Jpn. J. Trop. Agr. 46(2) : 94-99, 2002

Information

Cultivation of Amorphophallus paeoniifolius (Dennst.) Nicolson in Home Gardens in Java

Edi SANTOSA, Nobuo SUGIYAMA*,*3, Adolf Pieter LONTOH *2, SUTORO *2, Shoko HIKOSAKA* and Saneyuki KAWABATA*

Faculty of Agriculture, Bogor Agricultural University, Bogor, Indonesia * Graduate School of Agricultural and Life Sciences, University of Tokyo, Tokyo 113-8657, Japan *2 Research Institute for Food Crops Biotechnology, Bogor, Indonesia * 3 The corresponding author

Abstract Elephant foot yams are grown as ground-layer crops in home gardens because they are tolerant to low light intensities and low fertility. However, the cultural practices and use of elephant foot yams have not been studied. Therefore, field surveys and interviews of farmers were carried out in West, Central and East Java, and Yogjakarta. The number of home gardens in which elephant foot yams were cultivated was larger in Central Java than in West Java. Farmers use corms and leaves as staple crops and vegetables, respectively, as well as for feedstuffs. Some farmers harvest corms only when rice production is low. Although elephant foot yams play a minor role as food crops, they have a potential as industrial crop because they can be cultivated under the canopy of plantation crops. Key words Elephant foot yam, Home garden, Java

ジ ャ ワ の ホ ー ム ガ ー デ ン に お け る ゾ ウ コ ン ニ ャ ク の 栽 培Edi SANTOSA・ 杉 山 信 男*,*3・Adolf Pieter LONTOH*2・SUTORO*2・ 彦 坂 晶 子*・ 河 鰭 実 之*Faculty of Agriculture, Bogor Agricultural University, Bogoy, Indonesia*東 京 大 学 人 学 院 農 学 生 命 科 学 研 究 科 〒113-8657東 京 都 文 京 区 弥 生*2Reseaych Institute for Food Cyops Biotechnology, Bogor, Indonesia

要 約 ゾ ウ コ ン ニ ャ ク は低 照 度 に対 して 耐 性 が あ る た め,ホ ー ム ガ ー デ ンの 最 下 層 で 栽 培 され る.し か し,ゾ ウ コ ンニ ャ ク の栽 培,利 用 に 関 す る 研 究 は 少 な い.そ こ で,西 ジ ャ ワ,中 部 ジ ャ ワ,東 ジ ャ ワ お よ び ジ ョ グ ジ ャ カ ル タ州 で ホ ー ム ガ ー デ ン を調 査 し,農 民 へ の イ ン タ ビ ュ ー を 実 施 した.ゾ ウ コ ン ニ ャ ク を栽 培 す る ホ ー ム ガ ー デ ン の 数 は西 ジ ャ ワ よ り も中 部 ジ ャ ワ で 多 か っ た. 球 茎 を 主 食,葉 を 野 菜 と して 利 用 す る ほ か,飼 料 と して も利 用 され て い た.コ メ の生 産 量 が不 足 す る場 合 に の み,収 穫 を行 う農 民 も見 られ た.現 在,食 用 作 物 と して ゾ ウ コ ンニ ャ ク は 重 要 な役 割 を果 た して い な い が,プ ラ ン テ ー シ ョン の 林 床 下 で の 栽 培 が可 能 な こ と か ら,将 来,工 業 用 の原 料 を供 給 す る作 物 と して 有 望 と思 われ る. キ ー ワ ー ド ジ ャ ワ,ゾ ウ コ ンニ ャ ク,ホ ー ム ガ ー デ ン

