf loss was reduced whether guanfacine or clonidine were applied with ethephon, or 24 hours or 17 days before ethephon application. Guanfacine and clonidine reduced leaf loss induced by continuous exposure of potted calamondin trees to ethylene, and leaf loss was similar with guanfacine and 1-methylcyclopropene (1-MCP) treatments. In separate experiments, guanfacine and clonidine were unable to block ethylene perception in Arabidopsis seedlings and petunia flowers but promoted rooting in coleus and tomato vegetative cuttings, suggesting that these compounds have auxin-like activity. The results demonstrate the potential to enhance selectivity of abscission agents with guanfacine and clonidine. Chemical names used: 2-[(2,6-dichlorophenyl)amino]-2-imidazoline, clonidine; 5-chloro-3-methyl-4-nitro-pyrazole, CMN-P; [(2,6-dichlorophenyl)acetyl]guanidine, guanfacine; [(2-chloroethyl)phosphonic acid, ethephon; indole-3-butyric acid, IBA; 1-methylcyclopropene, 1-MCP.

INTERACTION OF TEMPERATURE AND CO2 ENRICHMENT ON SOYBEAN: GROWTH AND DRY MATTER PARTITIONING

1987 ◽  
Vol 67 (1) ◽  
pp. 59-67 ◽  
Author(s):  
NASSER SIONIT ◽  
B. R. STRAIN ◽  
E. P. FLINT
Keyword(s):  
Low Temperature ◽  
Environmental Control ◽  
Weight Ratio ◽  
Controlled Environment ◽  
Plant Responses ◽  
Growth Responses ◽  
Dry Matter Partitioning ◽  
Leaf Weight ◽  
Temperature Regimes ◽  
Increasing Temperature

Projected increases in atmospheric CO2 concentration will affect growth and productivity of many plant species under various environmental conditions. Since these increases in CO2 may also increase mean annual temperatures, it is important to determine how the soybean (Glycine max (L.) Merr.) will respond to changes in temperature regimes associated with atmospheric CO2 enrichment. Morphology and growth responses of the Ransom cultivar, which is adapted to a southern U.S.A. climate, to day/night temperature regimes of 18/12, 22/16, and 26/20 °C and atmospheric CO2 concentrations of 350, 675 and 1000 μL L−1 were studied in controlled environment chambers. Plant responses were determined at 20, 40, 67 and 115 (late senescence to maturity) days after planting. Plant height and number of branches increased slightly with CO2 enrichment and more significantly with increasing temperature. Root to shoot ratio remained unchanged at different CO2 concentrations but decreased as temperature increased. Leaf weight ratio and specific leaf weight decreased with increasing temperature. Low temperature reduced dry weight of all plant parts, but the reduction was ameliorated by increasing atmospheric CO2 concentration. The results show that increasing the atmospheric CO2 level causes soybean to grow more vigorously at low temperatures. Although controlled environment experiments have their drawbacks in regard to natural field conditions, the present data indicate that soybean will have enhanced growth even at moderately cool temperatures in the future global CO2 concentrations.Key words: Soybean growth, low temperature, CO2 × temperature interaction, environmental control

scholarly journals Geometric Modeling of the Valencia Orange (Citrus sinensis L.) by Applying Bézier Curves and an Image-Based CAD Approach

Agriculture ◽  
2020 ◽  
Vol 10 (8) ◽  
pp. 313
Author(s):  
Hector A. Tinoco ◽  
Daniel R. Barco ◽  
Olga Ocampo ◽  
Jaime Buitrago-Osorio
Keyword(s):  
Computer Aided Design ◽  
Citrus Sinensis ◽  
Geometric Modeling ◽  
Prediction Models ◽  
Two Dimensions ◽  
Radius Of Curvature ◽  
Computer Design ◽  
Bezier Curves ◽  
Bézier Curves ◽  
Valencia Orange

