Báo cáo khoa học nông nghiệp " Commercial and High Quality Cultivars of Root and Tuber Crops for Processing Purpose in the Northern and Central Vietnam " potx

Ministry of Agriculture & Rural Development




Commercial and High Quality Cultivars of Root
and Tuber Crops for Processing Purpose in the
Northern and Central Vietnam
(Project No. 008/07VIE)


Baseline Study
(Milestone 2)











Date: 22 July 2008




2

TABLE OF CONTENT

Executive Summary…………………………………………………………………………… 3
I. Background ……………………………………………………………………………… 4
II. Survey objectives…………………………………………………………………………… 4
III. Survey Methodology ……………………………………………………………………… 4

IV. Research results ………………………………………………………………………… 5


ATTACHMENT A: SURVEY QUESTIONNAIRE …………………………………………. 21



3

AusAID CARD Project 008/07VIE

Food Crops Research Institute, Vietnam and University of Sydney, Australia


Baseline survey on the current production and consumption of sweet potato in Quangtri,
Thanhhoa and Bacgiang provinces of Vietnam


Collaborating organizations:
- Food Crop Research Institute, Ministry of Agriculture and Rural Development (MARD),
Vietnam

- University of Sydney, Australia
Project leaders:
- Vietnamese Project Leader: A/Prof. Dr. Nguyen Van Tuat
- Australian Project Leader: Prof. Les Copeland

Haiduong, Vietnam, May 2008

Executive Summary

A survey of current practices for sweet potato cultivation and use was conducted by local
extension officers in Thanhoa, Bacgiang and Quangtri Provinces. The survey involved a
questionnaire (designed by FCRI in conjunction with the USyd partners; Attachment A) and
interviews in each of three communes in three districts in the three selected provinces, and
addressed issues including: source of planting materials; cultivation methods; planting and
harvest times; inputs; area planted, yield and dry matter content of tubers; use of sweet potato
tubers, leaves and stems. A brief, initial review of the sweet potato literature was also conducted,
which will be updated progressively during the project.

The following were among the conclusions of the survey:
• Farmers in the three provinces have been planting sweet potato for a long time and it has
brought considerable economic return for farmers in all three investigated provinces. Sweet
potato cultivation is been considered irreplaceable in the cropping systems.
• Sweet potato is planted in as a spring crop in Quangtri, mainly as a winter crop in Thanhhoa
and as a winter and spring crop in Bacgiang.
• Farmers in all investigated localities needed new, high yielding varieties with good quality,
and an accompanying advanced technical package on planting materials, cultivation,
maintenance techniques, processing, and storage. The cultivation techniques in all
investigated localities were based on the experience of farmers and were very backward.
• Sweet potato processed products were still very simple and poor. The stems and leaves were
mainly used for animal feed. Tubers were partly used for animal feed, for food and for other

purposes. Nevertheless, the processing products such as starch, chips and wines had not
been produced and considered important.
• Sweet potato products had been commercialized, and mainly traded at home and local
markets. However, the price was still low and not stable, while the production cost was still
high.



4
I. Background
The project "Development and Selection of Commercial and High Quality Cultivars of Root
and Tuber Crops for Processing Purpose in the Northern and Central Vietnam" has as its
objectives:
1. Choose a small number of sweet potato cultivars from those designated by FCRI as
potentially suitable for cultivating in locations in northern and central Vietnam and conduct
field trials in selected locations to evaluate these cultivars according to yield and dry matter
content for value-adding purposes
2. Development and evaluation of processing methods for sweet potato, for example production
of flour and starch for food processing and industrial applications, sweet potato chips, sweet
potato wine
3. Develop methods that can be used by small-holder farmers for fermenting leaves and stems
of sweet potatoes into a silage-type product for animal feeding
4. With the assistance of Australian experts, improve the science capacity of Vietnamese
researchers and extension workers in modern techniques for plant improvement, storage and
food processing technology, analysis of food quality
5. Improve of knowledge and skills of farmers for cultivation of sweet potato as part of a
sustainable farming system
6. Establish model sites to display advanced cultivation techniques, and organize field day
meetings to spread knowledge to farmers.

To fulfill these objectives, the review on current production and consumption of sweet potato is an
important first step, after which the design of the operational aspects of project will be fine tuned.
The questionnaire used to obtain information from the farmers is in Appendix A.

II. Survey objectives
- To evaluate the current production of sweet potato in the three provinces selected: Quangtri,
Thanhhoa and Bacgiang.
- To examine the current cultivation techniques for intensive sweet potato production
- To evaluate the status of consumption and processing of sweet potato

III. Survey Methodology
3.1 Methods
3.1.1. The survey locations
Three provinces selected were Quangtri, Thanhhoa and Bacgiang. Thanh Hoa, in Central VN, is
the largest province in VN in size and population. It is mostly flat with large areas of poor sandy
soils suitable for sweet potato cultivation. Bac Giang in North East VN, is located in a dry region
with many sloping areas and much potential area for upland crops. The soils are poor and
degraded. Quang Tri in central VN 550 km from Hanoi, is located at boundary between northern
and southern VN in a different climatic region from other sites, but suitable for upland crops. The
soils are heavier and marginal.
3.1.2 Methods for doing the survey
Method for choosing sample: In each province, three districts were selected, and in each
district, 3 communes were selected. In summary, 27 survey points (communes) were selected. In
each survey points, farmers were randomly selected for getting information.
Method for getting information: Interviewing method was used for getting information. Besides
of that the Participatory Rural Assessment (PRA) and questionnaire were also used for getting
the information. The interviewed people were explained and trained before interviewed. The data
were statically analyzed by using EXCEL program.

