Evaluation of chitting to enhance earliness of potatoes grown in southern Ontario

1994 ◽  
Vol 74 (1) ◽  
pp. 159-165 ◽  
Author(s):  
Alan W. McKeown
Keyword(s):  
Cold Storage ◽  
Potato Cultivars ◽  
The Other ◽  
Physiological Age ◽  
Degree Days ◽  
Southern Ontario ◽  
Degree Day ◽  
Lower Base ◽  
Low Degree ◽  
Rapid Accumulation

Potato cultivars Atlantic, Conestoga, Jemseg, Superior and Yukon Gold, grown for early markets and mid-season use in Ontario were evaluated for response to chitting in 1987 to 1989. Seed tubers were chitted at 8 °C commencing in January, for an average of 408, 284 or 172 degree-days (base 4 °C). Controls were stored at 4 °C. Plants emerged quicker from chitted seed and produced higher early yields than the controls. Approximately 260 degree-days of chitting was optimal for early yield of Jemseg and Superior. For maximum emergence, 318 degree-days was required for Jemseg. Commencing chitting before March did not increase yields for the other cultivars. Low degree-day requirements are likely the result of cold storage of seed prior to chitting, resulting in more rapid accumulation of degree-days and/or lower base temperatures for growth. Key words:Solarium tuberosum, cultivars, emergence, yield, physiological age

Distribution and Potential Spread of Japanese Knotweed (Polygonum cuspidatum) in Canada Relative to Climatic Thresholds

2010 ◽  
Vol 3 (1) ◽  
pp. 32-39 ◽  
Author(s):  
Robert S. Bourchier ◽  
Brian H. Van Hezewijk
Keyword(s):  
British Columbia ◽  
Minimum Temperature ◽  
Annual Precipitation ◽  
Suitable Habitat ◽  
Base Temperature ◽  
Japanese Knotweed ◽  
Degree Days ◽  
Southern Ontario ◽  
Degree Day ◽  
Daily Weather Data

AbstractJapanese knotweed (JK) is one of the most aggressive invasive plants known in the U.K., where its biology has been well-studied. It was introduced into Canada around 1900, but only recently has it become a serious concern in the province of British Columbia (BC). Climatic conditions, including annual degree days and mean-annual minimum temperatures at knotweed sites in British Columbia were modeled in BioSIM, using weather normals and long-term daily weather data, and compared to published thresholds (degree day = 2,505 DD, minimum temperature = −30.2 C, base temperature 0 C). The degree-day threshold was more limiting to JK in British Columbia than mean-minimum temperature (12.3% of province habitat was suitable for JK based on degree days compared with 26% for mean-minimum temperature). A new annual-precipitation threshold of 735 mm/year based on 95% of known knotweed sites in BC was identified. The best-fit logistic regression model included degree days and annual precipitation and predicted knotweed presence/absence with over 97% efficiency. Existing knotweed sites occupy just over half of the suitable habitat in BC, indicating there are still significant areas to be invaded. The limiting threshold for knotweed was reversed in Southern Ontario with between 35 to 53% of the habitat suitable based on minimum temperatures, whereas degree-day accumulations and annual precipitation were not limiting. Warmer temperatures from 2000 to 2008 resulted in an increase to 53% of the habitat in Southern Ontario being suitable for knotweed, compared to 35% when 1971 to 2000 weather normals were used. Different climatic thresholds among provinces might result in selection for different invasive knotweed genotypes. This could influence the success of biological control agents because of differential host suitability of knotweed genotypes. Habitat suitability maps generated will enable better targeting of knotweed surveys based on the risk of knotweed establishment.

scholarly journals Vernalization and Growing Degree-day Requirements of Thalictrum delavayi `Hewitt's Double'

HortScience ◽  
1997 ◽  
Vol 32 (3) ◽  
pp. 501D-501
Author(s):  
Keith A. Funnell ◽  
Bruce R. MacKay ◽  
Ning Huang
Keyword(s):  
Cold Storage ◽  
Production Scheduling ◽  
Base Temperature ◽  
Cut Flower ◽  
Vernalization Response ◽  
Degree Days ◽  
Degree Day ◽  
Yield And Quality ◽  
Flower Yield ◽  
Natural Photoperiod