Elephant foot yams (Amorphophallus paeoniifolius Introduction (Dennst.) Nicolson, synonym of A, campanulatus Home gardens can contribute significantly Decaisne) were one of the important staple to the household economy because many kinds foods in the 1940s and 1950s in Java, and were of materials needed for daily life can be cultivated or collected from the forest4). Since produced there. The dominant plants in home the 1960s and beyond, elephant foot yams have gardens are medicinal plants, fruit trees, been consumed only when rice production was vegetables, starchy food crops, spices, and trees low due to the long dry season spells. JANSENet for building materials and fuel woody 10,13)These al.4) reported that 100g of the edible portion plants have different height and light require contains 18 g carbohydrates, l to 5 g protein, 0.4 ments, generating a complex vertical structure to 2 g fat, 0.6 g fiber, 0.6 mg Fe and 434 IU as a whole. Under multi-storied polyculture vitamin A. The energy value is 420 kJ per 100 g. systems, crops at the ground level receive low OHTSUHI8)reported that A. campanulatus corms light intensities. contain starch, but not glucomannan, as reserve The cultivation of tuber crops, such as taro, carbohydrates. Although elephant foot yams are arrowroot, tannia, yams and elephant foot yams, often consumed in certain regions of Java, no is very common in home gardens, because statistical data are available on the production these crops are adapted to low light conditions5). and consumption. The objective of the present Received Oct. 4, 2001 study was to investigate how elephant foot yams Accepted Feb. 15, 2002 are cultivated and used in Java, Indonesia. SANTOSAet al.: Elephant Foot Yams in Home Gardens in Java 95

Fig. 1. Study sites for home gardens where elephant foot yams were cultivated.

Materials and Methods Field surveys were conducted in several areas in West Java, Central Java, Yogyakarta and East Java during May and June, 2000 (Fig. 1). These areas are located on the route explored by OHTSUKI18)to collect Amorphophallus species. At each study site, we interviewed ten farmers about the source of corms, number of elephant foot yam plants grown in home gardens, cultivation methods, area for planting, trees grown over the elephant foot yams, utilization of corms and leaves, cultivation of other tuber crops, methods of harvesting, processing and storage. The weight of the corms and the stem Fig. 2. Locations of home gardens where elephant diameter and height were measured for plants footyams are cultivated. sampled in home gardens. and East Java had compelled farmers to grow Results and Discussion elephant foot yams until recently. Characteristics of home gardens with elephant At the time of the field surveys, most of the foot yams plants in Central Java and Yogyakarta still had Elephant foot yams were cultivated in home green leaves, while the plants were just gardens in 11 of the 18 districts studied (61 %). developing leaves or had lost their leaves in In these 11 districts, 32.7% of the farmers other districts. It is possible that the growth cultivated elephant foot yams on the average. It stage may depend on climatic conditions, appears that the cultivation of elephant foot especially the time of the beginning of the dry yams is more common in Central Java and season. JANSENet al.4)stated that corms enter a Yogyakarta that in West Java (Table 1). KANO6) dormant period at the beginning of the dry reported that rice consumption per capita was season. higher in West Java than in Central and East Home gardens with elephant foot yams Java in the early 1980s, while corn consumption were located in lowlands, riverbanks, uplands, per capita was lower in West Java. He considered and forest margins (Fig. 2). Lowlands are mainly that this situation reflected the high productivity used as paddy fields and fishponds because the of paddy rice due to the well-developed irrigation water-table is high (less than one meter below systems in West Java. Therefore, it was likely ground) and rivers are sometimes flooded. that the low productivity of paddy rice in Central Therefore, it is likely that elephant foot yams 96 Jpn. J. Trop. Agr. 46 (2) 2002

Table 1. Percentage of home gardens growing elephant foot yams, and purpose of growth.

Note: S (staple foods), F (making flour), V (vegetables), D (feed for fish or disinfectant for ponds), C (feedstuff for cattle); + present and-absent.

are tolerant to the humid soil conditions, but the productivity in these wetlands has to be compared with that in the uplands. Elephant foot yams are usually grown in home gardens as ground layer crops. Plants grown alongside elephant foot yams are shown in Figure 3. Generally, the data revealed that elephant foot yams were cultivated without other species in 36% of the home gardens. ROSMANand RUSLI12)reported that elephant foot yams prefer shaded to open areas. PUSHPAKUMARI and SASIDHAR11)observed that the yield of elephant foot yams decreased when the light intensity decreased. However, SUFIANI16)reported that shading is necessary for Amorphophallus corms to enlarge. Thus, the appropriate light Fig. 3. Plants as shade sources for elephant foot intensity has not been fully determined. yams.

