Temperature Limits for the Brown Wheat Mite, in Colorado

2019 ◽  
Vol 112 (5) ◽  
pp. 2507-2511
Author(s):  
Rachael A Sitz ◽  
Erika S Peirce ◽  
Emily K Luna ◽  
Darren M Cockrell ◽  
Laura Newhard ◽  
...  
Keyword(s):  
Life History ◽  
Winter Wheat ◽  
Lethal Temperature ◽  
Supercooling Point ◽  
Cold Temperatures ◽  
Lethal Temperatures ◽  
Winter Cereals ◽  
Cold Tolerant ◽  
Heat Tolerant ◽  
Crop Planting

Abstract Brown wheat mites, Petrobia latens (Müller 1776, Acari: Tetranychidae), are sporadic yet economically damaging pests of winter cereals. In Colorado, their life history is closely tied to the development of winter wheat, where they are present in the field from crop planting in late September through harvest in early June. In order to withstand winter months, these mites are able to survive cold temperatures. However, the mechanisms of cold hardening and their temperature limits are unknown. This research documents the seasonal supercooling points of the brown wheat mite. Their seasonal average supercooling point stayed consistent throughout the year, never varying more than a degree from the overall average supercooling point of −17°C. The greatest variation in supercooling point was seen in the spring, during which supercooling point temperatures ranged from −9.2 to −25.5°C. We also documented the upper and lower lethal temperatures for the brown wheat mite. When comparing small nymphs to large nymph and adult stages, small nymphs were slightly more cold tolerant (lethal temperature estimates required to kill 99% of the population [LT99] were −30.8 and −30.6°C, respectively), but less heat tolerant (LT99 was 50 and 56°C, respectively).

Fructan in winter wheat, triticale, and fall rye cultivars of varying cold hardiness

1988 ◽  
Vol 66 (9) ◽  
pp. 1723-1728 ◽  
Author(s):  
Michio Suzuki ◽  
H. G. Nass
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Wheat Cultivar ◽  
Degree Of Polymerization ◽  
Lethal Temperature ◽  
Winter Wheat Cultivar ◽  
Freezing Resistance ◽  
Winter Cereals ◽  
Opposite Trend ◽  
High Concentrations

Eight winter wheat, one triticale, and three fall rye cultivars with mean lethal temperature (LT50) values from −5.5 to −20.0 °C were harvested in late November and analyzed for fructans. Fructose, sucrose, and oligofructans with a degree of polymerization (DP) of 6 or lower were found in all cultivars. The concentration of DP 4 fructan was higher than that of DP 5 in winter wheat and triticale, while the opposite trend was found in fall rye. Fructans with a DP of 7 or higher (high DP fructans) were found at high concentrations in hardy winter wheat and fall rye. The high DP fructan was very low or negligible in the least hardy winter wheat cultivar 'Super X'. Fructans in winter cereals consisted mainly of inulin type with a β-2-1 linkage. The activity of phlein sucrase, which catalyzes synthesis of phlein, was much lower in winter cereals compared with phlein-rich grasses. It was concluded that high DP fructans of inulin type in basal top tissues of winter cereals were more closely associated with freezing resistance than low DP fructans.

scholarly journals Growth and Phenology of Vulpia Myuros in Comparison with Apera Spica-Venti, Alopecurus Myosuroides and Lolium Multiflorum in Monoculture and in Winter Wheat

Plants ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1495
Author(s):  
Muhammad Javaid Akhter ◽  
Bo Melander ◽  
Solvejg Kopp Mathiassen ◽  
Rodrigo Labouriau ◽  
Svend Vendelbo Nielsen ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Weed Management ◽  
Lolium Multiflorum ◽  
Management Strategies ◽  
Integrated Weed Management ◽  
Growth Stages ◽  
Neighborhood Design ◽  
Alopecurus Myosuroides ◽  
Winter Cereals ◽  
Arable Weed

