著者

Yuya Mochizuki Tiejun Zhao Wataru Kanematsu Takashi Kawasaki Takeshi Saito Akio Ohyama Akimasa Nakano Tadahisa Higashide

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-055, (Released:2019-04-11)

被引用文献数

5

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To clarify the effect of ultrafine bubbles (UFBs) on the growth of tomato seedlings, we investigated elongation growth and dry matter production by analysing growth under different assimilation conditions and by modelling. The leaf area enlargement rate of plants grown with UFB nutrient solution increased and the specific leaf area (SLA) decreased at 18 days after sowing (DAS) relative to those grown without UFB solution. Thus, UFBs increased both leaf area and leaf thickness. UFB significantly increased the relative growth rate (RGR) and net assimilation rate (NAR) at 18 DAS, but there was no significant difference in SLA, RGR, and NAR between treatments at 25 DAS. These results were used to model plant growth with and without UFB treatment. In a second experiment, UFB treatment increased aboveground dry weight under a low-assimilation condition, but had no significant effect under a high-assimilation condition. Our model supported these results. It was also implied that UFB treatment affected leaf area expansion, but not dry matter production. Although the values predicted by the model were slightly lower than observed, it was possible to predict the effect of UFB treatment on plant growth with high accuracy.

著者

Mizuho Itoh Yasunaga Iwasaki Dong-Hyuk Ahn Tadahisa Higashide

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-381, (Released:2022-09-30)

被引用文献数

1

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The relationship between fruit Brix and the electrical conductivity (EC) of the nutrient solution was investigated under gradually increasing EC conditions to predict and control tomato fruit Brix in commercial greenhouses in Japan. Based on the three experiments, fruit Brix was significantly and highly correlated with the cumulative EC of the drainage during the period from anthesis to harvest (cECd). This relationship followed a linear regression function. We then modelled fruit Brix based on cECd and validated this model to predict and control fruit Brix in four other experiments in different growing seasons using two cultivars, slab substrates, and irrigation systems. Using this model, we calculated the target cECd (cECdt) to achieve a target fruit Brix of 6% or higher and used cECdt as an indicator to manipulate the EC of the nutrient solution. In the validation experiments, cECd was lower than cECdt at the beginning of harvest in all experiments. cECd reached cECdt at 72.3–214.0°C·day after the first harvest. When cECd was higher than cECdt, more than 86.9% of the fruit had a higher than Brix 6%. In addition, the marketable yield was higher than 88.2%. RMSEs between the observed fruit Brix and predicted fruit Brix were 0.60–1.25. These results indicate that our model can predict and control fruit Brix.

著者

Tadahisa Higashide

出版者

The Japanese Society for Horticultural Science

雑誌

The Horticulture Journal (ISSN:21890102)

巻号頁・発行日

pp.UTD-R019, (Released:2022-05-31)

被引用文献数

4

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The fresh fruit yield of tomatoes (Solanum lycopersicum) is determined by yield components and related traits. In low-truss cultivation in Japan, light use efficiency in the same cultivar is not significantly affected by plant density or seedling stage at transplanting. Total dry-matter production equals light use efficiency × light intercepted by plants. Light interception is determined by leaf area index and the light extinction coefficient in the plant canopy. Light use efficiency is determined by leaf photosynthetic rate and light extinction coefficient. Light use efficiency is expressed as a function of daytime CO2 concentration. The high yield of modern tomato cultivars in the Netherlands is due to an increase in total dry matter production of plants, not to an increase in dry matter partitioning of fruits. An increase in the photosynthetic rate and a decrease in the light extinction coefficient may have increased light use efficiency among Dutch cultivars. Although modern Japanese cultivars have a high content of both water and soluble solids of fruits, yield has not increased. Since the yield of greenhouse tomatoes in Japan has increased little since the 1980s, Japanese researchers have attempted to improve the yield using current Japanese cultivars. Crop growth models can help management decisions on cultural practices, control of greenhouse climate, fertilization, and irrigation. Several models of tomato growth including TOMSIM and TOMGRO have been developed. A growth model based on the relationships among yield components and related traits has been developed to predict dry matter production and yield of greenhouse tomatoes. The model recommended a leaf area index with the highest dry matter production at a certain solar radiation. To improve yield of greenhouse tomatoes by using the model, a one-year experiment was carried out in a greenhouse. The annual yield of tomatoes with Brix at least 5° was at least 50 kg·m−2 for a popular Japanese cultivar, ‘CF Momotaro York’. For the near future, the growth models show promise for growers in helping yield improvement and crop management in greenhouses.

