RESULTS OF AN EVALUATION AND SELECTION OFNEW SWEET POTATO VARIETIES IN BAC GIANG, THANH HOA AND QUANG TRI PROVINCES Project title: Selection and development sweet potato varieties with h
Trang 1RESULTS OF AN EVALUATION AND SELECTION OF
NEW SWEET POTATO VARIETIES IN BAC GIANG, THANH HOA
AND QUANG TRI PROVINCES
Project title: Selection and development sweet potato varieties with high root quality for food
processing in Northern and Central of Vietnam
Code of the project: CARD 008/07 VIE
Author(s): Nguyen Van Tuat1, Truong Cong Tuyen1, Nguyen Dat Thoai1, Truong Thi Thuy1, Tran
Quoc Anh1, Nguyen Phan Anh1, Do Thi Lieu1, Nguyen Thi Hoai1, Les Copeland2, Peter Sharp2, and Richard Trethowan2
Project implementing organizations:
Food Crop Research Institute, VAAS, Vietnam Sydney University, Australia
SUMMARY
The objectives of the CARD project entitled “Development and Selection of Commercial and High Quality Cultivars of Root and Tuber Crops for Processing Purpose in the Northern and Central Vietnam” between FCRI and Sydney University are to 1) Select a certain 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) Develop and evaluate processing methods for sweet potato, namely 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 farmer’s knowledge and skills in cultivation of sweet potato as a part of a sustainable farming system and 6) Establish model sites to display advanced cultivation techniques, and organize field day meetings to disseminate knowledge to farmers.
The project has been conducted in two years 2008-2009 and this report reflects the results of those activities in project sites that have been reviewed and discussed at the project completion meeting and the Public Forum in April 2009.
The results of field trial and evaluating new sweet potato varieties in Thanh Hoa, Quang Tri and Bac Giang provinces have indicated that among 11 varieties it has been chosen 3 good ones including VC68-2, VC 02-193 and VC 04-24 with the yield ranged from 13.64 to 23.6 tonnes/ha, compared to check control yielded 10.13 to 14.9 tone/ha
1 Introduction
The cultivation area of sweet potato in
Vietnam annually ranging
200,000-250,000 ha, with an average yield of 8
tonnes per ha Its product providing very
high potential of material for processing.
Sweet potato is growing well in various locations in northern and central VN, especially in regions where farmer income
is low In addition to its usefulness as a food for humans, and as a very good improver of soil fertility, texture and
Trang 2for value adding and as a source of feed for
animals from the unharvested parts Using
this crop can reduce the risk of major pests
and diseases of other crops like rice and
vegetables, thereby better protecting the
agricultural environment There is a market
for products from tuber crops such as
sweet potato, for example flour and starch
as a raw material for industry in the
manufacture of foods, confectionery,
pharmaceuticals, paper and textiles The
demand of starch for industry in Vietnam
annually is about one million tons, much of
which is imported The lack of good
cultivars and relevant technology for
cultivation and processing of sweet potato
means that this crop is not achieving its
great potential for contributing to
increasing income and providing
socioeconomic benefits for farmers in
poorer regions At FCRI, several sweet
potato cultivars, such as sweet potato No.8,
KB1, KL5, K4, K51, Advance 1, Advance
2 and Hoang Long, have been identified
for their agronomic and adaptive traits,
resistance to key insect pests and diseases,
and nutrient requirements However, these
cultivars have not been evaluated for yield
and dry matter production and
performance in processing The central
region and some northern provinces of
Vietnam have suitable growing seasons for
tuber crops The cultivation of sweet
potato crops in these regions needs to be
investigated as part of a sustainable
cropping system that increases farmer
income In this paper the research results
conducted from 2008-2009 of the CARD
project "Selection and development sweet
potato varieties with high root quality for
food processing in Northern and Central of
Vietnam” are highlighted.