5
3.1.3 The data collection and analysis methods
Participatory Rural Assessment (PRA) was used for collecting data. The investigator used
questionnaire to get information from the leader of communes and farmers through directly
interviewing them. The data were then statically analysed.

3.2 Investigation contents
3.2.1. Investigation of the current situation of sweet potato production
The data were collected as follows
- Area (ha)
- Yields (tonnes/ha)
- Total production (tonnes)
- Crop system formula of sweet potato
- Varieties
- The application of intensive cultivation techniques
3.2.2. The usage and consumption of sweet potato
- For human food
- For animal feed
- Sale in market
- Processing

IV. Research results

4.1. The situation of sweet potato production in the survey area
4.1.1. Land resources and the current situation of land usage at communes in the three
provinces

The results of survey in Table 1 show that the average population per commune ranged from
2708-8126 people. Quangxuong district of Thanhhoa province had the lowest population per
commune (2708.8). On the other hand Tinhgia district of Thanhhoa had the highest population
per commune (8126), followed by Hiephoa district of Bacgiang (7690) and Hailang district of
Quangtri (5049).

The average cultivated land per commune was various with districts and provinces, and it ranged
from 169.8-439.4 ha. Vietyen district of Bacgiang province had the largest average cultivated land
area per commune (666.9 ha), and Vinhlinh district of Quangtri had the lowest land area per
commune (169,8 ha).

The average sweet potato area per commune ranged from 10-61.3 ha. Dongson district of
Thanhhoa province had the lowest average sweet potato area per commune (10.0 ha). On the
other hand, Tinhgia district of Thanhhoa had the highest average sweet potato area per
commune (75 ha), followed by Tanyen district of Bacgiang province (61.3 ha), Quangxuong
district of Thanhhoa (54.7 ha) and Giolinh district of Quangtri province (47.6 ha).

Table 1: Population, main labor, the average cultivated land and sweet potato land area per
commune in 9 districts of 3 provinces

Quangtri Thanhhoa Bacgiang Province/ districts

Parameters
GL VL HL TG QX DS TY VY HH
Population
3947.7 3367.0 5049.7 8126.3 2708.8 3611.7 4223.1 5638 7690



6

Main labor
882.3 2418.3 3463.67 4221.7 1407.2 1876.3 1407.7 2796 3847
Cultivated land (ha)
439.4 169.8 210.0 1642.7 379.2 374.8 666.9 261.9 269.3
Sweet potato land (ha)
47.6 25.8 37.3 75 54.7 10.0 61.3 36.7 29.7
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

4.1.2. Growing season, the purpose of sweet potato production and suggestion
Data in Table 2 show that in Thanhhoa and Bacgiang province sweet potato was mainly
cultivated in the winter season. However, in Quangtri province, sweet potato was largely
cultivated in the winter-spring season. In Quangxuong and Dongson district of Thanhhoa, sweet
potato was also cultivated in the spring season.

The results of survey on the purpose of sweet potato cultivation show that 100% of interviewed
people indicated they grew sweet potato for getting leaves and stems to feed animals. About 30%
of tubers were used as human food and 30% of tubers were used as animal feed. In communes
of 3 investigated districts in Quangtri province, about 20% of tubers were used to produce food
processing product called “Khoaigieo). About 10-20% tubers were boiled and used, and about
10% of tuber was sale in the market.

The result of the investigation on people point of view about the cultivation of sweet potato in the
future indicated that 100% of interviewed people agreed that there was a need for change in
sweet potato cultivation in the near future. First, there was a need in the improvement of varieties,
especially replace the old varieties by the new ones with higher yield and better quality. Beside of
that 100% of interviewed people also advocated that along with new varieties, it was necessary to
focus on the development of new and advanced cultivation technical procedure.

Table 2: Percentage of sweet potato area in different growth season, the purpose for use
of sweet potato products, and the attitude of people towards the improvement of new
varieties and technology in the future


Quangtri Thanhhoa Bacgiang
Province/ districts

Parameters
GL VL HL TG QX DS TY VY HH
Crop productions (%)
Winter
0 0 0 75 100 100 100 100 100
Winter -Spring
100 100 100 25 0 0 0 0 0
Spring
0 0 0 0 100 100 0 0 0
Purposes for using sweet potato products(%)
Using stem, leaf for
animal feed
100 100 100 100 100 100 100 100 100
Using tuber for food
30 30 30 30 30 30 30 30 30
Using tuber for animal
feed
30 30 30 50 50 50 50 50 50

7
Using tuber for
processing “Khoai
Gieo”
a

20 20 20 0 0 0 0 0 0
Using for cooking
10 10 10 10 10 10 20 20 20
Marketing
10 10 10 10 10 10 10 10 10
Attitude of people towards the improvement of new varieties and technology in the future (%)
No need
0 33 0 0 0 0 0 0 0
Need
100 67 100 100 100 100 100 100 100
a
sun-dried sweet potato slices

Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

4.1.3. The real situation on the usage of sweet potato varieties in 3 investigated provinces
The result of collecting information on the use of sweet potato varieties in 3 provinces (Table 3)
shows that in all 3 investigated provinces, there are 100% of communes growing old sweet potato
varieties, with the exception of Tinhgia and Dongson districts of Thanhhoa where the new
varieties were cultivated under 33-67% of sweet potato cultivated areas.