The computer-aided design of fruits are used for different purposes, e.g., to determine mechanical properties by applying engineering simulations, to design postharvest equipment, and to study the natural changes related to the topology. This paper developed a methodology to model Valencia orange (Citrus sinensis), applying Bézier curves and an image-based CAD approach; the orange geometry was designed for different ripening stages. In the modeling process, a 3D construction was carried out using third-order Bézier curves, adjusted to the images taken in orthogonal planes. Four control points defined each profile to compose the geometric pattern of the orange, with geometric errors lower than 3%. Two prediction models were proposed to relate the orthogonal dimensions with a factor size; this means that two dimensions out of three can be predicted. The results showed that the shape ratios kept constant in any ripening stage; however, the radius of curvature evidenced differences in the analyzed shape profiles. The methodological framework presented in the paper might be used to draw other types of citrus fruits. This contribution is a tool to model fruits in 3D, instead of using expensive technological equipment, since it is only necessary to apply computer design tools.

scholarly journals Dynamics of phytohormones and their relationship with chalkiness of early indica rice under different post-anthesis temperature regimes

2017 ◽  
Vol 42 (1) ◽  
pp. 53-65
Author(s):  
Mohammed Humayun Kabir ◽  
Qing Liu ◽  
Yi Su ◽  
Zhigang Huang ◽  
Langtao Xiao
Keyword(s):  
High Temperature ◽  
Low Temperature ◽  
Indica Rice ◽  
Grain Filling ◽  
Flag Leaves ◽  
Content Ratio ◽  
Temperature Regimes ◽  
Head Rice ◽  
Grain Filling Period ◽  
Early Indica Rice

A pot experiment on an early indica rice cv. ‘Shenyou9576’ was conducted in the net house of Hunan Agricultural University, Changsha, Hunan, PR China during the early growing season of 2013 to investigate the influence of varying temperatures on chalkiness rate, head rice rate, and phytohormones, namely indole-3-acetic acid (IAA), gibberellins (GA1 and GA4), zeatin (Z), zeatin riboside (ZR) and abscisic acid (ABA) both in flag leaves and grain endosperm during grain filling period. The treatments comprised three temperature regimes which are designated as the high (35/28oC- day/night), low (25/20oC- day/night) and natural condition as the control (35/25oC- day/night). The results showed that the maximum chalkiness rate was 61.11% under high temperature and the minimum (22.59%) under low temperature. The lowest head rice rate was 42.76% under high temperature followed by 49.91% in the control, while the highest (62.33%) under low temperature. The contents of GA1, GA4, Z and ZR were decreased gradually from 7 to 35 days after anthesis (DAA) irrespective of treatments. IAA content began to decrease from 14 DAA and continued up to 35 DAA and ABA was reduced from 28 to 35 DAA under low temperature in comparison to control and high temperature. ABA content was increased from 7 to 21 DAA and then declined at high temperature. The results showed that contents of GA1, GA4, Z, ZR were high at low temperature compared to high temperature and control. IAA content was also high during grain development period at low temperature except 7 DAA. Higher phytohormone contents were observed in endosperm than in flag leaves. Phytohormone content ratio (endosperm: flag leaves) was found highest in IAA and the lowest in GA1. A significant positive correlation was found between ABA and chalkiness rate during early to mid grain filling period, while significant negative correlations were noticed between chalkiness rate and other phytohormones during grain filling period. Correlation results revealed that increased level of ABA during early to mid grain filing period caused by high temperature was more responsible for development of chalkiness.Bangladesh J. Agril. Res. 42(1): 53-65, March 2017

TEMPERATURE AND DROUGHT STRESS EFFECTS ON GROWTH AND DEVELOPMENT OF BAMBARA GROUNDNUT (VIGNA SUBTERRANEA L.)