2 Research contents and methods 2.1 Materials
Ten varieties were collected from Food Crops Research Institute, Hoang Long and local sweet potato varieties were used as the check varieties
2.2 Project sites
- Food Crops Research Institute experiment farm
- Bac Giang province (Bich Son-Viet Yen, Ngoc Chau-Tan Yen, Mai Trung-Hiep Hoa)
- Thanh Hoa province (Nguyên Binh-Tinh Gia, Quang Luu-Quang Xuong, Dong Thanh-Dong Son)
- Quang Tri province (Vinh Thai-Vinh Linh, Gio Hai- Gio Linh, Hai Quy- Hai Lang)
2.3 Research content
- Evaluate and select new potato varieties
in Bac Giang and Thanh Hoa based on quality and yield
- Evaluate and select new potato varieties
at FCRI based on quality and yield
- Evaluate and select new potato varieties
in Quang Tri based on quality and yield
2.4 Methodology
Experiment type
- Randomized complete block design (RCBD)
- Study area: 11 varieties x 4 replications x 15 m2= 660 m2
- Protection area: 340 m2
- Total area for one experiment = 1,000
m2
Planting method
- Cut and plant sweet potato root with the clean tools in all of the locations
- Distance: the distance between two plants in a row was 0.2 m and the density was 40,000 plants/ha
- Align the plant vertically to the bed surface
Planting time:
- Thanh Hoa and Bac Giang: 5-10th October
- Quang Tri: 15-20th December
Trang 3 Fertilization application
Fertilizer Kg /ha Kg (NPK)/ha
Cattle manure 15,000
Super Phosphate 550 90-100 kg
P/ha
- Mix all of the cattle manure and super
phosphate as well as 30% of urea and
30% of potassium for treatment
before planting
- Half of the remaining Urea and Kali
fertilizers were fertilized 20-25 days
after planting The other half was
added in 40 to 45 days after planting
Harvesting data collection
- For each treatment, sweet potato roots
were harvested from 4 m long section
in the middle of the bed
- Sweet potato roots were inspected
with criteria such as insects, diseases,
breakage for each treatment
- Counting the number of roots for each
treatment
- Weighing and grading roots: small
<30g, medium 30-50g, large >100g
Statistic analysis
Data were collected by the Vietnamese participants and analysed statistically
by the Australian experts
3 Research results and discussions 3.1 Evaluate and select new potato varieties in Bac Giang and Thanh Hoa based on quality and yield
The dry matter contents were determined for roots of the sweet potato varieties at all of locations in Bac Giang and Thanh Hoa, 2008 (Table 1) The highest dry matter content in these sweet potato varieties were 25.65% of HT2 and 25.38% of VC01 The values were much higher than those of Hoang Long (21.29%) and the local (20.49%) On the other hand, in the same varieties, the dry matter content in a location was different between locations For example, HT2 had high dry matter content of 33.5% and 30.73% in S2 and S6, respectively but only 24.6% and 18.57% in S1 and S3, respectively Therefore, varieties and environment caused different dry matter content of these sweet potato roots The main factor was the winter in Bac Giang (S1) and Thanh Hoa (S3) influencing unfavourably dry matter content
Table 1: Dry matter content (%) in root of Sweet potato varieties in Winter season 2008
Sites
LSD (5%) 3.317 3.969 1.651 1.904 2.34 3.056
Note:
S1= Bich Son-Viet Yen, Bac Giang S2= Cao Xa, Tan Yen, Bac Giang
S3= Dong Quang, Dong Son, Thanh Hoa S4= Mai Trung, Hiep Hoa, Bac Giang
S5= Nguyen Binh, Tinh Gia, Thanh Hoa S6= Quang Minh, Quang Xương, Thanh Hoa
- Evaluation of root yield: Root yield of the Bac Giang is shown in Table 2 In general, all
Trang 4potential yields due to the unfavourable
weather in all locations However, VC68-2,
VC04-24 and VC02-193 achieved higher root
yields of 13.75, 14.94 and 13.64 tonnes/ha,
respectively, than Hoang Long and the local variety with 10.62 and 10.13 tonnes/ha, respectively The location S1 had the highest root yield of the six locations