Use of elephant foot yams campanulatus var. sylvestris (acrid and wild types) KRISWIDARTI7)and WIDJAJA and LESTER17) and A. campanulatus var. hortensis (non-or less identified two forms of A. paeoniifolius, A. acrid and cultivated types). Farmers plant SANTOSAet al.: Elephant Foot Yams in Home Gardens in Java 97 elephant foot yams without knowledge of acridity. Cultivation methods Furthermore, farmers in Banjarnegara recognize Elephant foot yams are commonly planted that acridity depends on the growth stage; corms in the corners of home gardens, at the edge of are acrid when new leaves develop, and the fishponds, in dumping grounds, etc., as illustrated acridity disappears at the dormant stage. in Figure 4. Farmers usually invest little labor Farmers can easily recognize acridity if they for the growing of elephant foot yams. peel the corms. Therefore, they immerse acrid In Purbalingga, Purworejo and Majalengka, corms in flowing water for two or three days to most of the farmers harvested corms after the reduce the acridity. Non-acrid corms are usually leaves were dead from April through June. peeled, washed and boiled. Otherwise, the corms Corms are stored in a dry place or under a bed are sliced, dried and milled to make flour. The during the dry season and replanted when the flour is steamed with coconut milk and eaten rainy season starts. Sometimes, farmers plant with brown sugar. corms upside down because they believe that The use of elephant foot yams as a staple this practice will stimulate the enlargement of food is very common throughout Java (Table 1). corms, although this has not been ascertained The corms are boiled after peeling and sometimes experimentally. slicing. Making flour is another common use of In Banjarnegara, Kuningan, Blitar and elephant foot yams in Central Java, but the flour Purworejo, farmers do not harvest corms is made only in one district in West Java. annually. Corms are left in the ground, and dug Immature leaves are sometimes cooked as up whenever needed. After the dormant period, vegetables in Central and East Java. The fully corms develop new leaves. Most of the farmers expanded leaves are used as fish feed and as a harvest corms when a stem diameter of 10 cm disinfectant for fishponds in East and West Java. or larger is attained because corm weight is In Kuningan, West Java, farmers feed the corms related to the stem diameter. S0EMONOet al.15) and leaves of acrid varieties to pigs, while in reported that the stem diameter increased as East Java, cattle receive fresh corms which are the corm size increased. Usually the corm sliced and mixed with cassava. HEYNE3)reported weight reached 5 kg three years after planting. that elephant foot yam flour was added to forage JANSENet a1.4)reported that the corm weight can for cattle in the Kediri district of East Java. increase up to 25 kg under favorable conditions. SOEMONOet al.15) pointed out that corms could Several farmers in Purworejo estimate the corm be used as a food supplement and complement size based on the plant height. However, the because the contents of vitamins A and B are present study showed that the estimation of the relatively high. corm size based on the stem diameter was more

Fig. 4. Illustration of main component crops in a home garden in Puruwarejo, Central Java. 98 Jpn. J. Trop. Agr. 46 (2) 2002

Prospects for elephant foot yams

Elephant foot yams are a minor food crop in

Java because food supplies from other crops

have already increased. According to statistics,

paddy rice and maize production have increased during the past 5 years, while the production of

root crops such as sweet potato and cassava

decreased2). Therefore, not only elephant foot

yams but also other root crops have become less prominent.

Elephant foot yams played an important

role in the farm economy in the 1940s and 1950s

when people often experienced famine. Therefore,

people have a negative image of elephant foot

yams. In addition, low productivity, long period of time needed until harvest, and acridity may

account for some of the limited uses of elephant foot yams.

A campaign for •eFood security based on non

seed carbohydrates•f has been promoted in

Indonesia since the early 1990s, and the

government and private institutions plan to conserve indigenous genetic resources that will

be used to improve elephant foot yams for foods

and raw industrial materials. However, changes Fig. 5. Relationship between stem diameter (A), in land use from forest to agricultural land may cause genetic erosion. In the pine forests of plant height (B) and corm weight for plants harvested at the end of the growing season Central and West Java, wild specimens of the in study areas. Amorphophallus species can only be found close to pine trees, and not between pine trees. At

present, limited accessions are maintained at the Bogor Botanical Garden, Research Institute

accurate than that based on the plant height, as for Food Crop Biotechnology in Bogor, and

indicated by the correlation coefficients (Fig. 5). Bogor Agricultural University. Seed corms are usually received from In conclusion, elephant foot yams are not

neighbors and relatives, or collected from the important in the household of farmers. However, nearest forest. Usually, one to three corms are they have a potential as industrial crop because

planted in a home garden. In Kuningan, they can be cultivated under the canopy of

