Study of Parthenocarpy in Three Kiwifruit Commercial Cultivars

Figures & data

Figure 2. Fruit appearance and sections of fruits developed through artificial pollination, pistil removal with CPPU treatment, pistil removal, and natural pollination with CPPU treatment in three kiwifruit cultivars. A, ‘Rainbow Red’, B, ‘Kaimitsu’, and C, ‘Hayward’

Figure 1. Outline of the experimental design in this study

Table 1. Kiwifruit flowers, fruit bearing rate, and fruit dropping rate in each treatment in 2015

Variety	Treatment	Treated flowers	Bearing fruits	Bearing rate (%) ^a	Harvested fruits	Dropping rate (%) ^b
‘Rainbow Red’	Pistil removal	90	0	0	0	－
	Pistil removal + CPPU	90	90	100	45	50
	CPPU + Natural pollination	91	75	82	72	4
	Artificial pollination	150	136	91	131	3
‘Kaimitsu’	Pistil removal	109	61	56	17	72
	Pistil removal + CPPU	108	82	76	13	84
	CPPU + Natural pollination	106	106	100	55	48
	Artificial pollination	118	118	100	105	11
‘Hayward’	Pistil removal	101	0	0	0	－
	Pistil removal + CPPU	117	103	86	100	3
	CPPU + Natural pollination	104	82	79	80	2
	Artificial pollination	98	89	91	89	0

^aBearing rate (%) = Bearing fruits at day 30 after blooming /Treated flowers x 100.

^bDropping rate (%) = 100 - (Harvested fruits /Bearing fruits at day 30 after blooming x 100.

Table 2. Fruit weight, seed number, fruit quality, and ethylene production in each treatment in 2015

Variety	Treatment	Fruit weight (g)^a	Seed number per fruit^a	Fruit quality at harvesting time					Fruit quaity after ripening
				Number of fruits sampled	Soluble solid content (Brix)	Flesh firmness (N)	Titratable acidity (%)	Ethylene production (nL･g^−1･h^−1)	Number of fruits sampled	Soluble solid content (Brix)	Flesh firmness (N)	Titratable acidity (%)	Ethylene production (nL･g^−1･h^−1)
‘Rainbow Red’	Pistil removal + CPPU	29 ± 1 c^b	0 ± 0 c	9	14.4 ± 0.6a	20.5 ± 0.8b	1.71 ± 0.07b	n.d.^c	6	21.9 ± 0.3a	2.3 ± 5.2b	1.03 ± 0.11a	6.6 ± 0.4a
	CPPU + Natural pollination	66 ± 3b	209 ± 58b	10	7.4 ± 0.6b	26.9 ± 0.7a	1.94 ± 0.06a	n.d.	6	20.1 ± 0.7ab	4.1 ± 3.9a	0.76 ± 0.04a	2.9 ± 1.4ab
	Artificial pollination	79 ± 3a	680 ± 29a	10	6.2 ± 0.1b	28.7 ± 0.2a	1.86 ± 0.03ab	n.d.	6	19.6 ± 0.4b	3.9 ± 3.9ab	0.76 ± 0.06a	2.4 ± 1.2b
‘Kaimitsu’	Pistil removal	26 ± 4 c	0 ± 0 c	5	8.7 ± 0.6bc	25.0 ± 0.5a	2.47 ± 0.03a	n.d.	6	17.7 ± 0.4bc	4.3 ± 3.0a	1.92 ± 0.09b	4.1 ± 3.8a
	Pistil removal + CPPU	41 ± 2b	0 ± 0 c	5	20.0 ± 1.9a	13.2 ± 2.6b	2.48 ± 0.16a	n.d.	5	18.4 ± 0.6b	1.8 ± 4.8b	2.02 ± 0.10a	0.4 ± 0.4a
	CPPU + Natural pollination	74 ± 4b	46 ± 19b	10	11.1 ± 1.1b	21.6 ± 2.1a	2.32 ± 0.05a	n.d.	10	20.7 ± 1.2a	2.5 ± 7.0b	1.32 ± 0.19bc	0.5 ± 0.2a
	Artificial pollination	126 ± 1a	900 ± 29a	10	6.8 ± 0.1 c	26.8 ± 0.3a	2.32 ± 0.05a	n.d.	10	16.0 ± 0.1c	4.7 ± 1.7a	1.10 ± 0.05 c	5.8 ± 1.4a
‘Hayward’	Pistil removal + CPPU	80 ± 2a	0 ± 0 c	10	7.1 ± 0.1b	21.8 ± 0.4b	1.83 ± 0.02a	n.d.	10	16.3 ± 0.3a	4.2 ± 1.6b	1.13 ± 0.05a	9.2 ± 1.7a
	CPPU + Natural pollination	67 ± 3b	31 ± 10b	10	7.3 ± 0.4b	22.5 ± 0.3b	1.61 ± 0.09b	n.d.	10	16.0 ± 0.1a	5.1 ± 1.4a	1.15 ± 0.07a	2.2 ± 0.9b
	Artificial pollination	79 ± 3a	1114 ± 50a	10	9.4 ± 0.7a	23.9 ± 0.2a	1.95 ± 0.04a	n.d.	10	16.8 ± 0.4a	5.3 ± 1.0a	1.26 ± 0.06a	2.2 ± 0.7b

^aFruit weight was examined for all harvested fruits, whereas seed number per fruit was examined for 10 fruits.

^bMean ± S.E. Values within a column followed by the same latter in each variety are not significantly different at P < 0.05, according to Tukey’s multiple comparison test.

^cNot detected.

Table 3. Kiwifruit flowers, fruit bearing rate, and fruit dropping rate in ‘Kaimitsu’ in a repeated experiment in 2017

Place	Treatment	Treated flowers	Bearing fruits	Bearing rate (%) ^a	Harvested fruits	Dropping rate (%) ^b
Hamamatsu	Pistil removal	100	1	1	0	100
	Artificial pollination	103	89	86	86	3
Shizuoka	Pistil removal	60	9	15	1	89
	Artificial pollination	54	54	100	54	0

^aBearing rate (%) = Number of fruits at day 30 after blooming /Treated flowers x 100.

^bDropping rate (%) = 100 - (Harvested fruits /Number of fruits at day 30 after blooming x 100.