Table 2: Root yield (tonnes/ha) of sweet potato varieties in Winter 2008
LSD 1.87 1.28 2.68 0.70 0.76 1.83
CV% 6.20 6.90 15.00 3.60 4.00 10.20
Note:
S1= Bich Son-Viet Yen, Bac Giang S2= Cao Xa, Tan Yen, Bac Giang
S3= Dong Quang, Dong Son, Thanh Hoa S4= Mai Trung, Hiep Hoa, Bac Giang
S5= Nguyen Binh, Tinh Gia, Thanh Hoa S6= Quang Minh, Quang Xương, Thanh Hoa
The dry matter content of leaf of
vine-leaves as shown in Table 3, varied from 10.62
to 12.22% Most of the varieties had similar
values of dry matter content but No8 had the
highest average dry matter content of 12.22% The dry matter content of vine-leaves in Bac Giang (S2) and Thanh Hoa (S5) had high values of 11.52 and 12.56%, respectively
Table 3 Dry matter content (%) in vine-leaf of sweet potato varieties in Winter season 2008
LSD 1.48 1.90 0.99 1.27 2.32 1.40
CV% 8.10 9.70 5.10 6.80 10.90 7.90
Note:
S1= Bich Son-Viet Yen, Bac Giang S2= Cao Xa, Tan Yen, Bac Giang
S3= Dong Quang, Dong Son, Thanh Hoa S4= Mai Trung, Hiep Hoa, Bac Giang
S5= Nguyen Binh, Tinh Gia, Thanh Hoa S6= Quang Minh, Quang Xương, Thanh Hoa
Trang 5- The vine-leaf yields: The vine-leaf yields of the
new varieties in Bac Giang and Thanh Hoa in the
winter season 2008 were calculated and presented
in Table 4
- The unfavourable climate in the winter of 2008
affected the growth of the sweet potato varieties
and reduced the vine-leaf yield The highest
yield was only 8.01 tones/ha from TM1 while Hoang Long and the local variety had very low yields of 5.95 and 6.85 tonnes/ha, respectively
- In the same varieties, the vine-leaf yield in various locations was different Therefore, evaluation of adaptability of a variety to the environment is necessary
Table 4: Vine-leaf yield (tonnes/ha) of sweet potato in Winter season 2008
LSD 1.33 1.52 1.38 0.86 1.21 1.37
CV% 9.50 19.20 15.40 5.80 6.30 20.50
Note:
S1= Bich Son-Viet Yen, Bac Giang S2= Cao Xa, Tan Yen, Bac Giang
S3= Dong Quang, Dong Son, Thanh Hoa S4= Mai Trung, Hiep Hoa, Bac Giang
S5= Nguyen Binh, Tinh Gia, Thanh Hoa S6= Quang Minh, Quang Xương, Thanh Hoa
3.2 Evaluate and select new potato
varieties at the FCRI’ farm
To compare with the other locations, these
sweet potato varieties were also planted in
Food Crops Research Institute The criteria to
evaluate the quantity were also measured and
presented in the table 5 below that:
- The vine-leaf yield of the varieties
was equal or lower than the one of
the Hoang Long variety (control)
- The root yield is an important value
to be evaluated and selected a good variety VC04-24 and VC02-193 produced the root yields with 21.7 and 18.9 tonnes/ha much higher than the control (Hoang Long) with only 11.1 tones/ha
Trang 6Table 5 Yields of sweet potato varieties studied at FCRI’ farm in 2008
Varieties
Vine-leaf yield
(tonnes/ha)
Root yield
(tonnes/ha)
Root weight
(g)
Number
of root per plant
(#)
Grade ratio (%)
>100g 30-100g <30g
CV (%) 6.2 5.9 14.1 11.6 11.7 17.5 13.2 LSD0.05 1.28 1.28 14.2 1.10 5.97 7.0 6.97
Some quality criteria also were determined for
the sweet potato root from all the varieties The
table 6 below presented that:
- VC01 and VC68-2 achieved the highest
dry matter contents with 27.5% and 26%,
respectively in all the varieties These two
varieties had the highest softness with
score 5 These values of the varieties were
much higher than Hoang Long (the control varieties)
- Although VC04-24 and VC02-193 had the highest yields, the sweetness scores were only 4 It was concluded that that the VC01 and VC68-2 gave highest quality while VC04-24 and VC02-193 obtained highest quantity
Table 6 Yields, dry matter content, sensory value of sweet potato varieties in FCRI in Winter 2008
(%)
RDMY
(tonnes/ha)
SLDMC
(%)
SLDMY
(tonnes/ha)
Sweetness 1-5*
Softness 1-5*
LSD 0.05 0.56 0.33 0.85 0.1
* Note:
- RDMC= Root dry matter content - SLDMC= Vine-leaf dry matter content
