scholarly journals Harvest Date as a Factor in Carbohydrate Storage and Cold Hardiness of Cabernet Sauvignon Grapevines

1992 ◽  
Vol 117 (1) ◽  
pp. 32-36 ◽  
Author(s):  
Robert L. Wample ◽  
Andy Bary

Cold-hardiness evaluations and soluble and insoluble-nonstructural carbohydrate analysis of dormant Vitis vinifera L. cv. Cabernet Sauvignon buds and cane tissue indicate a positive relationship between soluble carbohydrates and primary bud cold hardiness. Seasonal variations in soluble and insoluble carbohydrates appear to be related to changes in air temperatures and the dormancy status of the tissues. No differences were found in bud cold hardiness and only limited differences in carbohydrate levels of buds or stem tissues collected over 3 years from early harvest, normal harvest, or unharvested vines. These findings contrast with the widely held opinion that delayed harvest or failure to remove fruit results in reduced cold hardiness as a consequence of low storage carbohydrate content of the plants.

1978 ◽  
Vol 110 (8) ◽  
pp. 877-882 ◽  
Author(s):  
Richard A. Werner

AbstractSnow depth is the most important environmental factor in the survival of overwintering Rheumaptera hastata (L.) pupae in interior Alaska. Pupae spend the winter in the leaf litter where litter temperatures are directly related to snow depth at given air temperatures. Winter survival is also dependent on the cessation of pupal development (diapause) and the development of cold-hardiness which is induced by certain physiological processes such as supercooling and changes in glycerol and carbohydrate levels. Glycerol content and supercooling are dependent on changes in carbohydrate levels which in turn are directly related to changes in the rate of pupal development prior to diapause.


HortScience ◽  
1994 ◽  
Vol 29 (12) ◽  
pp. 1453-1455 ◽  
Author(s):  
Tony K. Wolf ◽  
M. Kay Cook

Thermal analysis (TA) was used to evaluate dormant bud cold hardiness of nine Vitis cultivars weekly during the 1993–94 dormant period. TA hardiness estimates were expressed as either mean low-temperature exotherm temperature (MLTE) or temperatures lethal to 10% (LT10), 50% (LT50), or 90% (LT90) of dormant bud sample. A destructive freeze on 19 Jan. 1994 presented an opportunity to compare dormant bud field survival with laboratory estimates of bud hardiness that had been derived from TA. Vineyard air temperatures of –24C caused primary bud kill that ranged from a mean of 15% with `Concord' to 100% with `Viognier'. With the exception of `Viognier' and one of two `Cabernet Sauvignon' clones, field mortality levels were accurately bracketed by TA estimates of LT10, MLTE, and LT90 values, which had been obtained in the week preceding the freeze. `Viognier' bud hardiness was overestimated by ≈1.5C, and the hardiness of `Cabernet Sauvignon clone UCD#6' was underestimated by <1C. The discrepancy with `Viognier' may have been related to prior destruction of primary buds by bud necrosis and the misinterpretation of secondary bud exotherms as due to primary buds.


1979 ◽  
Vol 57 (9) ◽  
pp. 997-999 ◽  
Author(s):  
R. J. Reader

In laboratory freezing trials, cold hardiness of six types of bog ericad flowers differed significantly (i.e., Chamaedaphne calyculata > Andromeda glaucophylla > Kalmia polifolia > Vaccinium myrtilloides > Ledum groenlandicum > Vaccinium macrocarpon) at air temperatures between −4 and −10 °C but not at temperatures above −2 °C. At the Luther Marsh bog in southern Ontario, low temperatures (−3 to −7 °C) would select against May flowering by the least cold hardy ericads. Availability of pollinators, on the other hand, would encourage May flowering by the most cold hardy species. Presumably, competition for insect pollinators has promoted the diversification of bog ericad flowering peaks, while air temperature, in conjunction with flower cold hardiness, determined the order in which flowering peaks were reached.


