Surface-check variation in boxed-heart square timber of sugi (Cryptomeria japonica) cultivars dried by the conventional kiln drying

Journal of Wood Science

Official Journal of the Japan Wood Research Society

Table 1 Heartwood percentage (HWP) on the transverse face of the timber and moisture content of the green and dried timber (MC_GT, MC_DT)

Kiln group	Cultivar	Sample	N	H (m)	HWP (%)		MC_GT (%)		MC_DT (%)
Kiln group	Cultivar	Sample	N	H (m)	Mean	SD	Mean	SD	Mean	SD
1	Boka-sugi	B1	20	0.7–2.6	95.8***	7.8	87.3	11.5	19.4***	4.3
1	Boka-sugi	B4	20	6.4–8.3	35.4	18.0	120.9***	18.5	14.3	4.9
2	Aya-sugi	A1	15	0.6–2.4	100	0.0	23.0	4.5	13.7	4.7
2	Aya-sugi	A4	15	6.0–7.8	99.9	0.3	27.7**	2.2	16.5	2.3
3	Ryuunohige	R1	10	0.7–2.6	99.2***	2.5	65.7**	18.5	23.2**	6.0
3	Ryuunohige	R4	10	6.0–7.9	69.5	14.7	44.4	3.2	15.3	2.2
4	Yabukuguri	Y1	10	1.5–3.5	100	0.0	32.0	3.8	16.1	3.9
4	Yabukuguri	Y4	10	6.1–8.1	99.5	1.6	30.3	4.4	14.9	3.7
4	Kumotooshi	K1	10	1.5–3.5	96.1***	7.7	77.4***	22.7	32.7**	9.1
4	Kumotooshi	K4	10	6.1–8.1	69.5	17.6	43.8	14.7	21.0	6.5

N Number of boxed-heart squares, H height above the ground of the timer source, SD standard deviation
Asterisks show significant differences between timber 1 and timber 4 within cultivars using a paired t test (***P < 0.001, **P < 0.01)