- RDMY =Root dry matter yield - SLDMY= Vine-leaf dry matter yield
- 1-5*: score 1= not soft, not sweet; score 3= soft, relative sweet; score 5 = very soft, very sweet
Trang 73.3 Evaluate and select new potato
varieties at Quang Tri in Spring
season 2009
At Quang Tri, the sweet potato crop was
harvested in April 2009 The root, the vine and
leaves were taken to determine for the weight,
the yield and the other quantity criteria (Table
7)
- The vine-leaf yield of all sweet potato
varieties was improved very well
Most of the varieties had relatively
high vine-leaf yield about 19.7-26.9 tones/ha KL5 achieved with yield of 31.1 tonnes/ha, which was much higher than Hoang Long (control) with 19.9 tonnes/ha
- For the important criterion, the root yield was high with 21.6 from
VC04-24 and 23.6 tonnes/ha from VC02-193 Hoang Long (control) and the local variety had the lowest root yields of 16.6 and 14.9 tonnes/ha, respectively
Table 7 Yields of sweet potatoes in Quang Tri in the Spring Season 2009
Varieties
Vine-leaf yield (tonnes/ha)
Root yield (tonnes/
ha)
Average root weight (g)
Number
of root per plant (#)
Grade ratio (%)
>100g 30-100g <30g
-The quality criteria of dry matter content and
yield of root and vine-leaf, the sweetness and
softness of root were also determined for all
sweet potato varieties planted in Quang Tri at
the spring season 2009 (Table 8)
- In Quang Tri, all the varieties had high
dry matter contents from 27.6-35.2%
There were 8 varieties with the dry
matter content over 30% in which HT2
and VC01 achieved the highest contents
with 34.7 and 35.2%, respectively In
addition, the VC01 also obtained the
highest dry matter yield with 4.0
tonnes/ha
- VC01 and VC68-2 had the best softness with score 5 which was much higher than the scores of Hoang Long with 2 and the local with 1
- KL5 and Local had the best sweetness with score 5 which was higher than the scores of Hoang Long with 4
The sweet potato varieties planted in the sandy soil along the coast, Quang Tri province also provided very high dry matter of root and vine-leaf
Trang 8Table 8 Yields, dry matter content, sensory value of sweet potato varieties in Quang Tri (Spring
season 2009)
(tonnes/ha)
SLDMC
(%)
SLDMY
(tonnes/ha)
Sweetness 1-5*
Softness 1-5*
-* Note:
- RDMC= Root dry matter content - SLDMC= Vine-leaf dry matter content
- RDMY =Root dry matter yield - SLDMY= Vine-leaf dry matter yield
- 1-5*: score 1= not soft, not sweet; score 3= soft, relative sweet; score 5 = very soft, very sweet
Figure 1 New potential varieties of sweetpotato VC02-193 (left), VC68-2 (centre), VC04-24 (right)
4 Conclusions and recommendations
4.1 Conclusions
- In Bac Giang and Thanh Hoa provinces, low
temperatures and the short sunshine period of
the winter season 2008 impacted negatively
on the yields of vine-leaf and root of all sweet
potato varieties at the locations The varieties
VC68-2, VC04-24 and VC02-193 have
achieved the best root yields of 13.75, 14.94
and 13.64 tonnes/ha, respectively, which was
higher than those of Hoang Long and the
local check variety
- At the FCRI’s experiment station the varieties VC04-24 and VC02-193 have produced the highest root yields with 21.7 and 18.9 tonnes/ha while VC01 and VC68-2 provided the best sweetness and softness
- In Quang Tri province, the varieties VC04-24 and VC02-193 have obtained the highest root yield with 21.6 and 23.6 tonnes/ha, respectively The highest dry matter contents were found in HT2 and VC01 with 34.7 and 35.2%, respectively The VC01 and VC68-2 had the best quality criteria about sweetness and softness
Trang 94.2 Recommendations
Variety VC68-2 should be further improved
for quality trait and VC04-24 and VC02-193
for high yield in order to introduce new sweet
potato varieties for growing in Bac Giang,
Thanh Hoa and Quang Tri provinces in the
future
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