IJERD – International Journal of Environmental and Rural Development (2021) 12-2

Research article
erd

The Possibility of Producing and Distributing Healthy
Cassava Seeds in Cambodia
TAMON BABA*
College of Letters, Ritsumeikan University, Kyoto, Japan
Email: babatmn@gmail.com

HISAKO NOMURA
Faculty of Agriculture, Kyushu University, Fukuoka, JapanPAO SREAN
Faculty of Agriculture and Food Processing, National University of Battambang, Cambodia

THA THAN
Faculty of Agriculture and Food Processing, National University of Battambang, Cambodia

KASUMI ITOInternational Center for Research and Education in Agriculture, Nagoya University, Japan
Received 31 December 2020

Accepted 15 November 2021(*Corresponding Author)

Abstract This study discussed the possibility of producing and distributing healthy cassava
seeds in Cambodia. Since 2015, there has been no official healthy seed certification anddistribution system in Cambodia despite the rapid spread of the Sri Lankan Cassava Mosaic
Disease in Southeast Asia. To improve cassava production and its sustainability, we
conducted interviews using a structured questionnaire in Battambang and Pailin Provincesfrom April to November 2017 and received responses from 205 cassava producers. The
results showed that most producers reused seeds from the previous years' harvest andindicated considerable market interest for healthy cassava seeds in Cambodia. Finally, we
found that training and information on healthy seed production combined with stringent pestand disease monitoring efforts are essential. This study suggests that a market-based, healthycassava seed distribution system can be established in Cambodia.
Keywords cassava, seed production and distribution, Cambodia, sustainable,market-based solution

INTRODUCTION
Cassava (Manihot esculenta Crantz) is one of the largest staple crops in the world and one of themost important cash crops in Cambodia (FAO, 2020; MAFF, 2018). Although there are many uses
for cassava starch, from food to cosmetics, its utilization as a source of biofuel has increased its
demand in recent years. Cassava propagates from the cuttings of the remaining cassava stems after
its tuber is harvested (Tokunaga et al., 2018). Although propagation makes cassava grow fastercompared to plant growth from seed germination, once contaminated with a virus or a phytoplasma,
this propagation method has a negative impact. It could easily spread diseases like witches' broom(Alvarez et al., 2013) and harmful pests, such as mealybugs, red mites, and scale insects. Furthermore,
recently, Sri Lankan Cassava Mosaic Disease (SLCMD), which severely affects cassava and spreads
through whitefly and human factors, has spread rapidly in Southeast Asia (Wang et al., 2016; Uke etal., 2018).
In Cambodia, the government-led cassava extension system has been limited (MAFF, 2015;
Tokunaga et al., 2018). The Department of Agricultural Extension of the Ministry of Agriculture,Forestry, and Fisheries (MAFF) was established in 1995. However, their activities are limited due toa lack of funding, technical expertise, extension materials; an inadequate production and distributionⒸ ISERD

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IJERD – International Journal of Environmental and Rural Development (2021) 12-2system; and human resources to support extension processes. As a result, an official system forproducing and distributing cassava seeds has yet to be established.
In Ratanakiri and Battambang Provinces of Cambodia and Dak Lak and Tay Ninh Provinces ofVietnam, cassava seeds are informally distributed and self-regulated, without any active quality
certification schemes (Delaquis et al., 2018). Thus, traders play an important role in the long-distanceseed movement. The use of farm-saved seed and exchanges among acquaintances within thecommunity are most common. However, given the spread of SLCMD, this informal and selfregulated method of seed distribution has increased the chances of humans spreading the disease.
To remedy this situation and promote the country's economic growth, the Royal Government ofCambodia (RGC) recently announced its "National Policy on Cassava 2020-2025," which declaredcassava as one of the potential crops for agro-industrial development in Cambodia (RGC, 2020).
Therefore, MAFF and its allied universities are required to "promote and encourage propagation
farms and private cassava stem suppliers to sell and distribute healthy and disease-free cassava
stems." (RGC, 2020). However, even though this policy is relatively new, there have not been any
detailed discussions about the possibility of enabling the production of healthy cassava seeds.
Prior to the current policy discussion, since 2016, we have been conducting a project titled"Development and Dissemination of a Sustainable Production System Based on Invasive Pest
Management of Cassava in Vietnam, Cambodia, and Thailand" supported by the Japan Science andTechnology Agency and the Japan International Cooperation Agency. The project aims to establish
a sustainable production system that utilizes healthy seeds by developing a market-based
dissemination model that supports the private sector, producers, and the government, with amanagement system for invasive cassava diseases and pests. For this project, it was essential first toidentify the producers' cassava seed preferences, distribution, propagation methods, and demand for
healthy cassava seeds. Our projects contribute to creating a certified production and distribution
system for healthy cassava seeds, in line with the one envisioned by the Royal Government ofCambodia.
OBJECTIVE
This study aims to discuss the potential for healthy cassava seed production and distribution in theCambodian market by characterizing the present status of cassava seeds, including producers'
preferences for cassava varieties and their demand for healthy cassava seeds based on a structured
questionnaire interview. Finally, the project mentioned above focusing on the production system of
healthy seeds was used as a case study.
METHODOLOGY
We interviewed producers about the 2016-2017 cassava production cycle in two Districts of Pailin
Province and six Districts of Battambang Province, northwest of Phnom Penh, the capital ofCambodia, from April to November 2017 using a structured questionnaire. The total planted area of134,385 ha in Battambang is the largest cassava production land area among all Provinces andproduces 3,769,266 tons of cassava per year. Pailin Province has the fifth largest cassava plantedarea of 59,067 ha in Cambodia, producing 1,477,175 tons, the third-largest in terms of quantity(MAFF, 2018).
A stratified random sample based on the cassava planted area was applied to select therespondents. The total respondents included 205 cassava producers: 144 from Battambang Provinceand 61 from Pailin Province. All the questionnaires were valid. Then, qualitative and quantitative
analyses were applied.
RESULTS AND DISCUSSION
Some characteristics of the respondents are profiled below (Table 1). In the survey, only the primarycassava producers in the household were considered, comprising 93% males and 7% females. TheirⒸ ISERD210

