著者

Fumio Fukuda Yuki Tomita Yukihito Aishima Kumiko Koumoto Yuichiro Fujii Ken Hirano Kunihisa Morinaga Naohiro Kubota

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-012, (Released:2016-08-18)

被引用文献数

3

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Reddish pulp is one of the most serious disorders in peach production, in which originally white flesh undergoes pink to red discoloration with the development of a mealy texture. In order to clarify the relationship between the incidence of reddish pulp and flowering date, the occurrence of reddish pulp was investigated in ‘Benishimizu’ and ‘Shimizu Hakuto’ fruit with different flowering dates for three seasons. In both cultivars, the percentage of fruit with reddish pulp was higher in early flowering fruit than late flowering fruit in all three seasons. Analysis of pectin and boron contents in immature fruit sampled from June 23 to July 8, prior to observing the symptoms of reddish pulp, showed no statistically significant differences in pectin content between early and late flowering fruit. On the other hand, the boron content in flesh was significantly lower in early flowering fruit that bloomed on April 1 than in late flowering fruit that bloomed on April 11 in ‘Benishimizu’. In addition, a significantly higher total polyphenol content, which is one of the characteristics of reddish pulp, was found in early flowering fruit. The results indicate that the flowering date has a large impact on the incidence of reddish pulp, and the disorder is more prevalent in early than late flowering fruit. The possible relationships among the development of reddish pulp, boron deficiency, pectin content, and increase in total polyphenol content are discussed.

著者

Takashi Kawai Fumiya Matsumori Hidemi Akimoto Naoki Sakurai Ken Hirano Ryohei Nakano Fumio Fukuda

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-012, (Released:2018-07-14)

被引用文献数

15

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Split pit in peach (Prunus persica (L.) Batsch) fruit is an internal disorder that can have adverse effects on fruit quality and shelf stability. As it is difficult to distinguish split-pit fruit from normal fruit by appearance, a nondestructive detection method is desirable to determine accurately the timing of split-pit occurrence and remove unwanted fruit from trees. In our recent study, we used an acoustic vibration method for the nondestructive detection of split pit in harvested peach fruit. Here, we demonstrate that this method can be used to detect split pit in unpicked peach fruit. Time-course monitoring of growing fruit revealed that the ratio of the third (f3) to the second (f2) resonant frequency (f3/f2), which is an indicator of split pit in harvested fruit, abruptly increased in unpicked split-pit fruit from early June to early July. In contrast, the f3/f2 values of normal fruit remained low until harvest in late July. The increase in f3/f2 values of split-pit fruit was observed in early June (stage II of fruit growth) and/or from late June to early July (stage III of fruit growth), suggesting that, at least under the experimental conditions in the current study, pit splitting occurred at these two different timings. Split-pit fruit detection rate at harvest increased towards the end of the second split-pit occurrence and split pit could be predicted with high accuracy thereafter. These results collectively suggested that the timing of split-pit occurrence in unpicked peach fruit could be predicted accurately by measuring f3/f2 values and unwanted fruit with split pit could be distinguished from normal fruit on trees. We discuss the possible applications of the nondestructive acoustic vibration method in combination with fruit thinning and the future use of this method in research aiming to develop effective prevention methods or resistant cultivars with reduced split pit.

著者

Ryohei Nakano Hidemi Akimoto Fumio Fukuda Takashi Kawai Koichiro Ushijima Yosuke Fukamatsu Yasutaka Kubo Yuichiro Fujii Ken Hirano Kunihisa Morinaga Naoki Sakurai

出版者

一般社団法人 園芸学会

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.OKD-094, (Released:2017-10-12)

被引用文献数

15

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Split-pit in peach fruit is a problematic disorder. Split-pit fruit cannot be detected based on external appearance, and contamination of fruit by split-pit reduces its reliability in the marketplace. Here, we demonstrate that split-pit fruit can be identified by a nondestructive acoustic vibration method and a unique approach based on the ratio of the third (f3) to the second (f2) resonant frequency. The response-resonant frequency spectra showed that the peaks of f2 frequencies in split-pit fruit were shifted to much lower values than those in normal fruit, whereas those of f3 frequencies showed only small shifts. The calculated f3/f2 ratios in most normal fruit were in the range of 1.35–1.4, whereas those in split-pit fruit were 1.45–2.0. Analysis of more than 300 fruit samples revealed that by setting the f3/f2 cut-off value at >1.45, 95% of split-pit fruit in the fruit samples were detected, whereas only 1.5% of normal fruit were missorted as split-pit fruit. A model for simulating the vibration properties of peach fruit was developed by using the finite element method. The simulated vibration patterns showed that f3/f2 values were increased by the insertion of split pit, indicating that, at least partially, the observed high f3/f2 values in split-pit fruit directly reflected split-pit occurrence. These results clearly demonstrate that the use of f3/f2 ratios obtained using an acoustic vibration method can effectively detect fruit with split-pit. The possibility of installing acoustic vibration devices in peach sorting lines and the application of portable devices to unpicked fruit on the tree are discussed.