EFFECTS OF TEMPERATURE ON YIELDS AND HYDROLYZABLE CARBOHYDRATE CONTENT OF ALFALFA AND TIMOTHY SEEDLINGS

1967 ◽  
Vol 47 (5) ◽  
pp. 523-531 ◽  
Author(s):  
P. Dermine ◽  
M. Hidiroglou ◽  
H. A. Hamilton
Keyword(s):  
Growth Rate ◽  
Low Temperature ◽  
Sugar Content ◽  
Strong Dependence ◽  
Growing Season ◽  
Cold Temperature ◽  
Cold Period ◽  
Warm Temperature ◽  
Northern Ontario ◽  
Effects Of Temperature

Alfalfa and timothy seedlings were exposed to four temperature treatments, simulating conditions in an average growing season in northern Ontario. Highest yields were recorded under continuous warm temperature (26.7 °C day, 15.6 °C night) and the lowest under continuous cold temperature (15.6 °C day, 4.4 °C night). Warm temperature conditions followed by a cold period decreased growth rate, the effect being more severe on alfalfa than on timothy. Growth was slower at first for timothy than for alfalfa, but timothy growth rate eventually exceeded that of alfalfa.Alfalfa root weights showed a strong dependence on temperature and were closely related to herbage yields. Timothy root weights demonstrated a smaller reaction to temperature and little relationship with herbage production. Shoot: root ratios were higher in timothy than in alfalfa but showed no consistent relationship with temperature.Timothy had a higher hydrolyzable-sugar content than alfalfa. Continuous low temperature resulted in the lowest sugar content in both species, but exposure to low temperature following a warm period gave the highest content.

High Quality Silicon Epitaxy In An Ultra High Vacuum Rapid Thermal Cvd Reactor: An Application to Single Wafer Processing

1993 ◽  
Vol 303 ◽  
Author(s):  
Mahesh K. Sanganeria ◽  
Katherine E. Violetite ◽  
Mehmet C. ÖztÜrk
Keyword(s):  
Growth Rate ◽  
Low Temperature ◽  
Epitaxial Growth ◽  
High Throughput ◽  
Strong Dependence ◽  
High Vacuum ◽  
Ultra High Vacuum ◽  
Main Process ◽  
Silicon Epitaxy ◽  
Wafer Processing

ABSTRACTIn this paper, we report epitaxial growth of silicon in an ultra high vacuum rapid thermal chemical vapor deposition (UHV/RTCVD) equipment. In this study, our objectives were low temperature/low thermal budget processing and a high throughput compatible with single wafer manufacturing. The reactor consists of a load lock, a main process chamber and an intermediate cryopumped vacuum buffer chamber between the two chambers. An ultra-clean process environment was achieved using oil free pumps and point of use gas purifiers. The wafer is heated by a Peak Systems LXU-35 arc lamp through a quartz window. In this system, we achieved good quality silicon epitaxy at low temperature (T≤800°C) in the very low, 100 mTorr, pressure regime with high throughput (Growth rate>0.25 μm/min.). High growth rate was achieved using Si2H6 as the reactant gas instead of SiH4 or SiH2C12 which are more commonly used gases for epitaxial growth. High temperature in-situ cleaning was completely eliminated by initiating film growth on a hydrogen passivated surface obtained via dilute HF etching. Generation lifetimes in the 200-400μs range were measured for deposition temperatures of 700°C, 750°C and 800°C with no strong dependence on the deposition temperature.

The effects of temperature and daylength on the reproductive physiology of the viviparous seaperch, Cymatogaster aggregata Gibbons

1968 ◽  
Vol 46 (6) ◽  
pp. 1207-1219 ◽  
Author(s):  
John P. Wiebe
Keyword(s):  
Late Summer ◽  
Late Pregnancy ◽  
Early Summer ◽  
Reproductive Physiology ◽  
Cold Temperature ◽  
Late Winter ◽  
Warm Temperature ◽  
Cold Temperatures ◽  
Effects Of Temperature ◽  
Long Photoperiod