IJERD – International Journal of Environmental and Rural Development (2021) 12-2average age, cassava planting times, and cultivated area was 49 years for males and females, 4.08.
and 3.73 ha, respectively. As discussed below, 40% of producers purchased seeds for the 2016-2017
cycle. While currently there is no healthy seed distribution system, approximately 68% of
respondents showed a willingness to buy healthy seeds, and 72% showed a willingness to become
healthy seed producers.
Table 1 Descriptive summary of survey respondents
Variables
Gender (1=male, 0=female)Age (years)
Province (dummy)
Cassava planting times before the 2016-2017
cycle (times)
Total cassava cultivated area (ha)Purchased seeds for the 2016-2017 cycle or not(1=yes, 0=no)
Want to buy healthy seeds (1=yes, 0=no)
Want to be a healthy seed producer(1=yes, 0=no)

Mean
0.93
49.00
0.70

Std. Dev.
0.26
13.29
0.46

Min.
021
0

Max.
178
1

4.08

3.03

016

3.73

4.65

0.09

40

0.40

0.49

0

1

0.68

0.47

01

0.72

0.45

01(N=205)

First, the survey inquired about the cassava varieties used by the producers (Table 2). While
78.9% of answers included "Unknown" or nicknames in Khmer, such as "Kor Teul" (long neck) and"Masao" (starch), others provided a variety name. Although we cannot confirm the accuracy of theprovided variety names, our survey reveals that they mostly use Thai varieties such as Rayong 9,Rayong 90, and Houybong. Based on visual checks done by a descriptor created by our project, thevarieties called "Unknown," "Kor Teul," and "Masao" include KU50 and Rayong 7, which are also
from Thailand. The name "Masao" implies that producers care about the starch contents of thevariety; Masao varieties often have a reputation of containing a high starch content. We find that
Cassava producers prefer high starch content varieties. However, they do not have a very strong
preference over the specific variety and can accept the variants distributed in the market.
Table 2 Cassava varieties used by the surveyed producers
VarietyUnknown
Kor Teul
Masao
Malay
MeyongNamdeng
Red Petiole(Kandeng,Kanteng)Unknown
Number ofanswers%

Variety

7161
253
11

33.3%
28.6%
11.7%
1.4%
0.5%
0.5%

62.8%

Rayong 2
Rayong 3Rayong 4
Rayong 5
Rayong 9
Rayong 11
Rayong 90
818589Houybong

Thai varieties
Number ofanswers
112191961113%
0.5%
0.5%
0.9%
0.5%
4.2%
0.5%
4.2%
2.8%
0.5%
0.5%
6.1%
(N=213)

Second, the results showed that 40.0% of those surveyed did not buy cassava seeds because
they reused the seeds harvested from their fields in the previous cycle. Further, 76.9% of those whopurchased seeds bought them in their neighborhood, while 11.5% bought seeds imported fromThailand, and the remaining 11.5% bought seeds brought by road from Vietnam. This resultⒸ ISERD211

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complements the results of the previous study by Delaquis et al. (2018). These results show that seeds
can easily be imported and transported across different regions; diseases and pests could easily spread.
Third, we asked producers, "Do you want to purchase healthy seeds if they are available on themarket?" To this, 139 (67.8%) producers answered affirmatively, and of those, 48.8% bought seeds
in the 2016-2017 cycle. It implies 33.1% (=48.8% x 67.8%) of producers might purchase healthy
seeds in the future. Further, the average percentages of producers who want to buy healthy seeds ineach "Actually purchased group" and "Not purchased group" are significantly different at a𝑥 2 statisticof 8.227 (p-value<0.01) (Fig. 1).

