scholarly journals Changes in Promoter and Inhibitor Substances During Dormancy Release in Apple Buds Under Foliar-Applied Dormancy-Breaking Agents

2018 ◽  
pp. 1-20 ◽  
Author(s):  
Mohamed A. Seif El-Yazal
Keyword(s):  
Fruit Set ◽  
Phenolic Content ◽  
Bud Break ◽  
Dormancy Breaking ◽  
Hydrogen Cyanamide ◽  
Flowering Duration ◽  
Winter Conditions ◽  
Malus Sylvestris ◽  
Final Yield ◽  
Indole 3 Acetic Acid

The effect of hydrogen cyanamide (Dormex) at different concentrations for reaching early break dormancy in buds of "Astrachan" apple (Malus sylvestris, Mill) trees and their effects on metabolic changes in the content of buds from promoter and inhibitor substances during their release from dormancy was investigated. The efficiency of early bud break was noticed in varying degrees with Dormex at different concentrations. All applied concentrations led to early bud break, short flowering duration, high percentages of bud break and fruit-set, high contents of total indoles, indole-3-acetic acid, gibberellic acid, total and conjugated phenols and low content of abscisic acid and free phenols. These results were positively reflected in the final yield. Accordingly, we recommend using Dormex at 3% for reaching the early break dormancy in buds of "Astrachan" apple trees under Egyptian winter conditions and maximizing the yield by regulating the hormonal and phenolic content in buds.

scholarly journals Foliar-Applied Mineral Oil Enhanced Hormones and Phenols Content and Hastened Breaking Bud Dormancy In “Astrachan” Apple Trees

2018 ◽  
pp. 57-73 ◽  
Author(s):  
Mohamed A. Seif El-Yazal
Keyword(s):  
Fruit Set ◽  
Phenolic Content ◽  
Maximum Yield ◽  
Mineral Oil ◽  
Bud Break ◽  
Apple Trees ◽  
Flowering Duration ◽  
Winter Conditions ◽  
Ortho Cresol ◽  
Indole 3 Acetic Acid

The effect of mineral oil alone or in combination with Dintro-ortho-cresol (Universal) with different concentrations at early reaching break dormancy in buds of ‘Astrachan’ apple (Malus sylvestris, Mill) trees was investigated. Also, their effects on metabolic changes in the content of buds from promoter and inhibitor substances during their release from dormancy were detected. The efficiency of early bud break was noticed in varying degrees with mineral oil or Universal at different concentrations. It was observed that all applied concentrations lead to early bud break, short flowering duration, high percentages of bud break and fruit-set. In addition, high contents of total indoles, indole-3-acetic acid, gibberellic acid, total and conjugated phenols, as well as, low content of abscisic acid and free phenols were achieved. According to the results, it is recommended using 6% of mineral oil as operator safer bud break promoters for reach to the early break dormancy in buds of ‘Astrachan’ apple trees under Egyptian winter conditions and the maximum yield by regulating the hormonal and phenolic content in buds.

scholarly journals Hot Water Treatment Released Endodormancy but Reduced Number of Flowers in Potted Red Raspberry Plants

HortScience ◽  
2010 ◽  
Vol 45 (6) ◽  
pp. 894-898 ◽  
Author(s):  
Marja Rantanen ◽  
Pauliina Palonen
Keyword(s):  
Water Treatment ◽  
Dry Weight ◽  
Rubus Idaeus ◽  
Hot Water ◽  
Bud Break ◽  
Hot Water Treatment ◽  
Dormancy Breaking ◽  
Red Raspberry ◽  
Hydrogen Cyanamide ◽  
Sublethal Stress

Partially released dormancy causes poor and uneven bud break in temperate plant species like red raspberry (Rubus idaeus L.). Insufficient chilling may be a problem when raspberries are grown at southern latitudes and in year-round production. Dormancy may be released by sublethal stress in many species. We studied the effect of sublethal stress on endodormancy in red raspberry ‘Glen Ample’ and ‘Ottawa’. Canes growing in pots were treated with either hot water (45 °C, 1 h) or the dormancy-breaking chemical, hydrogen cyanamide (1.04%), after accumulation of 0, 240, 480, 720, 960, or 1200 h of chilling at 1 °C. Bud break, vegetative growth, and number of flowers were recorded during 12 weeks of greenhouse forcing after the treatments. Chilling increased bud break, growth, and dry weight of lateral shoots and number of flowers in both cultivars. During deepest endodormancy (0 and 240 h of chilling), treatment with either hot water or hydrogen cyanamide enhanced bud break and lateral shoot growth but could not completely replace chilling. In ‘Ottawa’, hydrogen cyanamide was more effective than hot water during deepest endodormancy, but hot water treatment broke dormancy effectively when 720 h of chilling had accumulated. For ‘Glen Ample’, hot water was as effective as hydrogen cyanamide in breaking endodormancy. Hot water treatment reduced the number of flowers in ‘Glen Ample’ during late endodormancy (720, 960, and 1200 h of chilling). The chilling requirement for ‘Ottawa’ was fulfilled between 720 and 960 h of chilling. However, in ‘Glen Ample’, 1200 h of chilling was not enough to fully release bud dormancy; bud break remained low and it was increased by dormancy-breaking treatments. Hot water treatment can be used to release endodormancy in raspberries, but treatment conditions need to be optimized to preserve crop potential. Chemical name used: hydrogen cyanamide (Dormex, Hi-Cane, Morgrapes).

