著者

Toshihiko Sugiura Makoto Takeuchi Takuya Kobayashi Yuta Omine Itaru Yonaha Shohei Konno Moriyuki Shoda

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-085, (Released:2023-11-02)

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The growing-degree-days (GDD) model for pineapple was developed to predict flowering and harvest dates; however, it has not been adapted to the climate in Japan’s growing regions, where air temperatures fluctuate over a wide range, and the prediction accuracy is low. The present study aimed to develop models for predicting flowering and harvest dates with high accuracy by analyzing a large phenological dataset from Japan’s main (Nago) and warmer (Ishigaki) production areas. The number of days between budding and flowering decreased at air temperatures of up to approximately 25°C and remained constant above 25°C. The number of days between flowering and harvest decreased until approximately 23°C. The effect of day length on both days to flowering and harvest was small. The relationship between air temperature and the developmental rate after budding to flowering and after flowering to harvest was modeled using the GDD and exponential function models, both with upper limits. The GDD model with an upper limit temperature was more accurate at predicting flowering and harvest dates compared to the conventional GDD model. In particular, the prediction accuracy of the harvest date was dramatically improved. Because the relationship between the developmental rate until flowering and the air temperature was exponential rather than linear, the exponential function model provided a more accurate prediction of the flowering date. The root-mean-square errors of the most accurate models were 3.7–6.1 days for predicting the flowering date and 6.1–10.2 days for the harvest date. We believe that these models will be useful for planning shipments of pineapple in regions with wide temperature ranges, such as Japan, and for cultivation management in response to climate change.

著者

Toshihiko Sugiura Makoto Takeuchi Takuya Kobayashi Yuta Omine Itaru Yonaha Shohei Konno Moriyuki Shoda

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.QH-055, (Released:2023-05-26)

被引用文献数

1

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Pineapples (Ananas comosus (L.) Merr.) are harvested throughout the year, with acid and soluble solid contents varying with season. However, there is a lack of knowledge about the relationship between the acid and soluble solid content and climatic factors. To investigate these relationships, we analyzed the acid and soluble solid content records of a large number of fruit harvested over 15 years from three production areas in Japan. Over the warm period (June to September) pineapple acid content was low, while over the cool period (December to April) it was high, regardless of the cultivar. Soluble solid contents were highest in June and lowest between September and March. Acid content at harvest inversely correlated with the temperature immediately before harvest, and the relationship modelled linearly with the mean temperature over the 10 or 20 days before harvest as a variable. The acid content of ‘N67-10’ is highly dependent on temperature, while that of ‘Okinou P17’ is stable regardless of temperature. The soluble solid content was affected by temperature over longer periods than the acid content and was modelled using a quadratic equation with the mean temperature over the 70–120 days before harvest as a variable. The approximate curve of soluble solid content peaked around 23°C. The majority of ‘Okinou P17’ fruit yielded a soluble solid content of > 15 °Brix over a wide temperature range (≥ 19°C), while the temperature at which most ‘N67-10’ fruit had soluble solid of > 15 °Brix was limited to a narrow range (22–23°C). Although the coefficients of both model equations were significant for all cultivars, the R2 of soluble solid content was smaller than that of acid content. These results contribute to understanding the relationship between acid and soluble solid content and temperature.

著者

Toshihiko Sugiura Mikio Shiraishi Shohei Konno Akihiko Sato

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-061, (Released:2017-04-26)

被引用文献数

12

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To develop a method for predicting the skin color of grape berries of three cultivars of Vitis labrusca L. × Vitis vinifera L. grown in Japan, we investigated the relationship between skin color and air temperature in the grape production areas of 18 prefectures. When mean air temperature during the 40 days before harvest date was ≥24°C, the skin color ratings of ‘Kyoho’, ‘Pione’, and ‘Suzuka’ were significantly negatively correlated with temperature. Skin color ratings decreased by about 1 unit per 1°C increase; at a given mean air temperature during this period, the rating of ‘Suzuka’ was higher (by 0.7 units) than that of ‘Kyoho’, which was higher (by 1.0 unit) than that of ‘Pione’. Because an approach to predict harvest date has not been established, we developed a method to predict skin color at harvest based on air temperature after the full-flowering date. We found the times that had a strong negative correlation between the mean air temperature and the skin color rating at harvest was 43 days from 50 DAF (days after full flowering) for ‘Kyoho’, 46 days from 46 DAF for ‘Pione’, and 42 days from 52 DAF for ‘Suzuka’. We obtained a linear regression equation for the relationship between the skin color rating at harvest and the mean air temperature during the periods. If the full-flowering date is known, it is possible to predict skin color at harvest by using this equation and the predicted air temperature after full flowering. We also developed a method for predicting anthocyanin contents in berry skins at harvest using significant regressions among the skin color rating, the skin anthocyanin content, and mean air temperature.