Articoli di riviste: "Wheat Effect of temperature on"

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Marcela, Hlaváčová, Klem Karel, Smutná Pavlína, Škarpa Petr, Hlavinka Petr, Novotná Kateřina, Rapantová Barbora e Trnka Miroslav. "Effect of heat stress at anthesis on yield formation in winter wheat". Plant, Soil and Environment 63, No. 3 (4 aprile 2017): 139–44. http://dx.doi.org/10.17221/73/2017-pse.

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Heat stress around anthesis is considered to have an increasing impact on wheat yield under the ongoing climate change. However, the effect of high temperatures and their duration on formation of individual yield parameters is still little understood. Within this study, the effect of high temperatures applied during anthesis for 3 and 7 days on yield formation parameters was analysed. The study was conducted in growth chambers under four temperature regimes (daily temperature maxima 26, 32, 35 and 38°C). In the periods preceding and following heat stress regimes the plants were cultivated under ambient weather conditions. The number of grains per spike was reduced under temperatures ≥ 35°C in cv. Bohemia and ≥ 38°C in cv. Tobak. This resulted in a similar response of spike productivity. Thousand grain weight showed no response to temperature regime in cv. Tobak, whereas in cv. Bohemia, a peak response to temperature with maximum at 35°C was observed. The duration of heat stress had only little effect on most yield formation parameters.

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Wosula, E. N., S. Tatineni, S. N. Wegulo e G. L. Hein. "Effect of Temperature on Wheat Streak Mosaic Disease Development in Winter Wheat". Plant Disease 101, n. 2 (febbraio 2017): 324–30. http://dx.doi.org/10.1094/pdis-07-16-1053-re.

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Temperature is one of the key factors that influence viral disease development in plants. In this study, temperature effect on Wheat streak mosaic virus (WSMV) replication and in planta movement was determined using a green fluorescent protein (GFP)-tagged virus in two winter wheat cultivars. Virus-inoculated plants were first incubated at 10, 15, 20, and 25°C for 21 days, followed by 27°C for 14 days; and, in a second experiment, virus-inoculated plants were initially incubated at 27°C for 3 days, followed by 10, 15, 20, and 25°C for 21 days. In the first experiment, WSMV-GFP in susceptible ‘Tomahawk’ wheat at 10°C was restricted at the point of inoculation whereas, at 15°C, the virus moved systemically, accompanied with mild symptoms, and, at 20 and 25°C, WSMV elicited severe WSMV symptoms. In resistant ‘Mace’ wheat (PI 651043), WSMV-GFP was restricted at the point of inoculation at 10 and 15°C but, at 20 and 25°C, the virus infected systemically with no visual symptoms. Some plants that were not systemically infected at low temperatures expressed WSMV-GFP in regrowth shoots when later held at 27°C. In the second experiment, Tomahawk plants (100%) expressed systemic WSMV-GFP after 21 days at all four temperature levels; however, systemic WSMV expression in Mace was delayed at the lower temperatures. These results indicate that temperature played an important role in WSMV replication, movement, and symptom development in resistant and susceptible wheat cultivars. This study also demonstrates that suboptimal temperatures impair WSMV movement but the virus rapidly begins to replicate and spread in planta under optimal temperatures.

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Balla, K., e O. Veisz. "Temperature dependence of wheat development". Acta Agronomica Hungarica 56, n. 3 (1 settembre 2008): 313–20. http://dx.doi.org/10.1556/aagr.56.2008.3.7.

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Among the abiotic stress factors influencing the growth and productivity of wheat varieties, extremely high temperatures have the most limiting effect. In an experiment set up in the gradient chamber of the Martonvásár phytotron to test the effect of various temperatures on four winter wheat varieties and one variety of spelt, substantial differences were observed in the heat stress tolerance of the varieties. There was a considerable reduction in the number of shoots and spikes as the result of heat stress, leading to a drastic loss of grain yield. It was clear from changes in the biomass and in the grain:straw ratio that extremely high temperatures led to a substantial reduction in the ratio of grain to straw in the varieties tested. In response to high temperature the wheat plants turned yellow earlier due to the rapid decomposition of the chlorophyll content. This resulted in a considerable shortening of the vegetation period and early ripening. Reductions in the parameters tested were observed at different temperature levels for each variety, indicating considerable differences in the ability of the varieties to adapt to abiotic stress factors.

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Tack, Jesse, Andrew Barkley e Lawton Lanier Nalley. "Effect of warming temperatures on US wheat yields". Proceedings of the National Academy of Sciences 112, n. 22 (11 maggio 2015): 6931–36. http://dx.doi.org/10.1073/pnas.1415181112.

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Climate change is expected to increase future temperatures, potentially resulting in reduced crop production in many key production regions. Research quantifying the complex relationship between weather variables and wheat yields is rapidly growing, and recent advances have used a variety of model specifications that differ in how temperature data are included in the statistical yield equation. A unique data set that combines Kansas wheat variety field trial outcomes for 1985–2013 with location-specific weather data is used to analyze the effect of weather on wheat yield using regression analysis. Our results indicate that the effect of temperature exposure varies across the September−May growing season. The largest drivers of yield loss are freezing temperatures in the Fall and extreme heat events in the Spring. We also find that the overall effect of warming on yields is negative, even after accounting for the benefits of reduced exposure to freezing temperatures. Our analysis indicates that there exists a tradeoff between average (mean) yield and ability to resist extreme heat across varieties. More-recently released varieties are less able to resist heat than older lines. Our results also indicate that warming effects would be partially offset by increased rainfall in the Spring. Finally, we find that the method used to construct measures of temperature exposure matters for both the predictive performance of the regression model and the forecasted warming impacts on yields.

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Šeruga, B., S. Budžaki, Ž. Ugarčić-Hardi e M. Šeruga. "Effect of temperature and composition on thermal conductivity of “Mlinci” dough". Czech Journal of Food Sciences 23, No. 4 (15 novembre 2011): 152–58. http://dx.doi.org/10.17221/3385-cjfs.

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The objective of this study was to determine the thermal conductivity of “Mlinci” dough T-500 and “Mlinci” dough T-500 with the addition of eggs, wheat germs and wheat bran in the temperature range of 40°C to 70°C. Thermal conductivity was determined using modifications of guarded hot plate steady state method. For all types of dough, thermal conductivity first increased with temperature and then, after reaching maximum values, it decreased. The maximum values for “Mlinci” dough T-500 containing wheat germs and bran were 54°C, and for “Mlinci” dough T-500 with eggs were 58°C. The minimal value of 0.347 ± 0.020 W/mK was determined for “Mlinci” dough T-500 at 39.38°C. The maximum value 0.585 ± 0.023 W/mK was determined for “Mlinci” dough T-500 with wheat bran at 54.39°C. The thermal conductivity of “Mlinci” dough T-500 with the addition of wheat germs and wheat bran was higher in comparison with the basic composition due to the elevated amounts of ash, water, proteins, and porosity, as well as non-homogeneity. Based on the experimental thermal conductivity values of “Mlinci” dough T-500 samples at various temperatures, quadratic polynomial equations were developed. The research results could be used for the modelling of the heat transfer of “Mlinci” dough T-500 during processing.  

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Ahmad, Tobeh, e Jamaati e. Somarin Shahzad. "Low temperature stress effect on wheat cultivars germination". African Journal of Microbiology Research 6, n. 6 (16 febbraio 2012): 1265–69. http://dx.doi.org/10.5897/ajmr11.1498.

