Báo cáo nghiên cứu khoa học " Extension and Farmer Adoption " pptx

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Milestone 8: Extension and Farmer Adoption

Deliverables:
• Training materials for extension worker training
• Assessment of impact and appropriateness of training for extension workers and
growers and survey of 2005 trainees to determine use of training material and
uptake by growers
• Quality specifications for at least 3 crops developed with assistance from Marketing
Companies

Training materials for extension work
In addition to the training materials produced for the workshops in Hanoi, Ho Chi Minh,
Dalat and Can Tho (previously supplied), several factsheers for extension officers have
been developed by the team:
• Greenhouse tomato production
• Greenhouse cucumber production
• An economic analysis of greenhouse tomato and cucumber production
• An introduction to hydroponic systems
• what protected cropping systems have been trialled in Vietnam
• what are the current recommendations
• ideas on how to develop systems that are economically viable
• retaining quality from farm to market
This publication will provide a resource that can be updated as technology and systems
continue to change in Vietnamese horticultural production systems (It is hoped that any
remaining project funding can be used to publish this).

In addition to this IAS has conducted a series of Farmer Field Schools (and developed
materials for) looking at the safe production of vegetables (Appendix 2).

Assessment of impact and appropriateness of training
Participant surveys were undertaken for the Can Tho and Dalat workshops (Dalat survey
workshop results attached as not previously supplied in earlier milestone – Appendix 3).
To evaluate the effectiveness and impact of farmer and extension training activities several
case studies were also undertaken. Some have been reported in a previous milestone (5)
where we reported on how:
1. Research and extension personnel had developed low tech hydroponic systems and
utilised these systems in their research activities. They are also called apon to give
advice to companies such as Hanoi Seed Company who are looking to improve
their hydroponic and greenhouse systems.
2. Mr Nguyen Hong Phong, Vegetable farmer and seedling producer, Lam Dong
province, has applied what he has learnt from project activities including:
• In-country training
• Australian study tour
• On-going advice provided by project staff
In this milestone Dr Vinh (IAS) provides a further update (Appendix 3) on changes that Mr
Phong has made since our previous milestone (also included). We can now see that not
only has Mr Phong made changes to his production methods but he is now looking at
implementing changes to his postharvest handling and marketing methods.

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Mr Pham Van Dung (IAS) also interviewed 3 further farmers in Lam Dong province to find
how the training in 2006 had impacted their production practices. Nguyen Van La (Phu
Thinh - Kim Dong), Nguyen Van Khoi (Tan Tien – An Duong) and Nguyen Van Chuyen
(Quy Nhat – Nghia Hang) were interviewed in August 2008 to determine what they had
applied form the training courses in 2006.
They were asked about how the project had helped them produce cucumbers or tomatoes
and in particular what knowledge they had gained. Their responses were that they had
learnt about:

-safe vegetable production
-using plastic mulch
-how to graft tomatoes
-what varieties have pest and disease resistance and how this can improve yield and
reduce pesticide usage
-how to apply IPM
-postharvest management of their crop
They were also asked what technologies they had applied. The most common changes that
had taken place were:
-using plastic mulch
-using improved varieties
They had also reduced their pesticide usage. Previously some growers had been spraying
15-20 times/crop but they had reduced this to 3-5 times/crop.

When asked why they had made these changes, the growers responded that:
-improved their return
-reduced pesticide usage
-improved yield and quality

Ideally we would have undertaken a more extensive survey of the 2006 training
participants, but as no baseline data was collected, the results would be hard to interpret.
Also in the 2006 workshops, the number of farmers participating was relatively small, but
this was rectified with the 2007 program.

Quality Specifications

As greenhouse producers are aiming for the top-end of the market, the best specifications
for them to utilise are those developed by the supermarkets. As part of this project we held
a series of discussions with Metro to discuss quality specifications, quality assurance and
how Metro goes about engaging farmers. At our workshop in Can Tho, a number of the

farmers asked specific questions of the Metro Can Tho management in how they might
look to become a Metro supplier. Attached in Appendix 4 are 3 vegetable specifications.
Discussions with the Metro Supply Chain Manager in Ho Chi Minh revealed that Metro
often has difficulty meeting these specifications. They were actively seeking engagement
with farmer groups through projects such as ours, as a way of trying to source product that
was produced to their specifications. Whilst in the case of our project we had completed
our training activities there is certainly the potential for other AusAID CARD projects to
follow up on this. Metro was very keen to work in with projects that were providing
farmer groups training in improved crop management and postharvest handling. This link
would be worth pursuing for future CARD projects.

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Appendix 1 – Fact Sheets

4
GROWING TOMATOES IN A
GREENHOUSE

5


This is a technique that summarises
the results of a research sub-project
titled “Research on ability of groing
tomatoes under polyethylene house
in Lamdong“ implemented by IAS
in co-operation with Gosford
vegetables & flowers research
Institute, Australia (Project 004/04
VIE).

It is a new technique, high effect.
The technical will be required
material facilities:

1. The polyethylene house: The
house frame are made of steel, rafter
are bamboo, roof is made of
polyethylene, gutter are made of
corrugated iron; arris is 4m in height,
the top of the house is 5.7m in
height, the roof of the house are
alternate and 0.7m in height. The
house surrounded by polyethylene
0.5m in height from ground, 0.5m to

2.7m in height by net with mesh
2mm, from 2.7m to 4m in height by
polyethylene. The columns of house
are made of steel which fixed stakes
in the ground 0.5m in deep and pour concrete 0.3m in height with 10cm in diameter.
Between the stakes 7m in distance, block house 3m in long.

2. Trellising sytem (ø = 3mm) have designed inside the house 2m in height from ground
and parallel; two lines 0.5m in distance and the same as the tomatoes bed on the ground.