The effects of temperature and photoperiod on the reproductive physiology of Cymatogaster aggregata are examined experimentally and related to the conditions in nature. In males an increasing or long photoperiod in late winter, spring, or early summer results in spermatogenesis, development of secondary sex structures, and reproductive behavior; warm temperatures markedly enhance these processes. The cold temperature and short photoperiod of the winter months promote testicular restitution and growth of spermatogonia.In females, oocyte formation is enhanced by the warm temperature (and perhaps decreasing photoperiod) of late summer and eariy autumn, while oocyte maturation is fostered by the cold temperatures of early winter. Early gestation requires a cold temperature but during late pregnancy a warm temperature will enhance growth of embryos.

ФОРМИРОВАНИЕ ПЕРЕХОДНОГО СЛОЯ ALN НА ТЕМПЛЕЙТАХ 3С-SIC/SI(111) МЕТОДОМ АММИАЧНОЙ МОЛЕКУЛЯРНО-ЛУЧЕВОЙ ЭПИТАКСИИ

2020 ◽  
Vol 96 (3s) ◽  
pp. 148-153
Author(s):  
С.Д. Федотов ◽  
А.В. Бабаев ◽  
В.Н. Стаценко ◽  
К.А. Царик ◽  
В.К. Неволин
Keyword(s):  
Crystal Structure ◽  
Growth Rate ◽  
Low Temperature ◽  
Surface Morphology ◽  
Single Crystal ◽  
Root Mean Square Roughness ◽  
Rate Variation ◽  
Mean Square ◽  
Nucleation Layer ◽  
Low Temperature Epitaxy

Представлены результаты изучения морфологии поверхности и структуры слоев AlN, сформированных аммиачной МЛЭ на темплейтах 3C-SiC/Si(111) on-axis- и 4° off-axis-разориентации. Опробован технологический режим низкотемпературной эпитаксии зародышевого слоя AlN на поверхности 3C-SiC(111). Среднеквадратичная шероховатость поверхности (5 х 5 мкм) слоев AlN толщиной 150 ± 50 нм составила 2,5-3,5 нм на темплейтах 3C-SiC/Si(111) on-axis и 3,3-3,5 нм на 4° off-axis. Показано уменьшение шероховатости смачивающего слоя AlN при изменении скорости роста. Получены монокристаллические слои AlN(0002) со значениями FWHM (ω-геометрия) 1,4-1,6°. The paper presents the surface morphology and crystal structure of AlN layers formed by ammonia MBE on 3C-SiC/Si(111) on-axis and 4° off-axis disorientation. It offers the technological approach of low-temperature epitaxy of the AlN nucleation layer on the 3C-SiC (111) surface. Root mean square roughness (5 х 5 |xm) of AlN layers with thickness of 150 ± 50 nm was 2,5-3,5 nm onto on-axis templates and 3.3-3.5 nm onto 4° off-axis. It appears that the RMS roughness of the AlN surface is changing with the growth rate variation. Single-crystal AlN(0002) layers with FWHM values (ω-geometry) of 1.4-1.6° have been obtained.

scholarly journals The Impact of Climate Change on the Sugar Content of Grapes and the Sustainability of their Production in the Czech Republic

2020 ◽  
Vol 13 (1) ◽  
pp. 222
Author(s):  
Miroslava Navrátilová ◽  
Markéta Beranová ◽  
Lucie Severová ◽  
Karel Šrédl ◽  
Roman Svoboda ◽  
...  
Keyword(s):  
Climate Change ◽  
Czech Republic ◽  
Sugar Content ◽  
Growing Season ◽  
Vegetation Period ◽  
The Czech Republic ◽  
Impact Of Climate Change ◽  
Secondary Sources ◽  
The Impact ◽  
Growing Region

