Flower initiation in relation to maturity in crop plants. III. The flowering response of early and late cereal varieties to Australian environments

1966 ◽  
Vol 17 (1) ◽  
pp. 1 ◽  
Author(s):  
Y Aitken
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Leaf Number ◽  
Flower Initiation ◽  
Tropical Environments ◽  
Before And After ◽  
Delayed Initiation ◽  
Tropical Australia ◽  
The Difference ◽  
Early Flower

The difference between early- and late-flowering characters in wheat, rye, barley, and oats has been studied by growing some Australian and overseas varieties in several field environments with mean temperatures ranging from 10 to 22°C, and mean photoperiod of 10½ to nearly 16 hr, together with vernalization and prolonged photoperiod. Similar genotypes were found in each of the four cereals. Early varieties all flowered at a low leaf number, which showed that the genotypes for early flower initiation in these varieties are almost or entirely insensitive to temperature and photoperiod. In consequence, varieties with such genotypes can be expected to flower early, even in tropical Australia. In contrast, the genotypes for lateness caused initiation at a higher leaf number, and more sensitivity to temperature and photoperiod, both before and after flower initiation. Contrary to the common assumption that very late varieties need a period of cold followed by long photoperiod for flower initiation, they were found to initiate both in summer (i.e, high temperature) and in winter (low photoperiod) at Melbourne. High temperatures (above 15°C), however, delayed initiation, which resulted in flowering at a higher leaf number than when the same varieties were grown at low temperatures. In addition, the young reproductive shoot died after initiation in a combination of high temperature and a 14–12 hr photoperiod, as happens when such varieties are springsown in temperate latitudes. Such a response also prevents flowering in tropical environments, where high temperatures are combined with a moderate photoperiod all the year round.

Some characteristics of "Carnamah", a very early-flowering strain of Trifolium subterraneum L., when grown as single plants

1961 ◽  
Vol 12 (1) ◽  
pp. 27 ◽  
Author(s):  
RC Rossiter ◽  
AJ Millington
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Early Flowering ◽  
Winter Period ◽  
Flower Initiation ◽  
Total Production ◽  
Initiation Rate ◽  
The Difference ◽  
Early Flower ◽  
Early Strain

A very early-flowering strain of subterranean clover was discovered in 1957 at Carnamah, W.A. From extensive studies at several field centres, it was demonstrated that the new strain – now called Carnamah – commenced flowering from 30 to 10 days before Dwalganup (the standard commercial "early" strain) when sown in the autumn-early winter period. With very early planting – late March – the difference in flowering time was even greater (about 45–50 days). The very early-flowering nature of the Carnamah strain is associated with early flower initiation. Rate of flower development (from flower initiation to flower appearance) in relation to temperature was similar for Carnamah and Dwalganup. Under spaced-plant conditions the total production of Carnamah was much less than that of Dwalganup, a finding which conforms to the results of previous single-plant studies. The new strain was not readily distinguished from Dwalganup, but several minor differences in morphology are mentioned. The chromosome number was normal for the species (2n = 16). The relevance of these data to sward conditions is discussed briefly, and it is suggested that the Carnamah strain may be more effective than Dwalganup in extending the "clover belt" inland in southern Australia.

scholarly journals Development and Abortion of Flowers in Capsicum annuum Exposed to High Temperatures

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 476A-476
Author(s):  
Ami N. Erickson ◽  
Albert H. Markhart
Keyword(s):  
Growth Rate ◽  
High Temperature ◽  
Capsicum Annuum ◽  
High Temperatures ◽  
Floral Development ◽  
Leaf Growth ◽  
Flower Initiation ◽  
Treatment Rate ◽  
Flower Bud ◽  
Stage Of Development

