Relationship between temperature and flowering in almond

1986 ◽  
Vol 26 (3) ◽  
pp. 399 ◽  
Author(s):  
K Rattigan ◽  
SJ Hill
Keyword(s):  
Continuous Function ◽  
Floral Development ◽  
Chilling Requirement ◽  
Flower Buds ◽  
Daily Minimum ◽  
Growing Degree Hours ◽  
Chill Unit ◽  
Temperature Records ◽  
Maximum Temperatures ◽  
Climate Station

Records of flowering in 12 almond cultivars over 7 years, together with temperature records from a standard climate station, were used to estimate the chilling requirement for dormancy break in flower buds and the heat sum requirements for floral development in each cultivar. Hourly temperatures were estimated from daily minimum and maximum temperatures. A continuous function relating hourly temperatures to rate of chilling was used to calculate daily chill unit accumulations. Requirements of 220-320 chill units were estimated and calculated heat sum requirements ranged from 5300 to 8900 growing-degree-hours above 4-5�C. These requirements were used to estimate the dates of 50% flowering for 1958-84.

Relationship between temperature and flowering in almond: effect of location

1987 ◽  
Vol 27 (6) ◽  
pp. 905 ◽  
Author(s):  
K Rattigan ◽  
SJ Hill
Keyword(s):  
Continuous Function ◽  
Threshold Temperature ◽  
Chilling Requirement ◽  
Flowering Date ◽  
Hourly Temperature ◽  
Single Location ◽  
Growing Degree Hours ◽  
Chill Unit ◽  
Maximum Temperatures ◽  
Different Climates

A model for the prediction of flowering date in almond requires estimates of the chilling and heat sum requirements. We estimated hourly temperatures from daily minimum and maximum temperatures. A continuous function relating hourly temperature to rate of chilling was used to calculate daily chill unit accumulations. Heat sums were measured as growing-degree-hours: the linear accumulation of hourly temperatures above a threshold temperature. Our model was tested with estimates derived from data obtained at 1 French and 2 Australian locations. The results indicate that estimates derived from data at a single location can be successfully used for other locations with different climates. The accuracy of flowering date prediction generally improves as the number of locations and years of data on which it is based increase. The predictions for the cultivars Mission and Nonpareil were within 5 days of the observed dates in 73 and 88% respectively of the locations-years examined. We concluded that the chilling requirement in almond is (mean � s.e.) 284 � 33 chill units and 3 groups of cultivars can be identified with respect to heat sum requirement in the ranges 5300-6300; 6800-7700 and 8200-8900 degree hours above 4.5�C.

scholarly journals VARIATIONS IN COLD HARDINESS CHARACTERISTICS AMONG PRUNUS SPECIES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1081c-1081
Author(s):  
S. Kadir ◽  
E. L. Proebsting
Keyword(s):  
Cold Hardiness ◽  
Xylem Vessel ◽  
Chilling Requirement ◽  
Prunus Species ◽  
Flower Buds ◽  
Flower Primordia ◽  
Vessel Elements ◽  
Chill Unit

Flower buds of 20 Prunus species representing 4 subgenera were collected during winter and spring of 1989-90. Buds were preconditioned at +3° or 7°C to test their minimum hardiness level (MHL) or the rate of hardiness increase. DTA revealed that most of the prunus species have flower primordia that supercool. The subgenus Padus have racemose inflorescences and do not deep supercool during dormancy. P. besseyi, P. nigra and P. americana had small exotherms between -22° and -27°C while P. davidiana and P. subhirtella had larger exotherms at higher temperatures. Exposure of flower buds to -7°C shifted LTES to lower temperatures and/or reduced the size of LTE, which became undetectable for many species including P. nigra and P. americana. P. davidiana and P. subhirtella increased hardiness by 6°/day at -7° while dormant. Deacclimation coincided with an increase in LTE50 and the development of xylem vessel elements in the bud axis, calyx and filaments as indicated by dye movenent. P. davidiana was the least hardy species and required only 700 chill units to satisfy the chilling requirement, while P. nigra and P. americana had LTE average of -26°C at MHL and required over 1000 chill unit accumulation.

