Phytotoxicity and Efficacy of Cycocel (Chlormequat Chloride) for Growth Control of Sweet Potato Vine (Ipomoea batatas Tricolor )

Transcription

1 toxicity and Efficacy of Cycocel (Chlormequat Chloride) for Growth Control of Sweet Potato Vine (Ipomoea batatas Tricolor ) By Heiner Lieth, Director Linda Dodge Shannon Still Ron Lane Jackie Bergquist Project: USDA Interregional Research Project #4 Project Number 3497A May, 004 Acknowledgements: Donors/Supporters: CDFA Minor Crops Research Grant, Project : Enhancement of the Western Region IR-4 Program to Address California Needs Kelly s Color Nursery, Davis CA UC Davis Environmental Horticulture IR4 Center Department of Environmental Horticulture University of California One Shields Ave. Davis, CA

2 PR.NO.: 3497A TRIAL: DATE: 5//04. INVESTIGATOR (Name, Address, Phone#): Dr. Heiner Lieth Department of Environmental Horticulture University of California One Shields Ave. Davis, CA 9566 Ph FAX IR-4 ORNAMENTAL DATA REPORTING FORM LOCATION OF TRIAL: Dept. of Env. Hort., University of California, Davis TRIAL TYPE greenhouse, container. PESTICIDE: COMMON NAME: Chlormequat chloride FORMULATION:.8% ai BATCH NO.: PRODUCT: Cycocel EPA REG. NO.: 4-74-AA MFG: American Cyanamid (BASF) 3. USE INFORMATION: COMMON NAME SCIENTIFIC NAME PLANT: Sweet potato vine Ipomoea batatas Tricolor REASON: reduction SOIL TYPE OR TYPE OF POTTING MIX: 50% UC Mix, 50% Perlite % SAND 5 %SILT % CLAY % OM 35 % Perlite 50 ph 6.5 SEEDING DATE EMERGENCE DATE TRANSPLANTING DATE: 3//04 PLANT OR POT SPACING 8 inches ROW SPACING 8 inches POT SIZE 4 inch PLOT SIZE 60 sq ft EXPERIMENTAL DESIGN randomized complete block with three blocks and 4 replicates per block 4. APPLICATION PARAMETERS: TYPE OF APPLICATION foliar spray, 6 oz. per treatment NO. OF APPLICATIONS two APPLICATION TYPE quart-size spray bottle NOZZLE TYPE/SIZE NOZZLE PRESSURE DELIVERY RATE CALIBRATION DATE(S) 5. APPLICATION SUMMARY: APPL.DATE RATES (a.i./a)* GROWTH STAGE 4//04 0, 0.8,.6, 3. fl. oz./gal. Transplanted cuttings (0, 750, 500, /9/04 0, 0.8,.6, 3. fl. oz./gal. Transplanted cuttings (0, 750, 500, 3000 *Be sure to provide units

3 PR.NO.: 3497A TRIAL: DATE: 5//04 IR-4 ORNAMENTAL DATA REPORTING FORM (Please type or print) 6. RAINFALL/IRRIGATION RECORDS: INCLUDE RAINFALL/IRRIGATION INFORMATION (printouts, IR-4 forms, etc.) Plants were irrigated as needed (daily) with half-strength Hoagland s solution 7. OTHER PESTICIDES, FERTILIZER, LIME AND ADJUVANTS USED: PRODUCT Talstar F (Bifenthrin) AMOUNT DATE 4/8/04 PRODUCT Distance AMOUNT DATE 4/8/04 PRODUCT Avid AMOUNT DATE 5/0/04 PRODUCT Conserve SC AMOUNT DATE 5/0/04 8. NARRATIVE SUMMARY OF METHODS AND RESULTS: (Use more pages if needed) Materials and Methods Plant Material and Culture. Cuttings with two nodes were taken from stock plants of Ipomoea batatas Tricolor on /9/04, treated at the base with powdered rooting hormone (Hormodin ) and stuck in six-packs containing 50% vermiculite and 50% perlite. The cuttings were placed in a mist bench with bottom heat of 75 F (4 C) under natural day length and allowed to root for nine weeks. On 3//04, the rooted cuttings were transplanted into 4-inch pots in a medium of 50% UC Mix and 50% perlite. The plants were grown for four weeks in a glasshouse under natural day length and average day/night temperatures of 78 F/65 F (5 C/8 C) (Figure ). The plants were watered as needed (at least once a day) with half-strength Hoagland s solution. Applications of pesticides as part of the general pest management program were made as needed (see No.7 above). Experimental Procedure. Forty-eight plants were randomly chosen and individually tagged for treatment with 0, 750, 500 or 3000 ppm Chlormequat chloride with replicates per treatment. The plants received two foliar spray applications of the designated treatment on 4//04 and one week later on 4/9/04 (Figure ). Plant leaves were sprayed to runoff using quart-sized manual spray bottles. The plants were arranged in a randomized complete block design with 3 blocks and 4 replicates per block on 4/30/04. toxicity observations using a numerical rating scale (Table ) were made weekly until 5//04 (4 weeks). The length of two branches per plant was measured weekly until 5//04 (4 weeks, 5 measurements). Statistical Analysis. The data were analyzed using Proc GLM of the Statistical Analysis System (SAS). The mean increases from the starting stem length were analyzed for significant differences using t-tests. The plants were arranged in a randomized, complete block design. Results toxicity. Chlormequat chloride at s of 0, 750, 500 or 3000 ppm had no phytotoxic effects on Ipomoea batatas Tricolor (Appendix A). Control of Plant Growth. The results show that Ipomoea is not affected by Chlormequat chloride. There were no significant differences for increase of stem length throughout the entire experiment (Figures 3 and 4, Appendix B). Discussion While there was no significant difference in increased stem length, there appeared to be a difference in plant growth when analyzing the photographs after the termination of the experiment. The plants in the 3000 ppm treatment appeared less full in total foliage than the other three treatments. However, the stem length increase was not different. The Chlormequat chloride may have some effect on branching for the Ipomoea but no effect on stem length. 3