The reason for planting old varieties: When was asked about the reason for the use of old

varieties, 67-100 of interviewed people in Quangtri province said that old varieties tolerated rather
well to drought, 33% indicated that old varieties had good quality, 33-67% agreed that the
planting materials of old varieties was cheap, and 33% gave the opinion that old varieties
tolerated well to pests and diseases.


Table 3: Information on the use of sweet potato varieties in 3 investigated provinces

Quangtri Thanhhoa Bacgiang Province/ districts

Parameters
GL VL HL TG QX DS TY VY HH
The percentage of farmers growing varieties (%)
New variety
0 0 0 67 0 33 0 0 0
Local variety 100 100 100 33 100 67 100 100 100
The reason for planting old varieties (%)
High price 0 0 33 0 0 33 0 0 0
High yield 67 67 67 0 0 33
Drought resist 67 100 67 0 0 0 0 0 0
High quality 0 0 33 100 100 33 100 100 67
cheap seed 0 67 33 33 0 0 0 0 0
Less disease 33 33 33 0 0 0 0 0 0
The reason for planting new varieties (%)
Yes 100 67 67 67 67 0 33 100 100
No 0 33 33 33 33 100 33 0 0
The source of getting information about new varieties (%)

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Committee 0 0 0 0 0 0 0 0 0
Extension 0 0 0 67 0 0 0 0 0
Neighbors 0 0 0 33 0 33 0 0 0
Public information
system
67 67 67 0 0 33 67 50 100
User’s Guide 0 0 0 0 0 0 0 0 0
Friends 33 33 33 0 0 0 33 50 0
The place for buying planting materials (%)
Institute 0 0 0 67 0 0 0 0 0
Project 0 0 0 0 0 0 0 0 0
Market 0 0 0 0 0 0 0 0 0
Seed company 0 0 0 0 0 0 0 0
Extension center 0 0 0 0 0 67 0 0 0
Neighbors 100 100 100 33 100 33 100 100 100
The activities in evaluation and selection of planting materials by farmers (%)
Yes 0 0 0 33 0 0 0 0 0
No 0 0 0 67 0 67 0 0 0
The people or organizations carrying activities in evaluation and selection (%)
commune 0 0 0 33 0 0 0 0 0
Farmer 0 0 0 0 0 0 0 0 0
Extension 0 0 0 0 0 0 0 0 0
Other 0 0 0 0 0 0 0 0 0
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

In Thanhhoa province, 67% of interviewed people reported that old varieties had high yield, 33-
100% believed that these varieties had good quality, and 33% indicated that the planting

materials from old varieties were cheap. In Bacgiang province, 67-100% of interviewed people
said that old varieties had good quality.

The reason for cultivating new varieties: When was asked about the use of new sweet potato
varieties, up to 67% of interviewed people in Quangtri province answered that they got
information from public information system (television, radio, paper …), while 33% informed that
the information was acquired through friends and relatives. In Thanhhoa province, 67% of
interviewed people reported that they got information about new varieties from agricultural
extension workers, 33% from public information system and 33% from friends and relatives. In
Bacgiang province, the number was 70% from public information system and 30% from friends
and relatives. It is understood that in Quangtri and Bacgiang provinces, where the extension
system has not been developed well, farmers get more information from public information
system and friends. On the other hand, in Thanhhoa province that has extension systems
developed well, more number of farmers got information from these systems.

The place of buying planting materials: When was asked where they bought planting
materials, nearly 100% of interviewed people answered that they bought from local markets or
neighbors. However, about 67% of farmers in Dongson district, Quangtri province informed that
they bought planting material through agricultural extension centers.



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Activities in selection of planting materials: The activities in evaluation and selection of
planting materials were still not considered important. In Quangtri and Bacgiang provinces 100%
of planting materials was not evaluated and carefully selected. In Thanhhoa province, only 10%
of communes carried out the activity in evaluation and selection of planting materials.

4.1.4. The technical procedure for multiplication of planting materials and cultivation

The results of survey on the technical procedure for multiplication of planting materials and
cultivation of sweet potato are presented in Table 4.

Generally, the activities in selection and maintenance of pure planting materials have not been
seriously considered. Almost 100% farmers in investigated communes used the poor planting
materials. With the exception of districts in Bacgiang province, farmers in other provinces used
planting materials that had been cultivated through more than 3 times.

The methods of maintenance and multiplication of planting materials: 100% of farmers
maintained and multiplied planting materials in their own garden by using the stems. There was
no farmer using the tuber roots as the initiated source for the multiplication of planting materials.

The use of different stem segments for planting materials: 100% of farmers often use the first
and second stem segments for planting. Farmers did not use the third and fourth segments for
planting.