scholarly journals Vegetative and Floral Chilling Requirements of Four New Kiwi Cultivars of Actinidia chinensis and A. deliciosa

HortScience ◽  
2008 ◽  
Vol 43 (3) ◽  
pp. 644-647 ◽  
Author(s):  
Clint Wall ◽  
William Dozier ◽  
Robert C. Ebel ◽  
Bryan Wilkins ◽  
Floyd Woods ◽  
...  
Keyword(s):  
Floral Development ◽  
High Heat ◽  
The Other ◽  
Chilling Requirement ◽  
Actinidia Chinensis ◽  
Risk Of Injury ◽  
Growing Degree Hours ◽  
Heat Requirement ◽  
Spring Frosts ◽  
Winter Chilling

Kiwifruit (Actinidia deliciosa A. Chev. and Actinidia chinensis Planch) require winter chilling to complete rest and growing degree hours to grow. This study was conducted to compare the chilling requirement and growing degree hours for budbreak and floral development of two female cultivars of A. chinensis, ‘Golden Sunshine’ and ‘Golden Dragon', two female cultivars of A. deliciosa, ‘AU Fitzgerald’ and ‘Hayward', and two male cultivars of A. deliciosa, ‘AU Authur’ and ‘Matua'. In 2005 and 2006, shoot cuttings were made from dormant 1-year canes at nodes 6 to 20, starting from the basal end of canes and held in cold storage at 4 °C. Cuttings were removed from storage and flowering was forced in a greenhouse maintained at 25 °C. Maximum budbreak was determined to be 700 h for ‘Golden Sunshine’, 800 h for ‘Golden Dragon’ and ‘AU Fitzgerald’, and 900 h for ‘Hayward’, ‘Matua’, and ‘AU Authur’. Growing degree hour to first budbreak were 9,500 h for ‘Golden Dragon’ and 15,000 h for ‘Golden Sunshine’, with the correlation of determination too low for the other cultivars. The high heat requirement for ‘Gold Sunshine’ would reduce the risk of injury by late spring frosts. Bloom period of both male cultivars overlapped with bloom periods for all cultivars except ‘Golden Dragon’ for fully mature vines in the field.

scholarly journals The genome of low-chill Chinese plum ‘Sanyueli’ (Prunus salicina Lindl.) provides insights into the regulation of the chilling requirement of flower buds

2020 ◽  
Author(s):  
Zhi-Zhen Fang ◽  
Kui Lin-Wang ◽  
He Dai ◽  
Dan-Rong Zhou ◽  
Cui-Cui Jiang ◽  
...  
Keyword(s):  
Genome Sequence ◽  
Molecular Mechanisms ◽  
Molecular Breeding ◽  
Agronomic Traits ◽  
Bud Break ◽  
Chilling Requirement ◽  
Flower Buds ◽  
Flower Bud ◽  
Protein Coding ◽  
Prunus Salicina

AbstractChinese plum (Prunus salicina Lindl.) is a stone fruit that belongs to the Prunus genus and plays an important role in the global production of plum. In this study, we report the genome sequence of the Chinese plum ‘Sanyueli’, which is known to have a low-chill requirement for flower bud break. The assembled genome size was 308.06 Mb, with a contig N50 of 815.7 kb. A total of 30,159 protein-coding genes were predicted from the genome and 56.4% (173.39 Mb) of the genome was annotated as repetitive sequence. Bud dormancy is influenced by chilling requirement in plum and partly controlled by DORMANCY ASSOCIATED MADS-box (DAM) genes. Six tandemly arrayed PsDAM genes were identified in the assembled genome. Sequence analysis of PsDAM6 in ‘Sanyueli’revealed the presence of large insertions in the intron and exon regions. Transcriptome analysis indicated that the expression of PsDAM6 in the dormant flower buds of ‘Sanyueli’ was significantly lower than that in the dormant flower buds of the high chill requiring ‘Furongli’ plum. In addition, the expression of PsDAM6 was repressed by chilling treatment. The genome sequence of ‘Sanyueli’ plum provides a valuable resource for elucidating the molecular mechanisms responsible for the regulation of chilling requirements, and is also useful for the identification of the genes involved in the control of other important agronomic traits and molecular breeding in plum.