3. Irrigation system: 1 tank 2000 liter, 1 filter and drip irrigation with output about 1.5-1.7
L/ hour/hole.
- The tank of water 3m in height and set up with filter, drip irrigation.
- On the bed set up two lines 0.4m in distance .

4. Muching plastic on the bed before transplanting and make holes to grow.

PROCEDURE OF TOMATOES GROWING TECHNIQUE

1. Seed
Tomato varieties with promising characteristics such as good growing ability, high
productivity good quality, pest tolerance were chosen. Curently, tomato varieties grown
commonly in Lamdong province are Red diamond which yield up to 60-70 tons/ha, Anna

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with 70-80 tons/ha. Beside these two varieties, Clarance and Labell, imported from
Australia, can be reached high potencial productivity about 300-400 tons per ha.

2. Crop
Because of growing in polyethylene house, tomatoes can be cultivated around the year.

3. Nursary
a/ Prepration of media grow seedlings: Media include: peat (70%), cow dung (25-29%),
coconut coin, lime, NPK fertilizer, Trichoderma fungi (about 1-5%). These ingredients
were mixed well and in cubated 3- 6
months, then they were ground
and put into holes of trays with
moisture enough for good
germination of seeds.

b/ Sowing: Seeds were sown into
holes by hand or special machine
(one seed into one hole), then
seeds were covered with a thin
layer of media. Trays containing
seeds were aranged into a block,
then they were covered with
canvas to stimulate germination.
After 3 to 5 days, the seeds were
germinated totally and trays were
arangred on nursary to taking care them. Seedlings were irrgated 1-2 times per day,
depending upon the moisture of the media. After 25-27 days of sowing, seedlings have 4-6
leaves, and then they were grafted with the rootstock of bacterial wilt resistant tomato. 10-
12 days after grafting, seedlings can be grown in the polyethylene house.
The seedlings which grow in the polyethylen house are healthy plants

4. Transplanting and taking care
a/ Prepare land, fertilizer
- Tomato usually like pH 5,5-7,5 (suitable of pH 6,0-6,5). If the land is acid soil then could
add more lime before cultivated.

- The land were plough and clean weeds; made bed 1,2m in wide, 15-20cm in heigh, 25-
30cm in gutter.
- Fertilizer: Amount of fertilizer for 1 ha grow tomatoes (to get yield about 150tons/ha)
- Cow dung: 40-50 tons
- Urea (46%N): 900-950kg
- Supper phosphate (16% P
2
O
5
): 850-900kg
- Potassium sulphate (62% K
2
O): 800-820kg
Put down basic fertilizer all cow dung, supper phosphate and ¼ potassium sulphate
on the bed side 10-15cm in deep and mixed. Amount of other fertilizer will be use for
irrigation in next periods.

b/ Transplanting and taking care
Transplants per ha will from 23.000 (40cm x 60cm)
Trellising sytem for tomatoes

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- Trellis is a steel 20cm length that have 2 hooks. Nylon strings were rewinded into the
trellis with the 8m length.
- The nylon strings were replaced stake that to be hung with two lines 0.5m in distance and
the same as the tomatoes bed on the ground.
- The nylon string were rewinded the main stem of tomatoes. When the stem of tomatoes
reached to 2m in heigh, 20cm of nylon string are took down by rotation of the hooks to
make tomato plant fall down a little. Taking down every 4-5 days .

c/ Take care
- Tomatoes were drop irrigated 1-2 times per day depend on moisture of ground (with
suitable about 70-80% for tomatoes to growing well).
- To prune branch and fruit: 10 days after grown were pruned, only one main stem per plant
and 4-5 fruits per cluster are kept.
- Add water by coolnet to keep humidity in polyethylene house: The water were
added the same as spray when plant growing at flower have fruirt set (suitable about 50-
55% of humidity).
- Fertigation
+ 15 days after transplanting applied additional fertilizer by fertigation: 1time per week, 15
minutes per time. 3kg urea and 2kg postassium sulphate were soaked and filtered that
diluted with concentrate about 0,5% for fertigation.
+ 35 days after transplanting will have increase number of time for fertigation: 5 days per
time, 15 minutes per time.

5. Plant protection
a/The main of insect and diesease
In nursary: Concerning to damping-off (Pythium or Rhizoctonia) and to used pesticide
with ½ concentrate of recommended on label of the product.
Leaf miner (Liriomyza tripholia): controlled by Ofunack, Trigard, Netoxin…
Damping-off (Pythium or Rhizoctonia): controlled by Benlat C, Rovral, Ridomil,
TopsinM

In Polyethylene house
Insects: little to occur:
Leaf miner (Agromyza): controlled by Vectimec, Trigard, Polytrin….
Thrip (Thrips spp.): controlled by Supracide, Polytrin, Actara, Oshin…
Aphids, white fly (Bemisia sp): controlled by Regent, Confidor, Actara, Mosfilan, Oshin…
Diseases: There are some disease pests of tomato including bacteria, fungi, and viruses
TYLCV: controlled by Confidor, Mosfilan, Actara, Oshin….

Early and late blights (Alternaria solani and Phytophtora infestans respectively) have
similar problems as with potato. Both are controlled with fungicides.
Rhizoctonia solani spp: controlled by Anvil, Validacin, Tilt, Monceren
Notice: should be change the pesticide to useful and high effect.
Bacterial wilt: controlled by using grafted seedling

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b/ IPM
* Cutural: Colection, remnants were destroyed after havest. Plough, applied
additional lime (600-650kg/ha). Crop rotation were best menthod by lettuce, leaf
vegetables,

* Biological: Should be used biology pesticide such as Bt, V-Bt, Pheromone,
Neem, Fungicide: Trichoderma, Validacin,

6. Harvest:
The fruirt apperance were redden colour that can be havest. Using scissor cut between
peduncle of single fruirt or a cluster that arranged in plastic container.