Reduction of floral number in Capsicum annuum has been observed during growth at high temperature. To determine whether decreased flower production or increased flower abscission is a direct response to high temperatures or a response to water stress induced by high temperatures, we compared flowers and fruit produced and flowers aborted to leaf growth rate, osmotic potential, stomatal conductance, and chlorophyll fluorescence of two cultivars. To determine the stage(s) of floral development that are most sensitive to high temperatures, flower buds were wax-embedded and examined at each stage of development during heat treatment. Rate of floral development also was examined. At first visible floral bud initiation, plants were transferred to each of three controlled environment growth chambers with set temperatures and vapor pressure deficits (VPD) of 25°C, 1.1 kPa; 33°C, 1.1 kPa; and 33°C, 2.1 kPa. Flower bud production and leaf growth rate were not significantly affected by high temperatures. Pepper fruit set, however, was inhibited at 33°C at either VPD. Preliminary water relations data suggested that water potentials were more negative under high temperature conditions. Differences in leaf fluorescence were statistically significant for temperature treatments, but not for VPD. Temperature is the primary factor in the decrease of fruit production in pepper. Decreased production is due to flower abortion and not to decreased flower initiation or plant growth.

scholarly journals Response of Mycorrhizal ’Touriga Nacional‘ Variety Grapevines to High Temperatures Measured by Calorespirometry and Near-Infrared Spectroscopy

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1499
Author(s):  
Amaia Nogales ◽  
Hugo Ribeiro ◽  
Julio Nogales-Bueno ◽  
Lee D. Hansen ◽  
Elsa F. Gonçalves ◽  
...  
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Near Infrared ◽  
Nir Spectroscopy ◽  
Temperature Adaptation ◽  
Biochemical Processes ◽  
Before And After ◽  
Heat Shocks ◽  
Temperature Exposure ◽  
Sensitive Parameters

Heat stress negatively affects several physiological and biochemical processes in grapevine plants. In this work, two new methods, calorespirometry, which has been used to determine temperature adaptation in plants, and near-infrared (NIR) spectroscopy, which has been used to determine several grapevine-related traits and to discriminate among varieties, were tested to evaluate grapevine response to high temperatures. ‘Touriga Nacional’ variety grapevines, inoculated or not with Rhizoglomus irregulare or Funneliformis mosseae, were used in this study. Calorespirometric parameters and NIR spectra, as well as other parameters commonly used to assess heat injury in plants, were measured before and after high temperature exposure. Growth rate and substrate carbon conversion efficiency, calculated from calorespirometric measurements, and stomatal conductance, were the most sensitive parameters for discriminating among high temperature responses of control and inoculated grapevines. The results revealed that, although this vine variety can adapt its physiology to temperatures up to 40 °C, inoculation with R. irregulare could additionally help to sustain its growth, especially after heat shocks. Therefore, the combination of calorespirometry together with gas exchange measurements is a promising strategy for screening grapevine heat tolerance under controlled conditions and has high potential to be implemented in initial phases of plant breeding programs.

scholarly journals Lethal Effects of High Temperatures on Brown Marmorated Stink Bug Adults before and after Overwintering

Insects ◽  
2019 ◽  
Vol 10 (10) ◽  
pp. 355 ◽  
Author(s):  
Davide Scaccini ◽  
Carlo Duso ◽  
Alberto Pozzebon
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Cost Effective ◽  
Temperature Tolerance ◽  
Brown Marmorated Stink Bug ◽  
Stink Bug ◽  
Response Curves ◽  
High Temperature Tolerance ◽  
Before And After ◽  
Temperature Exposure

The invasive brown marmorated stink bug, Halyomorpha halys, is causing economic and ecological damage in invaded areas. Its overwintering behavior warrants mitigation practices in warehouses and shipping operations. The aim of this study was to characterize the mortality response curves of H. halys adults to short high-temperature exposure. Here we compared field-collected individuals entering (ENA) and exiting diapause (EXA). EXA adults displayed increased susceptibility to high temperatures compared to ENA individuals. Complete mortality of all tested individuals was obtained after 10 min exposure at 50.0 °C, and after 15 (EXA) or 20 min (ENA) at 47.5 °C. The nutritional status of these insects had no effect on high-temperature tolerance. The mortality curves obtained here may be used for the definition of cost-effective heat treatments aimed at the H. halys control.

Flower initiation in relation to maturity in crop plants. I. Flower initiation in relation to maturity in some Australian oats (Avena spp.)