scholarly journals Phenotypic Variation of Length of Bud Dormancy in Apple Cultivars and Related Malus Species

1991 ◽  
Vol 116 (1) ◽  
pp. 100-106 ◽  
Author(s):  
Roberto Hauagge ◽  
James N. Cummins
Keyword(s):  
Bud Dormancy ◽  
Leaf Fall ◽  
Winter Conditions ◽  
Cu Accumulation ◽  
Malus Species ◽  
Growing Degree Hours ◽  
Chill Unit ◽  
Apple Cultivars ◽  
The Mean ◽  
Subtropical Environment

The chilling requirements (CR) to break bud dormancy in a broad range of apple cultivars (Malus ×domestica Borkh.) and related Malus spp. were assessed by periodic sampling and forcing of field-grown shoots as a function of chill unit (CU) accumulation and/or by the total growing degree hours (GDH) accumulated from leaf fall until the time of budbreak under a simulated subtropical winter. The mean number of CU required to break dormancy of field overwintered shoots varied between 218 ± 113 for `Anna' and 1516 ± 113 for `Wright #1'. However, most genotypes had CR between 800 and 1200 CU. Much wider variation for the length of bud dormancy was observed in plants growing under simulated subtropic winter conditions. Genotypes that had shown the lowest CR values under Geneva, N.Y., winters generally had the highest year-to-year variation in CR estimates. Cultivar bud CR values obtained under cold winters are related to field-observed CR estimates in a subtropical environment, but absolute values may differ markedly. Furthermore, several genotypes that show reasonable adaptation to the subtropics have similar or higher CR than apple cultivars with standard CR under Geneva conditions. In addition, enough CU accumulated under the simulated subtropic winters to break dormancy of standard apple cultivars. However, complete dormancy removal was observed only in cultivars well-adapted to a subtropical environment. This result indicates that in addition to CU accumulation, there are important interactions among cultivars and environmental factors that are responsible for terminating bud dormancy. Several cultivars and wild species have shown resistance to delayed foliation. Among the species, M. brevipes, M. rockii, M. spectabilis, and M. turesii are more tolerant than M. baccata and its hybrids, which are recognized for their adaptation to the subtropic environment.

scholarly journals Changes in Polyamine Content during Dormancy in Flower Buds of `Anna' Apple

1994 ◽  
Vol 119 (1) ◽  
pp. 70-73 ◽  
Author(s):  
Shiow Y. Wang ◽  
Miklos Faust
Keyword(s):  
Bud Break ◽  
Chilling Requirement ◽  
Flower Buds ◽  
Bud Development ◽  
Polyamine Content ◽  
Bud Growth

Polyamine, putrescine, spermidine, and spermine contents were determined during endodormancy in the buds of low-chilling-requiring `Anna' apples (Malus domestics Borkh.). Putrescine, spermidine, and spermine contents increased greatly in buds when their chilling requirement was satisfied. Polyamine biosynthetic inhibitors α -difluoromethylarginine (DFMA) or α -difluoromethylornithine (DFMO) reduced bud break and bud growth in concert with decreased polyamine titers. DFMO or DFMA did not inhibit bud break when it was applied to buds after they received the full chilling requirement. DFMO was more inhibitory than DFMA. The polyamine requirement was much higher for bud growth and bud development than during differentiation and bud break.