2016 ◽  
Vol 2 (1) ◽  
pp. 61-65 ◽  
Author(s):  
V. Melo-Ruíz ◽  
K. Sánchez-Herrera ◽  
H. Sandoval-Trujillo ◽  
R. Díaz-García ◽  
T. Quirino-Barreda

Escamoles, ant eggs (Liometopum apiculatum M), are edible insects consumed in great numbers and appreciated for their sensory characteristics, but not for their nutritional value. In Mexico, they reproduce in arid and semi-arid zones of Mexico and several states (Puebla, Tlaxcala, Hidalgo). Samples were gathered to determine reproduction conditions and perform an insect analysis to generate data composition in macronutrients, on dry basis, according to AOAC methods. The obtained data were: proteins: 42.12-50.63%; lipids: 30.27-34.96%; minerals: 6.53-7.85%; fibres: 1.91-2.56%; and soluble carbohydrates: 6.80-18.27%. Entomological material was collected in spring 2014, 3 nests for each zone, all from different altitudes and agroclimatic regions. Samples were representative for the insect supply in the areas studied. Insects are high in proteins and lipids, compared with most of the commonly consumed food, due to their high content of fatty acids; they must be refrigerated for later consumption. Minerals are moderated. Fibre and soluble carbohydrate levels are low, but an excess of proteins can be converted into carbohydrates via gluconeogenesis. Escamoles reproduce once a year in the spring, but sometimes one nest can provide escamoles eggs twice in the same season, once at the beginning and again at the end, depending on the biotic and abiotic conditions of their environment. Escamoles are a good source of nutrients; however, some rural people sell them to obtain extra income rather than consume them to improve their nutritional condition and welfare.


2016 ◽  
Vol 61 (1) ◽  
pp. 41-46
Author(s):  
Jwakyung Sung ◽  
Minji Cho ◽  
Yeonkyu Sonn ◽  
Hejin Yun ◽  
Seongsoo Kang ◽  
...  

1994 ◽  
Vol 21 (3) ◽  
pp. 255 ◽  
Author(s):  
IF Wardlaw ◽  
J Willenbrink

Wheat plants grown under non-stress conditions at a dayhight temperature of 18/13�C under glasshouse conditions from head emergence to maturity showed a maximum accumulation of water-soluble, non-structural carbohydrates 20-25 days after anthesis. This storage was largely as fructans with the timing and amount of storage and mobilisation varying between cultivars, although the maximum concentration (fructose equivalents per unit stem fresh weight) was similar in all cultivars. The main storage in the culm was located in the lower part of the peduncle enclosed by the flag leaf sheath, in the penultimate internode and for one cultivar also in the flag leaf sheath. 14CO2 pulse-chase studies showed that there was a considerable delay in the incorporation of flag leaf assimilates into stem fructans, a delay probably associated with transfer and metabolic processes in the stem itself. At anthesis, when soluble carbohydrates were rapidly accumulating in the culm, the level of activity of sucrose synthase (SS) in the penultimate internode was much greater than that of sucrose phosphate synthase (SPS). The activity of SS declined rapidly as active storage ceased. This pattern was the reverse of that found in the leaf where SPS, rather than SS, was initially high and declined towards maturity. These changes are discussed in relation to the possible role of sucrose synthesising enzymes, particularly SS, in the accumulation and mobilisation of stem reserves in wheat.


1977 ◽  
Vol 57 (4) ◽  
pp. 1141-1149 ◽  
Author(s):  
C. J. ANDREWS ◽  
M. K. POMEROY

The survival of winter cereal cultivars of contrasting cold hardiness was determined after various modifications of the winter environment at two locations in 3 yr at Ottawa, Ontario. Artificially produced ice covers reduced survival in all cases, and the severest damage was associated with high soil moisture at the time of ice formation. Maintenance of soil temperatures close to zero by replacement of an insulating snow cover over ice increased average survival by about 10% compared with non-insulated plots. Naturally formed ice covers were less damaging than those artificially produced, and in one case formation of an ice cover protected plants from very low air temperatures, resulting in greater survival than in control plots. Total removal of snow in January was severely damaging, while accumulation of snow at a snowfence allowed increased survival of all cultivars. The correlation between cold hardiness and survival in ice treatments was significant, but one wheat (Triticum aestivum L.) cultivar showed better survival than comparable wheats in a number of ice-stressed treatments, while not showing superiority in unstressed or controlled environment conditions.