1961 ◽  
Vol 12 (3) ◽  
pp. 371 ◽  
Author(s):  
Y Aitken
Keyword(s):  
High Temperatures ◽  
Low Temperatures ◽  
Subterranean Clover ◽  
Late Summer ◽  
Crop Plants ◽  
Leaf Number ◽  
Flower Initiation ◽  
Early Group ◽  
Wide Range ◽  
Cold Requirement

The description of oat varieties as early, mid, and late depends mainly on differences in their time of flower initiation. Flower initiation has been studied in varieties grown in southern Australia and ranging in maturity from first early to late. The time to flower initiation was found to depend greatly on the variety�s response to photoperiod and temperature. In all groups but the first early one, initiation was hastened by lengthening photoperiod and reducing temperature. The later the variety, the greater was the effect. Early varieties are those in which initiation occurs at a low leaf number over a wide range of photoperiods and temperatures. Late varieties result from initiation at a high leaf number, the delay compared with early varieties being due to sensitivity to high temperatures and to short photoperiods. These are the conditions prevailing after late summer and autumn sowings. Late varieties mature early in the field when grown either at low temperatures (below 50�F), or at slightly higher temperatures (below 60�F) and intermediate photoperiod. This is similar to the reaction of variety Clare in the second early group of' subterranean clover. Very late varieties of oats, similar to winter wheats which have a pronounced cold requirement for initiation, are not yet present in Australia.

Fracture and Viscoelastic Behavior of Some Polymers at High Temperatures

2005 ◽  
Vol 297-300 ◽  
pp. 384-389 ◽  
Author(s):  
Keisuke Ishikawa ◽  
Yasuhiro Takaku ◽  
Yasuo Kobayashi
Keyword(s):  
High Temperature ◽  
Applied Stress ◽  
High Temperatures ◽  
Viscoelastic Behavior ◽  
Molecular Structures ◽  
High Temperature Strength ◽  
Creep Life ◽  
Specific Strength ◽  
Mechanical Models ◽  
The Difference

Polymers are vital materials in better performance of specific strength. However their application can be restricted by the lower glass transition temperature, Tg. Some polymers have been developed as engineering plastics for the high temperature applications. We examined the high temperature strength of polymers at constant applied stress. The creep rupture and viscoelastic behavior were scrutinized for PC (polycarbonate) and PMMA (polymethyl methacrylate), which were quite different in the molecular structures. The former contains benzene rings and the latter is a single polymer. Tg is 423 K for PC and 378 K for PMMA. The large difference in the creep behavior was observed near Tg. The creep life strongly depends upon the applied stress just below Tg. The creep life is a function of the applied stress as follows. n life t − µ s . The stress exponent, n depends upon the temperature. Mechanical models were applied to evaluate the viscoelastic properties of the polymers at high temperatures. The viscosity rapidly decreased near Tg , regardless of the smaller decrease in the elastic constant. The results would be due to the difference in the molecular structures. The benzene ring could contribute to the higher resistance against the creep deformation through the higher viscosity.

Compression Studies on Particulate Composites of Ternary Al-Ti-Fe, and Quaternary Al-Ti-Fe-Nb and Al-Ti-Fe-Mn L12 Compounds

1990 ◽  
Vol 213 ◽  
Author(s):  
K.S. Kumar ◽  
M.S. Dipietro ◽  
J.D. Whittenberger
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
High Temperatures ◽  
Volume Fraction ◽  
Particulate Composites ◽  
Strain Rates ◽  
Warm Temperature ◽  
Monolithic Material ◽  
Alloying Additions ◽  
Before And After

ABSTRACTCompression studies were conducted on monolithic and TiB2 particulatereinforced composites of AI22 Fe3 Ti8, both with and without minor quaternary alloying additions (2 at.% Nb and 2 at.% Mn) as a function of temperature and as a function of strain rate at high temperature. The volume fraction of reinforcement was varied between 0 and 20 percent. The particulate reinforcements were found to be effective in increasing ambient- and warm-temperature strength; at high temperatures, the monolithic material is stronger than the composites, although the composites are superior at slow strain rates. The microstructures of the monolithic and composite specimens were examined before and after deformation to explain these observations.

