Studies to extend the dormancy of white yam (Dioscorea alata L)

Two experiments were conducted in 1987-88 in St. Lucia with a view to extend the dormancy of white yam (Dioscorea alata L). Experiment 1 compared different harvest dates, different storage temperatures and presence or absence of the tuber "head" in cultivar Oriental. Experiment 2 studied the effect of gibberellic acid (GA) solution (1000 p/m) on the dormancy of different cultivars of white yam. Tubers from the early harvest (15 November) had the longest dormancy period (over 7 months), which decreased progressively with delay in harvesting. Storing yam tubers at 20 ± 2°C extended the dormancy by over 5 months as compared to storing them at 30 ± 2°C. The presence or absence of the tuber "head" had no effect. The interaction effects due to dates of harvest X storage temperatures and storage temperatures X manipulation were significant. Cultivars of white yam differed significantly in their dormancy period. Treating the harvested tubers with GA (1000 p/m) for 2 hours extended the dormancy by over 4 months as compared to that of the control (water) treatment.

Download Full-text

Effects of gibberellic acid and storage temperature on the germination of hawthorn seeds

Journal of Forest Science ◽

10.17221/24/2017-jfs ◽

2017 ◽

Vol 63 (No. 9) ◽

pp. 417-424 ◽

Cited By ~ 1

Author(s):

Ahmadloo Fatemeh ◽

Kouchaksaraei Masoud Tabari ◽

Goodarzi Gholam Reza ◽

Salehi Azadeh

Keyword(s):

Electrical Conductivity ◽

Gibberellic Acid ◽

Water Uptake ◽

Temperature Regime ◽

Storage Temperature ◽

Fresh Weight ◽

Freeze Thaw ◽

Refrigerator Temperature ◽

And Storage ◽

Storage Temperatures

This study investigated methods to overcome seed dormancy in Crataegus pseudoheterophylla Pojarkova seeds. Seeds with and without endocarps were treated with gibberellic acid (GA3) at different concentrations and four storage temperatures. Then they were stratified in an alternate temperature regime. The amount of absorbed water in seeds with endocarps was monitored by measuring the fresh weight of seeds for 0, 24, 48, 72, and 96 h of imbibition. The electrical conductivity (EC) and the percentage of water uptake by seeds stored for 12 months at laboratory temperature, in a refrigerator, in a freezer, and in freeze-thaw conditions were measured. The highest germination (59.7%) was recorded in seeds without endocarps treated with 3,000 mg·l–1 GA3 and stored either in a laboratory or a refrigerator (32.7–35.3%). All treatments of seeds without endocarps where GA3 was applied showed statistically higher percentages of germination than the control. Seeds with endocarps stored at refrigerator temperature imbibed water up to 44.3% with increasing imbibition periods, whereas the amount of seeds that absorbed water in freezer and freeze-thaw conditions was almost the same. The tests showed the highest EC during storage in the freezer, with the lowest water uptake and viability in seeds stored during the freeze-thaw process.

Download Full-text

Germination and Storage of Vinca Seed Is Influenced by Light, Temperature, and Relative Humidity

HortScience ◽

10.21273/hortsci.27.9.993 ◽

1992 ◽

Vol 27 (9) ◽

pp. 993-996 ◽

Cited By ~ 5

Author(s):

William J. Carpenter ◽

Joseph F. Boucher

Keyword(s):

Relative Humidity ◽

Gibberellic Acid ◽

Catharanthus Roseus ◽

Continuous Light ◽

Seed Storage ◽

Germination Percentage ◽

Seed Moisture ◽

And Storage ◽

Storage Temperatures

Light, temperature, relative humidity (RH), and GA3 affect vinca [Catharanthus roseus (L.) G. Don] seed storage and/or germination. GA3 failed to increase the germination percentage in darkness but significantly increased the percentage in continuous light. Similarly, GA3 treatment reduced both the number of days required to achieve 50% of the final germination percentage (T50) and the span between 10% and 90% germination (T90 — T10) for seeds in light, but not in darkness. Germination percentages were maximal and about equal at 25, 30, or 35C in darkness; germination was lowest below 25C. Germination T50 and T90 — T10 required the fewest days between 25 and 35C. Reducing seed moisture from 9.9% to 3.9% increased the T50 from 2.4 to 3.0 days but failed to change germination percentages. Germination percentage declined linearly as seed storage temperatures were reduced from 5 to — 20C, whereas days to T50 increased. Seed storage for 12 months without reduction in germination percentage was possible at 5C and 11%, 33%, or 52% RH, but storage at 75% or 95% RH for periods exceeding 1 month reduced germination. Seeds stored at 33% or 52% RH required fewer days to T50 than did seeds stored at 11%, 75%, or 95% RH. Chemical name used: gibberellic acid (GA3).