Purbalingga and Purworejo, however, more plantation crops. than 10 plants were cultivated in home gardens. References Farmers dig a hole measuring 60 cm •~ 60 cm

•~ 60 cm, and then fill it with compost. The 1. AKUBA, R.H. and Z. MAHMUD 1991 Coconut based application of 30 t of farmyard manure and 150 farming systems at homegarden. Industrial Crop

kg N per hectare was recommended by PETEL Res. J. Bogor. 4:33-42. and MEHTA9). 2. BPS 2000 Statistical yearbook of Indonesia. Central Cormlets and superficial parts are used as Bureau of Statistics, Republic of Indonesia. pp. 610.

propagules3). JANSEN et al.4) pointed out that seed 3. HEYNE 1987 Useful Plants in Indonesia. I. Balitbang Kehutanan. (Jakarta) pp. 318. (in Indonesian) propagation is not common because seeds are not always available and show a dormancy 4. JANSEN, P.C.M., C. van der WILK, and W.L.A. HETTERSCHEID 1996 Amorphophallus Blume ex Decaisne. period. SOEMONO et al.15) and SEN et al.14) stated In: M. FLACH and F RUMAWAS (eds.). Plant Resource that crop productivity is highly correlated with of South-East Asia. Vol.9. Plant yielding non-seed the weight of seed corms. carbohydrates. Prosea Foundation (Bogor) 45-50. SANTOSAet al.: Elephant Foot Yams in Home Gardens in Java 99

5. JOHNSTON,M. and I.C. ONWUEME1998 Effect of Littro 7:17-21. (in Indonesian) shade on photosynthetic pigments in tropical root 13. RUSMINI,N. 1998 Role of home garden for Melayu crops: yam, taro, tannia, cassava and sweet potato. society in Deli Serdang, North Sumatra. Prosiding Expl. Agric. 34:301-312. Seminar Nasional Etnobotani III. (Bali) 199-204. (in 6. KANO, H. 1988 Analysis of Rural Economy in Indonesian) Indonesia. Keishosha. (Tokyo) p 316. (in Japanese) 14. SEN,H., BK. DASand D.B. GOSWANI1996 Growth and 7. KRISWIDARTI,T 1980 Elephant foot yam (Amorpho corm production of elephant foot yam as affected by - phallus campanulatus Bl.), an important crop for seed corm size, type, NK nutrition and harvesting carbohydrate sources. Buletin Kebun Raya 4:171- date and evaluation of the low cost storage methods. 173. (in Indonesian) In G.T. KURUP,MS. PALANISWAMI,V.P. POTTY,G. 8. OHTSUKI,T. 1968 Studies on reserve carbohydrates PADMAJA,S. KABEERATHUMMA,and S.V. PILLAI(eds.). of four Amorphophallus species, with special reference Tropical Tuber Crops: Problems, Prospects and to mannan. Bot. Mag. Tokyo 81:119-126. Future Strategies. Science Publ., (USA) pp. 597. 9. PATEL,B.M. and H.M. MEHTA1984 Effect of farmyard 15. SOEMONO,S., J.S. BAHARSJAH,J. WIROATMODJO and S. manure, spacing and nitrogen on yield of elephant TJITROSOEDIRDJO1986 The effect of corm weight on foot (Amorphophallus campanulatus Blume). Indian J. growth, yield and quality of elephant foot yams at Agron. 29:269-270. different age. Bull. Agron. 17:17-23. (in Indonesian) 10. PURNOMO1998 Kind of species in home garden of 16. SUFIANI,S. 1993 Ecological and agronomic properties coastal society in Yogyakarta Special District. of Amorphophallus species and standard quality for Prosiding Seminar Nasional Etnobotani III. Bali. export. Media Komunikasi Litbang Tanaman Industri p186-192. (in Indonesian) 12:11-16. (in Indonesian) 11. PUSHPAKUMARI,R. and V.K. SASIDHAR1992 Yield 17. WIDJAJA,E.A, and RN. LESTER1987 Morphological, variation of yams and aroids as influenced by shade anatomical and chemical analyses of Amorphophallus intensities. Indian J. Plant Physiol. 35: 345-350 paeoniifolius and related taxa. Reinwardtia 10: 271-280. 12. ROSMAN,R. and S. RUSLI1991 Elephant foot crops.