The method for planting sweet potato: 100% of farmers reported that they used the
conventional techniques available in the locals for cultivating sweet potato. The new cultivation
techniques for sweet potato had not been applied and seriously considered.

Table 4: Information of technology for planting of sweet potato in three provinces for
survey (% average of commune’s survey)

Qungtri Thanhhoa Bacgiang Province/ districts

Parameters
GL VL HL TG QX DS TY VY HH
Number of planting material generations used for planting (%)
One time

0 0 0 0 0 0 0 0 0
Two times 0 0 0 0 0 0 0 0
Three times 0 0 0 0 0 0 100 100 100
More than 3 times
100 100 100 100 100 100 0 0 0
Method for multiplication of planting materials (%)
By stems 100 100 100 100 100 100 100 100 100
By tubers 0 0 0 0 0 0 0 0 0
Types of stem segments used as planting materials (%)
1
st
and 2
nd
stem
segments
100 100 100 100 100 100 100 100 100



10
3
rd
stem segment 0 0 0 0 0 0 0 0 0
Others 0 0 0 0 0 0 0 0 0
Techniques for planting (%)
Traditional 100 100 100 100 100 100 100 100 100
New technology 0 0 0 0 0 0 0 0 0
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

4.1.5. Growth season, cultivation area and yield of sweet potato in 3 investigated provinces
The results of investigation in growth season, cultivation area and yield of sweet potato in 3
provinces are shown in Table 5.

Table 5: Crop production, cultivation area and yield of sweet potato in 3 investigated
provinces

Quangtri Thanhhoa Bacgiang Province/ districts

Parameters
GL1) VL HL TG QX DS TY VY HH
Winter season( ha)2) - - - 122,7 16,53 13,73 61,3 36,7 29,7
Planting time - - - Sep/Oct Sep/Oct Sep/Oct Sep/Oct Sep/Oct
Sep/
Oct
Time for harvesting - - -
Dec or
Jan
Dec or
Jan
Dec or
Jan
Dec or
Jan
Dec or
Jan
Dec or
Jan
Yield (ton/ha) - - - 8,7 6,7 5,3 13,06 11,2 12,6

Winter-Spring season
(ha)
47,6 25,8 37,3 0 0 0 0 0 0
Planting time Dec/.Jan
Dec/
Jan
Dec/
Jan
- - - - - -
Time for harvesting Jun/ Jul
Jun/
Jul
Jun/ Jul - - - - - -
Yield (ton/ha) 8,0 8,0 10,7 - - - - - -
Spring season (ha) 0 0 0 87,33 14,33 0.0 0 0 0
Planting time - - - Jan/ Feb Jan/ Feb Jan/ Feb - - -
Time for harvesting - - - May/ Jun May/ Jun May/ Jun - - -
Yield (ton/ha) - - - 14,0 11,32 7,33 - - -
Summer-Autumn
season (ha)
0 0 10 5 5 0 0 0 0
Purpose
Multiply
of seed
Multiply
of seed
Multiply
of seed
- - - -
Planting time - -

Sep and
Oct
Apr and
May
Apr and
May
- - - -
Time for harvesting - -
Dec/
Jan
Ju/ Aug Jul/ Aug - - - -
Yield (ton/ha) - - 6,0 - - - - - -
Note: 1) GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district
2) Data represented the average cultivation area per commune in a district.




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Winter growth season: In the winter season, sweet potato was planted only in Thanhhoa and
Bacgiang province. In Quangtri province, sweet potato had not been grown in this season. The
planting time is in September and November and the harvest time is around December and
January. The average cultivation area per commune in a district ranged from 13.3 ha to 122 ha in
Dongson district of Thanhhoa province. The yield was about 5.3-13.0 tons/ha.

Winter-spring growth season: In the winter-spring season, sweet potato was only planted in
Quangtri province. The planting time is from December to January and the harvest time is around
June and July.

The Spring season: Sweet potato is mainly planting in Thanhhoa province. The planting time is
from January to February and the harvest time is around May and June.

4.1.6. Land preparation and cultivation techniques
The results of survey on the methods of land preparation and cultivation techniques are shown in
Table 6.

Table 6: Methods used for soil preparation and planting sweet potato in three provinces

Quangtri Thanhhoa Bacgiang Province/ districts

Parameters
GL VL HL TG QX DS TY VY HH
Methods used for soil preparation (%)
By machine 0 0 0 0 0 100 33 0 0
By hand 66 66 66 0 0 0 0 0 0
By buffalo and cows 34 34 34 100 100 0 67 100 100
Others 0 0 0 0 0 0 0 0 0
Method for putting the planting materials (%)
Stand vertically against
the growing bed wall 0 0 0 0 0 0 0 0 0
Curve lines 100 100 100 0 0 0 100 100 100
Put horizontally in the
growing bed 0 0 0 100 100 100 0 0 0
Method for planting (%)
Use growing bed 100 100 100 100 100 100 100 100 100
No growing bed 0 0 0 0 0 0 0 0 0
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district

TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district




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Method for preparation of land: Farmer often prepares their land by buffaloes and cows. In
Thanhhoa and Bacgiang provinces, the percentage of farmers using animals for preparing land
was about 67-100%. On the other hand, the percentage of farmers using machines for preparing
their land was rather high in Dongson district of Thanhhoa province (100%) and Tanyen district of
Bacgiang province (33%). The percentage of farmers preparing land by hand was high in all
districts of Quangtri province (66%).

