IJERD – International Journal of Environmental and Rural Development (2018) 9-1

Research articleerd

The Effectiveness of Different Net-coverings on Production
Yield of Chinese mustard (Brassica juncea) at Royal
University of Agriculture
SOTH HONG *Department of Agricultural Engineering, GDA/MAFF, Phnom Penh, Cambodia
Email: hongmorhousoth@yahoo.com

LYTOUR LOR
Faculty of Agricultural Engineering, Royal University of Agriculture, Phnom Penh, Cambodia

BORARIN BUNTONGDivision of Research and Extension, Royal University of Agriculture, Phnom Penh, Cambodia

SOCHEATH TONGDivision of Research and Extension, Royal University of Agriculture, Phnom Penh, Cambodia

KAREN LEGRAND
Safe Vegetable Value Chain in Cambodia, University of California Davis, USA
Received 4 January 2018

Accepted 18 May 2018(*Corresponding Author)

Abstract Cambodia, among other nations in South East Asia, is a developing country that
relies on its agricultural sector. More than 70% of the population farms rice is a staple cropand vegetables as a secondary crop for domestic demand and consumption. In 2013,
Cambodia produced only 40-50% of the domestic demand for vegetables and the shortage
was filled by imported vegetables from neighboring countries including Vietnam andThailand. The shortage is caused by a number of factors including that vegetables arecultivated in small quantities and farmers lack funds to support improvements in crop
cultivation that are necessary to address climate change, poor irrigation systems, disease
outbreaks, and particularly crop destruction by pests. For instance, in 2016 crops in someprovinces of Cambodia were damaged by Spodpter spp. Other insects also cause crop
destruction which prompts farmers to change chemical pesticides to control additional pests.
Using chemical methods to control the variety of pests that destroy Cambodian crops is nota viable long-term solution because it affects the health of both producers and consumers,
the environment, and the microorganisms that are useful for cultivating high quality crops.
The net-house is an installation structure using high quality mosquito netting that tolerates
weather. It is suitable for growing vegetables and other crops because it creates a barrier
between pests and crops to prevent damage. Using a net-house is an effective way to reduce
pesticide use in vegetable production. It is also reported that net-houses have other benefits
such as preventing weeds, reducing soil moisture loss, depleting sunlight, increasing yields
and providing safe food. This research study has two aims (1) to assess the effects ofdifferent shapes of net-houses on growth and yield of Chinese mustard, and (2) to study theeconomic efficiency of growing Chinese mustard in differently designed net-houses.
Experiments were conducted in triplicate using Randomized Complete Block Design.
Treatments included standard net-house, covered-ridge net-house and open field as acontrol. Analysis revealed that using net houses increased the yield and economic efficiencyof growing Chinese mustard and that the degree of benefit was affected by the design of thenet house. Based on the results, recommendations are made about the most suitable method
for growing high quality, pesticide-free Chinese mustard.
Keywords net-house, IPM, humidity, soil erosion, Chinese mustardⒸ ISERD