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GROWING CUCUMBER IN A
GREENHOUSE

This is technique summarises results of a research project entitled “Research on ability of
groing cucumber under polyethylene house in Lamdong“ implemented by IAS in co-
operation with Gosford vegetables & flowers research Institute, Australia (Project 004/04
VIE).

It is a new technique, high effect. The technical will be required material facilities:

1. The polyethylen house: The house frame are made of steel, rafter are bamboo, roof is
made of polyethylen, gutter are made of corrugated iron; arris is 4m in height, the top of the
house is 5.7m in height, the roof of the house are alternate and 0.7m in height. The house
surrounded by polyethylen 0.5m in height from ground, 0.5m to 2.7m in height by net with
mesh 2mm, from 2.7m to 4m in height by polyethylen.
The columns of house are made steel which fix stakes in the ground 0.5m in deep and pour
concrete 0.3m in height with 10cm in diameter. Between the stakes 7m in distance, block
house 3m in long.
2. Trellising sytem (ø = 3mm) have designed inside the house 2m in height from ground
and parallel; two lines 0.5m in distance and the same as the cucumber bed on the ground.
3. Irrigation system: 1 tank 2000 liter, 1 filter and drip irrigation with output about 1.5-2l/
hour/hole.
- The tank of water 3m in height and set up with filter, drip irrigation.

- On the bed set up two lines 0.4m in distance .
4. Muching plastic on the bed before transplanting and make holes to grow


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PROCEDURE OF CUCUMBER GROWING TECHNIQUE

1. Seed
Cucumber varieties with promising characteristics such as good growing ability, high
productivity good quality, pest tolerance were chosen. Curently, cucumber varieties grown
commonly in Lamdong province are TN 140 which yield up to 30-32tons/ha. Beside these
two varieties, Status and Tohoku, which are varieties from Australia, can be reached high
potencial productivity about 100 tons per ha.

2. Crop
Because of growing in polyethylen house, cucumber can be cultivated around the year.

3. Nursery
a/ Prepration of media grow seedlings: Media include: peat (70%), cow dung (25-29%),
coconut coin, lime, NPK fertilizer, Trichoderma fungi (about 1-5%). These ingredients
were mixed well and in cubated 3-6 months, then they were ground and put into holes of
trays with moisture enough for good germination of seeds.
b/ Sowing: Seeds were sowing into holes by hand or special machine (one seed into one
hole), then seeds were covered with a thin layer of media. Trays containing seeds were
aranged into a block, then they were covered with canvas to stimulate germination. After 3
to 5 days, the seeds were germinated totally and trays were arangred on nursary to taking
care them. Seedlings were irrgated 1-2 times per day, depending upon the moisture of the
media. After 10-15 days of sown, seedlings have 4-6 leaves, cucumber can be grown in the
polyethylen house.
The seedlings which grow in the polyethylen house are healthy plants

4. Transplanting and taking care
a/ Prepare land, fertilizer
- Cucumber usually like pH 5,5-6,8 (suitable of pH 6,0-6,5). If the land is acid soil
then could add more lime before cultivated.
- The land were plough and clean weeds; made bed 1,2m in wide, 15-20cm in heigh, 25-
30cm in gutter.
Fertilizer: Amount of fertilizer for 1 ha growing cucumber (to get yield about 50tons/ha)
- Cow dung: 35-40 tons
- Urea (46%N): 300-350kg
- Supper phosphate (16% P
2
O
5
): 350-400kg
- Potassium sulphate (62% K
2
O): 250-300kg
Put down basic fertilizer all cow dung, supper phosphate, 1/10 amount of urea and 1/5
amount of potassium sulphate on the bed side 10-15cm in deep and mixed. Amount of
other fertilizer will be use for irrigation next period.

b/ Transplanting and taking care
Transplants per ha will have from 23.000 (40cm x 60cm)
Trellising sytem for cucumber
- Trellis is a steel 20cm length that have 2 hooks. Nylon strings were rewinded into the
trellis with the 8m length.
- The nylon were replaced stake that to be hung with two lines 0.5m in distance and the
same as the cucumber bed on the ground.

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- The nylon were rewinded the main stem of cucumber. When the stem of cucumber
reached to 2m in heigh, 20cm of nylon string are took down by rotation of the hooks to
make tomato plant fall down a little. Taking down every 3-4 days.

c/ Take care
- Cucumber were drop irrigated 1-2 times per day depend on humidity of ground (with
suitable about >80% for cucumber to growing well).
- To prune branch and fruirt: 10 days after grown were pruned only one main stem per
plant and 2-3 fruirts per cluster.
- Fertigation
+ 15 days after transplanting applied additional fertilizer by fertigation: 1time per week, 15
minutes per time. 3kg urea and 2kg postassium sulphate were soaked and filtered that
diluted with concentrate about 0,5% for fertigation.
+ 35 days after transplanting will have increase number of time for fertigation: 5 days per
time, 15 minutes per time.