Vulpia myuros has become an increasing weed problem in winter cereals in Northern Europe. However, the information about V. myuros and its behavior as an arable weed is limited. Field and greenhouse experiments were conducted in 2017/18 and 2018/19, at the Department of Agroecology in Flakkebjerg, Denmark to investigate the emergence, phenological development and growth characteristics of V. myuros in monoculture and in mixture with winter wheat, in comparison to Apera spica-venti, Alopecurus myosuroides and Lolium multiflorum. V. myuros emerged earlier than A. myosuroides and A. spica-venti but later than L. multiflorum. Significant differences in phenological development were recorded among the species. Overall phenology of V. myuros was more similar to that of L. multiflorum than to A. myosuroides and A. spica-venti. V. myuros started seed shedding earlier than A. spica-venti and L. multiflorum but later than A. myosuroides. V. myuros was more sensitive to winter wheat competition in terms of biomass production and fecundity than the other species. Using a target-neighborhood design, responses of V. myuros and A. spica-venti to the increasing density of winter wheat were quantified. At early growth stages “BBCH 26–29”, V. myuros was suppressed less than A. spica-venti by winter wheat, while opposite responses were seen at later growth stages “BBCH 39–47” and “BBCH 81–90”. No significant differences in fecundity characteristics were observed between the two species in response to increasing winter wheat density. The information on the behavior of V. myuros gathered by the current study can support the development of effective integrated weed management strategies for V. myuros.

scholarly journals Aroma Profile, Microbial and Chemical Quality of Ensiled Green Forages Mixtures of Winter Cereals and Italian Ryegrass

Agriculture ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 512
Author(s):  
Alemayehu Worku ◽  
Tamás Tóth ◽  
Szilvia Orosz ◽  
Hedvig Fébel ◽  
László Kacsala ◽  
...  
Keyword(s):  
Winter Wheat ◽  
Winter Barley ◽  
Italian Ryegrass ◽  
Chemical Quality ◽  
Winter Cereal ◽  
Aroma Profile ◽  
Winter Triticale ◽  
Winter Cereals ◽  
Mold And Yeast

The objective of this study was to evaluate the aroma profile, microbial and chemical quality of winter cereals (triticale, oats, barley and wheat) and Italian ryegrass (Lolium multiflorum Lam., IRG) plus winter cereal mixture silages detected with an electronic nose. Four commercial mixtures (mixture A (40% of two cultivars of winter triticale + 30% of two cultivars of winter oats + 20% of winter barley + 10% of winter wheat), mixture B (50% of two cultivars of winter triticale + 40% of winter barley + 10% of winter wheat), mixture C (55% of three types of Italian ryegrass + 45% of two cultivars of winter oat), mixture D (40% of three types of Italian ryegrass + 30% of two cultivars of winter oat + 15% of two cultivars of winter triticale + 10% of winter barley + 5% of winter wheat)) were harvested, wilted and ensiled in laboratory-scale silos (n = 80) without additives. Both the principal component analysis (PCA) score plot for aroma profile and linear discriminant analysis (LDA) classification revealed that mixture D had different aroma profile than other mixture silages. The difference was caused by the presence of high ethanol and LA in mixture D. Ethyl esters such as ethyl 3-methyl pentanoate, 2-methylpropanal, ethyl acetate, isoamyl acetate and ethyl-3-methylthiopropanoate were found at different retention indices in mixture D silage. The low LA and higher mold and yeast count in mixture C silage caused off odour due to the presence of 3-methylbutanoic acid, a simple alcohol with unpleasant camphor-like odor. At the end of 90 days fermentation winter cereal mixture silages (mixture A and B) had similar aroma pattern, and mixture C was also similar to winter cereal silages. However, mixture D had different aromatic pattern than other ensiled mixtures. Mixture C had higher (p < 0.05) mold and yeast (Log10 CFU (colony forming unit)/g) counts compared to mixture B. Mixture B and C had higher acetic acid (AA) content than mixture A and D. The lactic acid (LA) content was higher for mixture B than mixture C. In general, the electronic nose (EN) results revealed that the Italian ryegrass and winter cereal mixtures (mixture D) had better aroma profile as compared to winter cereal mixtures (mixture A and B). However, the cereal mixtures (mixture A and B) had better aroma quality than mixture C silage. Otherwise, the EN technology is suitable in finding off odor compounds of ensiled forages.

