Dormancy breaking of ‘Kampai’ peach trees with alternative products in subtropical regions

2022 ◽  
pp. 1-8
Author(s):  
R. E. Viol ◽  
P. M. Peche ◽  
D. H. Farias ◽  
L. V. Vilas Boas ◽  
P. N. Curi ◽  
...  
Keyword(s):  
Copper Sulphate ◽  
Calcium Nitrate ◽  
Negative Control ◽  
Production Cycle ◽  
Guaiacol Peroxidase ◽  
Dormancy Breaking ◽  
Water Control ◽  
Flower Opening ◽  
Hydrogen Cyanamide ◽  
Peach Trees

Abstract Peach trees initiate flowering and then dense budding when the temperatures in winter are steadily low. When temperatures during the winter are high or when the chilling accumulation needs of the cultivar are not met, it is necessary to apply chemicals that stimulate flowering and budding in a uniform manner. This study aimed to evaluate alternative products for breaking the dormancy of ‘Kampai’ peach trees in a subtropical region. The experiment was conducted with ‘Kampai’ peach trees in the 2018, 2019 and 2020 production with the following treatments: (1) negative control composed only of water (control); (2) positive control composed of hydrogen cyanamide at a dose of 1.5% (commercial product Dormex®) plus 4.5% mineral oil; (3) Erger G® organomineral fertilizer supplemented with calcium nitrate at a dose of 3%; (4) potassium nitrate at a dose of 5%; and (5) copper sulphate at a dose of 0.3%. We evaluated affected budding capacity, flowering, the production cycle, peach production, the quality of peach trees and the enzymatic activities of catalase and guaiacol peroxidase. Hydrogen cyanamide and the organomineral fertilizer Erger G® promoted earlier flowering and an earlier production cycle. On the other hand, hydrogen cyanamide and copper sulphate stimulated flower opening and peach production. The chemicals used decreased catalase activity (24 h after application) and increased guaiacol peroxidase activity (6 h after application). The application of copper sulphate may be an option to break the dormancy of peach trees in the subtropics.

scholarly journals Budbreak patterns and phytohormone dynamics reveal different modes of action between hydrogen cyanamide- and defoliant-induced flower budbreak in blueberry under inadequate chilling conditions

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256942
Author(s):  
Syuan-You Lin ◽  
Shinsuke Agehara
Keyword(s):  
Model Fitting ◽  
Vaccinium Corymbosum ◽  
Steady Increase ◽  
Dormancy Breaking ◽  
Water Control ◽  
Acetic Acid Production ◽  
Rapid Phase ◽  
Hydrogen Cyanamide ◽  
Yield Increase ◽  
Modes Of Action

Under inadequate chilling conditions, hydrogen cyanamide (HC) is often used to promote budbreak and improve earliness of Southern highbush blueberry (Vaccinium corymbosum L. interspecific hybrids). However, HC is strictly regulated or even banned in some countries because of its high hazardous properties. Development of safer and effective alternatives to HC is critical to sustainable subtropical blueberry production. In this study, we examined the efficacy of HC and defoliants as bud dormancy-breaking agents for ‘Emerald’ blueberry. First, we compared water control, 1.0% HC (9.35 L ha–1), and three defoliants [potassium thiosulfate (KTS), urea, and zinc sulfate (ZS)] applied at 6.0% (28 kg ha–1). Model fitting analysis revealed that only HC and ZS advanced both defoliation and budbreak compared with the water control. HC-induced budbreak showed an exponential plateau function with a rapid phase occurring from 0 to 22 days after treatment (DAT), whereas ZS-induced budbreak showed a sigmoidal function with a rapid phase occurring from 15 to 44 DAT. The final budbreak percentage was similar in all treatments (71.7%–83.7%). Compared with the water control, HC and ZS increased yield by up to 171% and 41%, respectively, but the yield increase was statistically significant only for HC. Phytohormone profiling was performed for water-, HC- and ZS-treated flower buds. Both chemicals did not increase gibberellin 4 and indole-3-acetic acid production, but they caused a steady increase in jasmonic acid (JA) during budbreak. Compared with ZS, HC increased JA production to a greater extent and was the only chemical that reduced abscisic acid (ABA) concentrations during budbreak. A follow-up experiment tested ZS at six different rates (0–187 kg ha–1) but detected no significant dose-response on budbreak. These results collectively suggest that defoliants are not effective alternatives to HC, and that HC and ZS have different modes of action in budbreak induction. The high efficacy of HC as a dormancy-breaking agent could be due to its ability to reduce ABA concentrations in buds. Our results also suggest that JA accumulation is involved in budbreak induction in blueberry.