著者

Yasushi Kawasaki Tadahisa Higashide

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-118, (Released:2017-11-17)

被引用文献数

1

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Fruit growth represents the balance between material influxes via xylem and phloem and efflux by transpiration via the stomata of the calyx and cuticle of fruit, which determines the yield and soluble solids content (SSC). Knowledge of these factors is important for the production of high-SSC tomato fruit, but no physiological indicator is available to allow prediction of fruit yield and SSC for breeding and crop production purposes. To identify indicators, we grew Japanese, Dutch, Japanese × Dutch, and high-SSC cultivars and sought correlations of the fluxes to fruit with yield and SSC. To estimate the contributions of the xylem, phloem, and transpiration fluxes to fruit weight increase, we measured 2-day growth rates of intact, detached, and heat-girdled (peduncle steamed for 90 to 120 s) fruits treated at 14, 28, or 42 days after flowering (DAF). Xylem influx was much lower in the high-SSC cultivar than in the others. Phloem influx was lower in the Dutch and hybrid cultivars at 28 DAF. Transpiration efflux was greater in the Japanese cultivar at 42 DAF. Fruit growth rate at 14 DAF was positively correlated with yield, and phloem influx per fruit weight increase at 14 and 28 DAF was positively correlated with SSC. These results show how the xylem, phloem, and transpiration fluxes of fruit can predict fruit yield and SSC. This information will help the production and breeding of high-SSC fruit.

著者

Tadahisa Higashide Ken-ichiro Yasuba Takeshi Kuroyanagi Akimasa Nakano

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.MI-010, (Released:2015-02-21)

被引用文献数

3 24

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To investigate the mechanism of yield increase by elevated carbon dioxide (CO2) and fogging in Japanese tomato cultivars (Solanum lycopersicum), total above-ground dry matter (TDM), fraction of dry matter distribution to fruit (FDF), and photosynthetic characteristics were measured in 3 Japanese cultivars grown in elevated CO2 with fogging and ambient CO2 without fogging. Fresh fruit yield and TDM were improved by the elevated CO2 and fogging in the 3 Japanese cultivars. Light use efficiency (LUE) was also increased by the elevated CO2 and fogging. No significant decrease in FDF was observed by the elevated CO2 and fogging in 2 Japanese cultivars, ‘Asabiyori 10’ and ‘Junkei Aichi Fast’. Thus, the increase in TDM by higher LUE contributed directly to the yield increase in these 2 cultivars. However, FDF in ‘Momotaro York’ was decreased significantly by the elevated CO2 and fogging. Thereby, the yield increase by the elevated CO2 and fogging was diminished in ‘Momotaro York’ in spite of the increase in TDM. The number of trusses having immature fruit in ‘Momotaro York’ under elevated CO2 and fogging was significantly higher than those of the others, although no increase in the number of trusses having immature fruit was observed in the other 2 cultivars. Although vegetative growth characteristics such as leaf area, LAI, and fresh and dry weights of leaves and stem were increased by the elevated CO2 and fogging, no negative effects such as a change in light-extinction coefficient and a decrease in maximum photosynthetic rate were observed. The elevated CO2 and fogging increased the number of harvested fruit but decreased weight per fruit, namely, fruit size, in the 3 cultivars.

著者

Tadahisa Higashide Akimasa Nakano Ken-ichiro Yasuba

出版者

園芸学会

雑誌

Journal of the Japanese Society for Horticultural Science (ISSN:18823351)

巻号頁・発行日

pp.CH-048, (Released:2014-05-09)

被引用文献数

2 19

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To improve the yield of a Japanese tomato (Solanum lycopersicum) cultivar and determine how fruit yield changes as a result of grafting, we investigated the effects of a Dutch rootstock [‘Maxifort’ (S. lycopersicum × S. habrochaites): Mx] on the dry matter (DM) production and fruit yield of Dutch and Japanese cultivars. The Japanese cultivar (‘Momotaro York’: My) grafted onto Mx (My/Mx: scion/rootstock) had significantly higher fresh and dry weights of fruits per unit area than My/My. Fruit fresh weight yield per unit area was highly correlated with fruit dry weight (DW) yield (r = 0.96–0.97, P < 0.001), and DW yield was significantly correlated with total aboveground DM (r = 0.71–0.96, P < 0.001) and with DM allocation to the fruits (r = 0.52–0.75, P < 0.01). Total aboveground DM (TDM) was significantly and highly correlated with light-use efficiency (r = 0.98, P < 0.001). However, there was no significant correlation between light-use efficiency and the maximum photosynthetic rate, stomatal conductance, or the light-extinction coefficient. Although stomatal conductance significantly (P < 0.05) differed between the rootstocks at 57 and 119 days after transplanting (DAT), there was no significant difference in the maximum photosynthetic rate between the scion/rootstock combinations at 57 and 119 DAT. These results indicated that the fruit yield of My could be improved by grafting onto Mx, and that the increases in yield and TDM were mainly determined by the increase in light-use efficiency.