Adaptation of winter cereal species to shade and competition in a winter/spring cereal forage mixture

1996 ◽  
Vol 76 (2) ◽  
pp. 251-257 ◽  
Author(s):  
V. S. Baron ◽  
E. A. de St Remy ◽  
D. F. Salmon ◽  
A. C. Dick
Keyword(s):  
Winter Wheat ◽  
Dark Respiration ◽  
Dominant Factor ◽  
Carbon Exchange ◽  
Area Index ◽  
Winter Cereal ◽  
Winter Triticale ◽  
Winter Cereals ◽  
Cereal Species ◽  
Shoot Weight

Spring planted mixtures of spring and winter cereals maximize dry matter yield and provide fall pasture by regrowth of the winter cereal. However, delay of initial harvest may reduce the winter cereal component and therefore subsequent regrowth yield. Research was conducted at Lacombe, Alberta to investigate the effect of time of initial cut (stage), winter cereal species (species) and cropping system (monocrop and mixture) on winter cereal shoot weight, leaf carbon exchange efficiency and shoot morphology. These parameters may be related to adaptation of winter cereals to growth and survival in the mixture. Winter cereal plants were grown in pails embedded in monocrop plots of fall rye (Secale cereale L.), winter triticale (X Triticosecale Wittmack) and winter wheat (Triticum aestivum L.) and in binary mixtures with Leduc barley (Hordeum vulgare L.). The plants were removed when the barley reached the boot (B), heads emerged (H), H + 2, H + 4 and H + 6 wk stages. Shoot weight was generally smaller in the mixture than in the monocrop and wheat was reduced more than fall rye and triticale in the mixture compared to the monocrop. Dark respiration rate (r = −0.54) and carbon exchange (r = 0.36) under low light intensity were correlated (P < 0.05) to shoot size in the mixture. Fall rye and winter triticale had lower dark respiration rates than winter wheat. Leaf area index (LAI) was closely correlated (r = 0.83 and 0.84) with shoot weight in both the mixture and monocrop. While species failed to exhibit clear cut differences for LAI, fall rye and winter triticale were reduced less than winter wheat in the mixture relative to the monocrop. Stage was the dominant factor affecting winter cereal growth in both cropping systems, but fall rye and triticale exhibited superior morphological features, and their carbon exchange responses to light were more efficient than wheat, which should allow them to be sustained longer under the shaded conditions of a mixture. Key words: Delayed harvest, shade, spring and winter cereal mixtures, adaptation, carbon exchange, respiration

SOME LETHAL TEMPERATURE RELATIONS OF TWO MINNOWS OF THE GENUS CHROSOMUS

1966 ◽  
Vol 44 (3) ◽  
pp. 349-364 ◽  
Author(s):  
Albert V. Tyler
Keyword(s):  
Thermal Shock ◽  
High Temperatures ◽  
The Other ◽  
Lethal Temperature ◽  
Lethal Temperatures ◽  
Equal Temperature

The resistance and tolerance of Chrosomus eos and Chrosomus neogaeus to high temperatures were examined. Tests were conducted with C. neogaeus in winter and with C. eos in winter and summer. For both species, death at high temperatures could be separated into three lethal patterns or "effects". The first effect seemed to be associated, at least in part, with thermal shock. Factors generating the other effects were not apparent.Both species showed about the same degree of tolerance and resistance to high temperatures when they were acclimated to 15 °C or higher. At 9 °C, C. eos was less tolerant to high lethal temperatures than was C. neogaeus.When equal temperature acclimations were compared, C. eos was more resistant to high lethal temperatures in summer than in winter.