Vernalization and growing degree-day requirements of Thalictrum delavayi `Hewitt's Double' were determined to improve the production scheduling of this cut flower crop. Two-year-old crowns of T. delavayi `Hewitt's Double', lifted in the fall, were exposed to cold storage for 0, 3, 6, 9, 12, or 15 weeks at 8 ± 1°C. After storage, the containerized plants were grown at Massey Univ., Palmerston North (40°20.S) in a greenhouse heated at 15°C and vented at 20°C, under a natural photoperiod (11 h increasing to 13 h) plus a 4-h night interruption between 2200 and 0200 HR. As buds continued to develop during storage at 8°C, growing degree-days calculations were made over both storage and greenhouse forcing periods. All plants flowered, but T. delavayi `Hewitt's Double' nevertheless showed a quantitative vernalization requirement, being fully saturated after 6 weeks of cold storage at 8°C. With a base temperature of 0°C, time to flowering reduced from 3338 degree-days without vernalization to an average 2804 degree-days subsequent to the saturation of the vernalization response (6 to 15 weeks of vernalization). Flower yield averaged between three and five stems per plant, with stem lengths ranging between 140 and 200 cm. Differences in flower yield and quality among storage durations were minor and not commercially significant.

scholarly journals Growing Degree-day Requirements for Scheduling Flowering of Scadoxus multiflorus subsp. katharinae (Baker) Friis & Nordal

HortScience ◽  
2008 ◽  
Vol 43 (1) ◽  
pp. 166-169 ◽  
Author(s):  
Keith A. Funnell
Keyword(s):  
Cold Storage ◽  
Growing Degree Days ◽  
Base Temperature ◽  
Leaf Lamina ◽  
Degree Days ◽  
Vegetative Shoot ◽  
Degree Day

Containerized plants of Scadoxus multiflorus subsp. katharinae (Baker) Friis & Nordal were forced to anthesis under three environments of contrasting temperature. Flowering performance, growing degree-days (GDD) requirements for timing of anthesis, and the influence of cold storage (12 °C for 4 weeks) before forcing were evaluated. Total forcing time from the beginning of the experiment until anthesis decreased with warmer forcing environment, ranging between 129 and 86 days. Across all forcing environments, use of GDD was readily able to explain differences in time to anthesis resulting from both cold storage and forcing. Using a base temperature of 5 °C, GDD requirements between beginning of the experiment and anthesis was 1166 ± 124 GDD, emergence of the vegetative shoot and anthesis 1075 ± 118 GDD, and appearance of the tips of the leaf lamina and anthesis 883 ± 91 GDD. Using a base temperature of 11.5 °C, GDD requirements between appearance of tip of the involucre and anthesis was 180 ± 44 GDD, and the whole involucre being visible and anthesis 144 ± 42 GDD. In the next year, validation of the GDD requirements was achieved by subsequently forcing a second population of plants to anthesis for a specific date.

A unified degree day model describes survivorship of Copitarsia corruda Pogue & Simmons (Lepidoptera: Noctuidae) at different constant temperatures

2008 ◽  
Vol 99 (1) ◽  
pp. 65-72 ◽  
Author(s):  
N.N. Gómez ◽  
R.C. Venette ◽  
J.R. Gould ◽  
D.F. Winograd
Keyword(s):  
Survival Curve ◽  
The United States ◽  
Physiological Age ◽  
Alien Invasive Species ◽  
Temperature Threshold ◽  
Base Temperature ◽  
Survival Curves ◽  
Degree Day ◽  
Effects Of Temperature ◽  
Lepidoptera Noctuidae

AbstractPredictions of survivorship are critical to quantify the probability of establishment by an alien invasive species, but survival curves rarely distinguish between the effects of temperature on development versus senescence. We report chronological and physiological age-based survival curves for a potentially invasive noctuid, recently described as Copitarsia corruda Pogue & Simmons, collected from Peru and reared on asparagus at six constant temperatures between 9.7 and 34.5°C. Copitarsia spp. are not known to occur in the United States but are routinely intercepted at ports of entry. Chronological age survival curves differ significantly among temperatures. Survivorship at early age after hatch is greatest at lower temperatures and declines as temperature increases. Mean longevity was 220 (±13 SEM) days at 9.7°C. Physiological age survival curves constructed with developmental base temperature (7.2°C) did not correspond to those constructed with a senescence base temperature (5.9°C). A single degree day survival curve with an appropriate temperature threshold based on senescence adequately describes survivorship under non-stress temperature conditions (5.9–24.9°C).

scholarly journals On Professors and Poor People—A Jurisprudential Memoir

2007 ◽  
Vol 22 (2) ◽  
pp. 527-543
Author(s):  
Robert E. Rodes
Keyword(s):  
The Other ◽  
Poor People ◽  
Public Agency ◽  
The Public ◽  
The Poor ◽  
Low Degree ◽  
Preferential Option ◽  
The Subject ◽  
The Rich ◽  
Security Deposits