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Sultana, Shamima, Md Asaduzzamana e Hasan Muhammad Zubair. "Effect of Temperature on Wheat-Ryegrass Seedlings Interference". Universal Journal of Agricultural Research 1, n. 2 (agosto 2013): 38–40. http://dx.doi.org/10.13189/ujar.2013.010204.

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Gaudet, D. A., e T. H. H. Chen. "Effect of freezing resistance and low-temperature stress on development of cottony snow mold (Coprinus psychromorbidus) in winter wheat". Canadian Journal of Botany 66, n. 8 (1 agosto 1988): 1610–15. http://dx.doi.org/10.1139/b88-219.

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The relationship between snow mold resistance and freezing resistance was studied under controlled-environment conditions, using winter wheat (Triticum aestivum L. em. Thell) cultivars varying in freezing resistance and resistance to cottony snow mold (Coprinus psychromorbidus Redhead & Traquair). Cultivars varying in freezing resistance were equally susceptible to C. psychromorbidus. There existed a negative relationship between snow mold resistance and freezing resistance. Sublethal, subzero freezing temperatures between −3 and −12 °C predisposed the winter wheat cultivar 'Winalta' to increased damage by C. psychromorbidus. A synergistic effect resulting in increased mortality was observed when winter wheat plants received a combination of low-temperature stress and inoculation with C. psychromorbidus. In hardened winter wheat plants, sublethal levels of snow mold damage following 6 weeks incubation with C. psychromorbidus resulted in a reduction in freezing resistance or LT50 (50% killing temperature) of approximately 7 °C compared with the noninoculated controls. The possible role of low-temperature stress on the susceptibility of winter wheats to C. psychromorbidus and of snow mold infection on the retention of freezing resistance in winter wheats during winter in the central and northern Canadian prairies is discussed.

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Reddy, L. V., R. J. Metzger e T. M. Ching. "Effect of Temperature on Seed Dormancy of Wheat 1". Crop Science 25, n. 3 (maggio 1985): 455–58. http://dx.doi.org/10.2135/cropsci1985.0011183x002500030007x.

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Rosell, Cristina M., e Concha Collar. "Effect of temperature and consistency on wheat dough performance". International Journal of Food Science & Technology 44, n. 3 (marzo 2009): 493–502. http://dx.doi.org/10.1111/j.1365-2621.2008.01758.x.

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Lu, Caiyun, Chunjiang Zhao, Xiu Wang, Zhijun Meng, Jian Song, Milt McGiffen, Guangwei Wu, Weiqing Fu, Jianjun Dong e Jiayang Yu. "Effect of Postsowing Compaction on Cold and Frost Tolerance of North China Plain Winter Wheat". International Journal of Agronomy 2017 (2017): 1–9. http://dx.doi.org/10.1155/2017/1316808.

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Improper postsowing compaction negatively affects soil temperature and thereby cold and frost tolerance, particularly in extreme cold weather. In North China Plain, the temperature falls to 5 degrees below zero, even lower in winter, which is period for winter wheat growing. Thus improving temperature to promote wheat growth is important in this area. A field experiment from 2013 to 2016 was conducted to evaluate effects of postsowing compaction on soil temperature and plant population of wheat at different stages during wintering period. The effect of three postsowing compaction methods—(1) compacting wheel (CW), (2) crosskill roller (CR), and (3) V-shaped compacting roller after crosskill roller (VCRCR)—on winter soil temperatures and relation to wheat shoot growth parameters were measured. Results showed that the highest soil midwinter temperature was in the CW treatment. In the 20 cm and 40 cm soil layer, soil temperatures were ranked in the following order of CW > VCRCR > CR. Shoot numbers under CW, CR, and VCRCR treatments were statistically 12.40% and 8.18% higher under CW treatment compared to CR or VCRCR treatments at the end of wintering period. The higher soil temperature under CW treatment resulted in higher shoot number at the end of wintering period, apparently due to reduced shoot death by cold and frost damage.

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Darwent, A. L., L. P. Lefkovitch e P. F. Mills. "Effect of soil temperature, seeding depth and cultivar on wheat tolerance to simulated ethalfluralin carryover". Canadian Journal of Plant Science 77, n. 1 (1 gennaio 1997): 181–88. http://dx.doi.org/10.4141/p96-069.

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Field and controlled environment experiments were conducted at Beaverlodge, Alberta to determine the effect of soil temperature, seeding depth and cultivar on wheat (Triticum aestivum L.) tolerance to ethalfluralin. In one experiment, ethalfluralin was applied and incorporated, and wheat was seeded at several depths in late April/early May when soil temperatures were lowest or in late May when soil temperatures had increased. Mean 3-yr wheat yields decreased by 45% as the rate of ethalfluralin increased from 0 to 0.75 kg ha−1 and by 21% as the depth of seeding increased from 4 to 12.5 cm but the effect of ethalfluralin on yields was similar regardless of the soil temperature (time of seeding). Mean plant density decreased by 55% as the rate of ethalfluralin increased and by 25% as the depth of seeding increased. Reductions in mean plant density from ethalfluralin were slightly greater when seeded into the warmer soils. In another experiment, the effect of ethalfluralin on the yields of three wheat cultivars, Laura, Conway and Biggar was similar, i.e. the cultivar × rate of ethalfluralin interaction was not significant. However, the mean plant density of Biggar, averaged over rates of ethalfluralin, was less than that of the other cultivars in 1 of 2 yr. In a controlled environment experiment, the oven-dry weight and percent emergence of wheat shoots of the cultivars, Katepwa, Laura and Conway, seeded at 1.5 or 4 cm into soils containing ethalfluralin at concentrations of 0 to 4 ppm and maintained at temperatures of 4.5 or 15 °C, were reduced by decreases in temperature and increases in the rate of herbicide and depth of seeding. However, the interaction of soil temperature × rate of ethalfluralin was not significant for the oven-dry weight of the wheat shoots and the reduction in percent emergence of the wheat shoots as the rate of ethalfluralin increased was only slightly greater at 4.5 °C than at 15 °C. These results indicate that soil temperature and cultivar selection have a minor effect on wheat tolerance to ethalfluralin while herbicide concentration and depth of seeding have a major impact. Key words: Ethalfluralin, wheat, seeding depth, soil temperature, cultivar

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Radford, BJ. "Effect of constant and fluctuating temperature regimes and seed source on the coleoptile length of tall and semidwarf wheats". Australian Journal of Experimental Agriculture 27, n. 1 (1987): 113. http://dx.doi.org/10.1071/ea9870113.

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Laboratory experiments were carried out to determine the effects of constant and fluctuating temperature regimes on the final coleoptile length of 8 wheat cultivars (Banks, Cook, Gatcher, Hartog, Kite, Oxley, Shortim and Spica) and the effect of environmental conditions during seed maturation (seed source) on the coleoptile length of 5 cultivars (Banks, Bass, Cook, Kite and Oxley). Mean coleoptile length decreased from 10.8 cm at 15�C to only 3.1 cm at 35�C, a reduction within this temperature range of 1 cm for every 2.6�C rise in temperature. This indicates that, in warm soil, shallow sowing is necessary for satisfactory wheat establishment. Fluctuating temperatures (� 5�C about the mean) further reduced coleoptile length. The temperature x cultivar interaction was significant, differences among cultivars in coleoptile length occurring more at low than at high temperatures. The mean coleoptile lengths of the 8 cultivars varied from 8.7 to 14.5 cm at 15�C, but only from 2.7 to 3.6 cm at 35�C. Tall wheat cultivars (Gatcher and Spica) generally had longer coleoptiles than the 6 semidwarf cultivars. Tall wheats also had near-maximum coleoptile length at a wider range of temperatures than semidwarfs. Different environmental conditions during seed maturation (glasshouse v. field) changed the ranking of cultivars with respect to coleoptile length. The coleoptiles of Cook and Oxley were significantly longer when seed was field-ripened rather than glasshouse ripened, while those of Banks, Bass and Kite were similar in length under both ripening environments.

