Evaluation of Blueberry Types and Cultivars for Early Market Production in Japan Using Unheated Plastic House Culture

Figures & data

TABLE 1 Air Temperature in an Unheated Plastic House and Outdoors, and the Temperature of the Soil in Pots in 2009

			Plastic house air		Pot soil		Outdoors air ^z
Month	Day	Days after Feb 10	Mean temp.	Mean minimum temp. (°C)	Mean temp.	Mean minimum temp. (°C)	Mean air temp. (°C)
Feb.	10–20	1–11	10.8	0.2	11.7	4.2	7.3
	21–28	12–19	12.8	0.5	13.8	6.4	4.8
March	1–10	20–29	13.3	1.7	14.6	7.5	7.1
	11–20	30–39	16.7	4.6	16.7	10.2	10.2
	21–31	40–50	16.1	3.4	16.1	10.3	8.0
April	1–10	51–60	20.0	3.4	19.5	11.8	12.8
	11–20	61–70	20.2	9.9	20.3	14.9	15.4
	21–30	71–80	18.6	5.3	18.4	12.4	14.3
May	1–10	81–90	21.4	10.9	20.7	16.0	18.2
	11–20	91–100	22.5	10.0	22.1	15.4	18.8
	21–31	101–111	22.8	13.7	22.6	18.4	19.5
June	1–10	112–121	23.0	13.3	22.4	17.5	19.4
	11–20	122–131	23.3	15.9	22.8	19.2	19.7
	21–30	132–141	26.0	14.2	25.6	21.6	23.3
July	1–10	142–151	26.0	17.4	25.4	20.8	23.4
	11–15	152–156	28.9	17.7	28.0	21.5	25.3
^zAt Tsuchiura-shi, arranged from Tsuchiura Weather Station's report.

TABLE 2 Flowering Time of Three Types of Blueberries Grown in an Unheated Plastic House in 2009

			Flowering time (days after February 10, 2009) ^x
Type ^z	Cultivar	Plant age (year)	20%	50%	80%	Flowering period ^w
NHb	Chandler	3	50 ^v a	56 ^v a	61 ^v a	11
	Hannah's Choice	3	40 ab	46 b	50 b	10
	Nelson ^y	4	40 ab	44 bc	47 c	7
SHb	Emerald	3	29 cd	35 e	38 f	9
	Sapphire	3	31 bcd	37 de	40 ef	9
	Star	3	30 bcd	35 e	38 f	9
	Magnolia ^y	4	33 bcd	37 d	40 ef	7
	Sharpblue ^y	4	26 cd	29 f	38 f	12
Rb	Austin ^y	4	37 bcd	42 c	47 c	9
	Brightwell ^y	4	35 bcd	39 d	45 cd	10
	Tifblue ^y	4	37 bc	42 c	47 c	19
^zNHb: Northern Highbush; SHb: Southern Highbush; Rb: Rabbiteye blueberry.
^ySame plants used in 2008 year test.
^xFlowering day of 20, 50, and 80% in the whole flower cluster per plant.
^wDays from 20% of flowering to 80% flowering.
^vWithin columns, different letters indicate significance at the 5% level by Duncan's range test.

TABLE 3 Harvesting Time and Fruit Growing Interval of Three Types of Blueberries in an Unheated Plastic House in 2009

			Harvesting time (days after February 10, 2009) ^x
Type ^z	Cultivar	Plant age (year)	20%	50%	80%	Fruit growing period ^w
NHb	Chandler	3	130 ^v a	137 ^v b	141 ^v a	81 ^v b
	Hannah's Choice	3	103 c	113 c	117 b	67 cde
	Nelson ^y	4	95 e	109 d	111 bc	65 cde
SHb	Emerald	3	99 d	105 e	113 b	70 cd
	Sapphire	3	91 f	101 f	113 bc	64 de
	Star	3	91 f	101 f	105 c	66 cde
	Magnolia ^y	4	95 e	105 e	106 c	68 cde
	Sharpblue ^y	4	91 f	104 e	106 c	72 c
Rb	Austin ^y	4	123 b	141 b	148 a	99 a
	Brightwell ^y	4	123 b	141 b	148 a	102 a
	Tifblue ^y	4	131 a	144 a	148 a	102 a
^zNHb: Northern Highbush; SHb: Southern Highbush; Rb: Rabbiteye blueberry.
^ySame plants used in 2008 year test.
^xHarvesting day of 20, 50, and 80% in the whole fruit per plant.
^wDays from 20% of flowering to 80% harvesting time.
^vWithin columns, different letters indicate significance at the 5% level by Duncan's range test.

TABLE 4 Estimation of Fruit Set and Yield per Plant of Three Types of Blueberries Grown in an Unheated Plastic House in 2009

					Yield/plant
Type ^z	Cultivar	Plant age (year)	Estimated No. of floret/plant ^x	Estimation of fruit set (%) ^w	No. of fruit	Total fresh fruit wt (g)
NHb	Chandler	3	225	22.9	51.5	109.1
	Hannah's Choice	3	225	19.1	43.0	78.6
	Nelson ^y	4	1,072	19.5	208.8	381.8
SHb	Emerald	3	210	58.2	122.3	222.1
	Sapphire	3	371	36.7	136.3	156.8
	Star	3	208	42.3	88.0	169.4
	Magnolia ^y	4	1,652	26.9	444.5	573.8
	Sharpblue ^y	4	704	44.5	313.5	344.2
Rb	Austin^y	4	1,096	34.4	376.5	532.8
	Brightwell^y	4	1,575	36.9	581.0	819.1
	Tifblue^y	4	1,463	35.4	518.0	650.7
^zNHb: Northern Highbush; SHb: Southern Highbush; Rb: Rabbiteye blueberry.
^ySame plants used in 2008 year test.
^xEstimate based on 20 flowers counted per plant and determined by multiplying the total No. of flowers cluster × No. of floret per plant.
^wCalculated by dividing the estimated total No. of fruit per plant by total No. of harvested fruit per plant.

TABLE 5 Fruit Quality Parameters of Three Types of Blueberries Grown in an Unheated Plastic House in 2009

Type ^z	Cultivar	Plant age (year)	Mean fresh weight (g) ^x	Soluble solid content (%) ^x	Citric acid content (%)	SSC/CAC ratio
NHb	Chandler	3	2.13 ^w a	9.5 ^w e	0.89 ^w a	10.6
	Hannah's Choice	3	1.78 b	9.6 e	0.47 e	20.4
	Nelson ^y	4	1.89 b	12.1 b	0.77 b	15.7
SHb	Emerald	3	1.83 b	9.5 e	0.65 c	14.6
	Sapphire	3	1.16 d	9.5 e	0.32 f	29.7
	Star	3	1.84 b	10.4 d	0.49 de	21.2
	Magnolia ^y	4	1.29 cd	11.5 c	0.81 b	14.2
	Sharpblue ^y	4	0.95 e	12.6 a	0.60 c	21.0
Rb	Austin ^y	4	1.42 c	12.4 ab	0.42 e	29.5
	Brightwell ^y	4	1.41 c	11.5 c	0.53 d	21.7
	Tifblue ^y	4	1.23 d	12.0 b	0.60 c	13.3
^zNHb: Northern Highbush; SHb: Southern Highbush; Rb: Rabbiteye blueberry.
^ySame plants used in 2008 year test.
^xMean of fruit at three harvest times; 20, 50, and 80%.
^wWithin columns, different letters are significant at 5% level by Duncan's range test.