But let the brother of low degree glory in his high estate: and the rich, in that he is made low.—James 1:9-10I am starting this paper after looking at the latest of a series of e-mails regarding people who cannot scrape up the security deposits required by the local gas company to turn their heat back on. They keep shivering in the corners of their bedrooms or burning their houses down with defective space heaters. The public agency that is supposed to relieve the poor refuses to pay security deposits, and the private charities that pay deposits are out of money. A bill that might improve matters has passed one House of the Legislature, and is about to die in a committee of the other House. I have a card on my desk from a former student I ran into the other day. She works in the field of utility regulation, and has promised to send me more e-mails on the subject. I also have a pile of student papers on whether a lawyer can encourage a client illegally in the country to marry her boyfriend in order not to be deported.What I am trying to do with all this material is exercise a preferential option for the poor. I am working at it in a large, comfortable chair in a large, comfortable office filled with large, comfortable books, and a large—but not so comfortable—collection of loose papers. At the end of the day, I will take some of the papers home with me to my large, comfortable, and well heated house.

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.

scholarly journals Ethylene and Lipoxygenase In Relation to Afterripening of Dormant NC-13 Peanut Seeds1,2

1985 ◽  
Vol 12 (1) ◽  
pp. 45-49 ◽  
Author(s):  
D. L. Ketring ◽  
H. E. Pattee
Keyword(s):  
Heat Treatment ◽  
Cold Storage ◽  
Ethylene Production ◽  
Sharp Increase ◽  
Gradual Increase ◽  
The Other ◽  
Immature Seeds ◽  
Positive Correlations ◽  
Mature Seeds

Abstract Following harvest, peanuts are usually subjected to a period of storage. During storage biochemical changes are known to occur. The objectives of this study were to determine the changes and relationship in ethylene production, germination, and lipoxygenase (LG) activity during cold storage of dormant NC-13 peanut seeds. Two seed lots (SL) were used: one grown in Oklahoma (SL80) and the other grown in N. Carolina (SL81). SL80 and SL81 were stored at 2 to 5 C for 193 and 242 days, respectively. Samples were taken at about 28-day intervals for determination of germination, ethylene production, and LG activity. Seeds of two and three maturities were tested for SL80 and SL81, respectively. As afterripening of stored seeds proceeded, ethylene production gradually increased, with the maximum at 48 hours of germination. Germination showed a concomitant gradual increase. Lipoxygenase activity of both seedlots was less for mature than for immature seeds and showed a sharp increase during storage at 2 to 5 C, particularly for immature seeds. After heat-treatment to break dormancy of sublots from SL81, there was a progessive increase in ethylene production and germination, but most notably for mature seeds. In contrast to ethylene production and germination, after heat-treatment LG activity declined. Linear correlation coefficient (r) values between ethylene production and germination were highly significant for mature seeds from SL80 at 48 and 72 hours of germination, but only at 72 hours for immature seeds. For SL81 as for SL80, significant positive correlations were found between ethylene production and germination. However, correlations between LG activity and the other variables were not significant except for mature seeds from SL81. Significant positive correlations for both ethylene production and germination with LG activity also existed for these seeds. But after heat-treatment these correlations no longer occurred. The data indicate that the metabolic processes related to ethylene production and germination are occurring simultaneously with those of LG activity. The possibility that metabolites from LG activity serve as substrates for ethylene production can not be precluded.

scholarly journals Pengaruh Suhu terhadap Perkembangan Pradewasa Parasitoid Eriborus argenteopilosus Cameron (Hymenoptera: Ichneumonidae)

2012 ◽  
Vol 13 (3) ◽  
pp. 250
Author(s):  
Novri Nelly ◽  
Trimurti Habazar ◽  
Rahmat Syahni ◽  
Damayanti Buchori
Keyword(s):  
Survival Rate ◽  
Temperature Effect ◽  
Development Time ◽  
Degree Days ◽  
Degree Day ◽  
Adult Parasitoid ◽  
Different Temperatures ◽  
Lepidoptera Pyralidae