5. Plant protection
a/ The main of insect and diesease
Nursary: Concerning to damping-off (Pythium or Rhizoctonia) and to used pesticide with
½ concentrate of recommended on label of the product. Both are controlled with Benlat C,
Rovral, Ridomil, Topsin M
Leaf miner (Liriomyza tripholia): controlled by Ofunack, Trigard, Netoxin…
Polyethylene house
Insects: little to occur:
Aphids (Aphis cracivora Koch): controlled by Confidor, Actara,
Thrip (Thrips spp.): controlled by Supracide, Polytrin, Actara, Oshin…
Aphids, white fly (Bemisia sp): controlled by Regent, Confidor, Actara, Mosfilan, Oshin…
Diseases: There are some disease pests of cucumber including bacteria, fungi, and many
viruses

Cucumber Mosaic Virus: The plant is stunted and foliage is mottled followed by occasional
wilt and death of leaves. It is vectored by aphids and the cucumber beetle are controlled
with Confidor, Mosfilan, Actara, Oshin….
Downy Mildew: (Pseudoperonospoa cubensis) is high in pickling cucumbers because
they are planted at such high densities. Yellow and brown spots appear on the upper leaf
surface, with a purplish mold on the underside. It is wind borne so it is practical to use
resistant varieties. Notice: should be change the pesticide to usful and high effect
b/ IPM
* Cutural: Colection, remnants were destroyed after havest. Plough, applied
additional lime (600-650kg/ha). Crop rotation were best menthod by lettuce, leaf
vegetables,

* Biological: Should be used biology pesticide such as Bt, V-Bt, Pheromone,
Neem, Fungicide: Trichoderma, Validacin,
6. Harvest:
The fruirt apperance were deep green colour that can be havest. Using scissor cut between
peduncle of single fruirt or a cluster that arranged in plastic container and to transport for
makets, supper makets.

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ECONOMIC EFFECT OF GROWING TOMATO AND CUCUMBER
ON GROUND AND ON MEDIA UNDER POLYETHYLEN HOUSE

In collaboration with The Gosford Vegetables & Flowers research Institute, Australia,
Vegetable Reaserch Department, Institute of Agricultural Sciences for Southern Vietnam
has conducted an experiment titled “Research on ability of groing tomatoes and cucumber
under polyethylene house in Lamdong“ This is an activitiy belongs to Project of 004/05
VIE funded by CARD Program.
The results of experiment showed that:
- Tomatoes grown on the ground gave a benefit of 48,211,000VND, meanwhile

tomato grown on media gave a loss of 23,276,000 VND per 1000m
2
.
- Similarly, cucumber grown on the ground gave a benefit of 25,560,000VND
meanwhile cucumber grown on media make a loss of 5,475,000 VND per
1000m
2
.
The main reasons are that price of media is high and the management of nutrition in
hydroponics was not so good as lacking of experience.
Table1. Benefit of 1000m
2
of tomato grown on ground in Lam Dong province
Vietnam, 2007
No. Item unit Quantity Price (VND) Cost (VND)
A Input
I Material
1
Organic fertilizer m
3
5 300,000 1,500,000
2
Lime kg 150 300 45,000
3
Urea kg 94 7,000 658,000
4
Super Phosphate kg 88 5,000 440,000
5
Kali Sulphate kg 80 7,000 560,000
6

Borax kg 5 12,000 60,000
7
Insecticides pack 50 20,000 1,000,000
8
Nylon for mulching roll 2 500,000 1,000,000
9
Grafted seedlings seedling 2700 380 1,026,000
10
Other 1 1,000,000 1,000,000
II
Labour Person/day 140 50,000 7,000,000
III
Annual input total (1) 14,289,000
IV
Annual Depreciation (2)
(plastic house and facilities)
5,000,000
V
Total (3=1+2) 19,289,000
B
Products (4) tons 15 4,500,000 67,500,000
C
Benefit (5=4-3) 48,211,000


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Table3. Benefit of 1000m
2
of tomato grown on media in Lam Dong province Vietnam,
2007

No. Item unit Quantity Price (VND) Cost (VND)
A Input
I Material
1
Media m
3
40 1,000,000 40,000,000
2
Chemicals 10,000,000
3
Insecticide pack 50 20,000 1,000,000
4
Nylon for mulching roll 2 500,000 1,000,000
5
Grafted seedlings seedling 2700 380 1,026,000
8
Other 1,000,000
II
Labour person/day 140 50,000 7,000,000
III Annual input total (1)

61,026,000
IV
Annual depreciation (2)
(plastic house and facilities)

5,000,000
V Total input (3=1+2)
66,026,000
B Products (4)

tons
9.5 4,500,000 42,750,000
C Benefit (5=4-3)
-23,276,000
Table 2. Benefit of 1000m
2
of cucumber grown on ground in Lam Dong province
Vietnam, 2007
TT Item unit Quantity Price Cost
I Input
1
Organic fertilizer m
3
4 300,000 1,200,000
2
Lime kg 100 300 30,000
3
Urea kg 70 7,000 490,000
4
Super Phosphate kg 65 5,000 325,000
5
Kali Sulphate kg 60 7,000 420,000
6 Insecticide pack 40 20,000 800,000
7
Nylon for mulching roll 2 500,000 1,000,000
8
Seedlings seedling 2700 250 675,000
9
others 1 1,000,000 1,000,000

Labour labour 100 50,000 5,000,000

Annual input total (1) 10,940,000

Annual depreciation (2)
(plastic house and facilities)
3,500,000

Input total (3) = (1)+(2)

14,440,000
II
Out put (4)
tons 8 8,000,000
64,000,000
II
Benefit (5)=(4)-(3)

49,560,000

Table 4. Benefit of 1000m
2
of cucumber grown on media in Lam Dong province
Vietnam, 2007

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TT Item unit Quantity Price Cost
I Input
1
Media m

3
40 1,000,000 40,000,000
2
Chemicals 8,000,000
3 Insecticide pack 20 20,000 400,000
4
Nylon for mulching roll 2 500,000 1,000,000
5
Seedlings seedling 2700 250 675,000
6
others 1,000,000
7
Labour person/day 100 50,000 5,000,000

Annual input total (1) 56,075,000

Annual depreciation (2)
(plastic house and facilities)
3,500,000

Input total (3) = (1)+(2)

59,075,000
II
Out put (fruit) (4)
tons 6,7 8,000,000
53,600,000
II
Benefit (5=4-3)

-5,475,000
AN INTRODUCTION TO HYDROPONIC SYSTEMS AND THEIR
MANAGEMENT
Sophie Parks

A range of hydroponic systems are used for commercial production of vegetables.
Essentially hydroponic systems supply nutrients to crop roots as a solution with the
irrigation water. Roots are suspended in a still or flowing solution or the solution is fed
through drippers to the plant supported in contained substrate. Soil is not used. Some
different types of hydroponic systems are described below. All hydroponic systems need to
provide plant roots with enough nutrients, water and oxygen for good growth.