The aim of the presented article is to evaluate the impact of climate change on the sugar content of grapes in the Czech Republic during the period 2000–2019 through selected indicators on the basis of available secondary sources. Attention is focused on the developments in both the main wine-growing regions of Moravia and Bohemia. In the field of viticulture and wine-growing, the sugar content of grapes, as a basic parameter for the classification of wines, plays an important role. In the Czech Republic, the average sugar content of grapes has had a constantly growing trend. This trend is evident both in the wine-growing region of Bohemia and in the wine-growing region of Moravia. The impact of climate change, especially the gradual increase of average temperatures in the growing season, cannot be overlooked. It greatly affects, among other things, the sugar content of grapes. Calculations according to the Huglin Index and the Winkler Index were used to determine the relationship between climate and sugar content. These indexes summarize the course of temperatures during the entire vegetation period into a single numerical value. The results show that both indexes describe the effect of air temperature on sugar content in both wine regions of the Czech Republic in a statistically significant way. The Huglin Index shows a higher correlation rate. The Winkler Index proved to be less suitable for both areas. Alternatively, the Winkler Index calculated for a shorter growing season was tested, which showed a higher degree of correlation with sugar content, approaching the significance of the Huglin Index.

scholarly journals Effects of floral thermogenesis on pollen function in Asian skunk cabbage Symplocarpus renifolius

2009 ◽  
Vol 5 (4) ◽  
pp. 568-570 ◽  
Author(s):  
Roger S. Seymour ◽  
Yuka Ito ◽  
Yoshihiko Onda ◽  
Kikukatsu Ito
Keyword(s):  
Growth Rate ◽  
Pollen Germination ◽  
Narrow Range ◽  
Temperature Tolerance ◽  
Early Spring ◽  
Long Period ◽  
Pollen Tube Growth Rate ◽  
Skunk Cabbage ◽  
Effects Of Temperature

The effects of temperature on pollen germination and pollen tube growth rate were measured in vitro in thermogenic skunk cabbage, Symplocarpus renifolius Schott ex Tzvelev, and related to floral temperatures in the field. This species has physiologically thermoregulatory spadices that maintain temperatures near 23°C, even in sub-freezing air. Tests at 8, 13, 18, 23, 28 and 33°C showed sharp optima at 23°C for both variables, and practically no development at 8°C. Thermogenesis is therefore a requirement for fertilization in early spring. The narrow temperature tolerance is probably related to a long period of evolution in flowers that thermoregulate within a narrow range.

EFFECTS OF TEMPERATURE ON RATE AND DURATION OF KERNEL DRY MATTER ACCUMULATION OF MAIZE

1988 ◽  
Vol 68 (4) ◽  
pp. 935-940 ◽  
Author(s):  
M. TOLLENAAR ◽  
T. W. BRUULSEMA
Keyword(s):  
Growth Rate ◽  
Zea Mays ◽  
Dry Matter ◽  
Zea Mays L ◽  
Dry Weight ◽  
Controlled Environment ◽  
Dry Matter Accumulation ◽  
Linear Kernel ◽  
Effects Of Temperature ◽  
Kernel Growth

The response of rate and duration of kernel dry matter accumulation to temperatures in the range 10–25 °C was studied for two maize (Zea mays L.) hybrids grown under controlled-environment conditions. Kernel growth rates during the period of linear kernel growth increased linearly with temperature (b = 0.3 mg kernel−1 d−1 °C−1). Kernel dry weight at physiological maturity varied little among temperature treatments because the increase in kernel growth rate with increase in temperature was associated with a decline in the duration of kernel growth proportional to the increase in kernel growth rate.Key words: Zea mays L, period of linear kernel dry matter accumulation, controlled-environment conditions, kernel growth rate

Reassessment of Maximum Growth Rates for C3 and C4 Crops

1978 ◽  
Vol 14 (1) ◽  
pp. 1-5 ◽  
Author(s):  
J. L. Monteith
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Growing Season ◽  
Maximum Growth ◽  
Maximum Growth Rate ◽  
Crop Growth ◽  
Close Inspection ◽  
Similar Difference ◽  
Photosynthetic Efficiencies

SUMMARYFigures for maximum crop growth rates, reviewed by Gifford (1974), suggest that the productivity of C3 and C4 species is almost indistinguishable. However, close inspection of these figures at source and correspondence with several authors revealed a number of errors. When all unreliable figures were discarded, the maximum growth rate for C3 stands fell in the range 34–39 g m−2 d−1 compared with 50–54 g m−2 d−1 for C4 stands. Maximum growth rates averaged over the whole growing season showed a similar difference: 13 g m−2 d−1 for C3 and 22 g m−2 d−1 for C4. These figures correspond to photosynthetic efficiencies of approximately 1·4 and 2·0%.