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Mikulíková, D. "The effect of friabilin on wheat grain hardness: a review". Czech Journal of Genetics and Plant Breeding 43, No. 2 (7 gennaio 2008): 35–43. http://dx.doi.org/10.17221/1911-cjgpb.

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A wheat marketing system established the primary classification of hexaploid wheat based on the endosperm texture, i.e. hardness or softness of the grain. Hardness affects a range of characters including the milling (tempering, milling yield, flour particle size, shape and density of flour particles), baking and end-use properties. Wheat grain hardness is largely controlled by genetic factors but it can also be affected by the environmental and other factors. The endosperm texture is primarily associated with the Hardness (Ha) locus on the short arm of chromosome 5D. It is regulated by friabilin. This 15 kDa starch surface protein complex is present in larger amounts in soft wheats compared to hard ones and consists of three major polypeptides: puroindoline a (Pina), puroindoline b (Pinb) and grain softness protein 1 (Gsp-1). The soft grain texture in wheat is a result of both puroindoline genes being in the wild type active form and bound to starch. When one of the puroindolines is either absent or altered by mutation, then the result is a hard texture. Gene sequence variation and mutation of both puroindoline genes account for the majority of variation in the wheat grain texture. The latter may serve as the potential for improvement of milling and baking wheat quality. However, many wheat varieties have the intermediately (mixed) hard endosperm and there is a wide variation between soft and hard grain texture. Grain hardness is affected by a number of factors beyond genetics including N management, tillage system, pest infestations, environment (location of growth, temperature and rainfall during the growing season) and their interactions, and factors such as moisture, gliadin composition, and content of lipids, starch and pentosans.

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Kaasová, J., B. Hubáčková, P. Kadlec, J. Příhoda e Z. Bubník. "Chemical and biochemical changes during microwave treatment of wheat". Czech Journal of Food Sciences 20, No. 2 (18 novembre 2011): 74–78. http://dx.doi.org/10.17221/3513-cjfs.

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The effect of microwave (MW) heating on the changes in wet gluten content, Gluten Index, Falling Number and amylographic characteristics was studied in sprouted wheat grain. Different moistures of wheat in two ranges of 10–11% and 15–17% and two end temperatures of MW heated samples (60 and 80°C) were applied to wheat samples. Falling Number and Gluten Index increased with increasing absorbed energy during MW heating, whereas gluten content decreased. Amylographic maximum increased due to a-amylase inactivation progressively with increasing absorbed energy as well. The greatest relative changes occurred when the end temperature of MW heated samples 80°C and moisture 15% were used. An improvement effect on the baking quality of sprouted wheat was found due to an increase in amylographic maximum with higher energy doses and higher end temperatures of MW heated samples. It was a consequence of Falling Number increase and Gluten Index increase with lower energy doses. The negative effect of higher energy doses was proved in a decrease in wet gluten content.  

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Stipešević, B., e E. J. Kladivko. "Effects of winter wheat cover crop desiccation times on soil moisture, temperature and early maize growth". Plant, Soil and Environment 51, No. 6 (19 novembre 2011): 255–61. http://dx.doi.org/10.17221/3583-pse.

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Two tillage systems for maize (Zea mays) after soybean (Glycine max), no-till (NT) and conventional till (CT), which consisted of double disking in the spring, were included in the experiment on two sites in Indiana, USA. Each tillage plot had three winter wheat (Triticum aestivum L.) cover crop levels: no cover crop (N), early desiccation (E), 3–4 weeks prior to planting the maize, and regular desiccation (R), within the maize planting week. Due to the mulching effect, both E and R for both tillage systems increased soil moisture, except in the case of spring drought, when E proved dominant. Soil temperature for both tillage systems showed N > E > R order. Young maize plants tended to grow taller and have greater shoot biomass in NT than in CT. Both E and R improved early maize growth. In the case of drought, the E proved significantly better for maize on both tillage treatments, due to the better soil water conservation, therefore the winter wheat cover crop should be desiccated early in given climate conditions.

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Borghi, B., M. Corbellini, M. Ciaffi, D. Lafiandra, Ede Stefanis, D. Sgrulletta, G. Boggini, Ndi Fonzo, Stefanis E. De e Fonzo N. Di. "Effect of heat shock during grain filling on grain quality of bread and durum wheats". Australian Journal of Agricultural Research 46, n. 7 (1995): 1365. http://dx.doi.org/10.1071/ar9951365.

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In southern Europe the Mediterranean climate is responsible for the remarkable variability in both yield and quality from year to year and also from location to location, but it offers also a unique opportunity for the production of high-quality wheats which are deficient in the European Economic Community. This study was conducted to determine the role of the fluctuation of temperatures during grain filling on the rheological properties of bread and durum wheats (Triticum aestivum and Triticum turgidum) as evaluated with a Chopin alveograph. During the 1991-92 season, four cultivars of bread and durum wheat were grown in several locations scattered along the Italian peninsula and the island of Sicily. In each location different temperature profiles were imposed during grain filling by anticipating or delaying sowing date or by covering the plots with plastic tunnels. Viscoelastic properties, evaluated by the variations in W, P and L alveograph parameters were significantly affected by the imposed treatments. In presence of a long period of temperature in the range of 30-35�C a dough 'strengthening' effect was observed, while frequent episodes of daily maximum temperatures above 35�C led to a dough 'weakening' effect. These results observed both in durum and bread wheat confirm those firstly detected on bread wheat in Australia in areas charcterized by a Mediterranean-like climate. The practical relevance of these effects differs in the two species: an increase of dough strength is considered detrimental in breadmaking quality, while it exerts a positive effect in pastamaking quality.

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Larney, F. J., T. Ren, S. M. McGinn, C. W. Lindwall e R. C. Izaurralde. "The influence of rotation, tillage and row spacing on near-surface soil temperature for winter wheat in southern Alberta". Canadian Journal of Soil Science 83, n. 1 (1 febbraio 2003): 89–98. http://dx.doi.org/10.4141/s01-076.

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Soil and crop management practices and their effects on surface residue levels can modify soil temperature. Our study investigated the effect of rotation, tillage and row spacing on near-surface (0.025 m) soil temperature under winter wheat (Triticum aestivum L.) in 1993-1994 and 1994-1995. The main treatment was winter wheat rotation: continuous winter wheat (WW); winter wheat-canola (Brassica campestris L.) (WC) or winter wheat-fallow (WF)] with tillage sub-treatments of conventional tillage (CT) vs. zero tillage (ZT) and row spacing treatments of uniform row (UR) vs. paired row (PR) spacing. From fall 1993 to spring 1994, ZT was cooler than CT by 1.2°C on the WC rotation, 1.1°C on WW and 0.4°C on the WF rotation. From fall 1994 to spring 1995, the magnitude of tillage differences was lower on all three rotations with ZT being cooler than CT by 0.1–0.9°C. The magnitude of the row spacing effect on soil temperature was less than that of the tillage effect. Extreme differences in soil temperature due to tillage were generally higher (1.0–4.9°C) on the WW and WC than the WF rotation (0.6–2.5°C) due to the presence of more crop residue. Results demonstrate that while ZT promotes overall cooler soils under winter wheat from fall to late spring, especially on continuously cropped (WW, WC) rotations, it also allows moderation of soil temperatures during extremely cold periods. Key words: Soil temperature, winter wheat, rotation, tillage, row spacing

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Robertson, Susan M., Scott R. Jeffrey, James R. Unterschultz e Peter C. Boxall. "Estimating yield response to temperature and identifying critical temperatures for annual crops in the Canadian prairie region". Canadian Journal of Plant Science 93, n. 6 (novembre 2013): 1237–47. http://dx.doi.org/10.4141/cjps2013-125.