Pearson chi2(1) = 8.227 Pr = 0.004

Fig. 1 Producers who want to purchase healthy seeds based on the 2016-2017 purchase record
Fourth, 71.7% of producers answered yes to the question, "Do you want to produce healthyseeds as a business?" Furthermore, the producers with a large cassava cultivation area were moreinterested in healthy seed production than smaller ones (Fig. 2). Additionally, this is statisticallysignificantly different at a𝑥 2 statistic of 10.262 (p-value<0.01). It implies that the larger the cassava
area producers have, the higher the willingness to be healthy cassava producers. Thus, larger landarea producers recognize the business opportunities present in the production of healthy seeds.

Pearson chi2(2) = 10.262 Pr = 0.006

Fig. 2 Producers who want to produce healthy seeds by cassava cultivation area
Thus, we find that producers can accept new varieties, and those who purchased stem seeds forthe 2016-2017 cycle are interested in purchasing healthy seeds. Additionally, those with a production
area of 1 ha or more are more interested in producing healthy seeds than those with less than 1 ha ofcassava production area. These results suggest that there is a potential market for healthy seed cassava
in Cambodia. Further, since the existing seed distribution method could spread pests and diseases
across Cambodia, establishing a market-based certified healthy seed production system could preventthe spread of pests and diseases like SLCMD.

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Based on the results above, our project started a healthy seed production system in Cambodia
on a trial basis (Fig. 3). In Cambodia, the National University of Battambang (NUBB) has a Cassava
Propagation and Distribution Center. In 2018, the project selected two varieties, KU 50 and Rayong
7, and started producing healthy seeds through careful monitoring and Polymerase Chain Reaction(PCR) testing. Then, the varieties were sold to three producers who wanted to be healthy seedproducers in Battambang Province (Producer A: 1,351 healthy seeds), Banteay Meanchey Province(Producer B: 599 healthy seeds and 400 additional healthy seeds in 2019), and the other producer in
Banteay Meanchey Province, who stopped production immediately because of weather conditions.
We found these producers interested in the project through the survey and personal communications
in our pursuit to find healthy seed producers, and we also introduced them to the NUBB. The priceis 1$ per 1 bunch (20 seeds), which was the market cassava price at the time of the study. Twoproducers in Banteay Meanchey Province were also supported by Deutsche Gesellschaft fürInternationale Zusammenarbeit. In 2019, in addition to these three producers, two more producers in
Battambang and Oodar Meanchey Provinces and the General Directorate of Agriculture (GDA) fieldin Battambang Province started to be healthy seed producers. With the prevalence of the spread ofSLCMD, gradually more producers became interested in becoming healthy seed producers.

Fig. 3 The healthy cassava seed distribution system at NUBB
These producers were trained periodically to monitor cassava fields and could independently
execute such monitoring techniques. They also received information packages and training on pests
and diseases and how to treat them. The monitoring system recommended by the project is as follows.
1. When the cassava plants start producing leaves, check each border and the middle of the fieldcarefully to find abnormal plants shorter than other plants or those that are yellow. 2. Check the stemfrom the bottom to the bud and the surface of the leaves to find pests, such as whitefly, mealybug,
red mite, and scale insect, diseases such as witches' broom, and SLCMD; and 3. Remove pests byhand, in case there are few. If the pest infestation is severe, use recommended chemicals to control
whitefly, a Sri Lankan cassava mosaic virus vector. 4. Finally, and most importantly, remove infectedor suspicious SLCMD plants from the field, bury or burn them, and replace them with healthy
cuttings.
At the time of harvest, and if the PCR test result of their samples at NUBB is negative, Producer
A and Producer B can sell these healthy seeds to the general producers who value such seeds. After
multiplying healthy seeds, the producers sold them in 2019 (Producer A: 2,000 stems (1 GDA field))and 2020 (Producer A: 2,400 stems (1 general producer and 1 GDA field); Producer B: 1,095 stems(11 general cassava producers)), while other healthy seed producers did not sell because they were
under multiplying their stems. Some of these general producers have become interested in producing
healthy seeds. They have joined our monitoring training to sell such seeds to other producers as abusiness.
These findings show that NUBB and healthy seed producers can become sources of trusted
cassava seeds for producers in Cambodia. While Cambodia has no official seed distribution system,
our system (including NUBB and the cassava producers) can be a pioneer model. However, theⒸ ISERD213

