THE EFFECT OF TEMPERATURE, MOISTURE AND NITROGEN ON THE RATE OF DEVELOPMENT OF SPRING WHEAT AS MEASURED BY DEGREE DAYS

1983 ◽  
Vol 63 (4) ◽  
pp. 833-846 ◽  
Author(s):  
H. R. DAVIDSON ◽  
C. A. CAMPBELL
Keyword(s):  
Spring Wheat ◽  
Standard Error ◽  
Time Scale ◽  
Field Experiments ◽  
Effect Of Temperature ◽  
Degree Days ◽  
Rate Of Development ◽  
Degree Day ◽  
Developmental Parameters ◽  
Growth Room

A phenological index based on meteorological parameters that accurately describes the development of wheat is urgently needed by agricultural researchers. In this study, a biometeorological time scale was proposed. It was developed from data obtained in a growth chamber study in which the effect of temperature, N fertility and soil moisture on spring wheat (Triticum aestivum L.) development were assessed. The model was then proofed using data from two field experiments. A normalized time scale was derived relating phenological development to percent SD, defined as ((number of days to a selected phenological stage)/(number of days to soft dough)) × 100. The degree day equation was modified to incorporate this time scale as:[Formula: see text]where K1 is a rate constant having units % SD∙°C−1∙day−1; bo is a base temperature below which no development occurs with units °C; and Tm is the mean daily temperature between growth stages S1 and S2. This equation was used to derive values for the developmental parameters. In the growth room K = 0.0875 (standard error 0.0045) and bo = 4.6 (standard error 0.99). Under fie d conditions K1 = 0.0935 (standard error 0.0123) and bo = 2.4 (standard error 2.213). The growth room and field parameters were not significantly different at the 5% probability level. Temperature was the only environmental parameter which influenced the rate of development under the conditions of this experiment. The number of days to the various developmental stages was inversely and linearly related to mean daily temperature over the 15–25 °C range. The degree day equation was shown to be a good index of development. Under fie d conditions the number of degree days to progress a crop to the flowering stage was 703 (standard error 9.4) and to the soft dough stage 1086 (standard error 15.4). The small variability in the values of the developmental parameters obtained in the growth room and field experiments were attributed to errors in the determination of phenological dates, and differences between temperature in the crop microclimate and measured temperatures from the standard meteorological site. A further modification to the degree day equation was postulated to account for the influence of daylength on wheat development.Key words: Temperature and development, moisture and development, degree days, development of wheat

scholarly journals Effect of Temperature on the Incubation Period and Leaf Colonization in Bacterial Blight of Anthurium

1999 ◽  
Vol 89 (11) ◽  
pp. 1007-1014 ◽  
Author(s):  
R. Fukui ◽  
H. Fukui ◽  
A. M. Alvarez
Keyword(s):  
Linear Relationship ◽  
Leaf Area ◽  
Incubation Period ◽  
Xanthomonas Campestris ◽  
Resistant Cultivar ◽  
Effect Of Temperature ◽  
Susceptible Cultivar ◽  
Degree Days ◽  
Degree Day ◽  
Leaf Tissues

Effect of temperature on leaf colonization in anthurium blight was studied using a bioluminescent strain of Xanthomonas campestris pv. dieffenbachiae. In a susceptible cultivar, colonization of leaf tissues (monitored by detection of bioluminescence) and symptom development (assessed visually) advanced rapidly at higher temperatures. For a susceptible cultivar, there was a linear relationship between degree-days and percent leaf area colonized by the pathogen, indicating that leaf colonization in a susceptible cultivar was a direct function of the cumulative effect of temperature. The degree-day intercept of the regression line represented the time from inoculation to detection of bioluminescence, and the slope indicated the increase of leaf colonization per degree-day. There also was a linear relationship between the logarithm of degree-days and the logarithm of percent leaf area showing visible symptoms in a susceptible cultivar. The degree-day intercept of this relationship represented the incubation period (about 500 degree-days). The degree-days required to detect bioluminescence was not considerably different between susceptible and resistant cultivars. However, the subsequent rates of leaf colonization were significantly lower for a resistant cultivar than for a susceptible cultivar in all temperature regimes. The results suggest that multiplication of the pathogen in the leaf tissues is optimized in the susceptible cultivar. In contrast, in the resistant cultivar, the defense mechanisms overshadow the temperature effect. The differential response to temperatures may be an additional indicator of cultivar susceptibility.

scholarly journals The effect of climatic factors on production of spring wheat quantity to quality ratio in southern Finland