Temperature effect on development time of the preadult parasitoid Eriborus argenteopilosus Cameron(Hymenoptera: Ichneumonidae) were studied to know development time, degree days and survival rate.Crocidolomia pavonana (Fabricius)(Lepidoptera: Pyralidae) larvae was exposed to E. argenteopilosus female andreared at four different temperatures i.e 160C, 200C, 250C and 300C. Data were analyzed using anova and linearregression to calculate degree day. At 200C E. argenteopilosus showed the highest degree day and survival rate(18.67 %), while at 300C nothing adult parasitoid emergenced. Degree day to development time of parasitoid attemperature 200C i.e fase egg-adult: 300.05; egg-pupae 173.35; pupae-adult 171.

scholarly journals Analisis Hubungan Sikap dan Pengetahuan Keluarga dengan Penerapan Program Indonesia Sehat dengan Pendekatan Keluarga

2020 ◽  
Vol 5 (1) ◽  
pp. 13
Author(s):  
Ifon Driposwana Putra ◽  
Ulfa Hasana
Keyword(s):  
Public Health ◽  
The Other ◽  
Bivariate Analysis ◽  
P Value ◽  
Cross Sectional ◽  
Family Approach ◽  
Low Degree ◽  
The Government ◽  
The Relationship ◽  
Improve Health

<p><em>The government has proclaimed Healthy Indonesia Program with Family Approach (PIS-PK), aiming to improve health level of its people; howeverthe implementation is far from satisfying and not equally distributed so that there is still a low degree of public health. This study aims to analyze the relationship between attitudes and family knowledge with the adoption of the Healthy Indonesia Program with a family approach in Pekanbaru. The type of research is descriptive correlation with cross sectional approach. The sample in this study was 100 families. The result of bivariate analysis showed that there was a significant correlation between family’s attitudes toward PIS-PK, with p value of 0.018. On the other hand, it also showed that there was no significant correlation between family’s knowledge toward PIS-PK, with p value only 0.159. It is hoped that this study can be used as leaning materials, references for health officers, as well as suggestions regarding the implementation of PIS-PK</em></p><p><em><em>Pemerintah telah membuat Program Indonesia Sehat melalui penedekatan keluarga (PIS-PK) dengan tujuan agar meningkatnya derajat kesehatan masyarakat, namun dalam penerapannya masih belum maksimal dan merata sehingga masih terdapat derajat kesehatan masyarakat yang masih rendah. Penelitian ini bertujuan untuk menganalisis hubungan sikap dan pengetahuan keluarga dengan penerapan Program Indonesia Sehat dengan pendekatan keluarga di Pekanbaru. Jenis penelitian desktiptif korelasi dengan pendekatan cross sectional. Sampel dalam penelitian ini adalah 100 Keluarga. Hasil analisis bivariat didapatkan bahwa ada hubungan yang signifikan antara sikap keluarga dengan penerapan PIS-PKmdengan p value adalah 0,018. Didapatkan juga bahwa tidak ada hubungan yang signifikan antara pengetahuan keluarga dengan penerapan PIS-PK dengan nilai p value adalah 0,159. Hasil penelitian ini dapat dijadikan bahan ajar dan menjadi acuan oleh petugas kesehatan serta menjadi masukan untuk dalam penerapan PIS-PK</em></em></p>

scholarly journals Equation Based New Methods for Residential Load Forecasting

Energies ◽  
2020 ◽  
Vol 13 (23) ◽  
pp. 6378
Author(s):  
S. M. Mahfuz Alam ◽  
Mohd. Hasan Ali
Keyword(s):  
Root Mean Square ◽  
Load Forecasting ◽  
Residential Building ◽  
The Other ◽  
Support Vector ◽  
Linear Regression Method ◽  
Mean Square ◽  
Performance Indices ◽  
Degree Days ◽  
Average Percentage

This work proposes two non-linear and one linear equation-based system for residential load forecasting considering heating degree days, cooling degree days, occupancy, and day type, which are applicable to any residential building with small sets of smart meter data. The coefficients of the proposed nonlinear and linear equations are tuned by particle swarm optimization (PSO) and the multiple linear regression method, respectively. For the purpose of comparison, a subtractive clustering based adaptive neuro fuzzy inference system (ANFIS), random forests, gradient boosting trees, and long-term short memory neural network, conventional and modified support vector regression methods were considered. Simulations have been performed in MATLAB environment, and all the methods were tested with randomly chosen 30 days data of a residential building in Memphis City for energy consumption prediction. The absolute average error, root mean square error, and mean average percentage errors are tabulated and considered as performance indices. The efficacy of the proposed systems for residential load forecasting over the other systems have been validated by both simulation results and performance indices, which indicate that the proposed equation-based systems have the lowest absolute average errors, root mean square errors, and mean average percentage errors compared to the other methods. In addition, the proposed systems can be easily practically implemented.

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