Figures (5)  Tables (2)

    • Figure 1. 

      (a)−(i) Distribution of fruit characteristics by maturity season groups MG1−4, with smoothed kernel density plots for continuous traits, and (j) bar plot for the discrete blush rating score trait. SSC = soluble solids content, TA = titratable acidity.

    • Figure 2. 

      Boxplots illustrating distributions (medians and central 50%) of fruit characteristics by (a), (b) maturity season groups MG1−4, and by (c), (d) genotypes in the groups. Genotypes are sorted by decreasing order of median value of the characteristic. SSC = soluble solids content.

    • Figure 3. 

      Pearson correlations between pairs of fruit characteristics. The blue to red color scale from −1.0 to 1.0 represents the range from the highest negative to highest positive correlations and the values near 0.0 indicate trivial to no correlations. High positive correlations (≥ 0.75) are between any two of fruit weight, flesh weight, diameter, and juice volume. Other correlations are moderate or weak.

    • Figure 4. 

      Regression and coefficient of determination (R2 value) of fruit weight with (a) equatorial diameter, (b) polar diameter, (c) pit weight, (d) flesh weight, (e) juice volume, and (f) SSC (soluble solid contents).

    • Figure 5. 

      Relationships of L vs a, L vs b, and b vs a, respectively, based on all L, a, and b values. The color of the data points is the approximate color of the peach.

    • Fruit weight (g) Pit weight (g) Flesh weight
      (g)      		 Average
      diameter (cm)      		 Firmness (kg) Juice volume (mL) SSC (°Brix) TA (%) SSC/TA ratio pH Blush rating
      (0−9)
      TO1 144 (141, 148)a 6.62 (6.42, 6.82)ab 138 (135, 142)a 6.53 (6.46, 6.60)a 4.40 (4.14, 4.65)a 17.4 (16.7, 18.1)a 11.9 (11.6, 12.3)c 0.77 (0.74, 0.81)b 15.4 (14.8, 16.1)b 3.66 (3.63, 3.69)a 7.1 (6.9, 7.4)a
      TO2 158 (154, 162)b 6.37 (6.17, 6.57)a 152 (148, 156)b 6.79 (6.72, 6.86)b 4.78 (4.52, 5.03)b 19.2 (18.4, 20.0)b 10.8 (10.5, 11.2)b 1.11 (1.07, 1.16)c 10.1 (9.67, 10.5)a 3.69 (3.66, 3.71)a 7.3 (7.1, 7.5)a
      TO3 172 (166, 177)c 6.90 (6.66, 7.15)b 164 (158, 170)c 7.02 (6.93, 7.10)c 4.72 (4.41, 5.03)ab 25.4 (24.1, 26.9)c 9.9 (9.6, 10.3)a 0.43 (0.41, 0.47)a 26.4 (24.4, 28.6)c 4.02 (3.99, 4.05)b 8.4 (8.2, 8.6)b
      MG1 145 (142, 148)b 6.77 (6.63, 6.92)b 138 (135, 142)b 6.53 (6.48, 6.59)b 4.48 (4.28, 4.67)b 20.0 (19.2, 20.7)b 10.0 (9.8, 10.2)a 0.58 (0.55, 0.61)a 25.2 (23.5, 26.8)c 3.98 (3.96, 4.00)c 8.2 (8.1, 8.4)d
      MG2 139 (135, 142)a 5.99 (5.84, 6.15)a 132 (129, 136)a 6.44 (6.37, 6.51)a 5.46 (5.20, 5.72)c 17.3 (16.5, 18.1)a 10.6 (10.3, 10.9)b 0.82 (0.79, 0.85)b 17.2 (16.4, 18.0)b 3.60 (3.58, 3.63)b 7.1 (6.8, 7.3)b
      MG3 149 (143, 155)b 6.61 (6.37, 6.85)b 143 (137, 149)b 6.68 (6.58, 6.78)c 5.14 (4.79, 5.48)c 17.7 (16.5, 18.9)a 12.5 (12.1, 12.9)c 1.07 (1.03, 1.12)c 11.6 (11.0, 12.2)a 3.46 (3.42, 3.49)a 7.7 (7.4, 8.0)c
      MG4 206 (199, 213)c 7.32 (7.07, 7.57)c 199 (191, 206)c 7.34 (7.25, 7.42)d 3.51 (3.22, 3.81)a 23.1 (21.6, 24.5)c 13.4 (13.1, 13.7)d 1.11 (1.06, 1.15)c 12.3 (11.7, 12.9)a 3.46 (3.43, 3.49)a 6.5 (6.2, 6.9)a
      WH1 147 (144, 150)a 6.77 (6.62, 6.92)c 140 (137, 144)a 6.60 (6.55, 6.66)a 5.13 (4.93, 5.33)b 18.3 (17.6, 18.9)a 10.7 (10.4, 10.9)a 0.91 (0.88, 0.95)b 12.4 (11.9, 12.9)b 3.72 (3.70, 3.74)b 7.1 (6.9, 7.3)a
      WH2 157 (154, 161)b 6.49 (6.34, 6.63)b 152 (148, 155)b 6.77 (6.71, 6.82)b 4.15 (3.95, 4.34)a 20.0 (19.3, 20.7)b 11.4 (11.2, 11.6)b 0.81 (0.79, 0.84)a 14.4 (14.0, 14.9)c 3.76 (3.74, 3.78)c 7.7 (7.5, 7.9)b
      WH3 162 (155, 170)b 6.16 (5.89, 6.44)a 155 (147, 163)b 6.85 (6.73, 6.96)b 4.24 (3.86, 4.62)a 19.4 (18.0, 20.9)ab 12.7 (12.3, 13.1)c 0.81 (0.77, 0.86)a 15.4 (14.5, 16.4)c 3.60 (3.56, 3.64)a 7.8 (7.4, 8.1)b
      WH4 153 (138, 170)ab 5.70 (5.19, 6.25)a 147 (132, 165)ab 6.70 (6.43, 6.97)ab 3.82 (2.90, 4.74)a 19.8 (16.5, 23.8)ab 12.0 (11.1, 13.0)bc 1.10 (0.98, 1.23)c 10.6 (9.27, 12.2)a 3.53 (3.44, 3.62)a 9.0 (8.5, 9.4)c
      z Statistical analysis was performed among the three trial orchards (TO1−3), four maturity groups (MG1−4) approximately close to the seasons of 'Gala', 'Harvester', 'Cresthaven', and 'O'Henry', and four weekly harvests (WH1−4), respectively, using linear mixed models and Sidak p-value adjustment for multiple comparisons (α = 0.05) in R software with the lme4 and emmeans packages. Means with the same letters within each factor are not significantly different.