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Robertson, S. M., Jeffrey, S. R., Unterschultz, J. R. and Boxall, P. C. 2013. Estimating yield response to temperature and identifying critical temperatures for annual crops in the Canadian Prairie region. Can. J. Plant Sci. 93: 1237–1247. Historical yield and temperature data, by municipal district for the three prairie provinces, are used to estimate the marginal effect of exposure to specific temperatures in defined ranges during the growing season. Incorporating these non-linear temperature effects into the model improves yield forecasting for Canadian prairie annual crops over models that use average temperatures or growing degree days. Critical maximum temperatures at which yields decline, calculated for winter wheat, spring wheat, durum wheat, barley, spring rye, fall rye, oats, canola and flax, range between 28 and 34°C, depending on the crop. Additional critical minimum and maximum temperatures are estimated using the marginal effect of exposure to specific temperatures in defined ranges. Estimates of critical maximum temperatures and their marginal impact on yields are important for research and policy analysis on various issues and problems, including climate change, risk management instruments such as crop insurance, and development of heat tolerant crop varieties.

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Grigor'eva, N. I., L. M. Chepel, S. P. Sirenko, T. M. Cheshko e V. I. Kiyko. "Effect of Electromagnetic Radiation and Temperature on Wheat Seed Viability". Telecommunications and Radio Engineering 57, n. 2-3 (2002): 7. http://dx.doi.org/10.1615/telecomradeng.v57.i2-3.170.

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AHMED, Mukhtar, e Fayyaz-ul HASSAN. "Cumulative Effect of Temperature and Solar Radiation on Wheat Yield". Notulae Botanicae Horti Agrobotanici Cluj-Napoca 39, n. 2 (21 novembre 2011): 146. http://dx.doi.org/10.15835/nbha3925406.

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The impact of temperature and solar radiations were studied as determinant factor for spring wheat grain yield. The data obtained at anthesis and maturity for grain number (GN), grain weight (GW) and grain yield (Y) were examined with mean temperature at anthesis (T1) and maturity (T2), solar radiation at anthesis (SR1) and maturity (SR2) and photothermal quotient (PTQ) at anthesis (PTQ1) and maturity (PTQ2). The data obtained was subjected to Statistica 8 software and scatter plot regression model was developed at 95% confidence interval with crop data and climate variables (T1, T2, SR1, SR2, PTQ1 and PTQ2). Results clearly indicated that yield remained directly proportional to solar radiation and temperature plus solar radiation (PTQ) while inversely to temperature under optimum other environmental resources. Direct relationship between PTQ and yield parameters confirmed that it determined crop yield and its management for variable environmental conditions need to be opted by adopting suitable sowing time as an adaptation strategy under changing climate.

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Çakmak, T., e Ö. Atıcı. "Effects of putrescine and low temperature on the apoplastic antioxidant enzymes in the leaves of two wheat cultivars". Plant, Soil and Environment 55, No. 8 (9 settembre 2009): 320–26. http://dx.doi.org/10.17221/1037-pse.

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The effects of putrescine (a polyamine), low temperature and their combinations on the activities of apoplastic antioxidant enzymes were studied in the leaves of two wheat cultivars, winter (Dogu-88) and spring (Gerek-79). Fifteen-day-old wheat seedlings were treated with putrescine solutions (0.1, 1 and 10mM) prior to cold treatment (5/3°C). The activities of apoplastic catalase, peroxidase and superoxide dismutase were determined in the leaves both under normal and cold conditions at 1, 3 and 5 days. The results indicate that cold treatment significantly increased the activities of apoplastic catalase, peroxidase and superoxide dismutase in winter wheat while not generally affecting spring wheat. Under control conditions, the putrescine treatments were more effective in increasing the enzyme activities in winter wheat than in spring wheat. However, under cold conditions, the putrescine treatments surprisingly induced enzyme activities in spring wheat while generally reducing those in winter wheat leaves. The results show that putrescine may act as an agent inducing primary changes in the apoplastic antioxidant system of wheat leaves during reactive oxygen species-mediated damage caused by low temperature stress.

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M.C., Narendra, Chandan Roy, Sudhir Kumar, Parminder Virk e Nitish De. "Effect of terminal heat stress on physiological traits, grain zinc and iron content in wheat (Triticum aestivum L.)". Czech Journal of Genetics and Plant Breeding 57, No. 2 (9 aprile 2021): 43–50. http://dx.doi.org/10.17221/63/2020-cjgpb.

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Heat stress is one of the major wheat (Triticum aestivum) production constraints in South Asia (SA), particularly in the Eastern Gangetic Plains (EGP) of India and Bangladesh. Malnutrition is also a severe problem among children and women in SA. Wheat varieties with high grain Zn/Fe are a sustainable, cost-effective solution in the fight against hidden hunger. Thirty wheat genotypes were characterised under the optimum temperature and heat stress conditions in 2016–2017 and 2017–2018 to study the response of the stress on the yield, physiological traits and grain Zn/Fe content. A significant genetic variation was observed for all the traits under the optimum temperature and stress conditions. The yield was reduced by an average of 59.5% under heat stress compared to that of the optimum temperature. A strong positive association of the canopy temperature depression (CTD) with the grain yield (GY) was observed under the heat stress. A negative correlation of the grain Zn/Fe with the yield was observed under the optimum temperature and heat stress conditions, while the association between the grain Zn and Fe was positive. The genotypes BRW 3723, BRW 3759, BRW 3797, BRW 160, HD 2967, HD 2640 were found to be heat-tolerant in both years. Among the tolerant genotypes, BRW 934, BRW 3807 and BRW 3804 showed a high zinc content and BRW 934, BRW 3797, BRW 3788 and BRW 3807 showed a high iron content, respectively. These genotypes can be explored in future breeding programmes to address the problem of nutritional deficiency.

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Mozafar, A., e J. J. Oertli. "Effect of temperature on ion efflux properties of leaf cell compartments in several chilling-sensitive and chilling-insensitive crop plants". Canadian Journal of Botany 65, n. 9 (1 settembre 1987): 1893–900. http://dx.doi.org/10.1139/b87-259.