Chemical methods on breaking dormancy of low chill nectarines: preliminary evaluations in subtropical Queensland

1988 ◽  
Vol 28 (3) ◽  
pp. 425 ◽  
Author(s):  
AP George ◽  
RJ Nissen
Keyword(s):  
Fruit Set ◽  
Potassium Nitrate ◽  
Yield Losses ◽  
Chemical Methods ◽  
Hydrogen Cyanamide ◽  
Breaking Dormancy ◽  
Fruit Maturity ◽  
Final Yield

Three chemicals, Alzodef (49% hydrogen cyanamide) at 20 mL/L, thiourea at 10 g/L and potassium nitrate at 40 g/L were tested either alone or in combination for their effects on breaking dormancy in the low chill nectarine cultivar Sunred in subtropical Queensland. Compared with potassium nitrate and thiourea, Alzodef proved more effective in breaking dormancy and advancing budbreak and fruit maturity. However, Alzodef reduced both fruit set and final yield. Yield losses were greater when application of Alzodef was delayed from 5 weeks to 1 week before natural budbreak.

scholarly journals Effect of a Late Spring Application of Hydrogen Cyanamide on High-Chill Peaches

Agronomy ◽  
2019 ◽  
Vol 9 (11) ◽  
pp. 726
Author(s):  
Chunxian Chen ◽  
Thomas G. Beckman
Keyword(s):  
Vegetative Growth ◽  
Fruit Set ◽  
Average Length ◽  
Late Spring ◽  
Spray Application ◽  
Dormancy Breaking ◽  
Hydrogen Cyanamide ◽  
Floral Buds ◽  
Lateral Shoots ◽  
Significant Difference

Due to a record low chilling accumulation in the winter of 2016–2017, many high-chill peach cultivars displayed almost no budbreak by mid-April of 2017 in central Georgia, USA, where budbreak usually occurs around mid-March. In this study, nine of these peach cultivars were used to study the effect of a late spring Dormex spray application (April 13, 2017) on subsequent budbreak, year-end cumulative vegetative growth, and following-season yield. Dormex was found to have strong stimulating effects on lateral budbreak, but little effect on terminal and floral budbreak. It also had apparent phytotoxic effects on lateral, terminal and floral buds, and growth. The effects varied among genotypes, tree ages, and shoot types. The peak of the effects occurred two weeks post-application. Most floral buds abscised before they swelled. Between Dormex-sprayed trees and unsprayed controls, there was no significant difference in the number and average length of the new lateral shoots by the end of 2017, nor in the number and weight of the fruit harvested in 2018. In conclusion, our data showed a late spring Dormex spray application stimulated earlier lateral budbreak and caused some level of phytotoxicity to all types of buds and new growth, but had little impact on flower budbreak, fruit set, year-end vegetative growth, or following-season yield. These findings provide useful information for growers, considering the need for spraying dormancy-breaking compounds when faced with insufficient chilling.

Different rates of hydrogen cyanamide in bud break of ‘Rocha’ pear tree

2021 ◽  
pp. 313-316
Author(s):  
M.M. Fagherazzi ◽  
L. Rufato ◽  
A.A. Kretzschmar ◽  
A.F. Fagherazzi ◽  
B. Bem ◽  
...  
Keyword(s):  
Bud Break ◽  
Hydrogen Cyanamide ◽  
Pear Tree

EFFECTIVE HYDROGEN CYANAMIDE (DORMEX®) APPLICATION FOR BUD BREAK, FLOWERING AND NUT YIELD OF PISTACHIO TREES CV. MATEUR IN WARM GROWING AREAS

2013 ◽  
Vol 50 (3) ◽  
pp. 398-406 ◽  
Author(s):  
MOHAMED GHRAB ◽  
MEHDI BEN MIMOUN
Keyword(s):  
Global Warming ◽  
Shoot Growth ◽  
Starch Content ◽  
Optimal Dose ◽  
Fruit Trees ◽  
Bud Break ◽  
Northern Tunisia ◽  
Hydrogen Cyanamide ◽  
Effective Hydrogen ◽  
Pistachio Trees

SUMMARYClimate change characterized by global warming is expected to have an incidence on fruit trees’ development and production. The severity of these effects depends on lack of chilling. The current study focused on the research of an optimal dose of hydrogen cyanamide (Dormex®) treatment which can advance the bud break of female pistachio trees (Pistacia veraL.) to ensure better blooming synchronization with pollinators. A field experiment was conducted in northern Tunisia (36°49′N, 9°48′E) on mature pistachio trees. Two hydrogen cyanamide treatments at 2% and 4% Dormex® were applied with reference to the control untreated trees. The flowering time, vegetative growth, starch content, productivity and nut characters were followed. Results show that 4% Dormex® advanced the normal bud break by 15 days and flowering by 11 days and improved natural pollination by synchronization of male and female flowers. Consequently, fresh yield and nut quality as split and blank rates and nut weight were improved. However, shoot growth, leaf area and starch content in current shoot seemed unaffected by hydrogen cyanamide applications. In conclusion, hydrogen cyanamide could be used as 4% Dormex® and sprayed 45 days before bud break to improve pistachio productivity and prevent anomalies of lack of chilling due to global warming that could be more frequent in the Mediterranean areas.

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