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Scientia Horticulturae 177 (2014) 108–111

Contents lists available at ScienceDirect

Scientia Horticulturae

journa l h om epa ge: www.elsev ier .com/ locate /sc ihor t i

hort communication

easonal growth and characteristics of fruits developed from delayedowers of ‘Fuyu’ persimmon

eong-Tae Choia,∗, Doo-Sang Parka, Eun-Seok Kima, Hyun-Yul Shinb, Seong-Mo Kangc

Sweet Persimmon Research Institute, Gyeongnam Agricultural Research and Extension Services, Gimhae 621-802, Republic of KoreaResearch and Development Bureau, Gyeongnam Agricultural Research and Extension Services, Jinju 660-985, Republic of KoreaDepartment of Horticulture, Institute of Agriculture and Life Science, Gyeongsang National University, Jinju 660-701, Republic of Korea

r t i c l e i n f o

rticle history:eceived 10 June 2014eceived in revised form 21 July 2014ccepted 29 July 2014vailable online 28 August 2014

eywords:iospyros kaki

a b s t r a c t

Growth and characteristics of the fruits developed from “delayed flowers” (DFs) of ‘Fuyu’ persimmon(Diospyros kaki) were investigated to determine their usefulness to supplement the frost-damaged normalflowers (NFs). In hand-pollinated trees without frost damage, DFs bloomed on June 6 and June 5 in 2012and 2013, respectively, 13 and 11 days later compared with NFs. DF fruit diameters were 5.8–9.4 mmless than the NF fruits on July 16 in both years, but the difference became 1.5–2.4 mm on August 27.Such a difference persisted until harvest on November 12. DF fruits at harvest weighed 6.6–7.3% lesscompared with NF fruits, an insignificant reduction. Skin color, firmness, and soluble solids of fruits were

loom dateull bloomaturing time

not different between both DF and NF. In trees with insufficient NFs due to spring-frost, DF bloomed 10days later than NF. DF decreased fruit drop under open pollination but produced more deformed fruits.DF fruits, containing more seeds, were not significantly lower in size, skin color, and soluble solids. It wasconcluded that DFs could yield marketable fruits with no delay in maturity although their size is slightlysmaller.

© 2014 Elsevier B.V. All rights reserved.

. Introduction

Thinning flower buds, leaving an NF bud on a fruiting shoot, isn important practice to produce quality fruits and minimize alter-ate bearing of ‘Fuyu’ persimmon in Korea. NF of ‘Fuyu’ persimmonlooms in late May in East Asia and the flower bud formation occursrom July to August the previous year (Rhee and Ko, 1973; Sobajima,979). However, the DFs, born above NF or alone on a shoot, bloombout 10 days later than NF and they form between March andarly April the current year (Sobajima, 1979). Along with concernor lower quality fruits resulting from DFs, they are removed asarly as possible to accelerate the growth of NF fruits.

On the other hand, spring frost at around the time of bud burstften damages buds in some areas, leaving insufficient number ofFs. Low yield is thus inevitable and shoot growth becomes tooxcessive. Therefore, in the frost-damaged trees, leaving some DFsay help maintain appropriate tree vigor and yield. Bloom delay in

ther fruit crops often decreases fruit size and delays harvest (Dayt al., 2008; Park and Kim, 2000; Sullivan, 1965), but it could not

∗ Corresponding author. Tel.: +82 55 254 1564; fax: +82 55 254 1559.E-mail addresses: stchoi1234@korea.kr, stchoi1234@hanmail.net (S.-T. Choi).

ttp://dx.doi.org/10.1016/j.scienta.2014.07.043304-4238/© 2014 Elsevier B.V. All rights reserved.

significantly affect fruit characteristics (Ebel et al., 1999; Melgaret al., 2010).

A 7-day delay of bloom in ‘Fuyu’ persimmon due to laterbud burst decreased fruit size but did not affect maturity indicessuch as coloration, soluble solids, and flesh firmness (Choi et al.,2013b). Hasegawa and Nakajima (1990) reported in mid-maturing‘Maekawa-Jiro’ persimmon that fruits harvested from DF, bloomed12 days later than NF, were smaller and less colored regardless ofseediness, but their soluble solids were not reduced in seeded ones.However, using DFs for their practical use in late maturing ‘Fuyu’was not considered. In this study, seasonal growth and characteris-tics of NF and DF fruits were compared to determine the usefulnessof DFs when NFs were insufficient due to frost damage.