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Abstract (sommario):

Ion efflux properties of leaf cell compartments were compared in several chilling-sensitive and chilling-insensitive plants : corn (Zea mays L. cv. Orla-312), cotton (Gossypium hirsutum L. cv. Stoneville-213), rice (Oryza sativa L. cv. M-9), spinach (Spinacia oleracea L. cv. Monnopa), and winter wheat (Triticum aestivum L. cv. Zenith). The effect of photoperiod and temperature (in spinach) and cold acclimation (in wheat) during growth on the subsequent response of cell compartments to temperature was also studied. Leaf strips loaded with Na+ (22Na) (all plants) and K+ (86Rb) (wheat only) were subjected to temperatures of 22, 15, 11, 7, and 3 °C to test efflux of tracers from various cellular compartments. When grown under identical conditions, compartmental absorption and efflux of tracers were different in corn, cotton, rice, spinach, and wheat. Changes in pretest growth conditions (in wheat and spinach) altered the uptake and efflux of tracers by leaf cells. The efflux data show that (i) the fast (free space?) compartment is temperature sensitive in several plants and (ii) not all compartments of every chilling-sensitive plant show increased leakiness at lower temperatures. Photoperiod (but not temperature) in spinach and cold acclimation in wheat were the factors that markedly altered efflux properties of cell compartments during growth. These observations are not fully consistent with models explaining chilling injury based on occurrence of cracks or pores in leaf cell membranes at lower temperatures. An alternative view based on built-in membrane channels is presented.

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25

Zhang, Su Feng, e Heng Yang. "Effect of Hot-Water Pre-Extraction on Alkaline Pulping Properties of Wheat Straw". Advanced Materials Research 236-238 (maggio 2011): 1174–77. http://dx.doi.org/10.4028/www.scientific.net/amr.236-238.1174.

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Abstract (sommario):

The alkaline pulping properties of wheat straw, which had been hemicelluloses pre-extracted with hot water, were studied. In this work, the process of hot-water extraction at various temperatures, reaction time and other conditions were investigated. The straws pre-extracted or not were made into pulp with NaOH-AQ at same conditions. Then the effects of pre-extraction on properties of straw pulp were studied. The results show that the yield, Kappa number and viscosity of the pulp are affected significantly by hemicelluloses pre-extraction process. The chemicals charge of the extracted straw in the pulping process is lower and shorter cooking time needed, the maximum pulping temperature reduced. These effects indicate that the action of hot-water pre-extraction before alkaline pulping is able to reduce effluent discharge and chemical demand to pulp, and it would be energy-saving. In this experiment, the optimum conditions of hot-water pre-extraction were: maximum temperature 140°C, heat-up time 30min, time at maximum temperature 60min and liquor ratio 1:10. The optimal pulping conditions were: alkali charge 12%, maximum temperature 155°C, heat-up time 90min, and holding time at maximum temperature 60min.

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26

Pokorný, J., A. Farouk Mansour, F. Pudil e V. Janda. "Effect of defatted soybean flour on the flavour of extruded mixtures with wheat flour". Czech Journal of Food Sciences 20, No. 6 (19 novembre 2011): 229–36. http://dx.doi.org/10.17221/3535-cjfs.

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Abstract (sommario):

Mixtures of wheat semolina, 5% glucose and 0–30% defatted soybean flour were used for the preparation of extruded samples using a pilot plant single screw extruder, maximum temperature being 140°C. The browning reactions were only moderate, the intensities of the trichromatic a* coordinate increased, and some changes were observed in chroma and the odour difference ΔE*. The sensory acceptability improved by increasing the content of soybean flour, the odour intensity increased, and some changes were observed in the sensory profile. Volatile substances were isolated using a SPME procedure, and the volatiles were separated using a Fisons GLC 8000 apparatus equipped with a mass spectrometer. Among the flavour active volatiles, pyrazines were the most prominent class of compounds, especially methyl and ethyl substituted derivatives. Pyrrole and furan substituted pyrazines were found only in small amounts because of the low extrusion temperature. Other furan and pyrrole derivatives had a lesser effect on flavour because of their relatively low amounts. Aldehydes, fatty acids, ketones, and other aliphatic derivatives contributed only a little to the resulting flavour. Compared to the mixtures of semolina and glucose only, the additions of defatted soybean flour moderately increased the number of substituted pyrazines detected in the extruded mixtures but increased substantially the pyrazine fraction in the total peak area. Among furan derivatives, 2-furancarboxaldehyde, 2-furanmethanol and 5-methyl-2-furyl alcohol belonged to the most prominent derivatives. Among other compounds, acetic acid, butyrolactone and maltol should be mentioned.  

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27

LIU, P., W. GUO, Z. JIANG, H. PU, C. FENG, X. ZHU, Y. PENG, A. KUANG e C. R. LITTLE. "Effects of high temperature after anthesis on starch granules in grains of wheat (Triticum aestivum L.)". Journal of Agricultural Science 149, n. 2 (8 dicembre 2010): 159–69. http://dx.doi.org/10.1017/s0021859610001024.

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Abstract (sommario):

SUMMARYThe effect of high temperatures (above 25°C) on starch concentration and the morphology of starch granules in the grains of wheat (Triticum aestivum L.) were studied. Wheat plants of cultivars Yangmai 9 (weak-gluten) and Yangmai 12 (medium-gluten) were treated with high temperatures for 3 days at different times after anthesis. The results showed that the starch concentration of grains given a heat-shock treatment above 30°C were lower than those developing at normal temperature in both cultivars. High temperature lowered starch concentration due to the decrease of amylopectin. Under the same temperature, the effect of heat shock from 6 to 8 days after anthesis (DAA) was the greatest, whereas from 36 to 38 DAA the effect was the least. The effects of high temperatures after anthesis on starch-pasting properties were similar to those on starch concentration, especially after 35–40°C treatments. The size, shape and structure of starch granules in wheat grains (determined by electron microscopy) after heat shock were visibly different from the control. When given heat shock during development, the starch granules in mature wheat grains were ellipsoid in shape and bound loosely with a protein sheath in Yangmai 9, while they were damaged and compressed with fissures in Yangmai 12, indicating the differences in resistance to high temperature between cultivars. Ratios of large (type-A) and small (type-B) starch granules significantly decreased under heat shock, which limited the potential sink size for dry matter deposition in the grain.

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28

KRISTENSEN, K., K. SCHELDE e J. E. OLESEN. "Winter wheat yield response to climate variability in Denmark". Journal of Agricultural Science 149, n. 1 (23 agosto 2010): 33–47. http://dx.doi.org/10.1017/s0021859610000675.

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Abstract (sommario):

SUMMARYData on grain yield from field trials on winter wheat under conventional farming, harvested between 1992 and 2008, were combined with daily weather data available for 44 grids covering Denmark. Nine agroclimatic indices were calculated and used for describing the relation between weather data and grain yield. These indices were calculated as average temperature, radiation and precipitation during winter (1 October–31 March), spring (1 April–15 June) and summer (16 June–31 July), and they were included as linear and quadratic covariates in a mixed regression model. The model also included an effect of year to describe the change in yield caused by unrecorded variables such as management changes. The final model included all effects that were significant for at least one of the two soil types (sandy and loamy soils). Seven of the nine agroclimatic indices were included in the final model that was used to predict the wheat grain yield under five climate scenarios (a baseline for 1985 and two climate change projections for 2020 and 2040) for two soil types and two locations in Denmark.The agroclimatic index for summer temperature showed the strongest effect causing lower yields with increasing temperature, whereas yield increased with increasing radiation during summer and spring. Winter precipitation and spring temperature did not affect grain yield significantly. Grain yield responded non-linearly to mean winter temperature with the highest yield at 4·4°C and lower yields both below and above this inflection point.The application of the model predicted that the average yield would decrease under projected climate change. The average decrease varied between 0·1 and 0·8 t/ha (comparable to a relative reduction of 1·6–12.3%) depending on the climate projection, location and soil type. On average, the grain yield decreased by about 0·25 t/ha (c. 3.6%) from 1985 to 2020 and by about 0·55 t/ha (c. 8·0%) from 1985 to 2040. The predicted yield decrease depended on climate projection and was larger for wheat grown in West Zealand than in Central Jutland and in most cases also larger for loamy soils than for sandy soils.The inter-annual variation in grain yield varied greatly between climate projections. The coefficient of variation (CV) varied between 0·16 and 0·46 and was smallest for wheat grown on loamy soils in Central Jutland in the baseline climate and largest for winter wheat grown under one of the 2040 climate projections. The increase in CV is not so much an effect of increased climatic variability under the climate change projections, but more an effect of increased winter temperature, where more extreme winter temperatures (lower or higher than the inflection point at 4·4°C) increased the effect of winter temperatures.

