U.S. flagAn official website of the United States government
                    Here's how you know **Official websites use .gov**
                            
                            A **.gov** website belongs to an official government organization in the United States.
 **Secure .gov websites use HTTPS**
                            
                            A **lock** (                            
                              A locked padlock                                                      
                            
                            ) or **https://** means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.


Menu Agricultural Research Service
						
                    U.S. DEPARTMENT OF AGRICULTURE
 Crops Pathology and Genetics Research: Davis, CA
 close



    Research

                    Research Projects
                                    Publications
                                    Collaborations
                                    News
                People

                    Staff Listing
                                    Careers


        


                    Outreach Events
                        UC Davis Picnic Day
                                    Kinders go to College
                                    STEM Girls
                                    Future Scientist Program
                                    Agriculture Future of America
                                    Wallace-Carver Fellowship
                                    Young Scholars Program
                                    Annual Awards Banquet
                    About Us
                        About Us
                                    Our Mission
                                    Principal InvestigatorsSearch small
                    Search
            
            ARS Home
                                About ARS
                                Contact Us




ARS Home Pacific West Area Davis, California Crops Pathology and Genetics Research Research Publications at this Location





- ARS National Programs
- Search for a scientific manuscript
- Search for a research project
- ARS Software
- Programs and Projects
- Collaborations
- Subjects of Investigation
- Publications
- Etiology and Biology of Tree Crop Diseases
- Rice Genetics
- Sustainable Floriculture
- Sustainable Viticulture

Title:   Author  item
                                            Jiang, Cai-Zhongitem
                                            WU, LANFANG - UC DAVIS, PLANT SCIENCESitem
                                            MACNISH, ANDREW - UC DAVIS, PLANT SCIENCESitem
                                            KING, ANN - UC DAVIS, PLANT SCIENCESitem
                                            YI, MINGFANG - UC DAVIS, PLANT SCIENCESitem
                                            REID, MICHAEL - UC DAVIS, PLANT SCIENCES
  Submitted to: Acta Horticulturae
                                    Publication Type: Peer Reviewed Journal
                                    Publication Acceptance Date: 6/1/2009
                                    Publication  Date: 12/1/2009
                                    Citation: Jiang, C., Wu, L., Macnish, A., King, A., Yi, M., Reid, M.S. 2009. Thidiazuron, a non-metablized cytokinin, shows promise in extending the life of potted plants. Acta Horticulturae. 847: 59-65.Interpretive Summary: Leaf yellowing, senescence, and abscission are significant problems that reduce the marketability and longevity of many cut flowers and potted flowering plants, including alstroemeria, lilies and chrysanthemums. In addition to the visual quality implications of leaf yellowing, it may have a physiological effect in reducing the photosynthesis that is crucial for normal flower development and longevity. 
Thidiazuron (TDZ), an inexpensive and non-metabolized phenyl-urea compound, has been shown to have a potent cytokinin-like activity at 50-100 times lower concentrations than the synthetic cytokinin benzylaminopurine (BAP). TDZ is commonly used at high concentrations as a defoliant in cotton production (‘Dropp’) and at low concentrations for tissue regeneration in culture. Ferrante et al. have demonstrated that TDZ dramatically retards chlorophyll degradation in leaves of cut flowers of alstroemeria, tulips and chrysanthemums. TDZ also was reported to markedly delay the onset of leaf senescence in Pelargonium and to reduce flower abscission and the senescence of leaves and flowers in cut inflorescences of phlox and lupins. Although the exact mode of action of TDZ is not well known, evidence suggests that TDZ can modulate cytokinin biosynthesis and/or metabolism, and may mimic the activity of auxin. It has been hypothesized that the long-lived cytokinin effect provided by TDZ treatment not only prevents leaf yellowing, but also reduces ethylene sensitivity.
Here we report the effects of spray-application of TDZ on leaf yellowing and display quality of potted plants. We examined the possible use of TDZ for delaying leaf yellowing in a range of potted plants, including geranium, freesia, Ornithogalum, and Euphorbia fulgens.  Spray treatments with 2 to 10 μM TDZ at the end of the production cycle had significant, sometimes spectacular effects on the postharvest performance of most species studied.  In addition to a considerable delay in leaf yellowing and/or abscission in most species tested, TDZ application improved display performance in a number of species.  In geranium, for example, the individual florets on TDZ-treated plants had a significantly longer life than those on control plants.  In E. fulgens, flowers lasted longer, and more flowers opened on the TDZ-treated plants.  Our results indicate significant potential for TDZ as a tool to improve the postharvest life of potted flowering and foliage plants.
                                Technical Abstract: Application of low concentrations of thidiazuron (N-phenyl-N’-1,2,3-thiadiazol-5-yl urea, TDZ) has been shown to be a very effective means of delaying leaf yellowing in cut flowers such as alstroemeria, stock, lilies and tulips.  We examined the possible use of this compound for delaying leaf yellowing in a range of potted plants, including geranium, freesia, Ornithogalum, and Euphorbia fulgens.  Spray treatments with 2 to 10 μM TDZ at the end of the production cycle had significant, sometimes spectacular effects on the postharvest performance of most species studied.  In addition to a considerable delay in leaf yellowing and/or abscission in most species tested, TDZ application improved display performance in a number of species.  In geranium, for example, the individual florets on TDZ-treated plants had a significantly longer life than those on control plants.  In E. fulgens, flowers lasted longer, and more flowers opened on the TDZ-treated plants.  Our results indicate significant potential for TDZ as a tool to improve the postharvest life of potted flowering and foliage plants.


Return to top


Connect with ARS Sign up


ARS Home
                            USDA.gov
                            Plain Writing
                            Policies & Links
                            Civil Rights Statements
                            FOIA
                            Accessibility Statement
                            Privacy Policy
                            Non-Discrimination Statement
                            Quality of Information
                            USA.gov
                            WhiteHouse.gov