TYPES OF HYDROPONIC SYSTEMS

Tank culture
Tank culture is the simplest form of hydroponics. Plants are suspended by a cover over a
tank of complete nutrient solution. Some tank systems require aeration of the nutrient
solution (Figure 1).

Figure 1. Aerated tank culture

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In one type of system described by Kratky (2004) the solution is still and plants are
supported by substrate within a small netted or perforated pot (Figure 2). The bottom of the
pot is immersed in the nutrient solution which supplies the plant with nutrients and water
through capillary action. The nutrient solution level drops as it is used by the crop until
10% of the original solution is left. The crop is then harvested or terminated.

Figure 2. Still tank culture


Four main concepts encapsulate still tank culture:
• Exposure to air and high relative humidity is important for the upper part of the root
system
• Drying out of roots must be avoided
• The lower part of the root system should gather water and nutrients
• The nutrient solution level can either be maintained or lowered but cannot be raised
(otherwise aeration of roots is reduced)

Advantages of tank culture:
• Simple to set up and manage
• No pumps or electricity required
• Very efficient in water and nutrient use
• Only an initial application of nutrient solution is required

Disadvantages of tank culture:
• Not as suitable for long crops
• High quality water is needed, as the salts increase in concentration, as the solution
is used
• Still nutrient solution can allow mosquitoes to breed

Flowing culture
In flowing culture plants are supported in a sloping shallow gully and the roots are
suspended in a flowing stream of nutrient solution (Figure 3). This is also called the
nutrient film technique (NFT). After passing down the gully the nutrient solution is
collected in a tank and pumped back to the top of the gully to continuously recycle the

nutrient solution. The gullies need to be large enough to support the root system of the

16
crop, and constructed to provide a constant flow rate of solution down each gully. Pooling
of the nutrient solution along the gully also needs to be avoided. To maintain adequate
aeration along the gully, the length ideally should be less than 30 metres and the slope steep
enough to allow a good flow rate of solution. As the gully length increases, a steeper slope
is required.


Figure 3. Flowing culture

Substrate culture
In substrate culture plants are grown in a soilless substrate held within a container (Figure
4). The substrate does not have any nutrient value for plant growth. The substrate needs to
have enough water holding capacity to maintain moisture around roots and also must
provide enough aeration to prevent waterlogging. Examples of substrates include gravel,
peat, coir, perlite, vermiculite, rockwool, scoria and sawdust. Mixes of different products
are also used. Water and nutrients are fed through a line supplying plants and the solution is
allowed to drain through the substrate and openings at the base of the container. Enough
nutrient solution is applied so that 10-20% drains from the pot. This prevents build up of
salts in the substrate and maintains the solution around the root zone. The drainage solution
(runoff) can be collected and continuously recycled through the system. This can be done
manually. For example, a bucket could be used to collect runoff from a simple gravity fed
system and returned to the raised solution feed bucket, or in larger systems, pumps can be
used to return water to feed tanks. When this drainage is not recycled the system is known
as a ‘run-to-waste’ system.


Figure 4. Substrate culture

Substrates in Vietnam

17
Vietnam has local sources of coir, peat and other products such as sugar cane waste, peanut
husks, rice husks, and volcanic rock. Hydroponic tomato and cucumber crops have been
successfully grown in Vietnam using combinations of these products. Providing that the
crop is well managed, many products and combinations of products can be used as a
growing medium. However, it is important to understand that products differ in their
characteristics. For example over time, peat is difficult to rewet when compared with coir
and other products. Vietnamese peat also has the ability to strongly fix phosphorus. Such
characteristics are not a problem when taken into consideration in the irrigation and
nutrition program.

Advantages of flowing and substrate culture:
• Suitable for long crops
• Lower quality water can be used if a run-to-waste system is used, or if nutrient
solution is changed frequently
• Root zone solution can be fine tuned

Disadvantages of flowing and substrate culture:
• Setup can be expensive and require a continuous supply of electricity
• These systems can be inefficient in water and nutrient use when nutrient solution is
not reused.
• Waste nutrient solution is produced
• A high level of technical knowledge is required

NUTRIENT MANAGEMENT OF HYDROPONIC SYSTEMS

It is important to have at least a basic understanding of the nutritional requirements of

plants, and of chemistry, in order to make up and manage hydroponic nutrient solutions.
Plants require large amounts of the macronutrients: nitrogen (N), potassium (K), calcium
(Ca), magnesium (Mg), phosphorus (P) and sulphur (S); in comparison to the
micronutrients: chlorine (Cl), iron (Fe), boron (B), manganese (Mn), zinc (Zn), copper
(Cu), nickel (Ni) and molybdenum (Mo). This is reflected in the concentrations of
macronutrients and micronutrients that are found in typical hydroponic nutrient solutions.

Preparing the nutrient solution
For those new to hydroponics an easy option is to buy and use a prepared hydroponic
fertiliser. Alternatively, a fertiliser mix can be made up with individual chemical
compounds, according to a nutrient recipe. The nutrient solution is made to the
concentration required for immediate use by the crop, or it is made up into two
concentrated stock solutions for convenience.