Fluoride Injury to Cut `Samantha' Roses May Be Reduced by Pulsing with Calcium Nitrate

HortScience ◽  
1990 ◽  
Vol 25 (10) ◽  
pp. 1270-1271 ◽  
Author(s):  
Caroline H. Pearson-Mims ◽  
Virginia I. Lohr
Keyword(s):  
Weight Gain ◽  
Calcium Nitrate ◽  
Flower Longevity ◽  
Fresh Weight ◽  
Flower Opening ◽  
Visual Symptoms ◽  
Flower Quality ◽  
Nitrate Pulse ◽  
Solution Uptake ◽  
Preservative Solutions

Cut `Samantha' roses (Rosa hybrida L.) were placed in deionized water or a 20-mm Ca(NO3)2 pulsing solution for 72 hours. Flowers then were held in preservative solutions containing 0 or 4 mg fluoride/liter. Fresh weight gain, solution uptake, degree of flower opening, and flower longevity were reduced in the presence of fluoride in the holding solution. Visual symptoms of injury and reduced flower quality also were noted in treatments with fluoride. Pulsing improved fresh weight gain and degree of opening of flowers held in solutions containing fluoride. Pulsing also delayed the onset of visual symptoms of fluoride injury. Water uptake for flowers that were pulsed and exposed to fluoride was not different from uptake for flowers exposed to fluoride alone. Flower longevity for roses in all treatments was increased by using the calcium nitrate pulse, but pulsed flowers in fluoride did not survive as long as the control flowers.

scholarly journals Synthesis of plate-like β-tricalcium phosphate nanoparticles and their efficiency in remineralization of incipient enamel caries

2019 ◽  
Vol 8 (4) ◽  
pp. 261-276
Author(s):  
Roghayyeh Marefat Seyedlar ◽  
Mohammadbagher Rezvani ◽  
Samira Barari ◽  
Mohammad Imani ◽  
Azizollah Nodehi ◽  
...  
Keyword(s):  
Tricalcium Phosphate ◽  
Calcium Nitrate ◽  
Negative Control ◽  
Second Phase ◽  
Calcium Nitrate Tetrahydrate ◽  
Enamel Caries ◽  
Nitrate Tetrahydrate ◽  
Addition Rate ◽  
Post Hoc ◽  
Caries Lesions

AbstractThe purpose of this study was to synthesize nano-sized β-tricalcium phosphate (nano-TCP) particles and determine its concentration-dependent properties on incipient enamel caries lesions. Nano-TCP was synthesized as a wet chemical through a method using low concentration of precursors and low addition rate of calcium nitrate tetrahydrate as a second phase. Morphology and phase composition of the particles were analyzed by SEM, XRD, and EDXA techniques. Incipient enamel lesions were created in human premolars with an acidic buffer. The teeth were then incubated in aqueous dispersions of nano-TCP as remineralization solutions. Sodium fluoride solution and deionized water were used as positive and negative control groups, respectively. The quality and thickness of the remineralized layer on enamel were investigated using SEM. The data were statistically analyzed by analysis of variance (ANOVA) and post hoc Tukey’s test. The synthesized nano-TCP mostly consisted of porous platelet-like crystals of 50–100 nm thickness and pore diameters of 100–300 nm. SEM observation showed that a homogenous layer was formed on the surface of the enamels remineralized in nano-TCP solutions. The thickness of the mineralized layer was dependent on the incubation time and nano-TCP concentration.

scholarly journals Effects of Homeopathic Arsenicum Album, Nosode, and Gibberellic Acid Preparations on the Growth Rate of Arsenic-Impaired Duckweed (Lemna gibbaL.)

2010 ◽  
Vol 10 ◽  
pp. 2112-2129 ◽  
Author(s):  
Tim Jäger ◽  
Claudia Scherr ◽  
Meinhard Simon ◽  
Peter Heusser ◽  
Stephan Baumgartner
Keyword(s):  
Growth Rate ◽  
Gibberellic Acid ◽  
Growth Rates ◽  
Statistical Power ◽  
Test System ◽  
Negative Control ◽  
Test Substance ◽  
Image Analysis System ◽  
Water Control ◽  
Analysis System