Method for putting planting materials on soil: 100% of farmers in Quangtri and Bacgiang
provinces planted sweet potato by putting the plant materials on the curve line (look like the boat).
In Thanhhoa province, farmers often put planting materials horizontally in the growing beds.

The techniques for cultivating sweet potato: All farmers (100%) in 3 provinces plant sweet
potato in the growing beds.

4.1.7. Fertilizer application regimes
The results of investigation on fertilizer application regimes are shown in Table 7. It is clear that
100% of farmers using the conventional application methods available in the locality. The
standard fertilizer application regime had not been applied in the farm.

Table 7: Fertilizer application regimes for sweet potato in three provinces

Quangtri Thanhhoa Bacgiang Province/ districts

Parameters

GL VL HL TG QX DS TY VY HH
Type of fertilizer application method used by farmer (%)
Traditional method
100 100 100 100 100 100 100 100 100
Standard method 0 0 0 0 0 0 0 0 0
Quantity of fertilizer applied per ha (kg)
Urea 246 226 180 106 146 160 176.4 140 134.4
Potassium 134 186 146 54 174 66 131.6 103.6 92.4
Phosphorus 434 434 366 266 186 566 420 327.6 316.4
Amount and time of fertilization
Base dressing
(before planting)
100P
+30
(N+K)
100NP
K
+20N
100P
100
(PC+P)
100
(PC+P)
+20N
100
(PC+P)
+50N
100
P+30N
100

(P+
PC)
+30(N
+K)
100
(P+PC
)
+30(N
+K)
First application
30(N+K
)
40N+5
0K
50(N+K)
100(N+K
)
30N+
50K
50N
+50K
40N+
50K
40(N+
K)
40(N+
K)
Second application
40(N+
K)

40N+
50K
50(N+K) 0
50(N+
K)
50K
30N+
50K
30(N+
K)
30(N+
K)
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

The amount of N, P, K fertilizer applied for sweet potato was various with different localities, and
there was a big difference in the amount of fertilizer applied in different regions.

The method of application was also various with different localities. Even in one district of a
province, the method of fertilizer application was also very different. This is a big issue should be
considered in the future.




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4.1.8. The situation of sweet potato trading
Table 8 presents the data on the current situation of sweet potato trading. After harvest, sweet
potato was often brought to the market. In Quangtri province, about 67-100% of sweet potato

tubers were transferred to the market. This number was about 33-67% for Thanhhoa, and 67-
100% for Bacgiang provinces.

Sweet potato products were often sale in the big volume (wholesale) and small amount (retail).
However, farmers often sale retail (Table 8).

Table 8: The current situation of trading of sweet potato in three provinces
Quangtri Thanhhoa Bacgiang Province/ districts

Parameters
GL VL HL TG QX DS TY VY HH
The percentage of farmers selling their products in the market (%)
Yes 100 100 67 67 33 67 67 100 100
No 0 0 33 33 67 33 33 0 0
The type of trading (%)
Wholesale 0 67 33 67 33 33 33 0 0
Retail 100 33 67 33 33 67 67 100 100
Both 0 0 0 0 0 0 0 0 0
The place that farmers used for trading (%)
In field 0 0 0 0 0 0 0 0 0
At local markets 67 67 33 67 33 67 67 100 100
At home 33 67 67 33 67 33 33 0 0
In the city 0 0 0 0 0 0 0 0 0
The percentage of farmers face difficulty in selling their products (%)
Have difficulty 67 100 100 33 0 67 67 67 100
No difficulty 33 0 0 67 100 33 33 33 0
The most serious problem that farmers face in selling their products (%)
Low price 67 100 100 0 67 33 0 0 0
Difficulty in storage 0 0 0 0 0 0 0 0 0
High price of

transportation
0 0 0 0 0 0 0 0 0
Unstable price 33 0 0 100 33 67 100 100 100
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

Farmers often sell sweet potato products at both home and local markets. In Vietyen and
Hiephoa of Bacgiang province, 100 % of farmers sell their products at the local markets. Farmers
in all 3 provinces did not sell products in the city.




14
With the exception of farmers in Quangxuong district of Thanhhoa, farmers often had difficulties in selling
their products, especially farmers in Bacgiang and Quangtri provinces. The high percentage (67-100%)
of farmers in Quangtri faced problem of low price, while most of farmers in Thanhhoa (33-100%) and
Bacgiang (100%) province had difficulty because of unstable price of their products in market.

4.1.9. The products processed from sweet potato
The result of the investigation on the type of products made from sweet potato is presented in
Table 9. In Thanhhoa province, the large percentage of sweet potato was used as vegetable (33-
67%). About 100% of sweet potato stems and leaves were used as animal feed. On the other
hand, about 30-50% sweet potato tubers were used for animal feed, and only about 30% tubers
was used as human food.

