CASSAVA CULTIVATION IN A TEMPERATE REGION ' A CASE STUDY IN KAGOSHIMA SOUTHERN PART OF JAPAN

CASSAVA CULTIVATION IN A TEMPERATE REGION – A CASE STUDY IN
KAGOSHIMA SOUTHERN PART OF JAPAN

Minami Sayaka1, Yabuta Shinn1, Matsumoto Satoshi2, Fukudome Yasuhiro2, Taura
Issei2, Kawamitsu Yoshinobu3, Imai Katsu4 and Hakoyama Susumu5*
1: Student of postgraduate course, Faculty of Agriculture, Kagoshima University, 2: Staffs in Experimental field
belonging to FA, Kagoshima Univ., 3: Professor, Crop Science Laboratory, FA, Univ. of the Ryukyus, 4:
Professor, Crop Science Laboratory, FA, Meiji Univ. and 5: Prof. of Tropical Crop Sci. FA, Kagoshima Univ.,
E-mail: hakoyama@agri.kagoshima-ac.jp, Korimoto 1-21-24, 890-0065, Kagoshima, Japan

KEY WORD: growth parameter, Mannihot esculenta, starch content, tuberous root weight
per plant
INTRODUCTION
World cassava production was 202 million tones in 1997, of which 53% was
produced in Africa, 30% in Asia and 17% in Latin & South America (FAO, 2007). During the
previous decade, production increased by about 30% in Africa, 20% in Asia and 13% in Latin
& South America, respectively (IFAD & FAO, 2000). Although still important as a staple
food, a feed for livestock and for starch manufacture, cassava has recently considered as a raw
material to make bio-fuels.
Kagoshima locates southern part of Japan with annual mean temperature of 18.3oC,
monthly average daily minimum temperature of 4.1oC in January and monthly average daily
maximum temperature of 32.0oC in August. Annual rainfall is 2280mm and several times of
frost are in the winter season, especially from December to March. This climate of
Kagoshima is not suitable condition but a marginal one for cassava growth.
However, cassava ranks very high among crops that convert the greatest amount of
solar energy into soluble carbohydrates per unit ground area. Among the starchy staples,
cassava accumulates carbohydrate about 40% higher than rice and 25% more than maize, and
starch content is about 24% (NYERHOWO, 2004) to 29% (WEÇOLOVIS et al., 2003). By
using the proper characteristics of cassava such as high efficiency to convert the solar energy
into carbohydrates per unit ground area, i.e. high ability of starch accumulation, it is useful to
enlarge cultivation areas with the marginal conditions like Kagoshima, and to produce an
alternative source of energy to fossil fuels, thus contributing to environmental sustainability.
The object of this study is to confirm whether economic production of cassava is possible in
an area with a marginal climate, such as Kagoshima.

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MATERIALS AND METHODS
Materials used in this study is a cultivar., IAC-576-70, of the cassava (Mannihot
esculenta Crantz ) , which were obtained from Instituto Agronomicas de Campinas, Sao
Paulo, Brazil, by a kindness of IAC staffs of cassava breeding section, Professor Dr. Silvio
JOSE BICUDO, UNESP/Botucatu-SP and Dr. Joao NAKAGAWA. Twenty-six cuttings, already
initiating sprouts from each axil on arrival at Kagoshima, were planted temporary in the
experimental field of Kagoshima University (UF) with the spacing of 30cm x 30cm on 8 July
2006. About two weeks later, 22 plants were transferred to a farmer’s field at Kiire (KF),
Kagoshima, with the spacing of 120cm between rows and 60cm between plants in the row.
Four plants with the spacing of 90cm x 120cm were maintained in UF. After transplanting, at
2-weekly intervals plant height and numbers of leaves per plant were measured for 5 plants at
KF and 4 plants at UF. At the final measurement on 19 December, tuberous root weight per
plant, starch value of tuberous root by specific weight method (WEÇOLOVIS et al., 2003)
and total dry weight per plant were determined.