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INTRODUCTION
Cambodia is a country located in tropical region with a monsoon wind, which is separated into themain two seasons: dry season and rainy season from May to October, and the dry season from
November to April. This climate conditions that cause the cultivation of almost all types of crops
grow well. Especially, most of vegetables commonly cultivated in lowland areas along rivers andother lowland areas. In that, vegetable crops with short harvesting time, such as mustard, are alsocultivated. Due to the increase in demand for vegetables, local farmers cannot supply to import
vegetables from neighboring countries such as Vietnam, Thailand, etc. These causes urge farmers
to find ways to produce high-yield vegetables. The population is growing rapidly, which is why
food demand is increasing every year. To solve these problems, scientists and technicians have
tried to study new techniques to increase food production to meet daily needs (Nai, 2005).
Many of these foods, such as rice, wheat, corn, beans, sesame, and all kinds of vegetables,
including Chinese mustard is a crucial crop to the people, Cambodian prefer to grow and take it asa vegetable to eat, or take it to cook for food and as supported substances such as protein, vitamins
and other minerals and has been widely grew in all of Cambodia, especially along the river andother provinces. Farmers often grow as small and medium scale to supply families and markets
with no technical limitations to increase yields. As a researcher for Chinese mustard grows welland no pests destroy and get better yields, we have to practice which techniques are relatively easy
to spend little bit and get high yields to apply these techniques to farmers and to make their family
life better (Chanchhaya, 2006).
The Net-house is an installation, which be built with large surface of net that allows plants togrow well and be environmentally-controlled to allow for better plant growth. In addition, the nethouse has many roles: reduce weed, reduce the loss of soil moisture, reduces soil erosion, prevent
sunlight, reduces the damaging as strong winds, increase yield and food safety to reduce soilerosion, and it is easy to harvest crops, use of nets is a good way to reduce the use of pesticides in
the production of vegetable crops (Dany, 2010).
Chinese mustard is a type of vegetable that prefers to grow and eat because it has many
benefits and is a crop that is resistant to hot and rainy those have same to the type of variety. Inaddition, Chinese mustard has no longevity of cultivation, farmers are often grown in vegetablegardens, family or farm produce for marketing in all seasons. Chinese mustard is a leafy vegetablethat can contribute to the nutritional content and can be processed according to the need forcooking, or boiling and mixing with other vegetables or eating raw shoots of young leaves, as wellas pickled mustard. Besides, it can be extracted deliciously and dried so that it can be stored for along time. On the other hand, about 20-30% of Chinese mustard seeds can be refined as cooking oiland good quality (Vanarith, 2005).
OBJECTIVES
The objectives of this experiment were (1) to assess the effects of different shapes of net-houses on
growth and yield of Chinese mustard and (2) to study the economic efficiency of growing Chinesemustard in differently designed net-houses.
METHODOLOGYThe Chinese mustard grown in front faculty of Agricultural Engineering in Royal University ofAgriculture, Cambodia, in two seasons, rainy and dry season during academic year 2016-2017. The
experiment was designed in a randomized block design with selection two models of net use andoutside as Control. There were 3 treatments in this experiment as shown in Table 1 below. For eachtreatment was done in three replicates of which one plot containing 3 m2 (1 m x 3 m) and all plotsof this experiment were 27 m2.

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IJERD – International Journal of Environmental and Rural Development (2018) 9-1Treatment- 1.T1: Opened-type (Control treatment)- 2.T2: Net-house (7 m x 4.50 m x 3.40 m)- 3.T3: Cover-bed net (3 m x 1 m x 1.5 m)

Fig. 1 Net-house

Fig. 2 Covered-bed net
After 12 days of germination stage, Chinese mustard plants were transplanted with a distanceof 0.01 m u 0.01 m between rows and plants, respectively.
The Chinese mustard plant soil was sandy silt, pH 7, humus 0.8, containing total Nitrogen(0.21%), total Phosphorous (0.08%), total Potassium (0.90%), total Carbon (0.156 mil/100 g soil),a C/N of 5, with Organic Matter 0.26% (GDA, 2016). Net-house has installed same size (7 m x
4.50 m x 3.40 m) with three net-house for three replicates on flat land located different places.
Covered-bed net has installed each bed with size (3 m u 1 m u 1.5 m) with three replicates to coveron each bed as well. The white net was used in this experiment and those were used same net for
all net-house with mesh (32*32). For outside, is conventional method that has no covering orControl treatment. Chinese mustard were harvested manually when they had reached proper stage
through cutting root, data collection was determined on number of insects, weight of weed, branchof plants, leaf area, weight per plant, and total weights. On economic analysis was determined ongross profit that took from calculation of total income minus total cost of Chinese mustard
production. Below were some formulas to calculate economic cost in Chinese mustard production.
Formula GP=TI – TC, and
TC=TFC + TVC
Where: GP = Gross profit (US$)
TI = Total income (US$)
TC = Total cost (US$)
TFC = Total fix cost (US$)
TVC = Total variable cost (US$) (Farris et al, 2010).
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Data as subjected to analyze of variance in Statistix 8 app. If interactions were significant, they weused explain the data. If interactions were not significant, means have separated with Tukey test.
RESULTS AND DISCUSSION
The Net-house and outside growing were determined in growth rate to analysis completely, asresult shown that each data in Table 2. In addition, ANOVA determined that Covered-bed, type ofgrowing and their two-way interactions had a significant effect on all measured characteristics ofChinese mustard interaction between different types of growing in net (Table 1).
Table 1 ANOVA table of Net-house Experiment on growing rate and total yield
S.O.V

Mean Square
Treatment
2.00
104.9311686.98
0.82
850.3888.94
1844.26
64.12

Replicate
2.00
0.39
1773.880.14
202.82
13.72
98.98
0.94

d.f
Insects (n/cm2)
Weeds (g)Branch/Plant
Leaf area (cm2)
Plant height (cm)Weight per plant (g)Total weight (t/ha)

