altering taproot architecture of black tupelo (nyssa sylvatica) to a more fibrous root system
DESCRIPTION
I presented this powerpoint at a national conference for the American Society of Horticultural Sciences in St. Louis on July 27, 2009. ABSTRACTThe demand for native plants in the urban landscape continues to increase. Traditional plant production methods in nurseries have had limited success in producing saleable plants from some of our native trees. One of the major difficulties relates to species that produce a taproot. I investigated alternate container production methods in a tree native to Illinois with multiple seasons of interest, the black tupelo (Nyssa sylvatica). Black tupelo is rarely found in the urban landscape because of a coarse root system rendering it difficult to transplant. Three existing root promotion techniques, air-root pruning, manual root pruning or auxin (K-IBA) dips, were used on container grown young seedlings and two-year-old transplanted liners. My objective was to alter taproot architecture of black tupelo and promote a more fibrous root system to alleviate transplant shock and facilitate field establishment. Results showed that superior root systems were produced using several air-root pruning containers that are also more economically feasible than similar standard containers. Higher concentrations of auxin resulted in an increase in all plant parts measured, with an increase in survival. Manual root pruning produced only minor benefit.TRANSCRIPT
ALTERING TAPROOT ARCHITECTURE OF BLACK TUPELO (NYSSA SYLVATICA) TO
A MORE FIBROUS ROOT SYSTEM
Jimmy Klick, M.S. - Urban Forestry
Advisor: Dr. David J. Williams
Research Introduction
Objective
Research Introduction
Air-root pruning Small Containers
Research Introduction
Air-root pruning Small Containers Medium Containers
Research Introduction
Air-root pruning Small Containers Medium Containers
Auxin (K-IBA) 0 mg/L 1875 mg/L 3750 mg/L 7500 mg/L
Data Collected
1
3
Root Rating
Density Mass Coarse roots Circling roots Dead roots
Ordinal Logistic Model
Root Rating Why?
Ordinal values No transformation Determines likelihood of something occurring
How does it work? Odds Ratio
Determines how different one treatment is from another
Confidence intervals
Results: Root Rating Small Containerscd ab de de bc a bc ef f
Root Structure (Visual observations)
Fabric Container Plant Band Container
Results: Root Rating Medium Containers
b b
aa
Results: Auxin Root Rating a
Survival Rate
0 mg/L: 40% 1875 mg/L: 75% * 3750 mg/L: 65% * 7500 mg/L: 70% *
* significant difference (P = 0.025)
Conclusions
Small air-root pruning containers Black fabric and Plant Band
Medium air-root pruning containers Black fabric and green mesh
Auxin dips Transplant survivability
Future Studies
Media Transplant Auxin Ordinal Logistics Model
Acknowledgements
Advisor: Dr. David J. Williams Committee: Dr. Gary J. Kling and Dr. Jeffrey O.
Dawson Joseph Castro and Massimo Bionaz for help with
statistical analysis IR-4 Program for funding my research assistantship High Caliper Growing Systems, Lacebark Inc.,
Nursery Supplies Inc. for providing containers