IV Supply, Demand and Policy Measures in the Postwar Era

Sweetpotato supply and demand has changed dramatically in Japan in the half century since the end of World War II. These changes can be classified into four periods. During the initial postwar recovery period (1945-60), food production increased and sweetpotatoes contributed to demands for a stable food supply. In the second period (1961-75), which corresponds to Japan's period of high economic growth, sweetpotatoes were increasingly used for starch-related products, fresh market sales, and feed. During the third period (1976-85), in which Japan's economy grew at a more stable rate, sweetpotatoes were used increasingly for processed foods and less for feed. Finally, during the current period of internationalization (1986- ), imports of sweetpotatoes have rapidly increased. The changes in market supply, demand and the measures taken during these four periods can be summarized as follows:

1. Changes in supply and demand

(1) Period of postwar recovery and increased food production (1945-1960)

• Farmers' household consumption accounted for more than 30% of total demand, but decreased to less than 20% in 1960, while use for feed and starch-related products increased.
  
• In 1955, sweetpotato production reached a record high of 7.18 million tons,

(2) Period of high growth (1961-1975)

• Use of sweetpotatoes for starch-related products material rapidly increased, accounting for more than 50% of all demand in 1967, but soon dropped off sharply, replaced by inexpensive imported corn. Sales of sweetpotatoes to fresh markets increased sharply after 1970.
  
• Production declined sharply, from 6.33 million tons in 1961 to 1.42 million tons in 1975.

(3) Period of stable growth (1976-1985)

• Use of sweetpotatoes for feed dropped sharply, from more than 20% of consumption to less than 10%. Sales to fresh markets and for starch-related products were flat, each accounting for about 30% of consumption. Use for processed foods tended to increase though overall volumes were small.
  
• Production was approximately 1.3 - 1.5 million tons.

(4) Period of internationalization (1986-today)

• Sales to fresh markets increased to 40%, while sales for starch-related products decreased to a little over 20%.
  
• Production trended downward, registering 1.11 million tons in the fiscal year 1996.

2. Policy measures taken

(1) Period of postwar recovery and higher food production (1945-1960)

• The Law for Stable Prices of Agricultural Products was enacted in 1953, under which the national government became a buyer of sweetpotato starch.

(2) Period of high growth (1961-1975)

• Efforts were made to improve and broaden the use of starch-rich varieties; also, to bring automation to cultivation through consolidation of small fields for streamlined cultivation.

(3) Period of stable growth (1976-1985)

• Development of collective farms with productive facilities was promoted by securing high-quality seeds and sprouts, and by improving machinery and facilities for storage, collection and delivery.
  
• In 1984, planned production of sweetpotatoes for starch-related products began.

(4) Period of internationalization (1986-today)

• In response to diversifying demand patterns, construction of facilities for wide-area collection and delivery, storage and processing was encouraged, to ensure more consistent product quality and supply. Advanced processing techniques were introduced.
  
• From 1995 to 2000, measures are being taken to secure and increase demand, and convert use for starch material particularly into processing and other promising sectors (while de-emphasizing starch-related applications).

3. Effects and evaluation of the policy measures

Area yields have been steadily improved by the development and spread of new varieties, the introduction of small- and medium-sized agricultural machines, and the establishment of a supply system for high-quality seeds and sprouts. As a result, area yields are now about twice 1945-1954 levels. At the same time, working hours have declined considerably. Recently, a self-propelled potato harvesting machine has been developed, and efforts are being made to encourage conditions supportive of more mechanized processing.

Although the scale of management has expanded little by little, the structure of small-scale production remains relatively unchanged; further improvements are needed. If domestic productivity is to be maintained at current levels, it will be essential to develop sprout planting machines as well as harvesters and to introduce direct sowing cultivation, in order to reduce production costs and labor requirements.

○ Historical changes in consumption of domestic seed potatoes, by use

(Units: %, 1,000 tons)

Year	Farmer's household use	For feed	For seed	For fresh markets	For processed foods	For starch-related products	For alcohol	Loss	Total	Total production
1955	26.6	16.0	3.9	7.5	0.3	29.4	12.3	4.0	100	7,180
1965	9.6	25.2	4.2	6.0	0.4	46.2	6.9	1.7	100	4.955
1975	9.6	23.5	5.1	25.2	2.8	25.7	3.8	4.3	100	1,417
1985	5.9	9.4	4.3	32.2	3.9	32.6	6.9	4.6	100	1,527
1995	6.6	5.7	3.9	40.6	8.0	25.0	6.1	4.0	100	1,181
1996	7.5	4.9	3.9	42.5	9.3	21.3	6.2	4.4	100	1,109
1997	7.4	4.2	3.6	42.0	9.2	24.3	6.6	2.8	100	1,130
1998	6.9	4.2	3.2	40.0	9.3	27.0	6.4	3.0	100	1,139