      Table 1. 

      Means, 95% confidence intervals, and letters of statistical significance of peach fruit characteristicsz.

    • Blush Ground Back Suture Shoulder Tip Flesh1 Flesh2 Pit hole Pit
      Hunter a MG1 17.76
      (16.95, 18.58)bc      		 19.67
      (18.86, 20.48)c      		 21.92
      (21.11, 22.73)b      		 22.78
      (21.97, 23.59)b      		 18.27
      (17.46, 19.08)b      		 21.84
      (21.03, 22.65)b      		 3.00
      (2.10, 3.90)a      		 3.40
      (2.51, 4.30)a      		 2.19
      (1.25, 3.13)a      		 10.97
      (10.12, 11.82)a
      MG2 16.73
      (15.72, 17.74)ab      		 17.57
      (16.56, 18.58)b      		 20.07
      (19.06, 21.08)a      		 20.20
      (19.18, 21.21)a      		 17.38
      (16.37, 18.39)ab      		 22.58
      (21.57, 23.59)b      		 5.98
      (4.94, 7.03)b      		 6.10
      (5.06, 7.15)b      		 8.69
      (7.64, 9.73)b      		 16.85
      (15.82, 17.89)b
      MG3 15.29
      (13.80, 16.79)ab      		 17.84
      (16.34, 19.33)b      		 21.76
      (20.26, 23.25)ab      		 21.19
      (19.69, 22.68)ab      		 17.13
      (15.63, 18.62)ab      		 23.19
      (21.70, 24.69)b      		 10.94
      (9.45, 12.44)c      		 10.95
      (9.46, 12.45)c      		 14.37
      (12.87, 15.86)d      		 10.21
      (8.71, 11.70)a
      MG4 18.68
      (17.40, 19.95)c      		 14.15
      (12.87, 15.42)a      		 20.98
      (19.70, 22.25)ab      		 20.20
      (18.93, 21.47)a      		 15.92
      (14.65, 17.19)a      		 18.66
      (17.39, 19.94)a      		 11.26
      (9.99, 12.53)c      		 11.55
      (10.28, 12.83)c      		 11.15
      (9.87, 12.42)c      		 10.00
      (8.70, 11.30)a
      Hunter b MG1 6.76
      (6.10, 7.43)a      		 20.17
      (19.52, 20.83)a      		 12.57
      (11.91, 13.22)a      		 12.52
      (11.86, 13.18)a      		 12.99
      (12.33, 13.65)a      		 11.20
      (10.54, 11.85)a      		 21.43
      (20.70, 22.15)a      		 20.44
      (19.71, 21.16)a      		 15.77
      (15.00, 16.53)c      		 21.65
      (20.97, 22.34)c
      MG2 7.39
      (6.57, 8.22)ab      		 20.87
      (20.05, 21.69)a      		 13.86
      (13.04, 14.68)b      		 12.53
      (11.71, 13.35)a      		 12.69
      (11.87, 13.51)a      		 14.30
      (13.48, 15.12)b      		 23.22
      (22.37, 24.07)b      		 22.84
      (21.99, 23.68)b      		 14.10
      (13.25, 14.95)b      		 16.94
      (16.10, 17.78)b
      MG3 6.14
      (4.93, 7.36)a      		 22.47
      (21.25, 23.68)b      		 14.31
      (13.09, 15.53)b      		 12.38
      (11.16, 13.60)a      		 13.92
      (12.71, 15.14)a      		 14.00
      (12.78, 15.21)b      		 27.18
      (25.96, 28.40)c      		 27.70
      (26.49, 28.92)c      		 5.58
      (4.36, 6.80)a      		 8.32
      (7.10, 9.54)a
      MG4 8.38
      (7.35, 9.42)b      		 26.66
      (25.63, 27.70)c      		 18.84
      (17.81, 19.88)c      		 15.64
      (14.60, 16.67)b      		 16.01
      (14.97, 17.04)b      		 20.98
      (19.94, 22.01)c      		 28.73
      (27.70, 29.77)c      		 28.69
      (27.65, 29.72)c      		 4.97
      (3.94, 6.01)a      		 8.31
      (7.26, 9.37)a
      y Statistical analysis was performed among the four maturity groups (MG1−4) using linear mixed models and Sidak p-value adjustment for multiple comparisons (α = 0.05) in R software with the lme4 and emmeans packages. Means with the same letters within each factor are not significantly different.

      Table 2. 

      Means, 95% confidence intervals, and letters of significance of values of the Hunter a and b color scale measured at different fruit spotsy.