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

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).

1965 ◽  
Vol 16 (1) ◽  
pp. 1 ◽  
Author(s):  
RD Asana ◽  
RF Williams

Experiments were conducted in controlled environments to determine the effects of high temperatures on grain development and yield in wheat. Two Australian and three Indian cultivars of wheat were exposed, from a week after anthesis until maturity, to "day" temperatures of 25, 28, and 3l°C, and "night" temperatures of 9 and 12°C. There was a mean reduction in yield of 16%' for the 6° rise in day temperature, but the cultivars did not differ significantly in their response to these temperatures. There were no significant effects of night temperature on grain weight, but stem weight was less at 12°C. Senescence was hastened only slightly by high day temperature, and there were no differential effects between cultivars in this respect.In a subsidiary experiment one Indian and five Australian cultivars were subjected to three day-night temperature regimes (24/19°, 27/22°, and 30/25°C). Highly significant but complex interactions were established between temperature regime and cultivar. A growth analysis for the Australian cultivars Ridley and Diadem indicated that the developing grain of Ridley had a greater capacity for growth than that of Diadem from the earliest stage. This, together with the confirmation of grain size as a very stable characteristic for all the varieties, points to the developmental and synthetic activity of the grain as an important determinant of grain yield. The relevance of this study to the production of wheat in India is briefly discussed.


2000 ◽  
Vol 134 (2) ◽  
pp. 221-226 ◽  
Author(s):  
MARINA I. SYSOYEVA ◽  
TATJANA G. KHARKINA

A method that allows the effect of temperature treatments on plant quality to be quantified is described. The proposed method is based on the analysis of temperature regions for plant quality characteristics and enables an easier and more precise analysis of the influence of day and night temperature on plant growth and development. Plant quality may be evaluated by the combination of any number of plant characteristics. The proposed method can assist growers in determining what temperature regimes are necessary to produce acceptable-quality crops on specified days.


Agronomy ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 2416
Author(s):  
Nnaemeka Emmanuel Okpala ◽  
Mouloumdema Pouwedeou Potcho ◽  
Muhammad Imran ◽  
Tianyue An ◽  
Gegen Bao ◽  
...  

Rice (Oryza sativa L.) is mainly grouped into indica and japonica varieties. The aim of this study was to investigate the effect of temperature on cooked rice elongation, cooked rice expansion, and rice fragrance. This study was conducted in three growth temperature chambers with indica cultivar Basmati 385 (B385) and japonica cultivar Yunjingyou (YJY). Grains of B385 grown in low-temperature regimes had the highest cooked rice elongation and expansion, whereas the grains of YJY grown in high-temperature regimes had the highest cooked rice elongation and expansion. Starch granules of B385 grown in low-temperature regimes were more compact and bigger, compared to grains grown in medium- and high-temperature regimes. Conversely, the starch granules of YJY grown in high-temperature regimes were more compact and bigger, compared to those grown in medium- and low-temperature regimes. Metabolomic analyses showed that temperature affected the rice metabolome and revealed that cyclohexanol could be responsible for the differences observed in cooked rice elongation and expansion percentage. However, in both B385 and YJY, grains from low-temperature regimes had the highest 2-AP content and the lowest expression levels of the badh2 gene. The findings of this study will be useful to rice breeders and producers.