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29

Slafer, Gustavo A., e H. M. Rawson. "Phyllochron in Wheat as Affected by Photoperiod Under Two Temperature Regimes". Functional Plant Biology 24, n. 2 (1997): 151. http://dx.doi.org/10.1071/pp96021.

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Abstract (sommario):

In this paper we describe the effects of photoperiod (9, 12, 15, 17, 19 and 21 h) and temperature (21/17 and 16/12°C) on rate of leaf appearance and phyllochron in two spring wheats, a semi-winter wheat, and a winter wheat. Under long photoperiods only, all leaves on the main culm of a cultivar emerged at a common rate within a temperature regime, so it was acceptable to assign a specific phyllochron to leaves irrespective of their level of insertion. Increased temperature significantly decreased phyllochron, but the degree of this effect differed between cultivars. As photoperiod was shortened below the optimum, phyllochron lengthened marginally and similarly in all varieties (by approximately 0.1 days per hour change in photoperiod). For very short photoperiods this was true only for the first six leaves, whilst for leaves at higher insertions there was a major effect of reducing photoperiod on lengthening phyllochron. The actual daylength required for producing this major effect on phyllochron was cultivar-dependent. These results suggest that, when making predictions of heading date using phyllochron, it may not be acceptable to assume that leaf number and time are always linearly related at shorter photoperiods, particularly when considering leaves at higher insertions.

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30

Macdowall, F. D. H., e J. A. Lowdon. "Leaf carbon isotopic composition (δ13C) and cold hardiness of wheat in relation to growth temperature and moisture stress". Canadian Journal of Botany 67, n. 9 (1 settembre 1989): 2828–32. http://dx.doi.org/10.1139/b89-363.

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Abstract (sommario):

Several cultivars of spring and winter wheats were grown simultaneously several times in environmental control rooms at (i) 25:20 °C (16 h light: 8 h dark), or (ii) 4:2 °C with continuous watering, or (iii) 25:20 °C with nighttime watering and daytime wilting. The mature leaf blades of late vegetative plants were collected, and their carbon isotope ratios (13C:12C) were measured by mass spectrometry and expressed as δ13C, with an accuracy of 0.2‰, to determine if physiological effects of environmental factors other than atmospheric isotope composition could be responsible for previously observed annual cycles in plant δ13C. In (i) and (ii), the values of leaf δ13C (−31 ± 1‰) were in the low end of the C3 range, but winter wheats were about 1.2‰ less negative than spring wheat. The values obtained in (i) were 2‰ lower (more negative) than in (ii) for both wheat types. These results might be indicative of lower carboxylation resistance in winter wheat than in spring wheat and at lower temperature than at higher temperature. The effect in the growth room of temperature alone quantitatively duplicated the seasonal effect in the field. Leaf δ13C values of plants in (iii) were at or beyond the high end of the observed C3 range, presumably as a result of daytime gas exchange limitations imposed by stomatal diffusion resistance and the consequent importance of nighttime phosphoenolpyruvate carboxylase activity. This drought effect was particularly pronounced in winter wheat.

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31

Prieto, Paula, Helga Ochagavía, Simon Griffiths e Gustavo A. Slafer. "Earliness per se×temperature interaction: consequences on leaf, spikelet, and floret development in wheat". Journal of Experimental Botany 71, n. 6 (26 dicembre 2019): 1956–68. http://dx.doi.org/10.1093/jxb/erz568.

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Abstract Wheat adaptation can be fine-tuned by earliness per se (Eps) genes. Although the effects of Eps genes are often assumed to act independently of the environment, previous studies have shown that they exhibit temperature sensitivity. The number of leaves and phyllochron are considered determinants of flowering time and the numerical components of yield include spikelets per spike and fertile floret number within spikelets. We studied the dynamics of leaf, spikelet, and floret development in near isogenic lines with either late or early alleles of Eps-D1 under seven temperature regimes. Leaf appearance dynamics were modulated by temperature, and Eps alleles had a greater effect on the period from flag leaf to heading than phyllochron. In addition, the effects of the Eps alleles on spikelets per spike were minor, and more related to spikelet plastochron than the duration of the early reproductive phase. However, fertile floret number was affected by the interaction between Eps alleles and temperature. So, at 9 °C, Eps-early alleles had more fertile florets than Eps-late alleles, at intermediate temperatures there was no significant difference, and at 18 °C (the highest temperature) the effect was reversed, with lines carrying the late allele producing more fertile florets. These effects were mediated through changes in floret survival; there were no clear effects on the maximum number of floret primordia.

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32

Dias de Oliveira, Eduardo, Helen Bramley, Kadambot H. M. Siddique, Samuel Henty, Jens Berger e Jairo A. Palta. "Can elevated CO2 combined with high temperature ameliorate the effect of terminal drought in wheat?" Functional Plant Biology 40, n. 2 (2013): 160. http://dx.doi.org/10.1071/fp12206.

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Abstract (sommario):

Wheat (Triticum aestivum L.) production may be affected by the future climate, but the impact of the combined increases in atmospheric CO2 concentration, temperature and incidence of drought that are predicted has not been evaluated. The combined effect of elevated CO2, high temperature and terminal drought on biomass accumulation and grain yield was evaluated in vigorous (38–19) and nonvigorous (Janz) wheat genotypes grown under elevated CO2 (700 µL L–1) combined with temperatures 2°C, 4°C and 6°C above the current ambient temperature. Terminal drought was induced in all combinations at anthesis in a split-plot design to test whether the effect of elevated CO2 combined with high temperature ameliorates the negative effects of terminal drought on biomass accumulation and grain yield. Biomass and grain yield were enhanced under elevated CO2 with 2°C above the ambient temperature, regardless of the watering regimen. The combinations of elevated CO2 plus 4°C or 6°C above the ambient temperature did not enhance biomass and grain yield, but tended to decrease them. The reductions in biomass and grain yield (45–50%) caused by terminal drought were less severe (21–28%) under elevated CO2 with 2°C above the ambient temperature. The amelioration resulted from a 63% increase in the rate of leaf net photosynthesis in 38–19 and a 39% increase in tillering and leaf area in Janz. The contrasting responses and phenological development of these two genotypes to the combination of elevated CO2, temperature and terminal drought, and the possible influences on their source–sink relationships are discussed.

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33

CALDERINI, D. F., L. G. ABELEDO, R. SAVIN e G. A. SLAFER. "Effect of temperature and carpel size during pre-anthesis on potential grain weight in wheat". Journal of Agricultural Science 132, n. 4 (giugno 1999): 453–59. http://dx.doi.org/10.1017/s0021859699006504.

