Journal APS Oct 2017

J ournal of the A merican P omological S ociety

216

feel with 0 = very firm to 3 = very soft. Berries with no visible disease symptom were scored as “no symptoms”. Fruit quality attributes [fruit mass, soluble solids concentration (SSC), pH, and titratable acidity (TA)] were determined at each harvest date on a second set of 10 fully ripe fruit with no visible disease symptoms. The fruits were weighed, crushed and filtered through cheesecloth. SSC was determined by placing a drop of the filtered juice on a handheld refractometer. Ten grams of the pureed fruit were mixed with 90 ml deionized water, and the pH of the solution was determined. Titratable acidity of the solution was determined by titrating to a pH of 8.2 with 0.1N NaOH while stirring the sample with magnetic stirrer.  Results of Study 1 indicated that ‘Sweetie Pie’ ‘Navaho’, ‘Apache’, and ‘Choctaw’ had a lower percentage of rosette infected tissue than ‘Kiowa’, ‘Shawnee’, and ‘Chickasaw’ (Table 1). In 2006 ‘Chickasaw’ and ‘Shawnee’ had higher rosette disease scores than the other seven cultivars in the trial. ‘Sweetie Pie’, ‘Kiowa’, ‘Shawnee’, ‘Rosborough’, ‘Chickasaw’, and ‘Navaho’ had a greater number of surviving plants per plot than the other three cultivars. ‘Kiowa’ and ‘Navaho’ had the firmest berries and the most berries with no disease symptoms, and ‘Kiowa’, ‘Navaho’, and ‘Sweetie Pie’ had the lowest total fruit rot disease score after 5 days incubation at 21 o C and near 100% relative humidity (Table 2). Berry mass of ‘Sweetie Pie’ was less than that of ‘Kiowa’, ‘Chickasaw’, and ‘Apache’ but was significantly higher than ‘Choctaw’ and ‘Arapaho’ (Table 3). SSC of ‘Sweetie Pie’ was lower than all cultivars but ‘Rosborough’, TA was among the lowest, and its pH was intermediate for the nine cultivars (Table 3). Study 2. Study 2 was established at McNeill, MS in 2009 to evaluate plant and fruit attributes and compare the performance of ‘Sweetie Pie’ to the thornless blackberry cultivars ‘Apache’, ‘Arapaho’, and Kiowa 30 0.80 f x 1.97 e 0.32 e 0.84 d 0.08 c 0.32 cd 60.7 a 29.3 a 1.28 f 1.67 d Navaho 22 0.95 ef 2.37 de 0.43 de 1.05 cd 0.12 bc 0.36 bcd 56.4 ab 26.4 a 1.36 ef 1.84 cd Sweetie Pie 12 1.30 de 2.45 cde 0.62 abcd 1.08 cd 0.12 bc 0.28 de 45.8 bc 11.7 bc 1.47 def 1.93 c Chickasaw 30 1.32 de 2.64 bcd 0.58 bcd 1.13 bcd 0.15 bc 0.39 bcd 46.0 bc 17.0 b 1.46 def 2.02 bc Arapaho 12 1.50 bcd 2.96 bc 0.63 abcd 1.58 a 0.20 ab 0.13 e 34.2 cd 10.8 bcd 1.58 cd 2.15 b Apache 17 1.42 cd 3.00 b 0.53 cde 1.20 bc 0.29 a 0.54 ab 32.9 d 8.5 cde 1.51 de 2.16 b Shawnee 30 1.78 bc 3.85 a 0.77 ab 1.68 a 0.17 bc 0.47 abc 27.3 d 3.3 de 1.86 b 2.61 a ‘Ouachita’ (Clark and Moore, 2005). Plots were arranged in a randomized block design Table 2. Study 1 : 2005 post-harvest fruit evaluation of nine blackberry cultivars from the 2002 blackberry cultivar trial, McNeill, MS, after 3 and 5 days incubation in humidity chamber. Table 2. Study 1: 2005 post-harvest fruit evaluation of nine blackberry cultivars from the 2002 blackberry cultivar trial, McNeill, MS, after 3 and 5 days incubation in humidity chamber. Total Disease Score z Fruit with No Disease Symptoms (%) Fruit Firmness y Cultivar N 3 day 5 day 3 day 5 day 3 day 5 day 3 day 5 day 3 day 5 day Gray Mold Disease Score z Disease Score z Ripe Rot

z Disease severity scored on visual rating of 0 = no symptoms to 3 = most severe symptoms. “Total fruit rot” is the sum of “gray mold”, “ripe rot” and “other” (data not shown) disease scores. y Berry firmness ratings: 0 = very firm to 3 = very soft. x Means within a column followed by the same letter do not differ significantly; Fisher's least significant difference (LSD), α = 0.05. Rosborough 29 1.87 b 3.89 a 0.71 abc 1.47 ab 0.20 ab 0.63 a 28.6 d 4.3 cde 1.76 bc 2.55 a Choctaw 24 2.50 a 4.03 a 0.82 a 1.43 ab 0.17 bc 0.40 bcd 11.7 e 0.4 e 2.14 a 2.62 a z Disease severity scored on visual rating of 0 = no symptoms to 3 = most severe symptoms. ”Total fruit rot” is the sum of the “gray mold”, “ripe rot” and “other” (data not shown) disease scores. y Berry firmness ratings: 0 = very firm to 3 = very soft. x Means within a column followed by the same letter do not differ significantly; Fisher’s least significant difference (LSD), α = 0.05.