2013 ◽  
Vol 50 (1) ◽  
pp. 72-89 ◽  
Author(s):  
IBRAHEEM AL SHAREEF ◽  
DEBBIE SPARKES ◽  
SAYED AZAM-ALI
Keyword(s):  
Low Temperature ◽  
Growth And Development ◽  
Dry Matter ◽  
Bambara Groundnut ◽  
Vigna Subterranea ◽  
Pod Yield ◽  
Growing Seasons ◽  
Temperature Regimes ◽  
Moderate Drought ◽  
Final Yield

SUMMARYThe effect of drought and temperature on the growth and development of bambara groundnut (Vigna subterranea (L.) Verdc.) was studied in controlled environment glasshouses in the United Kingdom. There were two landraces, S19-3 (from a hot, dry environment; Namibia) and Uniswa Red (from a cool, wet environment; Swaziland), two temperature regimes (23 °C and 33 °C) and three watering regimes (2006; fully irrigated), 2007 (drought imposed at 77 days after sowing (DAS)) and 2008 (drought imposed at 30 DAS)). Bambara groundnut responded to drought by slowing the rate of leaf area expansion and reducing final canopy size and total dry matter (TDM). Drought also caused significant reductions in pod dry matter, pod numbers and harvest index (HI), leading to a decrease in final yield that was different between landraces. Throughout the three growing seasons, landraces grown at 33 °C produced more TDM than the landraces grown at 23 °C. The two landraces differed in their phenology; S19-3 exhibited a reduced phenology where leaf numbers started to decrease before Uniswa Red at both temperatures, while Uniswa Red maintained the longest life cycle. The lowest pod yield was produced by Uniswa Red in 2008 at 33 °C (maximum of 35.5 gm−2), while S19-3 produced a minimum pod yield of 56.6 gm−2 at 33 °C, also in 2008. However, both landraces produced considerably more pod yield at 23 °C throughout the three growing seasons (minimum of 151 gm−2 and 162 gm−2 for Uniswa Red and S19-3, respectively). Under moderate drought, S19-3 at 33 °C gave the highest pod yield (365 gm−2) among the treatments throughout the three growing seasons and maintained HI better under drought. Despite being from a hot, dry environment, S19-3 also performed well at low temperature, which indicates the adaptation of S19-3 to low temperature that it also experiences in the country of origin.

Long-term effects of saline irrigation water on 'Valencia' orange trees: relationships between growth and yield, and salt levels in soil and leaves

2007 ◽  
Vol 58 (4) ◽  
pp. 349 ◽  
Author(s):  
L. D. Prior ◽  
A. M. Grieve ◽  
K. B. Bevington ◽  
P. G. Slavich
Keyword(s):  
Soil Salinity ◽  
Irrigation Water ◽  
Citrus Sinensis ◽  
Irrigation Management ◽  
Growth And Yield ◽  
Balance Model ◽  
Salt Treatment ◽  
Saline Irrigation ◽  
Valencia Orange ◽  
Eastern Australia

This study documents changes in yield, growth, soil salinity (ECe) and leaf sodium (Na) and chlorine (Cl) concentrations in mature Valencia orange [Citrus sinensis (L.Osbeck)] trees on sweet orange (Citrus sinensis) rootstock in response to increased levels of Na and Cl in irrigation water. Four levels of salt, ranging from the river-water control (0.44 dS/m) to 2.50 dS/m, were applied over a 9-year period through an under-tree microsprinkler system to trees in the Sunraysia area of the Murray Valley in south-eastern Australia. A salt-balance model showed that evapotranspiration was reduced by salinity, whereas leaching fractions increased from an average 24% in the control to 51% in the most saline treatment. The high leaching fractions were achieved as a result of freely draining soils and good irrigation management, and allowed us to maintain low to moderate levels of soil salinity throughout the trial and minimised the effect of salt treatment on fruit yield. Soil salinity increased almost linearly in response to irrigation-water salinity during the first year, and fluctuated seasonally thereafter; however, very few readings exceeded 3 dS/m, even in the highest treatments. By contrast, leaf Na and Cl concentrations in the highest salt treatment continued to increase over the first 4 years. The relationship between yield and soil salinity was extremely weak, but yield did decrease as foliar concentrations of Na and Cl increased: in Year 9, leaf Na in the highest treatment relative to the control was associated with a predicted reduction of 17% in yield and 59% in annual trunk-diameter growth.

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