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Abstract (sommario):

The effect of environmental conditions immediately before anthesis on potential grain weight was investigated in wheat at the experimental field of the Faculty of Agronomy (University of Buenos Aires, Argentina) during 1995 and 1996. Plants of two cultivars of wheat were grown in two environments (two contrasting sowing dates) to provide different background temperature conditions. In these environments, transparent boxes were installed covering the spikes in order to increase spike temperature for a short period (c. 6 days) immediately before anthesis, i.e. between ear emergence and anthesis. In both environments, transparent boxes increased mean temperatures by at least 3·8 °C. These increases were almost entirely due to the changes in maximum temperatures because minimum temperatures were little affected. Final grain weight was significantly reduced by higher temperature during the ear emergence–anthesis period. It is possible that this reduction could be mediated by the effect of the heat treatment on carpel weight at anthesis because a curvilinear association between final grain weight and carpel weight at anthesis was found. This curvilinear association may also indicate a threshold carpel weight for maximizing grain weight.

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34

Karpicka-Ignatowska, Kamila, Alicja Laska, Brian G. Rector, Anna Skoracka e Lechosław Kuczyński. "Temperature-dependent development and survival of an invasive genotype of wheat curl mite, Aceria tosichella". Experimental and Applied Acarology 83, n. 4 (4 marzo 2021): 513–25. http://dx.doi.org/10.1007/s10493-021-00602-w.

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Abstract (sommario):

AbstractQuantifying basic biological data, such as the effects of variable temperatures on development and survival, is crucial to predicting and monitoring population growth rates of pest species, many of which are highly invasive. One of the most globally important pests of cereals is the eriophyoid wheat curl mite (WCM), Aceria tosichella, which is the primary vector of several plant viruses. The aim of this study was to evaluate temperature-dependent development and survival of WCM at a wide range of constant temperatures in the laboratory (17–33 °C). The development time of each stage depended significantly on temperature and it was negatively correlated with temperature increase. At high temperatures (27–33 °C), individuals had shorter developmental times, with the shortest (6 days) at 33 °C, whereas at the lowest tested temperatures (17–19 °C), developmental time was almost 3× longer. Moreover, temperature had a clear effect on survival: the higher the temperature, the lower the survival rate. These data provide information promoting more efficient and effective manipulation of WCM laboratory colonies, and further our understanding of the ramifications of temperature change on WCM physiology and implications for the growth and spread of this globally invasive pest.

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35

Haigh, Ian M., e Martin C. Hare. "The Effect of Freezing Temperatures onMicrodochium majusandM. nivaleSeedling Blight of Winter Wheat". International Journal of Agronomy 2012 (2012): 1–5. http://dx.doi.org/10.1155/2012/359017.

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Abstract (sommario):

Exposure to pre-emergent freezing temperatures significantly delayed the rate of seedling emergence (P<0.05) from an infected and a non-infected winter wheat cv. Equinox seed lot, but significant effects for timing of freezing and duration of freezing on final emergence were only seen for theMicrodochium-infested seed lot. Freezing temperatures of−5∘C at post-emergence caused most disease on emerged seedlings. Duration of freezing (12 hours or 24 hours) had little effect on disease index but exposure to pre-emergent freezing for 24 hours significantly delayed rate of seedling emergence and reduced final emergence from the infected seed lot. In plate experiments, the calculated base temperature for growth ofM. nivaleandM. majuswas−6.3∘C and−2.2∘C, respectively. These are the first set of experiments to demonstrate the effects of pre-emergent and post-emergent freezing on the severity ofMicrodochiumseedling blight.

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36

Gilbert, J., A. Tekauz e S. M. Woods. "Effect of Storage on Viability of Fusarium Head Blight-Affected Spring Wheat Seed". Plant Disease 81, n. 2 (febbraio 1997): 159–62. http://dx.doi.org/10.1094/pdis.1997.81.2.159.

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Abstract (sommario):

The effects of storage temperature and duration on germination, emergence, and vigor of Fusarium head blight-affected seed were studied in the spring wheat cvs. Glenlea and Roblin. Seed was stored at -10, 2.5, 10, or 20°C. Germination was assessed at cold (5°C) and moderate 20/15°C for 16/8 h daily) temperatures following 0, 8, 16, and 24 weeks of storage. Emergence from a soilless mix was counted 10 days after planting. Vigor was assessed following germination by measuring root and shoot lengths and in emerged plants by determining dry shoot weights. Germination after storage at the three colder temperatures decreased with length of storage, but storage at 20°C did not affect germination. Overall, germination of Fusarium-affected seed at moderate temperatures was significantly lower than for healthy seed. Germination of infected seed at 5°C was better than at moderate temperatures, probably due to lack of fungal activity at low temperatures. Seed treatment with Vitaflo 280 improved germination, but not emergence, of infected seed. However, roots from treated infected seed were shorter than from untreated seed. Emergence of infected seeds was better after storage at 10 and 20°C than at -10 and 2.5°C. Storage temperature did not significantly affect vigor. Dry shoot weight at 14 days was lower after storage at -10 than at 20°C.

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37

Jansens, Koen J. A., Bert Lagrain, Ine Rombouts, Kristof Brijs, Mario Smet e Jan A. Delcour. "Effect of temperature, time and wheat gluten moisture content on wheat gluten network formation during thermomolding". Journal of Cereal Science 54, n. 3 (novembre 2011): 434–41. http://dx.doi.org/10.1016/j.jcs.2011.08.008.

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38

Cao, Weixing, e Dale N. Moss. "Temperature Effect on Leaf Emergence and Phyllochron in Wheat and Barley". Crop Science 29, n. 4 (luglio 1989): 1018–21. http://dx.doi.org/10.2135/cropsci1989.0011183x002900040038x.

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39

Hosain, Mojaffor, Raihanul Haque, Md Nazrul Islam, Habiba Khatun e Md Shams-Ud-Din. "Effect of temperature and loading density on drying kinetics of wheat". Journal of Experimental Biology and Agricultural Sciences 4, n. 2 (25 aprile 2016): 210–17. http://dx.doi.org/10.18006/2016.4(2).210.217.

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40

Liu, Leilei, Jifeng Ma, Liying Tian, Shenghao Wang, Liang Tang, Weixing Cao e Yan Zhu. "Effect of Postanthesis High Temperature on Grain Quality Formation for Wheat". Agronomy Journal 109, n. 5 (settembre 2017): 1970–80. http://dx.doi.org/10.2134/agronj2016.07.0427.

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41

Pinedo, M. L., G. F. Hernandez, R. D. Conde e J. A. Tognetti. "Effect of Low Temperature on the Protein Metabolism of Wheat Leaves". Biologia plantarum 43, n. 3 (1 settembre 2000): 363–67. http://dx.doi.org/10.1023/a:1026765504374.

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42

Cheng, J.-J., H. Li, B. Ren, C.-J. Zhou, Z.-S. Kang e L.-L. Huang. "Effect of canopy temperature on the stripe rust resistance of wheat". New Zealand Journal of Crop and Horticultural Science 43, n. 4 (2 ottobre 2015): 306–15. http://dx.doi.org/10.1080/01140671.2015.1098708.

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43

FARAHNAKY, A., e S. E. HILL. "THE EFFECT OF SALT, WATER AND TEMPERATURE ON WHEAT DOUGH RHEOLOGY". Journal of Texture Studies 38, n. 4 (agosto 2007): 499–510. http://dx.doi.org/10.1111/j.1745-4603.2007.00107.x.