Table 9: The main processing and products made from sweet potato

Quangtri Thanhhoa Bacgiang Province/ districts

Products
GL VL HL TG QX DS TY VY HH
Products made from sweet potato (%)
The use of stems and leaves
Used as vegetables 0 0 0 33 67 33 0 0 0
Using stem and leaf for
animal feed
100 100 100 100 100 67 100 100 100
The use of tubers
For animal feed 30 30 30 50 50 50 50 50 50
For food 30 30 30 30 30 30 30 30 30
For making the processed
product called “Khoai Gieo”
20 20 20 0 0 0 0 0 0
Others 20 20 20 20 20 20 20 20 20
Produce starch from sweet potato (%)
No 100 100 100 100 100 100 100 100 100
Yes 0 0 0 0 0 0 0 0 0
Processing products from starch of sweet potato (%)
Noodles 0 0 0 0 0 0 0 0 0
Flour 0 0 0 0 0 0 0 0 0
As rice sheet 0 0 0 0 0 0 0 0 0
Others 0 0 0 0 0 0 0 0 0
Produce wine from sweet potato (%)
No 100 100 100 100 100 100 100 100 100
Yes 0 0 0 0 0 0 0 0 0
Fermentation of stems and leaves of sweet potato for animal feed (%)
No 33 0 0 67 100 100 0 0 0

Yes 67 100 100 33 0 0 100 100 100
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

In Quangtri province, about 20% of tubers was used to produce the processing product
called ”Khoaigieo” and sale in markets as the local special product.
There was no food processing products of sweet potato such as noodle, sweet potato
paper as well as wines. However, the farmers had applied the process of producing animal feed



15
through fermentation of sweet potato stems and leaves. In Quangtri and Bacgiang provinces, up
to 67-100% of communes had the experience in producing animal feed from fermentation of stem
and leaves. However, in Thanhhoa province, there was no locality that applied these techniques
for producing animal feed.

4.1.10. The effects of sweet potato on social, economic and environmental conditions
The results of survey on the effects of sweet potato on social, economic and environmental
conditions (Table 10) showed that 100% of interviewed farmers had the opinion that sweet potato
had impact on raising pig, and 33% agreed that sweet potato reduced the spending on animal
feed.

Table 10: The effects of sweet potato in social, economic and environmental conditions

Qungtri Thanhhoa Bacgiang Province/ districts

Parameters
GL VL HL TG QX DS TY VY HH

Role of sweet potato with household (%)
To improve pig
husbandry
100 100 77 100 100 100 100 100 100
Save money
33 33 33 33 33 33 33 100 100
As manure 33 0 0 0 0 0 0 0 0
To improve buffalo and
fish
33 33 33 100 100 67 100 67 50
The effects on environment (%)
Have no effect 100 100 100 100 100 100 100 100 100
Have effect 0 0 0 0 0 0 0 0 0
Use too much fertilizer 0 0 0 0 0 0 0 0 0
Use to much pesticide 0 0 0 0 0 0 0 0 0
Water contamination 0 0 0 0 0 0 0 0 0
Erosion of land 0 0 0 0 0 0 0 0 0
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

Beside of that 33-100% of farmers indicated that sweet potato had the impact on raising buffalos, cows and
fish. On the other hand, the percentage of farmers using sweet potato as manual fertilizer for improvement
of soil condition was very low.

100% of farmers indicated that cultivation of sweet potato had no negative effects on
environment. Sweet potato did not need insecticides and fungicides as well as a large amount of

16
chemical fertilizers. Cultivation of sweet potato also caused no problem in soil erosion as well as
water pollution.

4.1.11. The difficulty in sweet potato production and some consideration
The result of survey on the major difficulties that farmers have to face when grows sweet
potato and the solution to that problem is presented in Table 11. Up to 100% of farmers in
Quangtri and Bacgiang provinces, and 33% in Thanhhoa province thought that the major difficulty
in sweet potato production was a low yield and the lack of advanced technical procedure.
Table 11: The main problems and the farmers needs when grow sweet potato

Quangtri Thanhhoa Bacgiang Province/ districts

Parameters
GL VL HL TG QX DS TY VY HH
The main problems when grow sweet potato (%)
Low yield 100 100 100 33 33 33 100 100 100
Do not have advanced
cultivation technique
100 100 100 33 33 33 100 100 100
Low price 67 100 100 - - - - 100 33
Low demand of market 100 100 100 67 100 67 - 100 100
Hight input 67 100 100 100 100 100 100 100 33
Difficult to store and
process
33 100 100 100 100 100 100 100 33
Farmers needs when grow sweet potato (%)
Training in cultivation
techniques
100 100 100 33 67 67 100 100 100

Training in product
processing
100 100 100 33 33 33 100 100 67
Training in storage
techniques
100 100 100 33 33 33 100 100 100
Training in maintenance of
planting materials
67 100 100 33 33 33 100 100 67
Have better new varieties 100 100 100 100 100 67 100 100 100
Others 67 100 100 - - - 100 100 100
Note: GL = Giolinh district; VL= Vinhlinh district; HL = Hailang district
TG = Tinhgia district; QX = Quangxuong district; DS= Dongson district
TY = Tanyen district; VY = Vietyen district; HH = Hiephoa district

Up to 67-100% farmers in Quangtri province, 33% of farmers in Hiephoa district and 100% of
farmers in Vietyen district of Bacgiang province reported that the low price of sweet potato
product was their main concern. On the other hand, the large number of farmers (67-100%)



17
indicated that the difficulty in sweet potato production was the high input, but the low consumption
demand in markets. Furthermore, 100% of farmers had opinion that they faced difficulty in
storage and processing of sweet potato after harvest.

