Prohexadione
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| General | |||||||||||||||||||
| Surname | Prohexadione | ||||||||||||||||||
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| Molecular formula | C 10 H 10 O 5 Approx | ||||||||||||||||||
| Brief description |
yellow powder with a sweet odor |
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| properties | |||||||||||||||||||
| Molar mass | 250.56 g mol −1 | ||||||||||||||||||
| Physical state |
firmly |
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| density |
1.45 g cm −3 |
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| Melting point |
> 360 ° C |
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| solubility |
very heavy in water (0.174 g l −1 at 20 ° C) |
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| As far as possible and customary, SI units are used. Unless otherwise noted, the data given apply to standard conditions . | |||||||||||||||||||
Prohexadione is a chemical compound from the group of carboxylic acids and a phytohormone . Prohexadione calcium inhibits certain steps in the gibberellin biosynthesis and is used in fruit, wine, arable and ornamental plant cultivation. Prohexadione is a plant growth regulator and also has a bactericidal effect. The compound was patented by Kumiai Chemical in 1983 .
Extraction and presentation
Prohexadione can be obtained by reacting diethylacetonyl succinate with sodium ethoxide , hydrogen chloride , propionyl chloride , 4- (dimethylamino) pyridine and sodium hydroxide .
use
The active ingredient prohexadione calcium is absorbed mainly through the leaf within a few hours after application. For optimal transport to the actual site of action in the cell's cytoplasm, it is necessary to set the spray liquid to a pH value of approx. 5.
Effect and indications
Through the targeted use of prohexadione calcium, the vegetative performance and the fruit yield of a pome fruit plant (with the exception of pears) can be brought into an optimal ratio. By regulating the growth, cutting costs are reduced and balanced yields are achieved. Due to the increased incidence of light, the color of the fruit improves. By activating plant defense mechanisms, Prohexadione has a preventive effect against secondary fire blight infections in pome orchards.
In grapevines, the application of Prohexadione Calcium during the flowering period can loosen up the grape structure. With compact grape varieties, this reduces the mutual pressing of the berries and the associated damage to the berry skin with subsequent fruit rot infestation ( botrytis , green rot, vinegar rot). With the loosening a better deposition of botryticides inside the grape is achieved. The effect mentioned is also accompanied by a reduction in yield.
In the cultivation of ornamental plants it is used preventively against bacterial leaf spot pathogens, fire blight ( Erwinia amylovora ) and to compress the shoots.
In agriculture, one can with prohexadione-calcium in winter wheat, winter barley, winter rye, triticale, spelled, summer durum wheat, spring wheat, spring barley and oats Internodienverkürzung be achieved. This solidification of the stalk reduces the storage of grain crops.
In sports and ornamental lawns, it is used to reduce the growth in the length of the grass shoots. Prohexadione calcium also inhibits flower formation in annual bluegrass ( Poa annua )
Problems
The date of use (stage of development of the crop in question), the temperature and humidity during and after application, the drying phase, the type of fruit and the variety play a decisive role in determining the effect. With some varieties the desired effects can be achieved well and with other varieties not at all. The annual successes (efficiency) also fluctuate strongly. These application problems make it difficult to use. For example, prohexadione calcium must be applied to the vine when the flowers are in bloom (mid-June) in order to reduce the occurrence of vinegar rot during the berry ripening phase in autumn. There is no prognosis for the occurrence of vinegar rot. A certain annual success rate can only be achieved through timely use.
Trade names
- Regalis ( BASF )
- Regalis Plus (BASF)
- Medax Top (BASF)
Admission
Prohexadione-Calcium was added to the list of active ingredients for pesticides permitted in the EU in 2000 . After this approval expired, the active ingredient was approved again by the EU Commission in 2011.
Plant protection products with the active ingredient prohexadione are approved in a number of EU countries, including Germany (since 2004) and Austria, as well as Switzerland.
Web links
- TUM Science Center Weihenstephan: Bioregulator with surprising side effects - medicine for fruit trees
- www.agrar.basf.at: BASF Regalis
- www.agrar.basf.at: BASF Medax Top
- Susanne Böll, Heinrich Hofmann, Peter Schwappach: Varietal-specific differences in fertility parameters and their significance for the application of the growth regulators GA 3 and Prohexadione-Calcium , Mitteilungen Klosterneuburg 59/2009, pp. 209–216.
- Wolfgang Renner: Bioregulators in viticulture - reduction of grape rot , experimental station for fruit and viticulture in Haidegg, Graz, Der Winzer, April 30, 2013, Österreichischer Agrarverlag, Vienna
Individual evidence
- ↑ a b c d e f g h Entry on Prohexadione Calcium in the GESTIS substance database of the IFA , accessed on January 9, 2019(JavaScript required) .
- ↑ Patent EP0123001A1 : Cyclohexane derivatives with plant growth regulating activity and application of these derivatives. Filed September 23, 1983 , published October 31, 1984 , Applicants: Kumiai Chemical Industry, Inventors: Kenji Motojima, Takeshige Miyazawa, Yasufumi Toyokawa, Masafumi Matsuzawa, Hiroshi Hokari, Shoji Kusano.
- ↑ Thomas A. Unger: Pesticide Synthesis Handbook . William Andrew, 1996, ISBN 0-8155-1853-6 , pp. 796 ( limited preview in Google Book search).
- ^ Office for Agriculture and Forests Töging / Inn: Use of growth regulators in grain ( Memento from March 6, 2014 in the Internet Archive )
- ↑ Directive 2000/50 / EC of the Commission of July 26, 2000 (PDF) for the inclusion of an active ingredient (prohexadione calcium) in Annex I of Directive 91/414 / EEC on the placing of plant protection products on the market.
- ↑ Implementing Regulation (EU) No. 702/2011 of the Commission of July 20, 2011 (PDF) for the approval of the active substance prohexadione according to Regulation (EC) No. 1107/2009 of the European Parliament and of the Council on the placing of plant protection products on the market and amending it of the Annex of the Commission Implementing Regulation (EU) No. 540/2011.
- ↑ General Directorate Health and Food Safety of the European Commission: Entry on Prohexadione in the EU pesticide database; Entry in the national registers of plant protection products in Switzerland , Austria and Germany ; accessed on February 18, 2016.