COLD HARDENING AND DEHARDENING RESPONSES IN WINTER WHEAT AND WINTER BARLEY

1975 ◽  
Vol 55 (2) ◽  
pp. 529-535 ◽  
Author(s):  
M. K. POMEROY ◽  
C. J. ANDREWS ◽  
G. FEDAK
Keyword(s):  
Winter Wheat ◽  
Cold Hardiness ◽  
Maximum Level ◽  
Freezing Temperature ◽  
Triticum Aestivum L ◽  
Winter Barley ◽  
Lethal Temperature ◽  
Hordeum Vulgare L ◽  
Wheat Seedlings ◽  
Time Required

Increasing the duration of freezing of Kharkov winter wheat (Triticum aestivum L.) demonstrated that severe injury does not occur to plants at a freezing temperature (−6 C) well above the lethal temperature for at least 5 days, but progressively more damage occurs as the temperature approaches the killing point (−20 C). High levels of cold hardiness can be induced rapidly in Kharkov winter wheat if seedlings are grown for 4–6 days at 15 C day/10 C night, prior to being exposed to hardening conditions including diurnal freezing to −2 C. The cold hardiness of Kharkov and Rideau winter wheat seedlings grown from 1-yr-old seed was greater than that from 5-yr-old seed. Cold-acclimated Kharkov winter wheat and Dover winter barley (Hordeum vulgare L.) demonstrated the capacity to reharden after varying periods under dehardening conditions. The time required to reharden and the maximum level of hardiness attained by the plants was dependent on the amount of dehardening. Considerable rehardening was observed even when both dehardening and rehardening were carried out in the dark.

Relative contributions of light interception and radiation use efficiency to the reduction of maize productivity under cold temperatures

2008 ◽  
Vol 35 (10) ◽  
pp. 885 ◽  
Author(s):  
Gaëtan Louarn ◽  
Karine Chenu ◽  
Christian Fournier ◽  
Bruno Andrieu ◽  
Catherine Giauffret
Keyword(s):  
Field Experiments ◽  
Light Interception ◽  
Leaf Length ◽  
Radiation Use Efficiency ◽  
Model Assessment ◽  
Cold Temperatures ◽  
Maize Productivity ◽  
Cold Tolerant ◽  
Use Efficiency ◽  
Radiation Use

Maize (Zea mays L.) is a chill-susceptible crop cultivated in northern latitude environments. The detrimental effects of cold on growth and photosynthetic activity have long been established. However, a general overview of how important these processes are with respect to the reduction of productivity reported in the field is still lacking. In this study, a model-assisted approach was used to dissect variations in productivity under suboptimal temperatures and quantify the relative contributions of light interception (PARc) and radiation use efficiency (RUE) from emergence to flowering. A combination of architectural and light transfer models was used to calculate light interception in three field experiments with two cold-tolerant lines and at two sowing dates. Model assessment confirmed that the approach was suitable to infer light interception. Biomass production was strongly affected by early sowings. RUE was identified as the main cause of biomass reduction during cold events. Furthermore, PARc explained most of the variability observed at flowering, its relative contributions being more or less important according to the climate experienced. Cold temperatures resulted in lower PARc, mainly because final leaf length and width were significantly reduced for all leaves emerging after the first cold occurrence. These results confirm that virtual plants can be useful as fine phenotyping tools. A scheme of action of cold on leaf expansion, light interception and radiation use efficiency is discussed with a view towards helping breeders define relevant selection criteria.

FACTORS AFFECTING THE COLD SURVIVAL OF WINTER CEREALS

1977 ◽  
Vol 57 (1) ◽  
pp. 213-219 ◽  
Author(s):  
L. V. GUSTA ◽  
D. B. FOWLER
Keyword(s):  
Winter Wheat ◽  
Cold Tolerance ◽  
Winter Rye ◽  
Factors Affecting ◽  
Winter Cereals ◽  
Higher Temperature ◽  
Thawing And Freezing Cycles

Several parameters affecting cold tolerance of winter cereals in artificial freeze tests were examined. Supercooling followed by freezing resulted in death occurring at a higher temperature than when freezing was initiated just below 0 C. The cold tolerance of fully acclimated crowns of winter wheat and a winter rye were reduced an average of 5 C after two thawing and freezing cycles. The duration of freezing in artificial freeze tests has a significant effect on the LD50 of winter cereals. Rapid thawing (2–4 C/min) resulted in death occurring at a higher temperature than slow thawing (0.5–2 C/h).