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44

van Herk, Willem G., e Robert S. Vernon. "Wireworm damage to wheat seedlings: effect of temperature and wireworm state". Journal of Pest Science 86, n. 1 (18 settembre 2012): 63–75. http://dx.doi.org/10.1007/s10340-012-0461-y.

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45

Moldestad, Anette, Ellen Mosleth Fergestad, Bernt Hoel, Arne Oddvar Skjelvåg e Anne Kjersti Uhlen. "Effect of temperature variation during grain filling on wheat gluten resistance". Journal of Cereal Science 53, n. 3 (maggio 2011): 347–54. http://dx.doi.org/10.1016/j.jcs.2011.02.005.

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46

Matić, Slavica, Maria Alexandra Cucu, Angelo Garibaldi e Maria Lodovica Gullino. "Combined Effect of CO2 and Temperature on Wheat Powdery Mildew Development". Plant Pathology Journal 34, n. 4 (1 agosto 2018): 316–26. http://dx.doi.org/10.5423/ppj.oa.11.2017.0226.

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47

Manoj-Kumar, A. Swarup, A. K. Patra, J. U. Chandrakala e K. M. Manjaiah. " Effect of elevated CO₂ and temperature on phosphorus efficiency of wheat grown in an Inceptisol of subtropical India". Plant, Soil and Environment 58, No. 5 (29 maggio 2012): 230–35. http://dx.doi.org/10.17221/749/2011-pse.

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Abstract (sommario):

In a phytotron experiment, wheat was grown under two levels of atmospheric CO2 [ambient (385 ppm) vs. elevated (650 ppm)], two levels of temperature (ambient vs. ambient +3°C) superimposed with three levels of phosphorus (P) fertilization: 0, 100, and 200% of recommended dose. Various measures of P acquisition and utilization efficiency were estimated at crop maturity. In general, dry matter yields of all plant parts increased under elevated CO2 (EC) and decreased under elevated temperature (ET); however, under concurrently elevated CO2 and temperature (ECT), root (+36%) and leaf (+14.7%) dry weight increased while stem (–12.3%) and grain yield (–17.3%) decreased, leading to a non-significant effect on total biomass yield. Similarly, total P uptake increased under EC and decreased under ET, with an overall increase of 17.4% under ECT, signifying higher P requirements by plants grown thereunder. Although recovery efficiency of applied P fertilizer increased by 27%, any possible benefit of this increase was negated by the reduced physiological P efficiency (PPE) and P utilization efficiency (PUtE) under ECT. Overall, there was ~17% decline in P use efficiency (PUE) (i.e. grain yield/applied P) of wheat under ECT.

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48

Sutka, J., e O. Veisz. "Reversal of dominance in a gene on chromosome 5A controlling frost resistance in wheat". Genome 30, n. 3 (1 giugno 1988): 313–17. http://dx.doi.org/10.1139/g88-055.

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Abstract (sommario):

The genetic effects on frost resistance, when chromosome 5A from wheat (Triticum aestivum L.) cultivars with varying degrees of frost resistance (Cheyenne, Hope) and T. spelta were substituted into an identical genetic background ('Chinese Spring') were analysed using the parents and the F1, F2, and BC progeny generations. In the crosses CS/Ch 5A × CS/Ts 5A and CS/Ch 5A × CS/H 5A, the parents differed from each other only with respect to chromosome 5A. In the first experiment, the F1 hybrids and the parents were frozen at temperatures of −10, −11, −12, −13, and −14 °C and in the second experiment at −10, −12, and −14 °C. Chromosome 5A of 'Cheyenne' was found to carry a gene controlling intense frost resistance and that of T. spelta and of 'Hope', a gene controlling weak frost resistance. For both pairs of parents and at all freezing temperatures the additive gene effect was greater than the dominant gene effect. The additive to dominant ratio changed from one freezing temperature to the other. At a high (−10 °C) freezing temperature frost resistance was dominant; as the temperature decreased, the direction of dominance was reversed and at the lowest (−14 °C) freezing temperature frost sensitivity became dominant.Key words: Triticum aestivum, wheat, chromosome substitution 5A, frost resistance, dominance.

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49

Ash, GJ, e RG Rees. "Effect of post-inoculation temperature and light intensity on expression of resistance to stripe rust in some Australian wheat cultivars". Australian Journal of Agricultural Research 45, n. 7 (1994): 1379. http://dx.doi.org/10.1071/ar9941379.

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Abstract (sommario):

Temperature sensitive resistance to stripe rust in selected Australian wheat cultivars was found to be most strongly expressed at a constant post-inoculation temperature of l9�C and at high light intensities. At 25�C the infection type on the susceptible host was reduced, indicating incompatability, while at the lower temperature of 13�C all cultivars were susceptible to the rust. At low light intensities there was a movement towards low infection types in cultivars possessing this resistance even at low temperatures. This made it essential to use high light intensities to differentiate this resistance to stripe rust. The host-pathogen interaction leading to the low infection types became irreversible after 6 to 7 days' exposure to the higher temperatures. As well as affecting disease progress towards the end of the growing season in the warmer areas of the wheat belt, this resistance could have a marked effect on the ability of Puccinia striiformis fsp. tritici to oversummer in the Australian wheat growing areas.

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50

LAURILA, H. "Simulation of spring wheat responses to elevated CO2 and temperature by using CERES-wheat crop model". Agricultural and Food Science 10, n. 3 (3 gennaio 2001): 175–96. http://dx.doi.org/10.23986/afsci.5692.

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Abstract (sommario):

The CERES-wheat crop simulation model was used to estimate the changes in phenological development and yield production of spring wheat (Triticum aestivum L., cv. Polkka) under different temperature and CO2 growing conditions. The effects of elevated temperature (3-4°C) and CO2 concentration (700 ppm) as expected for Finland in 2100 were simulated. The model was calibrated for long-day growing conditions in Finland. The CERES-wheat genetic coefficients for cv. Polkka were calibrated by using the MTT Agrifood Research Finland (MTT) official variety trial data (1985-1990). Crop phenological development and yield measurements from open-top chamber experiments with ambient and elevated temperature and CO2 treatments were used to validate the model. Simulated mean grain yield under ambient temperature and CO2 conditions was 6.16 t ha-1 for potential growth (4.49 t ha-1 non-potential) and 5.47 t ha-1 for the observed average yield (1992-1994) in ambient open-top chamber conditions. The simulated potential grain yield increased under elevated CO2 (700 ppm) to 142% (167% non-potential) from the simulated reference yield (100%, ambient temperature and CO2 350 ppm). Simulations for current sowing date and elevated temperature (3°C) indicate accelerated anthesis and full maturity. According to the model estimations, potential yield decreased on average to 80.4% (76.8% non-potential) due to temperature increase from the simulated reference. When modelling the concurrent elevated temperature and CO2 interaction, the increase in grain yield due to elevated CO2 was reduced by the elevated temperature. The combined CO2 and temperature effect increased the grain yield to 106% for potential growth (122% non-potential) compared to the reference. Simulating the effects of earlier sowing, the potential grain yield increased under elevated temperature and CO2 conditions to 178% (15 days earlier sowing from 15 May, 700 ppm CO2, 3°C) from the reference. Simulation results suggest that earlier sowing will substantially increase grain yields under elevated CO2 growing conditions with genotypes currently cultivated in Finland, and will mitigate the decrease due to elevated temperature. A longer growing period due to climate change will potentially enable cultivation of new cultivars adapted to a longer growing period. Finally, adaptation strategies for the crop production under elevated temperature and CO2 growing conditions are presented.;

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