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healthy seeds produced in this trial are not free from the risk of disease. Therefore, monitoring is an
essential part of healthy seed production. Nevertheless, the results show that a healthy seedproduction system centered on NUBB with well-trained healthy seed producers can positively affectthe cassava sector in Cambodia.
CONCLUSION
The study clarified that cassava producers in Cambodia could accept and produce healthy cassava
seeds. Producers care about the starch contents of the variety, though they do not have a very strong
preference for the specific variety and can accept variants distributed in the market. Those whopurchased seeds in the 2016-2017 cycle are still interested in purchasing healthy seeds. Additionally,
those with a cassava production area of 1 ha or more are more interested in producing healthy seeds
than those with less than 1 ha. Further, we demonstrated that the pilot project in Battambang Province
had created a healthy production system for cassava seeds in Battambang and Banteay Meanchey
Provinces, which has seen positive results. We emphasize that monitoring is an integral part of thehealthy seeds production system. While SLCMD has been spreading, producers have a high demand
for a healthy seed market. Therefore, our market-based production system can contribute toward
creating sustainable cassava production to help producers increase their income and improve thecountry's economic growth while meeting the policy aims of the Royal Government of Cambodia.
ACKNOWLEDGEMENTS
This research was supported by Science and Technology Research Partnership for SustainableDevelopment (SATREPS) in collaboration between Japan Science and Technology Agency (JST,JPMJSA1508) and Japan International Cooperation Agency (JICA). We would also like to thankDeutsche Gesellschaft für Internationale Zusammenarbeit for their cooperation.
REFERENCES
Alvarez, E., Pardo, J.M. and Truke, M.J. 2013. Detection and identification of 'Camdidatus Phytoplasma
asteris', Related phytoplasma associated with a witches' broom disease of cassava in Cambodia.
Phytopathogenic Mollicutes, 3 (2), 77.
Delaquis, E., Andersen, K.F., Minato, N., Le Cu, T.T., Karssenberg, M.E., Sok, S., Wyckhuys, K.A.G., Newby,J.C., Burra, D.D., Srean, P., Phirun, I., Le, N.D., Pham, N.T., Garrett, K.A., Almekinders, C.J.M., Struik,P.C. and de Haan, S. 2018. Raising the stakes: Cassava seed networks at multiple scales in Cambodia andVietnam. Front. Sustain. Food Sys., 2, 73.
Food and Agriculture Organization (FAO). 2020. Food and Agriculture Statistics, Retrieved from http://www.fao.org/faostat/en/#home
MAFF (Ministry of Agriculture, Forestry and Fisheries in Cambodia). 2015. Agricultural extension policy inCambodia. Ministry of Agriculture, Forestry and Fisheries, Cambodia.
MAFF (Ministry of Agriculture, Forestry and Fisheries in Cambodia). 2018. Annual reports of the Ministry ofAgriculture, Forestry and Fisheries. Cambodia.
RGC (Royal Government of Cambodia). 2020. National policy on cassava 2020-2025. Royal Government ofCambodia.
Tokunaga, H., Baba, T., Ishitani, M., Ito, K., Kim, O., Ham, L.H., Le, H.K., Maejima, K., Namba, S., Natsuaki,K.T., Dong, N.V., Nguyen, H.H., Nguyen, N.C., Vu, N.A., Nomura, H., Seki, M., Srean, P., Tanaka, H.,
Touch, B., Trinh, H.X., Ugaki, M., Uke, A., Utsumi, Y., Wongtiem, P. and Takasu, K. 2018. Sustainable
management of invasive cassava pests in Vietnam, Cambodia, and Thailand. In Crop Production underStressful Conditions: Application of Cutting-edge Science and Technology in Developing Countries,Springer Singapore, 131-157, Singapore.
Uke, A., Hoat, T.X., Quan, M.V., Liem, N.V., Ugaki, M. and Natsuaki, K.T. 2018. First report of Sri Lankan
cassava mosaic virus infecting cassava in Vietnam. Plant Dis., 102 (12).
Wang, H.L., Wang, X.W., Cui, X.Y. and Liu, S.S. 2015. First report of Sri Lankan cassava mosaic virus
infecting cassava in Cambodia. Plant Dis., 100 (5), 1029.

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