Production and Characteristics of Japanese Cucumber

Yoshiteru Sakata, Masami Morishita, and Keita Sugiyama

Kurume Branch, National Research Institute of Vegetables,
Ornamental Plants and Tea (NIVOT-krm) Japan

Additional index words. Japan, cucumber production

Abstract. Cucumbers are produced in adequate regions and seasons all over in Japan. The yields of open field culture (summer to fall harvest), delayed start culture (fall to early winter harvest), forcing culture (winter to early summer harvest) and semi-forcing culture (early spring to summer harvest) were 82.0, 55.8, 156.2, and 133.5 t·ha­1, respectively. Japanese cucumber cultivars used now are the progenies of hybrids between the South Chinese (SC) and North Chinese (NC) types. In the 1950s and 1960s, the cross-breeding between the NC and the SC were made and the cultivars used now have cool temperature tolerance and crispness in fruit texture with white spine. Grafting to Cucurbita sp. is widely (>90% in area) adopted to strengthen the disease resistance and tolerance to temperature stress, and to get bloomless type fruit that are welcomed by wholesale marketers and consumers. For forcing culture or semi-forcing culture, F1 cultivars Sharp One, Encore 8 and Encore 10 are mainly used. On the other hand, for open field culture and delayed start culture, F1 cultivars of Nankyoku 1 gou, Nankyoku 2 gou, Nankyoku 3 gou M gata, Top Green, Pilot, Shinhokusei 1 gou, Honor, Nao-yoshi, Climber 1 gou, Climber 2 gou, Hokuho 1 gou, Hokuho 2 gou, Suisei Fushinari, and Natu-suzumi are often cultivated. Most of the Japanese cultivars are monoecious although some are monogynoecious; all are parthenocarpic. The problems of overworking of farmers and stagnation of consumption are discussed.

Cucumber (Cucumis sativus L.) is one of the most popular vegetables in the world, especially in Asia and in Middle East and 23,051,000 t (FAO, 1996) are produced. The largest country for cucumber production is P. R. China. It produces cucumbers more than half (51.4%) of the world production of cucumbers. The other major production countries are Iran (5.4%), Turkey (5.0%), United States (4.3%), and Japan (3.6%).
In Japan, cucumber is the most popular vegetable. The shipment value of cucumber in the Tokyo Wholesale Market is always by far in first or second place, similar to tomato. The planted area and total amount of production in 1996 were 16,900 ha and 823,000 t, respectively (Ministry of Agriculture, Forestry and Fishery (MAFF, 1998). However, in general, the production of cucumber in Japan is gradually decreasing. Compared with 1970 data, the decreasing amounts are 16.8% in total production and 45.0% in planted area. Cucumber production in Japan is now facing several difficulties.

Cucumber production in Japan

Cultural systems. Cucumber production in Japan is divided into five general types of cultural systems. The most popular type is open-field culture. Seeds are sown in spring and fruit are harvested in summer to early fall. The second most popular type is delayed-start culture. Next in importance are forcing culture, semi-forcing culture, and early-start culture. All the representative types of culture systems are illustrated in Figure 1.

Production area. Cucumbers are produced in adequate regions and adequate seasons all over Japan. Various kinds of climates from subtropical to subfrigid exist in Japan although it is a small country. Japan is 3,000 km in length and the altitude is from sea level to 3,776 m at Mt. Fuji. The four seasons are clearly divided. Furthermore, the monsoon and the ocean currents around Japan also affect the climate.

 

 

Cucurbitaceae '98


In general, as the southwestern part of Japan is relatively warm in winter, forcing culture and semi-forcing culture are adopted there. Open-field culture and delayed-start culture are often adopted in the northeastern part of Japan and at elevated areas by utilizing their relatively cool conditions in summer. Major production prefectures in Japan and their representative climatic data are shown in Figure 2.

Grafting. Grafting to Cucurbita sp. was started in 1960, and is widely (>90 % in area) adopted now. The original purpose was to strengthen the resistance to fusarium wilt. Later, other merits were recognized. Grafted cucumbers are tolerant not only to diseases, such as fusarium wilt and phytophthora rot (Phytophthora melonis), but also to temperature stresses, cool or hot conditions. Since the finding that the blooming of cucumber fruit is controlled by rootstock cultivars, using the cultivars of bloomless rootstock became a standard for cucumber cultivation in 1975.