1990 ◽  
Vol 62 (3) ◽  
pp. 227-236 ◽  
Author(s):  
Jari Peltonen ◽  
Tuomo Karvonen ◽  
Erkki Kivi
Keyword(s):  
Grain Yield ◽  
Spring Wheat ◽  
Field Experiments ◽  
Climatic Factors ◽  
Wheat Yield ◽  
Grain Filling ◽  
Effect Of Temperature ◽  
Total Precipitation ◽  
Factors Affecting ◽  
Dry Conditions

Interrelationships between climatic factors and spring wheat yield and quality were examined with 21 years field experiments. The formation of gluten was less at dry conditions (total precipitation under 50 mm) and total precipitation exceeded 130—140 mm. The optimum daily temperature for gluten production was some 15—17°C during grain filling. The gluten content decreased if daily minimum and maximum temperatures exceeded 11—12°C and 21—22°C, respectively. The effect of temperature and rainfall were not, however, significant in early maturing varieties. The climatic factors and grain yield did not correlate. Grain yield and protein yield had strong positive relationship, which was perhaps a consequence of supply and utilization of nitrogen. It is concluded that climatic factors affecting yield to quality ration in wheat may be excessive rains before heading and high temperature during grain filling. Interaction between weather and nitrogen are discussed to optimize correct timing of nitrogen fertilization for amount and quality of economic wheat yield.

DEVELOPMENT OF THE CARROT RUST FLY, PSILA ROSAE (DIPTERA: PSILIDAE), RELATIVE TO TEMPERATURE IN THE LABORATORY

1981 ◽  
Vol 113 (7) ◽  
pp. 569-574 ◽  
Author(s):  
A. B. Stevenson
Keyword(s):  
Effect Of Temperature ◽  
Thermal Constant ◽  
Degree Days ◽  
Psila Rosae ◽  
Egg Hatch ◽  
Rate Of Development ◽  
Threshold Temperatures ◽  
Thermal Constants ◽  
The Relationship

AbstractThe effect of temperature on development of the carrot rust fly, Psila rosae (F.), was determined at constant temperatures in the laboratory. The relationship between rate of development and temperature was essentially linear from 10° to 17.5°C but began to diverge from linearity between 17.5° and 20°C. Estimated threshold temperatures (t) and thermal constants (K) for development of overwintered pupae were 2.3°C and 319 degree-days (dd) for first emergence and 1.8°C and 368 dd for 50% emergence. For laboratory-reared stages, t and K values were 4.1°C and 102 dd for egg hatch, 2.0°C and 642 dd for development from egg to mature larvae, and 3.0°C and 107 dd for pupation. Development in the laboratory from egg (less than 24 h old) to adult was completed in 59, 70, and 81 days at 20°, 17.5°, and 15°C respectively; no threshold or thermal constant was estimated because few or no individuals completed development to adult at 12.5° or 10°C within expected times, presumably because diapause was induced at these temperatures.

Predicting Yellow Nutsedge (Cyperus esculentus) Emergence Using Degree-day Models

Weed Science ◽  
1996 ◽  
Vol 44 (4) ◽  
pp. 821-829 ◽  
Author(s):  
Cheryl A. Wilen ◽  
Jodie S. Holt ◽  
William B. McCloskey
Keyword(s):  
United States ◽  
Predictive Models ◽  
Field Experiments ◽  
Temperature Data ◽  
Cyperus Esculentus ◽  
Degree Days ◽  
Model Accuracy ◽  
Yellow Nutsedge ◽  
Degree Day ◽  
The Relationship

We examined the relationship between temperature and emergence of yellow nutsedge tubers to generate predictive models for the arid southwestern United States. Field experiments were conducted in California and Arizona to obtain phenological and temperature data needed to generate degree-day models. The effect of air temperature on emergence was tested with available programs using four methods to calculate degree-days (single sine, double sine, single triangle, and double triangle). Separate models were tested for each genotype examined (Arizona source and California source) as no one model was a good predictor of emergence when data were pooled. Results indicate that there is year to year variation in model accuracy but predictions of date of emergence can be made to within 2 d of actual emergence. This information can be used to schedule cultivations to reduce early yellow nutsedge competition in the field.