2. Materials and methods

2.1. Trees without frost damage

Five ‘Fuyu’ persimmon trees, 18-year-old in 2012, were usedfor a 2-year experiment. They were randomly selected from the

plat orchard planted at 6 × 5 m spacing in Gimhae, Gyeongnamprovince, Korea and provided with standard cultural practices dur-ing the growing season. On May 21 or 22 in both years, all theflower buds were removed but one NF or DF in a fruiting shoot. Five

S.-T. Choi et al. / Scientia Horticulturae 177 (2014) 108–111 109

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Fig. 1. Growth of normal and delayed flower buds of ‘Fuyu’ persimmon on

espective flower buds were labeled as NFs and DFs in a tree in 2012nd six buds in 2013. Total number of the each flower buds was 25n 2012 and 30 in 2013. Flowers bloomed on May 22 to 25 for NFnd June 3 to 8 for DF in 2012, and May 22 to 27 for NF and June

to 6 for DF in 2013. Full bloom (bloomed over 80%) of DF was onune 6 and June 5 in the two years, respectively, 13 and 11 daysater than the NFs. All the flowers were hand-pollinated with ‘Zen-imaru’ pollens to prevent the fruitlets from dropping. Extensionrowth of shoots bearing NF and DF ceased when they bloomed;heir length ± SD was 29 ± 4 and 19 ± 1 cm in 2012 and 28 ± 7 and3 ± 3 cm in 2013, respectively.

Diameter of the labeled fruits was measured every other weekrom July 16 until harvest on November 12. After average weightas taken from the harvested fruits, skin color was measured asunter a values using a colorimeter (CM-2500d, Konica Minoltaensing Inc., Japan). A texture analyzer (Ver. 4.10.1., Labtron Co.,usan, Korea) equipped with a 5-mm plunger was used to mea-ure flesh firmness. Fruit juice was collected from mesocarps andotal soluble solids were determined using a digital refractometerPAL-1, Atago Co., Tokyo, Japan). The experiment was designed in

completely randomized design with five single-tree replicatesor each flower type. Data were presented as mean ± SD and com-ared by the Student’s t test at P ≤ 0.05 or P ≤ 0.01 using SigmaPlotrogram (Ver. 8.02, SPSS Inc., USA).

.2. Trees with frost damage

This experiment was conducted using 25-year-old ‘Fuyu’ trees,andomly selected from an orchard with 600 trees per ha inhangnyeong, Gyeongnam province. Around the time of bud burst

n spring of 2013, a heavy frost killed flower buds by 30 to 70%.fter thinning flowers or flower buds leaving one in a shoot onay 28, 90 flowers were labeled for NFs and DFs, respectively, from

en trees. Full boom was on May 28 for NF while it was on June 7or DF. The trees were 10–30 m apart from pollinizer ‘Zenjimaru’,nd left to be open-pollinated. Length ± SD of the shoots bearing

F and DF was 24 ± 13 and 20 ± 9 cm on May 28, respectively,hen their extension growth had ceased. Drop ratio of fruits was

alculated by counting fruits remained from bloom until October5. After harvesting 31 fruits each on October 24 from the two

30 and June 9 in 2012. They bloomed on May 24 and June 5, respectively.

flower types, length/diameter ratio of fruits was calculated andfruits having deformed shape were counted. Fruit characteristicswere determined as mentioned for the trees without frost damage.

Fruit characteristic data were collected from 31 single-fruitreplications for each flower type in a completely randomizeddesign, and presented as mean ± SD. Results were compared by theStudent’s t test at P ≤ 0.05 using SigmaPlot program (Ver. 8.02, SPSSInc., USA).

3. Results

3.1. Trees without frost damage

Fig. 1 shows that DF did not bloom by May 30, three daysafter petal fall of NFs. There was a significant difference in growthbetween of NF and DF fruits on June 9, 2012. Both the fruit diametersincreased in a double sigmoid pattern regardless of flower types(Fig. 2). Fruit diameter of DF was significantly lower throughout theseason in 2012 but only at the early stage of growth in 2013. Fruitdiameters of DFs on July 16 were 9.4 and 5.8 mm smaller than thoseof NFs in 2012 and 2013, respectively, but the respective differencedecreased to 2.4 and 1.5 mm on August 27, after which there wasno notable change until harvest. Fruit weight was not significantlydifferent on November 12 between the two flower types in bothyears, although the DF fruits were smaller by 6.6 to 7.3% (Table 1).There were no consistent differences in maturity-related charac-teristics such as skin color, flesh firmness, and soluble solids. DFfruits contained more seeds but the difference was not significant.

3.2. Tree with frost damage

In frost-damaged trees, 29% of the NF fruits dropped by October15 while the ratio was 6% for DF fruits (Table 2). DF fruit deformed 4-fold more than NF fruits although all the fruits were commerciallyacceptable. Although DF fruits were slightly smaller and poorly-

colored, the difference was not statistically significance. It wasnoted that flesh firmness, soluble solids, and length/diameter ratiowere not affected. DF fruits had 2.1 seeds more compared with 3.4of NF fruits.