The result of survey on the need of farmers growing sweet potato indicates that in Quangtri
province, up to 67-100% farmers wanted to get help in cultivation technique training, food
processing, storage, the maintenance of planting material training. In Bacgiang province, 67-
100% of farmers needed to get help in these trainings. In Thanhhoa province, however, only 33-

67% number of farmers needed these training. It may be that the farmers in Thanhhoa province
had better condition for reaching the new cultivation and food processing techniques.

The need for having better sweet potato varieties was high in all three provinces (67-100%). This
need of farmers should be considerately considered, and more new varieties should be tested
and evaluated in the field so that farmers might be able to get the better varieties in the future.

4.1.12. Economic efficiency of sweet potato production

4.1.12.1. Quangtri province
In Quangtri province, farmers could earn about VND 492.000 per perch (500 m2). The main
income was from selling products in market, and the main input was for fertilizers and labor
(Table 12).



Table 12: Production cost and income from cultivation of 500m
2
of sweet potato in the
Quangtri province in 2007.
Unit: 1000VND

Parameters Giolinh district Vinhlinh district Hailang district Average
Gross income
1355.0 1471.7 1203.3 1343.3
For selling
1133.3 1166.7 800.0 1033.3
For food
100.0 166.7 250.0 172.2
For animal

121.7 138.3 153.3 137.8
For seed material
0.0 0.0 0.0 0.0
Total cost
837.1 886.5 830.5 851.4
Planting materials
91.7 103.3 95.0 96.7
Organic fertilizer
80.0 93.3 80.0 84.4
nitrogen fertilizer
91.3 81.8 63.0 78.7
potassium fertilizer
60.0 84.0 66.0 70.0
phosphorus fertilizer
54.2 70.7 53.2 59.3
preparation of land
73.3 70.0 73.3 72.2
Labor
340.0 320.0 340.0 333.3



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Water
31.7 40.0 38.3 36.7
Other
15.0 23.3 21.7 20.0
Net income
517.9 585.2 372.8 492.0

4.1.12.2. Thanhhoa province
Farmers in Thanhhoa province could earn about VND 571.000 from cultivation of 500 m
2
(0.05
ha) of sweet potato. The main income was from feed for animals while the main production cost
came from fertilizers and preparation of land.


Table 13: Production cost and income from the cultivation of 500m
2
of sweet potato in the
Thanhhoa province in 2007.
Unit: 1000VND

Parameters Tinhgia district
Quangxuong
district
Dongson
district
Average
Gross income
1480.1 1164.9 1271.7 1305.6
For selling
360.0 73.3 550.0 327.7
For food
86.7 100.0 176.7 121.1
For animal
1016.7 968.3 536.7 840.5
For seed material
16.7 23.3 8.3 16.1

Total cost
822.3 617.2 764.3 734.6
Planting materials 90.0 87.3 65.0 80.8
Organic fertilizer 166.7 216.7 201.7 195.0
nitrogen fertilizer
30.3 41.5 43.0 38.3
potassium fertilizer
18.7 14.7 23.3 18.9
phosphorus fertilizer
26.7 30.3 58.0 38.3
Preparation of land
290.0 226.7 293.3 270.0
Labor
186.7 0.0 80.0 88.9
Water
13.3 0.0 0.0 4.4
Other
0.0 0.0 0.0 0.0
Net income
657.8 547.7 507.4 571.0



4.1.12.3. Bacgiang province
Farmers in Bacgiang province could earn about VND 387.200 per 360 m
2
of sweet potato. The
main income was from selling products in market and using as animal feed. On the other hand,
the main production cost was from buying fertilizers and paying labor forces (Table 14).

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Table 14: Production cost and income of cultivation of one perch 360m
2
of sweet potato in
Bacgiang province in 2007.

Unit: 1000VND

Parameters
Tanyen
district
Vietyen
district
Hiephoa
district
Average
Gross income
916.7 1166.7 1200.0 1094.4
For selling
366.7 700.0 533.3 533.3
For food
200.0 200.0 166.7 188.9
For animal
350.0 266.7 500.0 372.2
For seed material
0.0 0.0 0.0 0.0
Total cost

674.3 768.3 679.2 707.3
Planting materials
70.0 73.3 73.3 72.2
Organic fertilizer
80.0 86.7 80.0 82.2
nitrogen fertilizer
44.3 46.5 36.5 42.4
potassium fertilizer
42.0 51.0 36.7 43.2
phosphorus fertilizer
38.0 44.2 39.3 40.5
Preparation of land
80.0 80.0 80.0 80.0
Labor
306.7 346.7 293.3 315.6
Water
13.3 40.0 40.0 31.1
Other
0.0 0.0 0.0 0.0
Net income
242.3 398.3 520.8 387.2