1991 ◽  
Vol 116 (6) ◽  
pp. 1013-1018 ◽  
Author(s):  
Susan E. Trusty ◽  
William B. Miller

Postproduction changes in carbohydrate types and quantities in the leaves, stems, and inflorescences of pot chyrsanthemums [Dendranthema × gramfiflorum (Ramat.) Kitamura `Favor'] placed in interior conditions were investigated. Fructans, sucrose, glucose, and fructose were present in all plant parts. In inflorescences and leaves, an additional unidentified substance was present. All plant parts decreased in dry weight during the postproduction evaluation. This decrease was accompanied by overall reductions in total soluble carbohydrates (TSC) and starch. The appearance of leaves and stems was acceptable throughout the experiment. Leaves lost significant amounts of TSC during the first 4 days postproduction (DPP), due primarily to a 76% decrease in sucrose concentration. After 4 DPP, leaf and stem TSC remained relatively unchanged. In inflorescences, petal expansion continued through 12 DPP. Visible signs of senescence, including loss of turgor, color changes, and inrolling of petal edges were observed at 20 DPP, and by 28 DPP, the plants were determined unacceptable for consumer use. Inflorescences increased in fresh weight, but not dry weight, during petal expansion, then each decreased. Inflorescence TSC fell from 146 mg.g-1 dry weight at O DPP to 11 mg.g-1 at 28 DPP. Reducing sugars accounted for 84% of the inflorescence TSC at 4 DPP, dropping to 48% at 28 DPP. Fructan concentration decreased through 16 DPP and then remained unchanged, while starch levels rose from 25 to 34 mg·g -1 dry weight through 12 DPP, then decreased. Fractans decreased in polymerization during petal expansion. This result suggests an alternate use of fructans and starch as pools of available reserve carbohydrate during petal expansion in chrysanthemum.


HortScience ◽  
1994 ◽  
Vol 29 (5) ◽  
pp. 446d-446
Author(s):  
H. C. Wien ◽  
A. D. Turner

When bell pepper plants are subjected to high temperatures or low irradiance during flowering, abscission of flowers and flower buds can be severe enough to limit yields. Both types of stresses may lead to reduction of carbohydrate levels in the reproductive structures, and evolution of the abscission-causing hormone ethylene. In two greenhouse experiments, plants were subjected to combinations of 30 or 20 C air temperature and unshaded or heavily shaded conditions for one week at anthesis of the first flower. In a third experiment, plants were subjected to total darkness and temperatures of 30, 20 or 15 C for one week at the same stage of growth. In all experiments, levels of soluble carbohydrates and starch declined under low or zero light conditions, with rate of decrease proportional to the air temperature. Abscission of reproductive structures was not well correlated with carbohydrate levels: in spite of low sugars and starch, plants darkened for 7 days at 15 C showed no abscission. Levels of the ethylene precursor ACC in the buds, though variable, rose just before abscission began, but remained low in non-abscising treatments.


HortScience ◽  
1991 ◽  
Vol 26 (11) ◽  
pp. 1404-1406 ◽  
Author(s):  
Jeanine M. Davis ◽  
Wayne H. Loescher

Diurnal fluctuations in soluble carbohydrates and starch were monitored in young (expanding), mature (first fully expanded), and old (nearing senescence) celery (Apium graveolens L.) leaves. In all tissues, mannitol and sucrose were the carbohydrates present in the highest concentrations. In old and young leaflets and their petioles, there was little change in levels of mannitol and sucrose in 26 hours. In mature leaflets, sucrose accumulated in the light and decreased in the dark; mannitol increased slightly in late afternoon. Starch concentration, although quite low, showed definite diurnal fluctuations in mature leaflets, but only small changes in young and old leaflets. Both sucrose and mannitol were present in mature petiole phloem tissues. Mannitol concentrations were high in the adjacent storage parenchyma tissue, but sucrose was almost undetectable. These data support earlier findings that sucrose is produced, translocated, and metabolized throughout the celery plant. Mannitol is also translocated, but also serves as a major storage carbohydrate in leaf tissues, especially petiole parenchyma. Starch serves as a minor short-term storage compound in leaflets.


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