scholarly journals Aircraft Takeoff Performance in a Changing Climate for Canadian Airports

Atmosphere ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 418
Author(s):  
Yijie Zhao ◽  
Laxmi Sushama
Keyword(s):  
Climate Change ◽  
Climate Model ◽  
Regional Climate ◽  
Daily Maximum ◽  
Daily Minimum ◽  
Weight Restriction ◽  
South Central ◽  
Aircraft Performance ◽  
Maximum Temperatures ◽  
Projected Changes

Temperature and wind are major meteorological factors that affect the takeoff and landing performance of aircraft. Warmer temperatures and the associated decrease in air density in future climate, and changes to crosswind and tailwind, can potentially impact aircraft performance. This study evaluates projected changes to aircraft takeoff performance, in terms of weight restriction days and strong tailwind and crosswind occurrences, for 13 major airports across Canada, for three categories of aircraft used for long-, medium- and short-haul flights. To this end, two five-member ensembles of transient climate change simulations performed with a regional climate model, for Representative Concentration Pathway (RCP) 4.5 and 8.5 scenarios, respectively, are analyzed. Results suggest that the projected increases in weight restriction days associated with the increases in daily maximum temperatures vary with aircraft category and airfield location, with larger increases noted for airfields in the south central regions of Canada. Although avoiding takeoff during the warmest period of the day could be a potential solution, analysis focused on the warmest and coolest periods of the day suggests more weight restriction hours even during the coolest period of the day, for these airfields. Though RCP8.5 in general suggests larger changes to weight restriction hours compared to RCP4.5, the differences between the two scenarios are more prominent for the coolest part of the day, as projected changes to daily minimum temperatures occur at a much faster rate for RCP8.5 compared to RCP4.5, and also due to the higher increases in daily minimum temperatures compared to maximum temperatures. Both increases and decreases to crosswind and tailwind are projected, which suggest the need for detailed case studies, especially for those airfields that suggest increases. This study provides useful preliminary insights related to aircraft performance in a warmer climate, which will be beneficial to the aviation sector in developing additional analysis and to support climate change adaptation-related decision-making.

scholarly journals High crop load and low temperature delay the onset of bud initiation in apple

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Julian Kofler ◽  
Anton Milyaev ◽  
Filippo Capezzone ◽  
Slobodan Stojnić ◽  
Nikola Mićić ◽  
...  
Keyword(s):  
Floral Development ◽  
Morphological Changes ◽  
Flower Formation ◽  
Heat Accumulation ◽  
Flower Bud ◽  
Crop Load ◽  
Biennial Bearing ◽  
Growing Seasons ◽  
Growing Degree Hours ◽  
Bud Initiation

AbstractThe reproductive cycle of apple (Malus × domestica Borkh.) starts with the induction of floral development, however, first morphological changes within the bud appear during the following period of bud initiation. This study identifies the onset and duration of bud initiation in the apple cultivars ‘Fuji’ and ‘Gala’, characterized by biennial and non-biennial bearing behaviour, respectively, and describes the effect of crop load and heat accumulation on the temporal pattern of floral development. The onset of flower bud initiation in heavy cropping ‘Gala’ trees was delayed for 20 days compared to trees with no crop load, but the rate of initiation was not affected by crop load. Bud initiation on heavy cropping ‘Fuji’ trees was minor, whereas trees with no crop load started initiating buds 19 days earlier than those of ‘Gala’ despite the same cropping status and growing degree hours in a given year. The onset of bud initiation in ‘Fuji’ ‘off’ trees was 5 and 20 days after summer solstice, respectively, in two consecutive growing seasons, suggesting that this process is driven by heat accumulation rather than by daylength. The results indicate, that the genetic make-up of the cultivar determines the onset of bud initiation. This can be delayed by increasing crop loads and low temperatures at the beginning of the flower formation process.

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