加工用トマト収穫機の開発研究

第1報 慣行収穫法の実態と機械収穫の可能性について

抄録

For many years, mechanical harvesting of processing tomatoes was considered to be impossible in Japan, because of the intensive cultivation in small and narrow fields, and the wide variation in fruit maturation caused by rain and inconstant weather. Therefore, Japan is lagging far behind the West in the study of mechanical harvesting.
Recently, due to Japan's rapid industrial development, labor for harvesting tomato is becoming more difficult and expensive to procure. In addition, the international liberalization of trade requires lower harvesting costs.
In response this situation, a study was conducted from 1968 to 1978 at the Shinshu University; 1) to investigate time foctors in the traditional hand-picked harvest and to estimate the propriety of mechanical harvesting, 2) to measure the physical properties of fruits, and mechanical damages in their harvesting, 3) to investigate structures of vines and field conditions, 4) to design and test compact machines, and 5) to discuss the utility of these machines.
In this paper, 1) was described and its result, in summary are as follows.
(1) Average working time by the traditional hand picking methods was calculated with successive data from the Department of Agriculture; and today, working time has reached 142.4hrs/10a and occupies 52.2% of total working time for processing tomato culture.
(2) Simplification of the hand picking motion (therblig), does not increase picking efficiency significantly.
(3) In order to estimate the practicality both of the once-over harvest method and the combination of hand selection and once-over method, the yield by each method was compared to the yield by the traditional hand picking method, using varieties of Wasedaruma and Chico III. The ratios of yields by three mathods were estimated using both the field test data and histrical data. It was found that in proportion to the high yield of the effective but time-consuming traditional method, the once-over harvest produced a yield of about 60-70%, and the combination method produced a yield of about 75-85%.
It seems that adoption of the once-over principle to Japanese fields leaves some difficult problems behind us. But as the suitable varieties for mechanical harvesting are still developing, the fully mechanical or the semi-mechanical harvest method can soon be implemented in place of traditional hand picking method in various areas.