2016 ◽  
Vol 50 (6) ◽  
Author(s):  
Kiran Ba

Three chickpea genotypes (Annigeri-1, JG-11 and JG-14), with five dates of sowings (40th to 48th standard meteorological week (SMW) with an interval of two weeks) were evaluated in field to study the effect of temperature regimes on pollen sterility per cent (%), phenological characters and productivity. Pollen sterility per cent increased significantly from D1 to D3 dates of sowing and then decreased towards D5 date of sowing. JG-14 and JG-11 recorded less pollen sterility as compared to Annigeri-1 at all the dates of sowing. When the low temperature around 9.7 oC to 11.0 oC the pollen sterility per cent was increased (44 to 62 %). The third date of sowing was showed significantly greater duration of flowering (25, 32 and 32 days), total number of flowers (225, 195 and 97) produced with respect to the genotypes (Annigeri-1, JG-11 and JG-14) and longer cool season during flowering produced average number of flowers per day per plant (9.00, 6.09 and 3.03), with optimum flowers to pod ratio (3.42, 2.60 and 1.39). Accumulation of more heat units measure (GDD, 1735) untill physiological maturity helps to get a higher yield (28.52 q per hectare) with a test weight of 19.6 g and more number of pods and seeds per plant.


Weed Science ◽  
1988 ◽  
Vol 36 (5) ◽  
pp. 545-552 ◽  
Author(s):  
K. Neil Harker ◽  
Jack Dekker

A growth cabinet study was conducted to evaluate the effect of temperature on the distribution of several herbicides in quackgrass. Uniformly labeled14C-sucrose and the radiolabeled herbicides glyphosate, sethoxydim, cloproxydim, the butyl ester of fluazifop, the methyl ester of haloxyfop, and the ethyl ester of quizalofop were applied to quackgrass grown at three day / night temperature regimes (10/5, 20/15, and 30/25 C). Seven days after treatment the plants were harvested, lyophilized, and later sectioned, mapped, and oxidized in preparation for14C quantification. Quackgrass rhizome growth was more vigorous at 20/15 than 30/25 or 10/5 C. of the herbicides tested, haloxyfop was the most inhibitory to rhizome growth. Temperature increases from 10/5 to 20/15 or from 20/15 to 30/25 C resulted in more translocation to shoots. Increasing temperature had various effects on translocation to rhizomes depending on the chemical applied. At all three temperature regimes, more14C was recovered from distal than basal buds in plants treated with14C-sethoxydim. In contrast, at all three temperature regimes, similar amounts of14C were recovered from the distal and basal buds of plants treated with 14-C-sucrose.


Author(s):  
Kai Wei ◽  
Zi-xuan Liu ◽  
Ying-chun Liang ◽  
Ping Wang

To consider the rail pads of thermoplastic polyurethane elastomer (TPE), chloroprene rubber (CR), and ethylene propylene diene monomer (EPDM) that are usually used in the Chinese subway as test subjects, their static stiffness at temperatures of −40℃ to 70℃ was measured by a universal testing machine equipped with a temperature control box. Then, the influence of the temperature-dependent stiffness of the rail pads on the vertical vehicle-track coupled vibrations was investigated with application of a vehicle-track coupled dynamic model. It was found that the static stiffness of these rail pads exhibits a nonlinear variation with temperature. Their static stiffness is considerably sensitive to temperatures below 20℃, when the CR rail pad is the most sensitive. At temperatures above 20℃, their static stiffness slightly alters with increasing temperature. The temperature-dependent stiffness of these rail pads mainly affects the vertical vibrations of the vehicle system above the one-third octave center frequency of 31.5 Hz and the vertical rail vibrations near the center frequency of 63 Hz. Moreover, the influence of the low-temperature stiffness of rail pads at −40℃ to 20℃ is far greater than the effect of the high-temperature stiffness of rail pads at 20–70℃. Thus, TPE, CR, and EPDM rail pads have excellent high-temperature stability and adverse low-temperature sensibility.


HortScience ◽  
2005 ◽  
Vol 40 (4) ◽  
pp. 1031A-1031
Author(s):  
Elsa Sánchez ◽  
Kathleen Kelley ◽  
Lynn Butler

