Table 4

Effect of cultivar, cluster thinning, and growing season on vegetative growth of own-rooted grapevines in the Yakima Valley, WA. Note: data were not collected in 1997 and 1998.

	Shoot length at bloom (cm)			Leaf area at bloom (m²/vine)
Treatment	1999	2000	2001	1999	2000	2001
Cultivar
Cabernet Sauvignon	64 a^a	63	75	8.58	7.81 a	8.14
Riesling	67 a	55	67	8.19	6.53 b	6.31
Chenin blanc	55 b	55	72	8.73	8.11 a	8.63
Thinning
Early	64 a	57	71	8.57	7.41	7.84
Late	66 a	59	71	8.96	7.47	7.63
Control	56 b	57	72	7.96	7.57	7.60
Interaction	ns^b	ns	ns	ns	ns	ns

	Mean leaf size (cm²/leaf)			Shoot maturity at harvest^c
	1999	2000	2001	1999	2000	2001
^aMeans within columns followed by different letters differ significantly at p < 0.05 by Duncan’s new multiple range test.
^bCultivar x thinning interaction; , , **, ns: significant at p < 0.05, 0.01, 0.001, or not significant, respectively.
^cNumber of internodes/shoot with brown periderm.
^dnc: data not collected.
Cultivar
Cabernet Sauvignon	73 a	72	71 a	nc^d	14	11
Riesling	72 a	67	63 b	nc	12	11
Chenin blanc	66 b	66	74 a	nc	12	11
Thinning
Early	71 ab	68	69	nc	13	10
Late	73 a	71	69	nc	13	11
Control	67 b	67	71	nc	12	11
Interaction	**	ns	ns		ns	ns