EFFECT OF TEMPERATURE ON THE LIFE-CYCLE OF ANAX JUNIUS (ODONATA: AESHNIDAE) IN CANADA

1971 ◽  
Vol 103 (12) ◽  
pp. 1671-1683 ◽  
Author(s):  
Robert Trottier
Keyword(s):  
Life Cycle ◽  
Laboratory Experiments ◽  
Field Studies ◽  
Migration Pattern ◽  
Effect Of Temperature ◽  
Threshold Temperature ◽  
Degree Days ◽  
Rate Of Development ◽  
Resident Population ◽  
Anax Junius

AbstractThe effect of temperature on the rate of development of Anax junius Drury was studied. Monthly larval samples were carried out for 2 years and laboratory experiments were conducted at constant temperatures. Field studies, at a eutrophic pond near Toronto, showed that in Canada populations of A. junius are not only maintained by migrants each year but also by residents. Two distinct populations were found, a summer (non-resident) population which developed from oviposition to emergence in approximately 3 months, from June to September, and an overwintering (resident) population which overwintered as half-grown larvae and developed in approximately 11 months from mid-July of one calendar year to the end of June of the next year. The former population was larger and comprised approximately 48% males and the latter was smaller and comprised approximately 41% males. A threshold temperature of development of 8.7° ± 0.1 °C was determined in the laboratory for the development of final-instar larvae of the summer population. The rate of development of final-instar larvae, reared at constant temperature, was similar to that of the entire summer aquatic stages which developed in fluctuating temperature. An average of 1332 degree-days ± 1% was required for development from the onset of oviposition to the onset of emergence of the summer population; whereas 20.5% more degree-days were required for the development of the overwintering population, employing the threshold temperature of 8.7 °C as determined for the summer population.It is recommended that correlation between degree-day totals and duration of larval development be used in further studies as a means for understanding the migration pattern and also the climatic limit of distribution for A. junius.

The effect of temperature on rates of development of larval Protostrongylus spp. (Nematoda: Metastrongyloidea) from bighorn sheep, Ovis canadensis canadensis, in the snail Vallonia pulchella

1985 ◽  
Vol 63 (6) ◽  
pp. 1445-1448 ◽  
Author(s):  
J. Samson ◽  
J. C. Holmes
Keyword(s):  
Bighorn Sheep ◽  
Ovis Canadensis ◽  
Effect Of Temperature ◽  
Thermal Constant ◽  
Temperature Threshold ◽  
Degree Days ◽  
Rate Of Development ◽  
Slow Development ◽  
Third Stage ◽  
Stage Development

The rate of development of Protostrongylus stilesi and (or) Protostrongylus rushi in the intermediate host Vallonia pulchella was related linearly to temperature between 10 and 30 °C. The temperature threshold was 8 °C and the thermal constant was 305 degree-days. Infected snails kept at 10 °C for several days and then transferred to 25 °C produced third-stage larvae faster than expected. Rates of development of Protostrongylus spp. applied to field conditions indicated that most of the first- to third-stage development occurs during the summer, very slow development takes place in the autumn or the spring, and none occurs over the winter. These data reinforce the hypothesis formulated by D. A. Boag and W. D. Wishart that snails on the bighorn sheep wintering grounds are responsible for transmission of the lungworms to sheep in autumn.

FACTORS AFFECTING ADULT EMERGENCE AND MATING BEHAVIOR OF THE EASTERN SPRUCE BUDWORM, CHORISTONEURA FUMIFERANA (LEPIDOPTERA: TORTRICIDAE)

1975 ◽  
Vol 107 (9) ◽  
pp. 967-977 ◽  
Author(s):  
C. J. Sanders
Keyword(s):  
Field Experiments ◽  
Choristoneura Fumiferana ◽  
Adult Emergence ◽  
Spruce Budworm ◽  
Field Conditions ◽  
Continuous Illumination ◽  
Degree Days ◽  
Factors Affecting ◽  
Eastern Spruce Budworm ◽  
Duration Of Copulation

AbstractLaboratory and field experiments indicate that the female spruce budworm (Choristoneura fumiferana (Clem.)) pupal stadium requires approximately 122C degree-days above a threshold of 7.2 °C (45°F), the male 124. Emergence time on any given day depends on temperature but is independent of photoperiod. Under field conditions male and female budworm mate only once per 24-h period. In the laboratory under continuous illumination females mate repeatedly and males readily mate a second time within a few hours, but the duration of the second copulation is abnormally long. The probability of multiple matings under field conditions is reduced by the restricted period of sexual activity coupled with the duration of copulation and the lower competitiveness of mated insects. Antennae are essential to the male for successful copulation.

scholarly journals Interactions Between Chill-Hours and Degree-Days Affect Carpogenic Germination in Monilinia vaccinii-corymbosi

2001 ◽  
Vol 91 (1) ◽  
pp. 77-83 ◽  
Author(s):  
H. Scherm ◽  
A. T. Savelle ◽  
P. L. Pusey
Keyword(s):  
Laboratory Experiments ◽  
Field Experiments ◽  
Degree Days ◽  
Carpogenic Germination ◽  
Conditioning Period ◽  
Low Degree ◽  
Heating Degree Days ◽  
Relationship Of ◽  
High Degree ◽  
The Relationship