V. Conclusions
• The area under sweet potato in all investigated communes of 3 provinces (Quangtri,
Thanhhoa and Bacgiang) was very large. Farmers in these communes have been planting
sweet potato for a long time, and this plant has been considered irreplaceable in the crop
systems.
• Sweet potato was planted in 3 growth seasons, winter, winter - spring and spring crops. In
Quangtri province, sweet potato was mainly cultivated as the winter-spring crop. On the other
hand, in Thanhhoa and Bacgiang provinces, sweet potato was largely cultivated as the winter

and spring crops, respectively.
• Farmers in all investigated localities really needed the new varieties with high yield and good
quality accompanying with the advanced cultivation technical package.
• The cultivation techniques in all investigated localities were based on the experience of
farmers and really backward. Particularly, the fertilizer application regime was not unique, the



20
amount of fertilizers applied was not suitable and the ratio among fertilizer type (N: P: K) was
not proportioned well, the application time was not accurate and reasonable.
• Sweet potato products had been commercialized, and mainly traded at home and local
markets. However, the price was still low and not stable while the production cost was still
high.
• Sweet potato processed products were still very simple and poor. The stems and leaves were
mainly used for animal feed. Tubers were partly used for animal feed, for food and for other
purposes. Nevertheless, the processing products such as starch, chips and wines had not
been produced and considered important.
• In the future, farmers need help from scientists and research organizations in many areas.
These include: replacing the old varieties by the new ones with high yield and good quality;
training in techniques of cultivation, processing, storage and maintenance of planting
materials as well.
• Sweet potato cultivation has brought the considerable economic return for farmers in all three
investigated provinces. In Quangtri province, the economic return from sweet potato was
about VND 9.840.000/ha. Those in Thanhhoa and Bacgiang provinces were VND
11.420.000/ha and VND 10.841.600/ha, respectively.
• For further development of sweet potato production in Vietnam, we suggest that new varieties
accompanying with the technical package (cultivation, processing, storage and planting
material maintenance techniques) should be tested and brought into use. Furthermore, the
training for farmers in those techniques as well as the building the field exhibition model for

farmer learning and following is also considered very important.




21
ATTACHMENT A: SURVEY QUESTIONNAIRE

Food Crops Research Institute, Vietnam and
University of Sydney, Australia
AusAID CARD Project

Questionnaire for sweet potato growers: survey of production and
processing at Quangtri, Thanhhoa and Bacgiang province in 2008

1. Name of intervewer
2. Date of interview
3. Name of cummune/farmer
Province:
District:
4. Sex: Male Female
5. Education level:

5a. Do you have access to the internet?

6. How many people in your family?: number who can
provide farm labor
7. How big is your farm?: sµo m2
8. What area on your farm is planted to sweet potato per year?:
sµo m2

9. How many sweet potato crops did you plant in the last three years?




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Which crop do you usually plant sweet potato?
- Winter crop
- Spring crop

If you did not grow sweet potato, what was the main reason?


Would you consider growing sweet potato in the future?

10. For which purpose did you plant sweet potato?
- For food in your household
- Animal feed
- Processing
- For commercial
11. What variety of sweet potato are you planting?
- Why do you prefer to use this variety?
High price High quality
High yield Low cost of planting
material
Drought resist
Less disease

12. Would you use new sweet potato varieites for planting?
Yes No

13. Do you have any information about new sweet potato varieties ?
Yes no



23
- What kind of information if answer yes?
Committee Common information
Extensioner User’s Guide
Neighbours Friends

14. How many times (generations) has the variety you have been growing
been multiplied?
- One time - Two times - Three
times - More than three times
15. How did you multiply seed?
- By stem - By tuber
16. Do you use local variety or new variety?
Where did you buy new variety?
Institute Seed company

Project Extension

Market Neighbours

Do you have information on evaluation and selection before
planting?

Yes No

Who does the evaluation and selection in your local area?

Commune Extensioner

Farmer Other

17. What kind of stem do you use for planting?



24
- Stem 1 - Stem 2
- Stem 3 - Other
Why do you use this stem?
18. What method did you use for planting Sweet potato?
- Traditional method - New Technology
19. When did you planting sweet potato?
(For Area (sao 360/500 m2) according to region)
Unit Data in 2007
Area Winter season sµo
Planting time day
Time for harvesting day
Yield kg/sao
DiÖn tÝch vô xu©n
Planting time day
Time for harvesting day
Yield kg/sao

20. Income and spending per sao (360/500 m2) for planting sweet potato
Data in 2007 Target Planting

Season
Unit
Quality Unit
price
Total
Gross income kg
For selling kg
For food kg
For animal feedi kg
For seed kg



25
Total cost
For seed kg
For manure kg
Urea kg
Potassium kg
Phosphorus kg
Prepare land planting '000 ®
Labour '000 ®
Water for irrgation '000 ®
Other '000 ®
income


21. How did you prepare the soil prior to planting?

By Machine By Buffalo

By Hand Other
22. How did you plant ting sweet potato?
- Method for planting of stem
Ap tuong Mui thuyen Straight


- Method for growing

Bed No bed


23. Fertilizer method
Traditional method Accordance with the process

Detail: Basal fertilizing (%): Apply additional fertilizer 1 (%)
Apply additional fertilizer 2 (%)