Walleye (Stizostedion vitreum vitreum) and Yellow Perch (Perca flavescens) Populations and Fisheries of the Red Lakes, Minnesota, 1930–75

1977 ◽  
Vol 34 (10) ◽  
pp. 1774-1783 ◽  
Author(s):  
Lloyd L. Smith Jr.
Keyword(s):  
Growth Rate ◽  
Yellow Perch ◽  
Climatic Factors ◽  
Perca Flavescens ◽  
Growing Season ◽  
Commercial Fishery ◽  
Class Strength ◽  
Parent Stock ◽  
Catch Statistics

In an investigation of the commercial fishery of Red Lakes, Minnesota, for the 46-yr period 1930–75, catch statistics were analyzed, and the dynamics of the perch and walleye populations were examined. Mean annual yields of walleye for two statistical periods, 1930–53 and 1954–75, were 309,900 and 245,100 kg, respectively for walleyes, and 96,400 and 109,500 kg for perch. Annual abundance (CPE based on average catches per day per 5-net units of gill nets) varied from 3.8 to 64.6 kg for walleye, and from 2.5 to 34.4 kg for perch. Causes of fluctuations in harvestable stock were directly related to strength of year-classes and to growth rate during the season of capture. Year-class strength was not related to the abundance of parent stock or of potential predators. The respective strengths of year-classes of perch and walleye in the same year were positively correlated (r = 0.859, P < 0.01), and are directly related to climatic factors. Growth rate of walleye in different calendar years varied from +30.7 to −42.2% of mean growth, and that of perch from +13.4 to −8.6% (1941–56). Growing season began in mid-June and was almost over by September 1. Walleye yield could be enhanced by starting harvest July 1 instead of early June. Perch yield could be improved by harvesting small perch. Key words: Percidae, Perca, population dynamics, Stizostedion, long-term yield

scholarly journals Seed mass effects on germination and growth of diverse European Scots pine populations

1994 ◽  
Vol 24 (2) ◽  
pp. 306-320 ◽  
Author(s):  
P.B. Reich ◽  
J. Oleksyn ◽  
M.G. Tjoelker
Keyword(s):  
Growth Rate ◽  
Relative Growth Rate ◽  
Scots Pine ◽  
Field Experiments ◽  
Seed Mass ◽  
Growing Season ◽  
Turkish Population ◽  
Dry Mass ◽  
Relative Growth ◽  
Mass Effects

Seedlings of 24 European Scots pine (Pinussylvestris L.) populations were grown in controlled environment chambers under simulated photoperiodic conditions of 50 and 60°N latitude to evaluate the effect of seed mass on germination and seedling growth characteristics. Seeds of each population were classified into 1-mg mass classes, and the four classes per population with the highest frequencies were used. Photoperiod had minimal influence on seed mass effects. Overall, seed mass was positively related to the number of cotyledons and hypocotyl height. Populations differed significantly in seed mass effect on biomass. In northern populations (55–61°N), dry mass at the end of the first growing season was little affected by seed mass. However, dry mass in 9 of 15 central populations (54–48°N) and all southern (<45°N) populations correlated positively with seed mass. Relative growth rate was not related to seed mass within or across populations, and thus early growth is largely determined by seed mass. Relative growth rate also did not differ among populations, except for a geographically isolated Turkish population with the highest seed mass and lowest relative growth rate. After one growing season, height was positively correlated (r2 > 0.6) with seed mass in 15 populations. To check the duration of seed mass effects, height growth of 1- to 7-year-old field experiments established with the same seed lots were compared. Seed mass effects on height were strongest for 1-year-old seedlings and declined or disappeared by the age of 5–7 years among central and southern populations, but remained stable over that time in northern populations.

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