Shimotsuke, Japan
Shimotsuke, Japan

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Hayashi S.,Japan National Agriculture and Food Research Organization | Saito S.,Japan National Agriculture and Food Research Organization | Iwasaki Y.,Miyagi Prefectural Agriculture and Horticulture Research Center | Yamamoto S.,Japan National Agriculture and Food Research Organization | And 2 more authors.
Japan Agricultural Research Quarterly | Year: 2011

One of the direct approaches for obtaining a high yield of strawberries is high-density cultivation. Such cultivation improves the efficiency of space utilization in a greenhouse; however, it requires the movement of planting benches. The aim of this study is to develop a circulating-type movable bench system for strawberry cultivation that realizes high-density cultivation and improves work efficiency. The developed system, which is 16.0 m long and 9.2 m wide, consists mainly of two longitudinal conveying units, two lateral conveying units, two nutrient supply units, a chemical sprayer, 62 planting benches, and a control unit. The design of the longitudinal conveying mechanism combining the rotating and sliding movements of rods for pulling the benches and a method of controlling the conveying units achieves effective circulation, resulting in a cycle time of 67.0 s during which the successive bench reaches the initial position. This cycle time could be shortened by increasing the speed of lateral conveying. The planting density obtained using this approach is 16.0 to 20.0 plants m -2, which is roughly 2 to 2.5 times the plant density obtained in the conventional method of cultivation. Furthermore, the four cultivars used in this study showed vigorous growth, and the cultivars Akihime and Moikko showed a marketable yield twice as high as the conventional yield. © 2011 JIRCAS.


Takahashi T.,Chiba University | Ishigami Y.,Chiba University | Goto E.,Chiba University | Niibori K.,SEIWA Co. | Goto K.,SEIWA Co.
Environmental Control in Biology | Year: 2012

A new tomato growth model was developed based on an existing growth model to predict the growth and yield of tomato plants cultivated with a low node-order pinching system at high plant density, under annually variable environmental conditions in Japan. Over a 5-year period, we obtained the growth and yield data of 2 tomato Japanese cultivars in a large-scale commercial greenhouse, in correlation with environmental data (i.e., radiation, air temperature, humidity). We calculated the wink strength of each vegetative organ and fruit and determined cultivar specific constants, by modifying an existing process growth model developed for long-term cultivated tomatoes. The accuracy of the modified simulation, regarding the growth and yield of tomato plants, cultivated with a low node-order pinching system at high plant density, was improved by the modification of cultivar specific constants and calculation methods of fruit sink strength, with an overall error of just 16.5%.

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