Yield. The yield of cucumber in Japan was 48.7 t·ha­1 (1996) and is relatively high compared with other countries in the world. The yield progress is evident in recent years. Compared with 1970s data, the yield has increased from 30.6 to 48.7 t·ha­1, that is, a 59 % increase in yield. According to the accurate yield data from MAFF, which is quite different from the FAO data due to the different sampling methods, the yields of open-field culture (summer to fall), delayed-start culture (fall to early winter), forcing culture (winter to early summer) and semi-forcing culture (early spring to summer) were 82.0, 55.8, 156.2, and 133.5 t·ha­1, respectively (FAO, 1995).

Price. The price of cucumbers sold in Japan is considerably high and relatively stable. The yearly average shipment price for farmers is 1.6 to 2.0 U.S. dollars/kg and the yearly average retail price is 3.0 to 3.5 U.S. dollars/kg. The fluctuation of the shipment price is rather stable from 1.3 to 2.8 U.S. dollars/kg (1995). The monthly change of shipment amount and price of cucumber in the Tokyo Wholesale Market are shown in Figure 3.

Use. Until the 19th century, cucumber had been used mainly for pickles and was not popular in urban areas in Japan. Other cucurbits, such as oriental pickling melon, were regarded as more important and more delicious than cucumber. There have been many types of pickles. Simply brined type, seasoned in rice bran type or secondary processed type from brined are now popular.

Recently, cucumber has been used as one of the most important elements of salad. Suno mono, sliced cucumber seasoned with vinegar, sugar and soy sauce is also served. Small amounts are cooked as Chinese or Italian dishes. Asa-zuke, a kind of fresh pickle that is just soaked in seasoning solution and Korean type hot Kimuchi are regarded as a kind of salad and are commonly served.

Characteristics of Japanese cucumber cultivars

History. Japanese cucumber cultivars used now are the progenies of the hybrid between the South Chinese (SC) and North Chinese (NC) types. The SC type has black spines on the fruit surface and can grow under cool conditions. The NC type has white spines, high temperature tolerance, and is crispier than the SC type, which means that the NC type is regarded as being more delicious than the SC type by the Japanese. In the 1950s and 1960s, the cross-breeding between the NC and the SC types were made and the cultivars used now have cool temperature tolerance and crispness in fruit texture with white spines on fruit surface (Fujieda, 1994).

Sex expression. Most of the Japanese cultivars are monoecious and some are monogynoecious, but all are parthenocarpic. Gynoecious type is of current interest, but has not been adopted yet. From the viewpoint of the labor distribution, short-term but multiple culture system (40 to 70 days harvest in combination with five to six times crops a year in two greenhouses) is now being considered. In such a cultural system, the mono-gynoecious and gynoecious types are more suitable than the ordinary monoecious type that is mostly used now.

 

Figure 1. Representative cucumber culture systems in Japan.

Figure 2. Main production areas of cucumber in Japan. The climates of the representative cities are also shown down part of this Figure. Fukushima: main area for summer and fall propduction by open field or sheltered culture. Maebashi (Gunma); main area for year-round production by forcing and delayed start culture.Miyazaki; main area for winter and spring production by forcing culture.

Figure 3. Monthly changes of shipment amount and price of cucumber in the Tokyo wholesale market.



Size and shape. There are some strict standards for fruit size. In general, the best fruit size for fresh cucumbers are at a very young stage, 22 cm in length and 100 g in weight. The harvested fruit are divided into five ranks (SS, S, M, L, others) with the length (and weight) variation.

By the curvature of the fruit, they are divided again into three or four ranks (A, B, C, others), because Japanese do not like curved fruit at all. From the combinations of size and shape differences, there are seven to 11 ranks in the Japanese market. One of the standards adopted in Saitama prefecture is shown in Table 1. Price examples of each rank are also listed in Table 1.

Qualities. Crispness is the most important point for the quality due to the fact that the Japanese mainly eat cucumber in fresh salads. The firmness of the fruit flesh and the proportion.between pericarp and placental tissue mainly contribute the crispness.

Currently, Japanese prefer glittering cucumbers, which we call bloomless cucumber, although bloomless fruit are not as crisp as normal bloomed fruit.