Eight edamame [Glycine max (L.) Merrill] cultivars were evaluated in the field in 2002, 2003, and 2004 to determine their suitability for growing in central Pennsylvania. Each cultivar was direct seeded and data collected included plant populations (percentage of stand) and marketable yields. Plant populations ranged from less than 1% to 81% and, with one exception in 2002, were below 80%. Eighty percent plant populations or higher are considered optimal. Based on sub-optimal plant populations, none of the edamame cultivars evaluated in the field were determined to be suitable for direct seeding in central Pennsylvania. The effect of temperature on seedling emergence, and therefore, plant populations was then studied. Four of the edamame cultivars used in the field trial were evaluated in growth chambers programmed with varying day/night temperature regimes. Seedling emergence varied by cultivar and was generally below 80% with two exceptions. When grown in a 21.1 °C day/15.6 °C night temperature regime, `Butterbeans' and `Early Hakucho' exceeded 80% seedling emergence. These methods could be used to produce transplants; however, the economic feasibility of doing so should first be evaluated. In the field trial, conclusions on marketable yields were unattainable because soybean plants are known to compensate in yield for plants missing in sub-optimal plant populations. Plant compensation and sub-optimal plant populations rendered yield comparisons between cultivars questionable. The issue of sub-optimal seedling emergence and plant population needs to be studied further before suitability of growing these edamame cultivars in central Pennsylvania can be determined.


2005 ◽  
Vol 15 (3) ◽  
pp. 672-676 ◽  
Author(s):  
Elsa Sánchez ◽  
Kathleen Kelley ◽  
Lynn Butler

Eight edamame (Glycine max) cultivars were evaluated in the field in 2002, 2003, and 2004 to determine suitability for growing in central Pennsylvania. Data collection included plant populations (percent stand), marketable and unmarketable yields and edamame pod and bean quality indicators. Plant populations varied by year and cultivar and were generally below 80%. The effect of temperature on seedling emergence, and therefore plant populations, was evaluated for four edamame cultivars by using growth chambers programmed with varying day/night temperature regimes. Seedling emergence varied by cultivar and was generally below 80% with two exceptions. When grown in a 70/60 °F day/night temperature regime, `Butterbeans', and `Early Hakucho' exceeded 80% seedling emergence. In the field trial, plant populations affected marketable yields. Pod and bean quality were dependent on cultivar. Results indicated that `Butterbeans', `Early Hakucho', `Green Legend', `Shironomai', `Butterbaby', and `Lucky Lion' appear promising for growing in Pennsylvania based on pod and bean quality. However, the issue of poor seedling emergence and plant populations presents a major constraint to commercial production and needs to be studied further.


HortScience ◽  
2013 ◽  
Vol 48 (1) ◽  
pp. 47-52 ◽  
Author(s):  
Veronica L. Justen ◽  
Vincent A. Fritz

Turnips (Brassica rapa. subsp. rapa L.) produce glucosinolates (GSLs), thioglucosides whose hydrolyzed derivatives have been shown to provide chemopreventive benefits. Two cultivars of turnips [‘Just Right’ (JR) and ‘Scarlet Queen’ (SQ)] were grown under three different temperature regimes to assess the role of temperature on GSL production in roots and shoots. When compared with low-temperature treatments, high-temperature treatments increased total and individual GSLs in a tissue- and genotype-specific manner. When compared with low-temperature treatments, total GSLs were ≈70% and 130% higher in JR shoots and roots, respectively, grown at high-temperature treatments. High temperatures also increased total GSLs in SQ shoots and roots by ≈80% and 85%, respectively, when compared with low temperatures. Gluconasturtiin (GNS, 2-phenylethyl GSL) concentration was inversely correlated with temperature with high-temperature treatments resulting in 20% and 48% less GNS than low-temperature treatments in JR and SQ roots, respectively. The indolic GSL, 1-methoxyglucobrassicin (1MGB; 1-methoxy-3-ylmethyl GSL), was the root GSL most elevated by increased temperature resulting in a 1000% increase on average in both cultivars between the low- and high-temperature treatments. These results show promise for the use of temperature to enhance the health-promoting properties of turnip because 1MGB has potent chemopreventive effects. Gene expression analysis suggests that some BrMYB transcription factor expression levels are associated with temperature-dependent changes in GSL accumulation; however, this association varies between cultivar and tissue type.


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