Table 2.

Frequency of major instructional topic occurrence in the syllabi of 68 collegiate arboriculture courses taught in the U.S. Syllabi were compiled in 2009 and comprise 41 courses from two-year programs and 27 courses from four-year programs.

	Topic frequency in course syllabi (%)
Major instructional topics	Overall	Four-year programs	Two-year programs	P-value^{^z}
Pruning	85	89	83	0.4970
Disorders	81	89	76	0.1730
Physiology/Biology	79	82	78	0.7320
Risks/Hazards	79	85	76	0.3393
Soils/Nutrition	75	78	73	0.6677
Planting	74	78	71	0.5193
Selection	62	63	61	0.8689
Climbing	57	59	56	0.7965
Water relations	56	59	54	0.6490
Preservation/Construction	53	59	49	0.3969
Safety	53	52	54	0.8839
Tools/Equipment	53	52	54	0.8839
Appraisals	32	37	29	0.5029
Benefits/Values of trees	29	22	34	0.2910
Site assessment	28	30	27	0.8012
Careers	27	30	24	0.6318
Lightning protection	27	26	27	0.9342
Identification	21	0	34	0.0007
Surveys/Inventories	15	11	17	0.4970
Felling	13	7	17	0.2498
Certification	12	0	20	0.0145
Law/Legal issues	10	15	7	0.3195

↵^z