RESULTS AND DISCUSSION
Climate at Kagoshima
Annual change of monthly mean, maximum, and minimum temperature, monthly
precipitation, and monthly amounts of solar energy from 1971 to 2000 at local Meteorological
Observatory at Kagoshima 33.33oN and 130.32oE, are shown in the Figures 1 and 2. The
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Fig.1. Annual change of monthly average daily mean,
1
2
3
4
5
6
7
8
9 10 11 12
maximum and minimum temperature during
month
'71-'00 and in '06 at Kagoshima
m onthly average daily mean tem perature during '71-'00"
Fig.2. monthly average precipitation and
m onthly average daily maxim um tem perature during '71-'00"
solar energy at Kagoshima
m onthly average daily minim um temperatre during '71-'00
m onthly average daily mean tem perature in '06
m onthly average daily maxim um tem perature in '06
monthly average of precipitation during '71-'00
m onthly average daily minim um temperature in '06
monthly average of solar energy during '71-'00


duration of monthly mean temperature above 20oC is only 6 months, May to October, which
is not long enough to be for ideal growing cassava, but monthly precipitation and solar energy

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are not limiting factors. However, duration of monthly mean temperature above 15oC is ?
months longer than that of monthly mean temperature above 20oC. These climatic features
show that cassava can be grown at Kagoshima.
Cassava Growth
The cassava cuttings differentiated several shoots, developed several leaves and grew to
about 25cm in height during two weeks after temporally planting at UF. After transplanting at
KF until middle September, cassava grew well in terms of plant height and numbers of leaves
developed because of consistent high summer temperatures. These growth parameters of
cassava were superior at UF than at KF throughout growth cycle with statistical significance
(p<0.05), except for plant height during October and for number of leaves after a
250
350
A) Plant height
B) Number of leaves per plant
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Fig.3.Time course of cassava growth in plant height (A) and numbers of leaves (B)
UF
KF
Arrows in the Figure show the day of typhoon and vertical bar at each

observation represents standard deviation.

typhoon (Figure 3.). At KF, cassava growth seemed to be delayed by root injury at the time of
transplanting from UF. Some shoots apices were broken or damaged by strong typhoon winds
on 18 September. Although, this damages were minimized by pre-protect treatments, it was
more serious at UF than at KF. At harvest, plants were height 2m or more with about 200
leaves per plant.
Tuberous root weight and starch content
The mean tuberous root weight per cassava plant at harvest was 4.10kg at UF, 2.19kg at
KF. Although the experiment was small in scale because of limited plant material available,
these tuberous root weight correspond to yields about 38t/ha at UF and 30t/ha at KF
respectively. The starch value of about 17, based on specific weight method, is equivalent to a
starch content of about 23%. While root weight differed significantly (p<0.01), starch content

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did not differ between two fields. These results show that tuberous root fresh weight per plant
and starch content were not inferior to the results by NYERHOWO (2004) and WEÇOLOVIS
et al., (2003), even though growth period was only 5 months. This fact suggests a possibility
to be cultivated cassava economically in a temperate region like as Kagoshima.
Table 1 Tuberous root weight per plant and starch value at harvest
Plants
Numbers of tuberous
Tuberous roots
tuberous root
Field
Harvest date
Starch value
measured
root per plant
weight
gravity
UF
19-Dec
3
-
4100
1.094
17.02
KF
11-,19-Dec
8
22.4?n=5)
2193
1.095
17.16
t-value



t= 4.62
t= 0.085
t= 0.085

statistic significance


P<0.01
NS
NS

NS mean no significance statistically in the t-test

Cassava yield (dry matter base) has been increased by 90 percent during 1971-1996 in the
highland tropics as a result of the cultivation of newly released cassava varieties. In region
with elevations above 2000m or in mountainous areas, however, cold temperatures limit
cassava cultivation (CGIAR, 1996), suggesting that temperature is the major limiting factor
for cassava growth.

CONCLUSION
Our results from a small scale, one-year trial showed that cassava can be cultivated in a
temperate region, producing plants of good height and leaf numbers per plant, and adequate
tuberous root production and starch accumulation. It is considered that cassava can be
cultivated economically even in mid-latitudinal areas, i.e. temperate regions. However, some
technological developments will be needed, such as the breeding of a new low- temperature-
tolerant variety and reducing the cost of crop maintenance during winter, etc.

REFERENCES
FAO. FAO Statistics, Production of Selected Agricultural Commodities 2004. 2007
IFAD & FAO. The World Cassava Economy, Facts, Trends and Outlook. 2000.
NYERHOWO, T. J. Cassava and the future of starch Electronic Journal of
Biotechnology?Vol.7 No.1, Issue of April 15, 2004.
WEÇOLOVIS, J.; UNFRIED, J.R & MONTALVAN, R. Starch content variation in cassava
cultivars during four harvesting seasons in Marechal Cândido Rondon, Brazil. Crop
Breeding and Applied Biotechnology, v. 3, n. 4, p. 255-260, 2003.

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CGIAR: Mandated food crops. In 25 years (1971-1996) of food and agriculture improvement
in developing countries. http://www.worldbank.org/html/cigar/25years/mand.html

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