Download Full-text

Influence of Harvest Dates on Quality, Storage Capacity and Sensory Attributes of European Plum cv. Green Gage

Food Science and Technology International ◽

10.1177/1082013209350537 ◽

2009 ◽

Vol 15 (6) ◽

pp. 527-534 ◽

Cited By ~ 9

Author(s):

M. Guerra ◽

M.A. Sanz ◽

P.A. Casquero

Keyword(s):

Storage Time ◽

Storage Capacity ◽

Harvest Date ◽

Consumer Acceptance ◽

Nondestructive Measurement ◽

Harvest Dates ◽

Quality Threshold ◽

And Storage ◽

Early Harvest ◽

Minimum Quality

The aim of this work was to determine storage capacity and changes in quality and consumer acceptance in plum harvested at different dates as well as to determine which instrumental parameters show good correlation with consumer acceptance and sensory properties. Both harvest date and storage time played a significant role in quality and sensory characteristics. Incidence of internal breakdown (IB) was significantly higher in fruit harvested last and increased significantly until the end of storage. Market life of ‘Green Gage’ plum varies from 20 days in fruit harvested on the last harvest date to 40 days in fruit harvested on earlier dates. When storage is needed, firmness, the best harvest index, should be higher than 42 N in order to extend market life and prevent IB damages in ‘Green Gage’ plums. However, fruit from early harvest dates has a lower consumer acceptance than fruit from late harvest dates (low TSS:TA). Thus, a minimum quality threshold based on TSS:TA (18.9) has been established over which consumer liking for European plums cv. Green Gage improves significantly. High linear regression between a* and TSS:TA would allow to use the a* color parameter as a nondestructive measurement to estimate consumer acceptance.

Download Full-text

Growth Regulators and Storage Temperature Govern Germination of Coreopsis Seed

HortScience ◽

10.21273/hortsci.27.11.1190 ◽

1992 ◽

Vol 27 (11) ◽

pp. 1190-1193 ◽

Cited By ~ 2

Author(s):

William J. Carpenter ◽

Eric R. Ostmark

Keyword(s):

Relative Humidity ◽

Gibberellic Acid ◽

Growth Regulators ◽

Storage Temperature ◽

Seed Storage ◽

Temperature Regimes ◽

Alternating Temperature ◽

And Storage ◽

Storage Temperatures ◽

Growth Regulator Treatment

The storage and germination environments were evaluated to determine the cause of low total germination percentages and highly irregular germination of Coreopsis lanceolata L. seed. Highest total germination and most rapid and uniform germination of seed occurred at constant 15C, other constant temperatures and all alternating temperature regimes caused lower total germination or delayed it. Seeds tolerated -20C during storage, but total germination was reduced below -5C. Recently harvested seeds had 44% total germination, but 54% to 81% germination was achieved after 6 hours of soaking seeds in 1000 ppm GA3, 1000 ppm ethephon, or 25 ppm kinetin alone or in combination. Growth regulators reduced the number of days to 50% of final germination (T50), and the span in days between 10% and 90% of germination (T90 - T10). Storing fresh seeds without chemical treatment for > 6 months at 5C and 10% to 20% relative humidity (RH), or 15C at 20% to 35% RH, increased total germination to 75% and 80%, respectively. Ten days were required to achieve T50 after 5 to 6 months of storage at 5C and 10% to 20% RH or 15C and 10% to 40% RH, with longer periods to T50 at other storage durations and RH levels. The germination spans (T90 - T10) were lengthened the higher the seed storage temperatures between 5 to 25C, with longer spans as seed storage durations and relative humidities increased. Total germination was similar after storing seeds at 5 or 15C and 10% to 30% RH and after soaking recently harvested seeds in GA3 + ethephon, but the days to T50 and T90 - T10 were shorter after growth regulator treatment. Chemical names used: (2-chloroethyl) phosphonic acid (ethephon); gibberellic acid (GA3); 6-furfurylaminopurine (kinetin).