110 S.-T. Choi et al. / Scientia Horticul

Fig. 2. Seasonal changes in diameter of fruits developed from normal and delayedflowers of ‘Fuyu’ persimmon. They bloomed on May 22 to 25 and June 3 to 8 in 2012,and on May 22 to 27 and June 3 to 6, respectively, in 2013. Vertical bars indicate SD.NS, *,** Nonsignificant or significant at P ≤ 0.05 or P ≤ 0.01, respectively.

Table 1Characteristic of fruits developed from normal and delayed flowers in ‘Fuyu’ persimmon

Flower Avg wt (g) Skin color (Hunter a)

November 12, 2012

Normal 241 ± 16 34.5 ± 2.1

Delayed 225 ± 10 36.0 ± 2.4

Significance NS NS

November 12, 2013

Normal 233 ± 17 25.9 ± 2.6

Delayed 216 ± 15 24.2 ± 2.2

Significance NS NS

Values are mean ± SD.NS Nonsignificant at P ≤ 0.05.

a Normal and delayed flowers bloomed on May 22 to 25 and June 3 to 8, in 2012 and on MFruits were harvested on November 12 in both years.

Table 2Fruit drop ratio and characteristics of fruits developed from normal and delayed flowers

Flower Droppedb (%) Deformed (%) Avg wt (g) Skin color (Hunter a) F

Normal 29 3 205 ± 22 13.1 ± 5.0 2Delayed 6 12 193 ± 21 10.3 ± 4.6 2Significance NS NS N

Values are mean ± SD.NS, * Nonsignificant or significant at P ≤ 0.05.

a 30 to 70% of terminal buds in 1-year-old shoots were frost-damaged in early spring of

respectively. Flowers were open-pollinated and the fruits were harvested on October 24.b Percent of fruits dropped by October 15.

turae 177 (2014) 108–111

4. Discussion

Smaller diameter of DF fruits at the early stage of growth wasdue to their late bloom. However, it was interesting to note thatthe difference of fruit diameters between NF and DF fruits declinedsoon after and did not change much after August 27. The resultshowed that the fruit maturing time of DF was not delayed com-pared with that of NF. In fact, fruit characteristics at harvest, shownin coloration, firmness, and soluble solids, were not significantlydifferent between the two types of flowers. Had the fruits of NFand DF been at different stage of maturity, the characteristics wouldhave been significantly different in skin coloration, soluble solids,and flesh firmness, all of which are known to rapidly change duringmaturation in late autumn (Choi et al., 2013a; Sobajima, 1979).

In some other fruit crops, it is known that bloom delay reducesfruit size and delays harvest time (Blanpied and Little, 1991; Parkand Kim, 2000; Sullivan, 1965). It has been reported that DF reducedfruit size and coloration in mid-maturing ‘Maekawa-Jiro’ persim-mon (Hasegawa and Nakajima, 1990). However, late bloom inpeach trees treated with Ethrel did not delay harvest, nor did itreduce fruit size (Ebel et al., 1999). In addition, our findings arein general agreement with the previous results in that fruit solublesolids of DF were not changed in seeded ‘Maekawa-Jiro’ (Hasegawaand Nakajima, 1990), and that a 7-day delay of bloom due to latebud burst did not delay fruit maturation in ‘Fuyu’ persimmon (Choiet al., 2013b). The insignificant difference in fruit maturation couldbe due to greater effect of environmental and cultural conditions onmaturity (Choi et al., 2013b; Mowat and George, 1994). Cell divisionof persimmon fruits occurs actively at full bloom and the numberof cell is significantly related to fruit size at harvest (Hamada et al.,2008; Hirata and Hayashi, 1978). Therefore, the similar weight ofNF and DF fruits under the same cultural condition suggests thatcell numbers of DF fruits are unlikely to be significantly fewer than

the NF fruits. Less growth of the shoots bearing DF as mentionedabove could have unfavorably affected fruit growth, especially in2012.

without spring frost damage.a

Firmness (N) Soluble solids (Brix) Seeds (No./fruit)

28.3 ± 2.3 15.2 ± 0.7 4.7 ± 0.530.5 ± 3.1 15.1 ± 0.3 5.3 ± 0.6

NS NS NS

23.0 ± 0.6 16.5 ± 0.3 5.7 ± 1.022.1 ± 2.4 16.3 ± 0.5 6.1 ± 0.7

NS NS NS

ay 22 to 27 and June 3 to 6, respectively, in 2013. All flowers were hand-pollinated.