If buying a prepared hydroponic fertiliser, it is important to ensure that it contains sufficient
calcium and magnesium. The hydroponic solution specialist Rick Donnan recommends that
the content of calcium should be as much as, or up to 30% less than, the amount of nitrogen
present. Magnesium needs to be at a content of about 20-30% of the amount of calcium
present. Additionally he recommends avoiding fertilisers that contain urea, or those that
have over 10% of total nitrogen in the ammonium form.

It is often practical for commercial hydroponic growers to prepare concentrated stock
solutions which can then be stored before being diluted and delivered to the crop. In this
case two different stock solutions (labelled A and B), are needed to avoid precipitation of

18
calcium phosphate, calcium sulphate and iron phosphate in these highly concentrated
solutions. The stock solutions are 100 to 200 times stronger than the solution given to
plants. Stock solutions also need to be kept out of the cold, ideally between 27-30
o

C, to
prevent precipitation. Most nutrient solution recipes in use commercially are generally
similar in composition. An example of a nutrient recipe is the “Huett” lettuce formulation
which is also suitable for tomatoes (Table 1).

Table 1. Standard ‘Huett’ lettuce formulation. Recommended starting and to-up solutions are the same.
Equal volumes of A and B stock solution are to be used. For starting solution, to 1000 litres of water
add 3.4 litres of A and 3.4 litres of B.
Solution Compound Elemental
composition
(%)
Stock solution
(g compound/L)
#
pH>6.0 pH<6.0
A Calcium nitrate
Ca(NO
3
)
2
– H
2
O

18.8 Ca
15.5 N
109 109

*
Iron chelate (Fe EDTA)

13.2 Fe 5.6 5.6
B
+
(MAP) ammonium
phosphate (NH
4
H
2
PO
4
)

12.2 N
26.9 P
8.7 Nil
Potassium dihydrogen
phosphate (KH
2
PO
4
)

28.7 K
22.8 P
16.3 29.0
Potassium nitrate (KNO
3
)

38 K
13 N
133.3 133.3
Magnesium sulphate
(MgSO
4
)

9.8 Mg
13 S
58.1 58.1
Boric acid (H
3
BO
3
)

17.7 B 0.35 0.35
Zinc sulphate (ZnSO
4
.7H
2
O)

22.7 Zn 0.2 0.2
Manganous sulphate
(MnSO
4
.H

2
O)

32.9 Mn 0.2 0.2
Copper sulphate
(CuSO
4
.5H
2
O)

25.6 Cu 0.035 0.035
Sodium molybdate
(Na
2
MoO
4
.2H
2
O)
39.7 Mo 0.01 0.01
*
Adjust amount of iron chelate depending on elemental Fe content of chelate.
+
Increase amount in stock solution if pH is drifting upward in recirculating system.
#
If pH of nutrient solution in recirculating system is greater than (>) 6.0.

Managing irrigation and the nutrient solution
Still tank culture, as described by Kratky (2004), is designed to require only simple nutrient

solution management. Once the solution has been made up to the desired concentration,
which depends on the tank size and crop type, enough is added to the tank to last for the
duration of the crop.

In flowing and substrate culture, nutrient management becomes more complex, particularly
when solutions are recirculated. A crop will perform best when the grower aims to keep
conditions constant around the plant roots.


19
There are some simple tools available that can be used to assist in the management of water
and nutrients around the plant roots. These include monitoring of runoff volume in
substrate systems, and testing the solution for acidity/alkalinity (pH), nutrient concentration
(electrical conductivity or EC) and nitrate concentration. In NFT systems you can simply
monitor the recirculating solution. In substrate systems, the runoff/drainage solution from
plant substrates is collected over a 24 hour period for monitoring purposes. If
measurements are made on a daily basis, these factors can be viewed over time along with
the crop performance history, to help the grower make crop management decisions.

Percentage runoff
Percentage runoff is useful for tailoring irrigation to the conditions as it provides an
indication of plant water use. You will need to know the volume of water being delivered
to each plant (water input) in this time to calculate the percentage runoff. To measure
percentage runoff, collect the runoff from several plants in a container over a 24 hour
period. You will need to know the volume of water being delivered to each plant (water
input) in the 24 hour period to calculate the percentage runoff. Percentage runoff should be
below about 20%. Use the following equation to calculate percentage runoff.

Percentage (%) runoff = water input volume
X 100

runoff volume

As a system is managed more efficiently the percentage runoff is reduced. Efficient
systems produce less than 5% runoff.

Maintaining pH and EC levels
The acidity or alkalinity (pH) of a feed solution generally needs to be between 5.5 and 6.5.
The requirements may vary depending on the crop being grown. Chemicals can be used to
adjust the pH of the solution being delivered to the crop. To reduce the pH phosphoric acid
or nitric acid is used and to increase the pH potassium hydroxide is used. As plants take up
nutrients and water from the solution the pH may drift around the root zone. Monitoring the
runoff solution over 24 hours, particularly from substrate systems, provides an indication of
the pH in the root zone. The pH of runoff solution should be about 6.0-7.0. If this drifts, the
ratio of ammonium and nitrate nitrogen in the feed solution can be adjusted to correct the
root zone pH.