Cultivars. There are a few F1 cultivars used in forcing culture or semi-forcing culture. The leading cultivar is 'Sharp One' (Saitama Gensyu Ikuseikai). 'Encore 8' and 'Encore 10' (Tokiwa Kenkyujo) are also grown. There are a lot of cultivars for forcing culture or semi-forcing culture, of course, but they are reduced to a few cultivars by the strict standards of the farmers and the wholesale marketers.

On the other hand, there are many F1 cultivars grown for the open field culture and delayed start culture. Tokiwa Kenkyujo-bred cultivars include 'Nankyoku 1 gou, 'Nankyoku 2 gou', 'Nankyoku 3 gou M gata', 'Top Green', 'Pilot', and 'Shinhokusei 1 gou'; Saitama Gensyu Ikuseikai-bred cultivars include 'Honor', 'Nao-yoshi', 'Climber 1 gou', 'Climber 2gou', 'Hokuho 1 gou', and 'Hokuho 2 gou'. The Kurume Gensyu Ikuseikai-bred 'Suisei Fushinari' and the Takii Seed bred 'Natu-suzumi' are often cultivated.

 

Table 1. Prices of cucumbers for the curvature and size standards adopted in Saitama prefecture, 1987.z

Curvature Size ranks

Rank (cm) Parameter SS S M L Others

A 0.0­1.5 Weight (g) 70­80 80­100 100­120 120­140 140

Length (cm) 17­20 18.5­23 19­25 20­25 25

Price 1.85 2.31 1.92 1.54

B 1.5­3.0 Weight (g) 70­100 100­120

Price 1.85 1.54

C 3.0­5.0 Weight (g) 70­150

Price 1.15

Others 5.0 Weight (g)

Price 0.77

zPrice in U.S. dollars/kg (1 U.S. dollar = 130 Japanese Yen).

 


Problems occurring in Japan

Overworking of farmers and stagnation of consumption are the main problems in cucumber production. Young family members often do not want to succeed at their parents' farms because cucumber production is hard work in hot and humid conditions and the income is relatively lower than that of the other jobs. The low income is due to the low price of cucumbers compared with other commodities. It is the problem not only for cucumber farmers but also for all other farmers. Low price and low income will be improved if the consumption of cucumber will greatly increase. The authors want to discuss labor saving and stagnant consumption.

Work sharing. To save time and labor, separation of seedling production from fruit production is gradually becoming widespread. All the Japanese farmers have had the ideology that only good seedling can produce good yields. So they never entrusted their seedling production to other farmers. The limited spare time during the harvesting period does not sufficient to take care of their grafted-seedling production. Recently, the techniques for seedling production have so improved that even grafted seedlings can be produced in a plug-tray system. Grafted-seedling production by specialists assures farmers of a constant supply of seedlings with excellent quality for multiple, short-term crops. This enables farmers to find time for relaxation.

Correction of the standard of fruit size. Simplification of the fruit standards, or the leveling of the price differences among the ranks would help to reduce the time to harvest and grade the

fruit. More than 60% of the labor time is used in the process of harvesting, ranking and packaging, which are mainly done in the farmers' houses. In the case of cucumber, as very young fruit are harvested, harvesting once or twice a day is necessary.

Broadening the fruit size grades will also be effective in reducing time in separating the fruit. Although most Japanese consumers prefer 100 g cucumber to bigger ones, younger consumers may possibly accept larger size cucumbers if the flavor is new and tasty. It will be beneficial if the consumers will accept the English forcing type cucumber or newly bred big size cucumbers. These changes will not occur quickly.

Stagnant consumption. Development of new uses and introduction of new types of cucumbers will help to increase demand. The use of cucumber consumption in Japan is limited, as mentioned in the use, because only one type, which does not have variation of fruit quality such as, crispness, taste and shape, is used in every dish.

Cucumber has only little nutritious value for people. Some new important elements, such as a physiologically functional constituent, contained only in cucumber would help increase demand.

Literature cited

FAO Production Yearbook . 1996. 50:134­135.

Fujieda, K. 1994. Cucumber, p 69­73. In: Horticulture in Japan. Organizing Committee XXIVth Intl. Hort. Congr. Publ. Comm. (ed.).

Cucurbitaceae '98