Download Full-text

Harvest Date Effects on Maturity, Quality, and Storage Disorders of `Honeycrisp' Apples

HortScience ◽

10.21273/hortsci.40.1.164 ◽

2005 ◽

Vol 40 (1) ◽

pp. 164-169 ◽

Cited By ~ 22

Author(s):

Christopher B. Watkins ◽

Mustafa Erkan ◽

Jacqueline F. Nock ◽

Kevin A. Iungerman ◽

Randolph M. Beaudry ◽

...

Keyword(s):

Storage Temperature ◽

Titratable Acidity ◽

Harvest Date ◽

Soluble Solids ◽

Harvest Dates ◽

Wide Range ◽

Soft Scald ◽

And Storage ◽

Storage Temperatures ◽

Storage Disorders

`Honeycrisp' is a new apple [Malus sylvestris (L.) Mill. var. domestica (Borkh.) Mansf.] cultivar that has been planted extensively in North America, but the storage disorders soggy breakdown and soft scald have resulted in major fruit losses. The effects of harvest date and storage temperature on fruit quality and susceptibility of fruit to these disorders have been investigated in Michigan, New York, and Maine. Internal ethylene concentrations were variable over a wide range of harvest dates, and a rapid increase in autocatalytic ethylene production was not always apparent. The starch pattern index, soluble solids content, titratable acidity and firmness also appear to have limited use as harvest indices. Development of soggy breakdown and soft scald is associated with later harvest dates and storage of fruit at temperatures of 0 to 0.5 °C compared with higher storage temperatures. It is recommended that `Honeycrisp' be stored at 3 °C, although storage disorders still can occur at this temperature if fruit are harvested late. In addition, greasiness development may be worse at higher storage temperatures.

Download Full-text

Gibberellic Acid Slows Postharvest Degreening of 'Oroblanco' Citrus Fruits

HortScience ◽

10.21273/hortsci.36.5.937 ◽

2001 ◽

Vol 36 (5) ◽

pp. 937-940 ◽

Cited By ~ 17

Author(s):

Ron Porat ◽

Xuqiao Feng ◽

Moshe Huberman ◽

David Galili ◽

Raphael Goren ◽

...

Keyword(s):

Gibberellic Acid ◽

Storage Temperature ◽

Color Change ◽

Progressive Increase ◽

Fruit Color ◽

Slight Effect ◽

Peel Color ◽

Early Maturing ◽

And Storage ◽

Storage Temperatures

'Oroblanco' is an early-maturing pummelo-grapefruit hybrid (Citrus grandis Osbeck × C. paradisi Macf.). The fruit are usually picked and marketed while the peel color is still green; however, in some cases they can lose this green color during postharvest shipping and storage, which diminishes their commercial value. The effects of storage temperatures, gibberellic acid (GA), ethylene, and 1-methylcyclopropene (1-MCP) on the degreening of 'Oroblanco' fruit were examined. Storage temperature was critical for retaining fruit color: at 2 °C the fruit remained green for a period up to 5 weeks, whereas at storage temperatures of 6, 12, and 20 °C there was a progressive increase in the rate of degreening. Applications of GA, either as preharvest sprays or as postharvest dip treatments, effectively retained the green fruit color. Ethylene exposures up to 100 μL·L-1 for 3 days had only a slight effect on fruit degreening, and 1-MCP treatments up to 200 nL·L-1 for 16 hours had no effect at all. The slight influence of ethylene and the ineffectiveness of 1-MCP on fruit color change can not be attributed to difficulties in their application, since in the same experiments ethylene markedly induced peduncle abscission, and 1-MCP effectively inhibited this ethylene effect. Accordingly, ethylene had only a relatively small effect on the induction of chlorophyllase enzyme activity in green 'Oroblanco' peel tissue.

Download Full-text