4 PR.NO.: 3497A TRIAL: DATE: 5//04 9. GOOD RESEARCH PRACTICE STATEMENT: I acknowledge that I have read and followed the IR-4 Research protocol and completed this trial following good agricultural practice, or reported any deviations (note any changes from authorized protocol in narrative). SIGNATURE Dr. Heiner Lieth, PRINCIPAL INVESTIGATOR DATE 4

5 PR.NO.: 3497A TRIAL: DATE: 5//04 Figure. Greenhouse air temperatures during experiment to determine effects of Chlormequat chloride on Ipomoea batatas Tricolor. 5

6 PR.NO.: 3497A TRIAL: DATE: 5//04 Figure. Ipomoea batatas Tricolor plants were sprayed with 0, 750, 500 or 3000 ppm Chlormequat chloride on 4//04 and 4/9/04. Table. Numerical plant damage rating scale used for phytotoxicity determinations. Rating Description of plant damage 0 No damage No visible damage but unintended (non-permanent) impact Slight leaf/tissue damage (curling leaves, necrosis, etc.) 3 Marginal chlorosis on some leaves (damage on up to 0% of plant) 4 0% 0% of plant damaged 5 Significant damage to much of plant (30% - 40%) 6 40% 60% of plant damaged 7 Chlorosis or necrosis on most of plant (60% - 70%) 8 Abscised leaves, branch dieback 9 Tissue severely damaged (80% - 00% of plant) 0 Complete kill 6

7 PR.NO.: 3497A TRIAL: DATE: 5//04 Control 750 ppm 500 ppm 3000 ppm Block A Control 750 ppm 500 ppm 3000 Block B Control 750 ppm 500 ppm 3000 ppm Block C Figure 3. Ipomoea batatas Tricolor plants 4 weeks after applications of 0, 750, 500 or 3000 ppm Chlormequat chloride. 7

8 PR.NO.: 3497A TRIAL: DATE: 5//04 Increased Shoot ppm 750 ppm 500 ppm 3000 ppm weeks after treatment Figure 4. Effect of two foliar applications of Chlormequat chloride on branch length increase of Ipomoea batatas Tricolor four weeks post-treatment (n = ). 8

9 PR.NO.: 3497A TRIAL: DATE: 5//04 APPENDIX A PHYTOTOXICITY REPORT FORM: Ipomoea Treatment Rate oz. ai/gal Blk Rep 4/3/04 4/30/04 5/07/04 5/5/04 5//04 Control 0 A Control 0 A Control 0 A Control 0 A Control 0 B Control 0 B Control 0 B Control 0 B Control 0 C Control 0 C Control 0 C Control 0 C Control 0 Avg A A A A B B B B C C C C Avg A A A A B B B

10 PR.NO.: 3497A TRIAL: DATE: 5//04 Treatment Rate oz. ai/gal Blk Rep 4/3/04 4/30/04 5/07/04 5/5/04 5//04.6 B C C C C Avg A A A A B B B B C C C C Avg NOTE: DEFINE MEASUREMENT OF PHYTOTOXICITY, OR INDEX OF INJURY (0=NO INJURY, 0=COMPLETE KILL) See Table. *Be sure to provide units 0

11 PR.NO.: 3497A TRIAL: DATE: 5//04 APPENDIX B EFFICACY REPORT FORM (BRANCH LENGTHS): Ipomoea Treatment Rate oz. ai/gal Blk Rep 4/3/04 4/3/04 4/30/04 4/30/04 5/07/04 5/07/04 5/5/04 5/5/04 5//04 Control 0 A Control 0 A Control 0 A Control 0 A Control 0 B Control 0 B Control 0 B Control 0 B Control 0 C Control 0 C Control 0 C Control 0 C Control 0 Avg A A A A B B B B C C C C Avg A A A A B B B //04

12 PR.NO.: 3497A TRIAL: DATE: 5//04 Treatment Rate oz. ai/gal Blk Rep 4/3/04 4/3/04 4/30/04 4/30/04 5/07/04 5/07/04 5/5/04 5/5/04 5//04.6 B C C C C Avg A A A A B B B B C C C C Avg //04 Efficacy Scale: The length of two branches per plant was measured *Be sure to provide units