The target EC of a nutrient solution can vary according to the crop being grown, stage of
growth and climatic conditions. The most common unit of measurement for EC is
milliSiemens per centimetre (mS/cm). First, water quality needs to be assessed before
being used for hydroponic solution. Water can contain dissolved ions such as sodium,
chloride, calcium, magnesium and bicarbonate increasing the EC. Species differ in their
tolerance of higher solution EC (salinity). For example, tomatoes are considered tolerant,
cucumbers moderately tolerant and capsicums sensitive to high solution EC. At an EC of
4.5 mS/cm tomatoes may not experience reduced growth but capsicums may suffer a 25%
reduction in growth. Lettuces are grown at a lower EC range of between 0.5-2.5 mS/cm. In
substrate systems the EC of runoff solution is an indication of the root zone EC. When a
plant is fruiting or experiencing hot and windy conditions more water is taken up by the
plant than nutrients, increasing the EC of the root zone solution. In this situation damaging
levels of EC in the root zone can be avoided by lowering the EC of the feed solution or by
increasing the amount of runoff (i.e. increase volume of feed solution).

20
Treatment of waste nutrient solution or runoff
Waste nutrient solution can become a serious environmental problem if it is not treated
appropriately. A substrate system that does not recirculate drainage produces more waste
nutrient solution than other types of systems. Systems that do recirculate nutrient solution
require periodic nutrient solution replacement and so still produce some waste solution. A
simple and effective treatment of runoff waste water can be achieved using a constructed
reed bed or a wetland system. The waste water enters the reed bed or wetland system and
the waste nutrients are removed through filtration and by vegetation. The wetland system
itself can produce crops such as kang kong.

References and resources:
Badgery-Parker, J. 2003. Managing waste water with a wetland, NSW Agriculture,
Orange, Australia

Casper Publications web site:

Dirou, J., Headley, T., Huett, D., Stovold, G. and Davison, L. 2003. Constructing a reed
bed to treat runoff water – a guide for nurseries NSW Agriculture, Orange, Australia.

Huett, D. 1993. Managing nutrient solutions in hydroponics. NSW Agriculture, Orange.

Kratky, B. A. 2004. A suspended pot, non-circulating hydroponic method. Acta
Horticulturae 648, 83-89.

Mason, J. 2005. Commercial Hydroponics. 2
nd
Ed. Kangaroo Press, Sydney Australia.

Morgan, L. 2003. Hydroponic Lettuce Production, A comprehensive, Practical and
Scientific Guide to Commercial Hydroponic Lettuce Production. Casper Publications,
Sydney, Australia.

21
Appendix 2

HRDP-IV. IAS UPDATE NEWS


TRAINING AND ORGANIZING FARMER’ FIELD SCHOOL
AND FARMERS’ EXPERIMENT
(activity of IAS, 1-3 December 2006)

Reported by Dr. Ngo Quang Vinh

From 1 to 3 of December, 2006 a training course titled “ Training and organizing Farmer’
Field School (FFS) and Farmers’ Experiment (FE)” was conducted in Tra Vinh. The
training course gathered 45 farmers from Safe vegetable production group (7 women) and
it is given lectures by 1 Dr., 2 MScs. 2 BScs. specializing on IPM, Plant Protection and
PAR. The course spent 2 days and a haft in class room and a haft day on the field for
practice.

Purpose of the training:
1. Introduce farmers and Local authority the necessary of “ farmers research and solve
their problem themselves” and the new way/approach to help farmers of Agricultural or
Science Institution.
2. Concept of Participatory Action Research (PAR), method to organize group of PAR
farmers and conduct activities.

3. Help farmers to organize 3 groups of PAR and guide them to conduct 6 FFSs and an FE
with the help of facilitators (Leading farmers, Extension Staff and IAS staff).
4. Discuss and make plan to conduct FFS with pak choi, Chinese kale, lettuce and celery
as well as an FE with selecting net to provide shade to coriander and celery
5. Improve key knowledge of farmers to participate PAR group including:
• IPM principle on vegetable and apply it in production of pak choi, Chinese kale,
lettuce and celery.
• Basic understanding about disease, basic understanding about chemicals for disease
control, use chemicals to control disease in IPM on Vegetables.
• Basic understanding about insects, basic understanding on chemicals for insect
control, use chemicals to control insects in IPM on Vegetables
(learning in class and practice on the field to identify diseases and insects)
• Contain and method of learning on the field (observe, discuss, take notes …) with
guideline to take notes
• Contain and method of learning in the PAR club (problems, discuss, solution or
methods …)
6. Guide farmers to make insect-traps and raising worm to have adult insects that used for
learning and applying into their insect control

Results of the training
• Participants understand lectures and happy to join PAR groups.
• 3 groups of FFS are organized with 1 head farmers and 2 facilitators (leading
farmer,
Extension staff, IAS staff). Each group will conduct 2 FFSs in 2 crops (times).
• 3 FFSs and 1 FE will be conducted on December, 3 other FFSs will be conducted
on January 2007.

22

Next activities

As the plan, on 10 and 11 December 3 group of FFS will organize the first meeting with
joining of IAS, AEC staff (as facilitators). The meeting will discuss more detail and decide
(by farmers themselves) all things about organization and technical problem that each
group has to do. After the meeting, FFS and FE will be started.