This study evaluated the effects of homeopathically potentized Arsenicum album, nosode, and gibberellic acid in a bioassay with arsenic-stressed duckweed (Lemna gibbaL.). The test substances were applied in nine potency levels (17x, 18x, 21x–24x, 28x, 30x, 33x) and compared with controls (unsuccussed and succussed water) regarding their influence on the plant’s growth rate. Duckweed was stressed with arsenic(V) for 48 h. Afterwards, plants grew in either potentized substances or water controls for 6 days. Growth rates of frond (leaf) area and frond number were determined with a computerized image analysis system for different time intervals (days 0–2, 2–6, 0–6). Five independent experiments were evaluated for each test substance. Additionally, five water control experiments were analyzed to investigate the stability of the experimental setup (systematic negative control experiments). All experiments were randomized and blinded. The test system exhibited a low coefficient of variation (≈1%). Unsuccussed and succussed water did not result in any significant differences in duckweed growth rate. Data from the control and treatment groups were pooled to increase statistical power. Growth rates for days 0–2 were not influenced by any homeopathic preparation. Growth rates for days 2–6 increased after application of potentized Arsenicum album regarding both frond area (p< 0.001) and frond number (p< 0.001), and by application of potentized nosode (frond area growth rate only,p< 0.01). Potencies of gibberellic acid did not influence duckweed growth rate. The systematic negative control experiments did not yield any significant effects. Thus, false-positive results can be excluded with high certainty. To conclude, the test system withL. gibbaimpaired by arsenic(V) was stable and reliable. It yielded evidence for specific effects of homeopathic Arsenicum album preparations and it will provide a valuable tool for future experiments that aim at revealing the mode of action of homeopathic preparations. It may also be useful to investigate the influence of external factors (e.g., heat, electromagnetic radiation) on the effects of homeopathic preparations.

scholarly journals TIMING APPLICATION OF HYDROGEN CYANAMIDE (DORMEX) TO PEACH TREES USING A MODIFIED CHILLING MODEL

HortScience ◽  
1995 ◽  
Vol 30 (3) ◽  
pp. 430b-430
Author(s):  
Arlie A. Powell ◽  
Karl Harker
Keyword(s):  
Hydrogen Cyanamide ◽  
The Past ◽  
Proper Timing ◽  
Peach Trees

This multifaceted study was conducted over the past 6 years in Alabama to determine the efficacy of using hydrogen cyanamide to replace lack of chilling in peaches and to develop a working chilling model to allow proper timing of application. Several timings (0%, 25%, 50%, and 75% chilling accumulation) for each chilling level and rates (0%, 0.5%, 1.0%, and 2.0% v/v of 50% hydrogen cyanamide) were evaluated in commercial orchards using replicated studies. It was determined that for Dormex to be effective, 60% to 65% of chilling for the cultivar involved must be accumulated, accompanied by no bud activity beyond bud swell. Rates of 0.5% and 1% v/v of 50% work well with the latter preferred. A computer chilling model was developed to assist growers with proper timing of application.

H2O2 is involved in the dormancy-breaking effect of hydrogen cyanamide in grapevine buds

2008 ◽  
Vol 55 (2) ◽  
pp. 149-155 ◽  
Author(s):  
Francisco J. Pérez ◽  
Ricardo Vergara ◽  
Sebastián Rubio
Keyword(s):  
Dormancy Breaking ◽  
Breaking Effect ◽  
Hydrogen Cyanamide ◽  
Grapevine Buds

scholarly journals Biochemical Responses of Peach Leaves Infected with Taphrina Deformans Berk/Tul.

2017 ◽  
Vol 65 (3) ◽  
pp. 871-878 ◽  
Author(s):  
Lyubka Koleva-Valkova ◽  
Neshka Piperkova ◽  
Veselin Petrov ◽  
Andon Vassilev
Keyword(s):  
Molecular Mechanisms ◽  
Agricultural Science ◽  
Phytopathogenic Fungus ◽  
Antioxidant Systems ◽  
Guaiacol Peroxidase ◽  
Anthocyanin Content ◽  
Total Polyphenols ◽  
Peach Trees ◽  
Leaf Curl Disease ◽  
Plastid Pigments

The phytopathogenic fungus Taphrina deformans causing the so called “leaf curl disease” in peach trees leads to severe yield losses due to the development of leaf hypertrophy and subsequent necrosis and scission. Because of its economic importance, the molecular mechanisms underlying the onset and progression of the disease are of considerable interest to the agricultural science. In this study various biochemical parameters, including the activities of the antioxidant enzymes guaiacol peroxidase, syringaldazine peroxidase and catalase, total polyphenols and anthocyanin content, concentration of free proline, antiradical activity and quantity of plastid pigments, were characterized. All these were measured in both leaves with clear symptoms and distally situated leaves from the same plant that show no signs of the infection. The results demonstrate that the pathogen induces considerable biochemical changes concerning enzymatic and non‑enzymatic elements of the plant defense and antioxidant systems. Moreover, it seems that the fungus provokes a systemic response detectable even in the tissues without observable symptoms.

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