scholarly journals Treatments to Accelerate Leaf Development in Blueberries

HortScience ◽  
1997 ◽  
Vol 32 (4) ◽  
pp. 595D-595 ◽  
Author(s):  
Gerard Krewer ◽  
D. Scott NeSmith ◽  
Ben Mullinix
Keyword(s):  
Flower Development ◽  
Leaf Development ◽  
Late Summer ◽  
Bud Break ◽  
Benzyl Adenine ◽  
Flower Buds ◽  
Hydrogen Cyanamide ◽  
Dormancy Period ◽  
Spring Leaf ◽  
Vegetative Bud

Poor blueberry leaf development is a serious problem in medium and low chilling regions which leads to smaller, later ripening fruit and reduced bush vigor. Dormex (hydrogen cyanamide) and Promalin or Accel (6-benzyl adenine plus gibberellins A4 and A7) were used in the experiments. Dormex 1991-1995 trials with applications at the end of the dormancy period (February) looked promising but were not uniformly successful. In 1996, applications were made starting in mid-dormancy (early-mid January) about 6-8 weeks before normal bud break. Spring vegetative bud development was greatly accelerated with minimal advance in flower development. Mid-dormancy Dormex rates of 1.5% to 2% appear promising. Dormex application after bud break or at excessively high rates will kill flower buds, but has excellent potential as a bloom thinning agent for juvenile blueberry plants. Promalin or Accel applications post bloom significantly accelerated spring leaf development. Late summer applications of Promalin significantly increased fall growth and number of side shoots.

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.

scholarly journals Crosstalk Pathway between Trehalose Metabolism and Cytokinin Degradation for the Determination of the Number of Berries per Bunch in Grapes

Cells ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 2378
Author(s):  
Ayane Moriyama ◽  
Chiho Yamaguchi ◽  
Shinichi Enoki ◽  
Yoshinao Aoki ◽  
Shunji Suzuki
Keyword(s):  
Cultured Cells ◽  
Growing Season ◽  
Cytokinin Oxidase ◽  
Flower Formation ◽  
Bud Break ◽  
Flower Buds ◽  
New Information ◽  
Trehalose Metabolism ◽  
Cultivation Techniques

In grapes, the number of flowers per inflorescence determines the compactness of grape bunches. Grape cultivars with tight bunches and thin-skinned berries easily undergo berry splitting, especially in growing areas with heavy rainfall during the grapevine growing season, such as Japan. We report herein that grape cytokinin oxidase/dehydrogenase 5 (VvCKX5) determines the number of berries per inflorescence in grapes. The number of berries per bunch was inversely proportional to the VvCKX5 expression level in juvenile inflorescences among the cultivars tested. VvCKX5 overexpression drastically decreased the number of flower buds per inflorescence in Arabidopsis plants, suggesting that VvCKX5 might be one of the negative regulators of the number of flowers per inflorescence in grapes. Similarly, the overexpression of grape sister of ramose 3 (VvSRA), which encodes trehalose 6-phosphate phosphatase that catalyzes the conversion of trehalose-6-phosphate into trehalose, upregulated AtCKX7 expression in Arabidopsis plants, leading to a decrease in the number of flower buds per Arabidopsis inflorescence. VvCKX5 gene expression was upregulated in grapevine cultured cells and juvenile grape inflorescences treated with trehalose. Finally, injecting trehalose into swelling buds nearing bud break using a microsyringe decreased the number of berries per bunch by half. VvCKX5 overexpression in Arabidopsis plants had no effect on the number of secondary inflorescences from the main inflorescence, and similarly trehalose did not affect pedicel branching on grapevine inflorescences, suggesting that VvCKX5, as well as VvSRA-mediated trehalose metabolism, regulates flower formation but not inflorescence branching. These findings may provide new information on the crosstalk between VvSRA-mediated trehalose metabolism and VvCKX-mediated cytokinin degradation for determining the number of berries per bunch. Furthermore, this study is expected to contribute to the development of innovative cultivation techniques for loosening tight bunches.

Predicting vegetative bud break in two arctic deciduous shrub species, Salix pulchra and Betula nana

Oecologia ◽  
2000 ◽  
Vol 124 (2) ◽  
pp. 176-184 ◽  
Author(s):  
E. W. Pop ◽  
S. F. Oberbauer ◽  
G. Starr
Keyword(s):  
Bud Break ◽  
Shrub Species ◽  
Betula Nana ◽  
Deciduous Shrub ◽  
Vegetative Bud

scholarly journals Flower Bud Stage and Chill Hours Influence the Activity of GA3 Applied to Rabbiteye Blueberry

HortScience ◽  
1992 ◽  
Vol 27 (4) ◽  
pp. 316-318 ◽  
Author(s):  
D.S. NeSmith ◽  
Gerard Krewer
Keyword(s):  
Gibberellic Acid ◽  
Growth Regulator ◽  
Flower Development ◽  
Fruit Set ◽  
Developmental Stages ◽  
Single Application ◽  
Flower Buds ◽  
Flower Bud ◽  
Vaccinium Ashei

Individual flower clusters of `Tifblue' rabbiteye blueberry (Vaccinium ashei Reade) were treated with 300 ppm GA at several flower bud stages to determine the activity of the growth regulator in promoting fruit set. Applications were made one time only at a specified stage of flower development, or once followed by a second application. A single application of GA when flower buds had elongated but corollas had not expanded (stage 5) led to the largest increase in fruit set. Two applications of GA, 10 to 18 days apart, increased fruit set compared with a single application at flower developmental stages other than stage 5. Fruit set promoted by a single spray of GA imposed on fully expanded corollas (stage 6) decreased with increasing number of chill hours (350, 520, 760, or 1150). Chemical names used: gibberellic acid (GA).

scholarly journals GA3 SPRAYS ALTER THE FATE OF LATERAL MERISTEMS OF `REDKIST' PEACH.

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1167b-1167
Author(s):  
Daniel L. Ward ◽  
Bradley H. Taylor
Keyword(s):  
Mode Of Action ◽  
Flower Buds ◽  
Flower Bud ◽  
Developmental Fate ◽  
Winter Temperatures ◽  
Vegetative Bud

G A3 sprays were applied to 10 primary scaffold limb replications with a handgun at three concentrations (25, 50, 100 mg/l), from May to September 1989. Flower bud thinning with G A3 applied in the year prior to bloom was examined for its effect on the developmental fate of lateral meristems. Limbs treated in late May had, on average, 45% more flower buds survive near-critical winter temperatures than did controls. During the period of greatest sensitivity to Flower Bud Density (FBD) reduction, GA3 treated limbs had vegetative bud densities (VBD) higher than control (on average 45% greater at 100 mg/l). On 9 June 100 mg/l reduced FBD by 78% compared to control and increased VBD by 57%, while on 6 July the same concentration. reduced FBD by 94% but VBD was increased by only 32%. These results appear to support the hypothesis that GA3 induced FBD reduction has more than one mode of action.

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