in ‘Fuyu’ persimmon with spring frost damage.a

irmness (N) Soluble solids (◦Brix) Seeds (No./fruit) Length/diameter ratio

3.2 ± 2.5 15.1 ± 0.7 3.4 ± 1.9 0.68 ± 0.033.0 ± 4.1 15.1 ± 0.7 5.5 ± 1.8 0.66 ± 0.02S NS * NS

2013. Full bloom was on May 28 and June 7 in 2013 for normal and delayed flowers,

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Seedless ‘Fuyu’ fruits are likely to drop easily due to their lowarthenocarpic nature (Kaura, 1941). More seeds in DF fruits shouldave helped maintain good fruit set in an orchard under a well pol-

inated condition. On the other hand, deformed fruits of DF mayeduce their marketability to some extent. In conclusion, DF fruitsrow faster at their early stage of growth and reach to the sim-lar level of NF fruits in weight and maturity at harvest despiteheir late bloom. Leaving some DF buds at the time of bud thin-ing should help secure yield in those trees in which spring frostilled a significant portion of NFs.

cknowledgement

This research was supported in part by Rural Developmentdministration, Republic of Korea (Project no. PJ0085782013).

eferences

lanpied, G.D., Little, C.R., 1991. Relationships among bloom dates, ethyl-ene climacteric initiation dates, and maturity-related storage disordersof Jonathan apples grown in Australia. Postharvest Biol. Technol. 1,3–10.

hoi, S.T., Park, D.S., Son, J.Y., Park, Y.O., Hong, K.P., Cho, K.S., 2013a. Climate-related

changes in fruit growth of ‘Fuyu’ persimmon during the harvest season. KoreanJ. Horticult. Sci. Technol. 31, 32–37.

hoi, S.T., Park, D.S., Son, J.Y., Park, Y.O., Hong, K.P., Cho, K.S., 2013b. Effect of delayedspring growth on its final shoot and fruit growth of ‘Fuyu’ persimmon. J. Agric.Life Sci. 47, 111–117.

turae 177 (2014) 108–111 111

Day, K., Lopez, G., DeJong, T., 2008. Using growing degree hours accumulated thirtydays after bloom to predict peach and nectarine harvest date. Acta Hortic. 803,163–167.

Ebel, R.C., Caylor, A., Pitts, J., Boozer, B., 1999. Effect of Ethrel on bloom delay, harvestdate, and fruit weight of ‘Empress’ peach. HortTechnology 9, 65–67.

Hamada, K., Hasegawa, K., Kitajima, A., Ogata, T., 2008. The relationship betweenfruit size and cell division and enlargement in cultivated and wild persimmons.J. Horticult. Sci. Biotechnol. 82, 218–222.

Hasegawa, K., Nakajima, Y., 1990. Effects of flowering date, seediness, GA treatmentand location of fruits in the foliar canopy on the fruit quality of persimmon(Diospyros kaki Thunb.). J. Jpn. Soc. Horticult. Sci. 59, 263–270.

Hirata, N., Hayashi, S., 1978. Physiological study of developing and ripening fruitsof the Japanese persimmon IV. Morphological studies of the Japanese persim-mon fruit in two cultivars (‘Fuyu’, seeded variety and ‘Hiratanenashi’, seedlessvariety). Bull. Fac. Agric. Tottori Univ. 30, 14–25.

Kaura, M., 1941. Studies on physiological drops in persimmon II. Relationshipbetween seedlessness of the fruits and physiological drop. J. Jpn. Soc. Horticult.Sci. 12, 247–283.

Melgar, J.C., Dunlop, J.M., Albrigo, L.G., Syvertsen, J.P., 2010. Winter drought stresscan delay flowering and avoid immature fruit loss during late-season mechanicalharvesting of ‘Valencia’ oranges. HortScience 45, 271–276.

Mowat, A.D., George, A.P., 1994. Persimmon. In: Schaffer, B., Andersen, P.C. (Eds.),Handbook of Environmental Physiology of Fruit Crops. Vol. I. Temperate Crops.CRC Press, Boca Raton, FL, USA, pp. 209–232.

Park, Y.S., Kim, S.R., 2000. Changes in cold injury and fruit quality in loquat fruit asinfluenced by bloom dates. J. Korean Soc. Horticult. Sci. 41, 623–626.

Rhee, Y.S., Ko, K.C., 1973. Study on the flower bud differentiation of main fruit treesin Korea 1. Study on the time of initiation of flower bud differentiation on leading

fruit varieties in the localities of Korea. J. Korean Soc. Horticult. Sci. 13, 115–123.

Sobajima, Y., 1979. Flower bud formation and fruit growth of Japanese persimmons.Stud. Inst. Hort. Kyoto Prefect. Univ. 9, 157–169.

Sullivan, D.T., 1965. The effect of time of bloom of individual flower on the size,shape and maturity of apple fruits. Proc. Am. Horticult. Sci. 87, 41–46.