23
Appendix 3 Dalat Training Course and Case Studies

REPORT ON DALAT TRAINING COURSE
1. TITLE OF TRAINING COURSE
Workshop on Quality Assurance, Post harvest and horticultural “Good Agricultural
Practice” Protected cropping systems

2. Introduction
- DATE: 3-4 May, 2007
- PLACE: Dalat city, Lamdong Province, Vietnam
- Orgnizational board:
+ In Vietnam:
Dr. Le Thi Khanh, Head of Horticulture Department
Dr. Tran Van Minh, Director of Hue University of Agriculture and Forestry (HUAF)
Dr. Nguyen Van Ket, Dean of Agronomy Faculty, Dalat University
MSc. Le Thi Nhu Bich, Vice Dean of Agronomy Faculty, Dalat University
Eng. Ho Cong Hung, researcher of Horticulture Department
MSc. Nguyen Dinh Thi, Teacher of Plant Physiology Department
+ In Australia:
Dr.Suzie Newman, Research Horticulturist (Post harvest)
Dr. Nguyen Quoc Vong, Research Horticulturist (Plan breeding)

Dr. Sophie Parks, Research Horticulturist (Plant Physiology)
Mr. Joseph Ekman, Extension Horticulturist (Quality Assurance Systems)
- Resource persons:
+ Lead farmers from Provinces of Central Vietnam
+Extensionist, PPD come from 12 Provinces of Central Vietnam (Nghean, Hatinh,
Quangbinh, Quangtri, Thua Thien Hue, Danang, Quangnam, Quang ngai, Binh dinh, Phu
yen, Khanh hoa, Ninh thuan)
+ Leaders from Companies (Organik Company, Clean soil Company), Farmings, PPD
+ Provincial government office in charge of agriculture, Farmings from seeds and seedling
producers
+ Seed distributors or sellers
+ Representatives come from Universities (HUAF, Dalat University, Thu Duc
University from Ho Chi Minh City)
+ Representatives come from Lam Dong Province, Districts belong Lam Dong
Province
+ Representatives come from companies: Ho Chi Minh city, Dalat City, Lam Dong
Province, Danang city
+ Reporters from Gosford Horticultural Institute, RIFAV, IAS, Ho Chi Minh
Univesity, HUAF
3. Objective
Providing basic knowledge on Quality Assurance, Post harvest and horticultural “Good
Agricultural Practice” Protected cropping systems;
to exchange and to share experiences and information among participants
for vegetable development safe in Central Vietnam

4. Program of training course
4.1. Reporter
- The Theory :
+ Green house crop production

24
+Good Agricultural Practices (GAP), Port harvest quality management - from farm
to market
+ Vegetable production and to apply of high - technology in vegetable growing in
Vietnam, high - technology Vegetable and flower development in Dalat and Lam Dong
Province
+ Processing technology of vegetable from vegetable Companies
+ To approach new techniques for farmers
+ To exchange and to share experiences and information among participants

4.2. To visit
To visit vegetable hydroponics in Dalat University, processing house from Organik
Companies, Vegetable Farms, Net house and vegetable growing in net house in farmers
Dalat

4.3. To discuss, exchanging and sharing experiences
- Discussion, exchange experiences together in the meeting room thought pictures, to talk
themself

5. RESULTS
The training course opened on 3-4 May, 2007 by Dr. Le Thi Khanh, Head of Horticulture
Department; Dr. Tran Van Minh, Director of HUAF and 68 participants from Lead
farmers, Extensionist, PPD from Provinces of Central Vietnam
Leaders from Companies (Organik Company, Clean soil Company), Farmings,
PPD, Provincial government office in charge of agriculture in Dalat
Time from 3 to 4, May 2007, 9 lectures and 9 special topic have been presented by
9 speakers who are Doctors from RIFAV, HUAF, IAS
Total: 68 trainees are lead farmers, Extensions, lead farmers, PPD, Companies,
leader from local, government
In which Female: 16 trainees occupying 23.5 %

Male: 52 trainees occupying 76.5 %


* On 3 May, contents of the presentations and practice covered on:
- In the morning: (On 3 May,2007)
+Introducing CARD 004/04VIE project
+ The Challenges of Vietnamese horticultural industry in the new era of WTO
+ Greenhouse crop production
+ High - tech Agriculture and orientation of approach
+ To apply of high - tech and orientation of high - technology Vegetable and
flower development in Dalat and Lam Dong Province
+ Discussion among trainees this topics

- In afternoon (on 3 May, 2007)
+ Vegetable production and to apply of high - technology in vegetable growing in
Vietnam
+ Port harvest quality management - from farm to market
+ Good Agricultural Practices (GAP)
+ Production and distribution of safe vegetable from Central Vietnam Provinces
+ Discussion among trainees this topics


25
- on 4 May, contents
Field trips:
+ Visiting on net house and production vegetable in net house,
+ Vegetable organic
+ Post harvest technology
+ Store technology
+ Processing technology

+ Discussion among trainees this topics
* Discussion and evaluation of the training course
Total participants in training course are 68 people who are invited from main from
lead farmer, extensions, PPD, Provincial government office in charge of agriculture,
Companies, seeds sellers, producers product seedlings
Every participant was provided a set document in which all reporters were given.
Basing on the activities of the training course and especially, the evaluation of participants,
it could be said that training course has been successful.
The aims of training course have been obtained.
The documents of work were requested by farmers in Central Vietnam

6. FEEDBACK FROM TRAINEES
- To sum up from evaluation opinion of trainees:
68 evaluation papers have been done (including participants were given certificate)
Table 1. The results of feedback from training course on
3-4 May, 2007 IN Dalat city (unit: %)
No. and item Agree of participants %
Clearly 100 1. Objective of training course
Not very clear 0
Very good 100
Good 0
2. Objective of training course obtained
Fairly 0
Very co responsively and very
well
100
Corresponsive and well 0
Fairly 0
3. Teaching method and level of teachers
and reporters presented (correspond with

extentionists and farmers)
Not corresponsive and well 0
Very good and useful 100
Good and useful 0
4. Content of training course
Poor and unuseful 0
Very good 18.8
Good 8.1
5. Learning of participants/Participation of
trainees
Fairly 73.1
Well 100
Fairly 0
6. Communicate ability of teachers in
training course

Bad 0
Very good and enought 0
Good and enought 100
Fairly 0
7. Documents and facilities for
presentation of raining course
Poor and lack 0
Enough/OK 6.3 8. Duration of training course
Too long 0