The Effects of Scarification On Kentucky Coffee Tree Seeds Bobby Nance HORT 2244

Gymnocladus dioicus Landscape value: great for large areas like parks or golf courses 60 to 75’ in height 40 to 50’ in width Propagated by: Seeds, cuttings, and grafting Rich moist soil, zones 3-8 Known to handle: Drought Urban conditions Full sun

Scarification Scarification is the cutting of the seed coat using abrasion, thermal stress, or chemicals to encourage germination Basically, used to knock through the seed coat with the goal of imbibing the seed with water to promote germination Methods of scarification used in my project: Sulfuric Acid treatment: 4 hour soaking duration Heavily sanded treatment using 100 grit sandpaper Lightly sanded treatment using 100 grit sandpaper Moderately sanded treatment by rubbing on coarse cement One group of seeds was left unscarified as a control group

Sulfuric Acid Treatment Duration: 4 hours Triple rinsed afterwards Employed with 4 seeds

Sanding Scarification Treatment 2 seeds: 100 grit sand paper -One heavily sanded -One lightly sanded Rubbed against coarse GH cement floor: -One moderately sanded Determined heavily, moderately, and lightly on the amount of endosperm exposed through the seed coat

Sanding Treatment From left to right: the seed that was heavily sanded exposing much of the endosperm, the seed that was lightly sanded showing minimal exposure of the endosperm, and the seed was coarsely sanded using the rubbing technique against a coarsely textured surface exposing a moderate amount of the endosperm.

The Set up 4” Pots -Each labeled with corresponding contents Media: -75-85% Canadian sphagnum peat moss -horticultural grade perlite -dolomitic limestone mix (aka- #1 Mix in GH)

Progression: Control Group Surprising results for being unscarified. Seed coat is very thick and hard.

Progression: Sulfuric Acid Expected results from scarified seeds by sulfuric acid

Progression: Heavily Sanded Had not germinated on first check up, very slow results, showed less growth than control and sulfuric acid treated group

Progression: Moderately Sanded Not very impressive results

Progression: Lightly Sanded Comparative results to heavily sanded

Results: The better Performing Sulfuric Acid Treated Control

Results: Low Performing Heavily Sanded Moderately Sanded Lightly Sanded (best of three)

Conclusion Better early vegetative growth gave rise to better root growth and vigor, based on IAA theory from Plant Propagation Lecture. Showing the movement of IAA an auxin to the roots. Supplementing the conclusion that greater foliage development can lead to a more extensive root system (Harris, Cuttings 3 Lecture).

What was learned? I learned that it was possible to propagate Kentucky Coffee Tree seeds without scarification at all, which I thought was impossible. I also learned that scarification by sanding is not very effective and that scarification by sulfuric acid can show favorable results.

References http://plants.ces.ncsu.edu/plants/all/gymnocladus-dioicus/ http://en.wikipedia.org/wiki/Scarification_%28botany%29 Dirr, Michael, and Charles W. Heuser. The Reference Manual of Woody Plant Propagation: From Seed to Tissue Culture. Portland, OR: Timber, 2006. Print. Harris, Roger. "Cutting Propagation." Plant Propagation Lecture. Virginia, Blacksburg. 19 Mar. 2014. Lecture.