The relationship of cumulative chill-hours (hours with a mean temperature <7.2°C) and heating degree-days (base 7.2°C) to carpogenic germination of pseudosclerotia of Monilinia vaccinii-corymbosi, which causes mummy berry disease of blueberry, was investigated. In two laboratory experiments, pseudosclerotia collected from rabbiteye blueberry in Georgia were conditioned at 5 to 6°C for 26 to 1,378 h prior to placement in conditions favorable for germination and apothecium development. The number of chill-hours accumulated during the conditioning period affected the subsequent proportion of pseudosclerotia that germinated and produced apothecia, with the greatest incidence of carpogenic germination occurring after intermediate levels of chilling (≈700 chill-hours). The minimum chilling requirement for germination and apothecium production was considerably lower than that reported previously for pseudo-sclerotia from highbush blueberry in northern production regions. The rate of carpogenic germination was strongly affected by interactions between the accumulation of chill-hours and degree-days during the conditioning and germination periods; pseudosclerotia exposed to prolonged chilling periods, once transferred to suitable conditions, germinated and produced apothecia more rapidly (after fewer degree-days had accumulated) than those exposed to shorter chilling periods. Thus, pseudosclerotia of M. vaccinii-corymbosi are adapted to germinate carpogenically following cold winters (high chill-hours, low degree-days) as well as warm winters (low chill-hours, high degree-days). Results were validated in a combined field-laboratory experiment in which pseudosclerotia that had received various levels of natural chilling were allowed to germinate in controlled conditions in the laboratory, and in two field experiments in which pseudosclerotia were exposed to natural chilling and germination conditions. A simple model describing the timing of apothecium emergence in relation to cumulative chill-hours and degree-days was developed based on the experiments. The model should be useful for better timing of field scouting programs for apothecia to aid in management of primary infection by M. vaccinii-corymbosi.

Factors influencing grain N concentration of hard red spring wheat in the semiarid prairie

1997 ◽  
Vol 77 (1) ◽  
pp. 53-62 ◽  
Author(s):  
C. A. Campbell ◽  
F. Selles ◽  
R. P. Zentner ◽  
B. G. McConkey ◽  
R. C. McKenzie ◽  
...  
Keyword(s):  
Water Use ◽  
Spring Wheat ◽  
Soil Test ◽  
Fertilizer N ◽  
Degree Days ◽  
Hard Red Spring Wheat ◽  
Brown Soil ◽  
Soil Zone ◽  
Factors Influencing ◽  
N Concentration

Prairie producers are now being rewarded with significant premiums for producing wheat (Triticum aestivum L.) of high protein concentration. We analyzed data from two 12-yr experiments conducted on a medium-textured Orthic Brown Chernozem at Swift Current, Saskatchewan, to determine and quantify factors influencing grain N concentration of hard red spring wheat grown on stubble land. Results of one of the 12-yr studies, a snow management × fertilizer N, zero-tillage experiment, showed that under hot, dry conditions, grain N concentration was very high and increased with moderate rates of fertilizer N (FN), then levelled off at higher rates of N. Under cool, wet conditions, grain N first decreased (due to N dilution by yield) then increased with further addition of FN. Under warm intermediate moisture conditions, grain N concentration increased at moderate rates in response to FN. Data for the two 12-yr experiments were pooled and multiple regression, with backward elimination, and stepwise selection used to develop the relationship:Grain N (g kg−1) = −7.63 + 0.05 WU − 0.000094 WU2 + 0.30 SN − 0.0022 SN2 − (0.0010 SN × WU) + (0.0017 FN × SN) + 0.0189 DD (R2 = 0.64, P = 0.001, n = 262)where WU = water use (mm), SN = soil test N (kg ha−1), FN = (kg ha−1), and DD = degree-days >5 °C (°C-days) from 1 May to 31 August. WU was available spring soil water in 0- to 1.2-m depth plus 1 May to 31 July precipitation, and SN was NO3-N in the 0- to 0.6-m depth, measured in the fall. We attempted to validate this model using data from a long-term crop rotation and a fertilizer trial experiment in the Brown soil zone, a tillage × rotation experiment in the Dark Brown soil zone in Saskatchewan, and an irrigation × N fertilizer experiment in the Brown soil zone of southern Alberta. Validation met with only modest success (R2 up to 0.70, P = 0.001). Generally, estimated grain N concentrations were lower than the measured values. Water use (negatively related) and temperature (DD) (positively related) were the most important factors influencing grain N, while FN and SN (positively related) were much less important. Because of the complexity of response in grain N to the aforementioned factors, and since farmers cannot predict weather conditions, fertilizer management to achieve high protein remains a challenge under dryland conditions. Key words: Soil test N, fertilizer N, available water, degree-days

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