scholarly journals Rice cold tolerance at the reproductive stage in a controlled environment

2006 ◽  
Vol 63 (3) ◽  
pp. 255-261 ◽  
Author(s):  
Renata Pereira da Cruz ◽  
Sandra Cristina Kothe Milach ◽  
Luiz Carlos Federizzi
Keyword(s):  
Cold Tolerance ◽  
Oryza Sativa L ◽  
Variable Temperature ◽  
Reproductive Stage ◽  
Spikelet Fertility ◽  
High Yield ◽  
Cold Temperatures ◽  
Cold Tolerant ◽  
Rice Genotypes ◽  
Highly Correlated

Cold tolerance of rice (Oryza sativa L.) during the reproductive stage is important to guarantee high yield under low temperature environments. Field selection, however, does not allow identification of adequate tolerance sources and limits selection of segregating lines due to variable temperature. The objective of this study was to devise methods for distinguishing rice genotypes as to their cold tolerance at the reproductive stage when evaluated under controlled temperature. The effect of cold temperatures was investigated in six rice genotypes at 17°C for varying length of time (three, five, seven and ten days) at two reproductive stages (microsporogenesis and anthesis). Cold tolerance was measured as the percentage of reduction in panicle exsertion and in spikelet fertility. Evaluating cold tolerance through the reduction in panicle exsertion did not allow for the distinction between cold tolerant from cold sensitive genotypes and, when the reduction in spikelet fertility was considered, a minimum of seven days was required to differentiate the genotypes for cold tolerance. Genotypes were more sensitive to cold at anthesis than at microsporogenesis and, as these stages were highly correlated, cold screening could be performed at anthesis only, since it is easier to determine. Rice cold tolerance at the reproductive stage may be characterized by the reduction in spikelet fertility due to cold temperature (17°C) applied for seven days at anthesis.

scholarly journals Impact of Constant Versus Fluctuating Temperatures on the Development and Life History Parameters of Aldrichina grahami (Diptera: Calliphoridae)

Insects ◽  
2019 ◽  
Vol 10 (7) ◽  
pp. 184 ◽  
Author(s):  
Wei Chen ◽  
Li Yang ◽  
Lipin Ren ◽  
Yanjie Shang ◽  
Shiwen Wang ◽  
...  
Keyword(s):  
Life History ◽  
Ambient Temperature ◽  
Developmental Rate ◽  
Threshold Temperature ◽  
Life History Parameters ◽  
Temperature Regimes ◽  
Cold Tolerant ◽  
Constant Versus ◽  
Forensic Tools ◽  
Fluctuating Temperatures

Necrophagous fly species are commonly used as forensic tools to estimate the minimum postmortem interval (PMImin). Many researchers raised necrophagous flies under constant temperature regimes to collect their developmental data. However, in most forensic cases, the ambient temperature fluctuates. In order to investigate a forensically important fly developmental mode (the Isomegalen diagram, Isomorphen diagram and Thermal summation models) and make comparisons of the developmental rate between constant temperatures and fluctuating temperatures, we used Aldrichina grahami (Diptera: Calliphoridae) to investigate the life history parameters at eight constant temperatures ranging from 8 to 36 °C. We also compared developmental rate of A. grahami in three groups of constant versus fluctuating temperatures: 8 °C vs. 6–12 °C, 12 °C vs. 10–16 °C, and 16 °C vs. 14–20 °C. Our data showed that A. grahami is cold tolerant with a mean (±SE) development threshold temperature (D0) of 3.41 ± 0.48 °C and a thermal summation constant (K) of 8125.2 ± 288.4-degree hours. The three groups subjected to fluctuating temperatures took longer to develop compared to those developing in constant temperatures when simulated in a model. These results not only provide detailed developmental data for the use of A. grahami in the estimation of the PMI, but also indicate that ambient temperature fluctuation must be taken into consideration for the use of all necrophagous fly species.

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