scholarly journals Use of sodium chloride and zeolite during shipment of Ancistrus triradiatus under high temperature

2011 ◽  
Vol 9 (4) ◽  
pp. 909-914 ◽  
Author(s):  
Wilson F. Ramírez-Duarte ◽  
Carolina Pineda-Quiroga ◽  
Nhora Martínez ◽  
Pedro R. Eslava-Mocha
Keyword(s):  
Water Quality ◽  
High Temperature ◽  
Sodium Chloride ◽  
Dissolved Oxygen ◽  
High Temperatures ◽  
Quality Parameters ◽  
Water Quality Parameters ◽  
High Concentration ◽  
Before And After ◽  
Total Ammonia

The use of sodium chloride (0.5 g/L and 1 g/L) and zeolite (22.7 g/L) during shipment (48 h) of Ancistrus triradiatus at high temperatures (between 24.5 and 34ºC) were evaluated. Several water quality parameters (dissolved oxygen, pH, conductivity, and total ammonia) were measured before and after shipment. Glycemia was measured before shipment and at 24 and 48 h after shipment. After shipment, a resistance test was carried out in a high concentration of sodium chloride, and mortality was recorded after shipment, and 7 days post-shipment. While the two evaluated substances increased survival of A. triradiatus challenged by high temperatures during shipment, the best result was obtained with 1 g/L of sodium chloride.

scholarly journals Temperature and nitrogen nutrition in relation to flowering and fruiting in tomatoes.

1970 ◽  
Vol 18 (2) ◽  
pp. 111-115
Author(s):  
A.A. Abdalla ◽  
K. Verkerk
Keyword(s):  
High Temperature ◽  
High Temperatures ◽  
Nutrient Solution ◽  
Temperature Regime ◽  
Nitrogen Nutrition ◽  
High Temperature Regime ◽  
N Supply ◽  
The Difference

Plants at the high temperature regime (35 degrees -day, 25 degrees C-night) had higher N contents than plants at the normal temperature regime (22 degrees -day, 18 degrees C-night). The difference was greater when plants were supplied with N-containing nutrient solution than when supplied with N-deficient nutrient solution. It was concluded that, at high temperatures, high N supply was not detrimental and may be beneficial. (Abstract retrieved from CAB Abstracts by CABI’s permission)

scholarly journals Influence of thermal treatment on color change of beech wood with red heartwood

2016 ◽  
pp. 239-256
Author(s):  
Nebojsa Todorovic ◽  
Zdravko Popovic ◽  
Goran Milic ◽  
Ranko Popadic
Keyword(s):  
High Temperature ◽  
Thermal Treatment ◽  
Cross Section ◽  
Color Change ◽  
Beech Wood ◽  
Color Difference ◽  
Mean Values ◽  
Before And After ◽  
Section Surface ◽  
The Difference

The goal of this word was to examine the parameters of color of beech wood before and after thermal treatment, and to determine if there is a difference in color between sapwood and red heartwood before and after application of high temperature. Samples were treated at temperatures of 170?C, 190?C and 210?C, respectively, during 4 hours. Color coordinates (CIEL*a*b* system) were measured before and after treatment by using the following parameters: ?L, ?a, ?b and ?E - color change. Color was assessed at four spots on the radial and cross-section surfaces of wood and their mean values were taken for further calculations. Acquired results show that the applied heat treatment of sapwood did not significantly influence the change of color difference between cross-section and radial surfaces. The difference between cross-section and radial surfaces, in nontreated red heartwood was smaller than that measured in sapwood. The color difference of nontreated sapwood and red heartwood was more pronounced on the radial than on the cross-section surface. Application of high temperature caused a significant decrease of this difference. Temperature of 210?C caused the smallest color difference between these two parts of wood which was in this research determined on the radial surface. It was concluded that the applied thermal treatment almost equalized the colors of sapwood and red heartwood, especially on the radial surface, and from this aspect it can be concluded that these two parts of beech wood were completely equalized. It should also be noted that in the case of equalized properties, sapwood and red heartwood can be equally applied in a final product made of thermally treated beech wood.

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