Error
4.00
0.56
463.34
0.37
18.38
3.51
58.41
2.02Total
8.00

CV (%)
4.55
23.91
6.11
3.50
7.16
10.89
10.59

Note: S.O.V. = Sources of Variance; d.f. =degree of freedom; CV. = coefficient of variance;ns, ***, **, * non-significant and significant at P≤ 0.001, P≤ 0.01 and P≤ 0.05 respectively

Table 2 Treatment of each replicates of chili yield and total yield characteristics
Treatments

23.28a13.44b
12.67c***186.730.0001
4.55

Total Weigh (t/ha)

T1
T2
T3
Meaning
F-valueP-value
CVInsect(N/cm2)

Weigh ofweed(g)113.6990.0866.27ns
3.64
0.125723.91

Number ofleaf(N/plant)
9.39
10.24
10.33
ns
2.20
0.2268
6.11

Leafarea(cm2)
109.61c116.45b141.58a**46.26
0.00173.50

20Weigh perplant(g/plant)
51.25c61.06b98.25a**31.57
0.0035
10.89

Weigh persquare meter(t/ha)
9.10c
12.90b
18.30a**32.07
0.0034
10.56

18.30
12.90

15
10Plantheight(cm)
20.74c26.19b
31.63a**25.30
0.0054
7.16

9.10

50
Opened-Type

Net-house

Covered-Bed

Fig. 3 Total weight of all treatments in t/ha
For production cost, Chinese mustard production costs have calculated AVERAGE of total
weight per bed with 3 m2 (1 m x 3 m) through first and second season. At first season of Openedtype, Net-house, and Covered-ridge weights per bed are 2.97, 3.87, and 5.49 kg/bed. In the table
was separated costs into 2 types that were fixed cost and variable cost.
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Table 3 Production Cost Analysis on each treatment in dollars ($)
Production cost
Fixed cost (FC)
Irrigated tank(280 L)(5 years)
Water sprayer
Net (Mesh size=32)
Wood posts
Wood barBambooCable
Variable cost (VC)
Land preparation
Seeds or variety
Chemical fertilizer
Water for irrigation
Cow manure
Power tiller renting
Weed cleaning cost
Installation cost
Yields
WeightTotal cost (TC)
Include labor force
Not include labor force
Total income (TI)
ProfitInclude labor force
Not include labor force

FormulaOpened-type

Net house

Covered-ridge

20 $ / 5 years / 4 times / 3 places0.33330.33330.3333

3 $ / 3 years / 8 times
29.40 $ for small and139.93 $ for nethouse (period 5years up and 8times)(9 post x 5 $) / 7 years / 8 times(13 bars x 5 $) /3 years / 8 times / 6 plots
3 $ / 2 years / 8 time
10 $ / 500 m / 8 times

0.375

0.375

0.375

-0.5830

0.735

0.00250.08350.45
0.00250.18750.0025(5 $ / 162 m2) x (1 time)
1 $ / 2 times
40 $ / 50 kg / 5 times(35 days) x 3 L x 2 times x 0.5/1000
2.5 $ / 100 kg / 30 times
2.5 $ / 162 m2 / 1time(5 $ / 27 ridges) x 3 times(10 $ / 27ridges / 6 beds)

0.0102
0.5
0.16
0.105
0.00080.01540.5555-0.0102
0.5
0.16
0.105
0.00080.01540.5555
0.06170.0102
0.5
0.16
0.105
0.00080.01540.5555
0.0617

2.97

3.87

5.49

2.05780.55555.94003.88223.88225.38453.23600.61727.74004.50404.50407.12283.04200.6172
10.9800
7.93807.938010.3628(0.91 kg/m2, 1.29 kg/m2, 1.83 kg/m2) x 3

Price x kg (1 kg = 2 $)Total income (TI) - TC

On the result, number of insects shown that much insects treatment was T1=23.28 N/cm2, andleast insects was T3=12.67 N/cm2 which be used covered-bed net had a significant 0.1% with
CV=4.55% and P-value = 0.0001. For leaf area, the biggest size treatment was T3=141.38 cm2 andthe smallest size treatment was T1= 119.61 cm2 had a significant 1% with CV=3.50% and P-value= 0.0017. In addition, plant height of each treatment had a significant 1% with CV=7.16% and Pvalue = 0.0054 shown that the tallest treatment was T3=31.63 cm and the shortest treatment was
T1=20.74 cm. Also, weight per plant of each treatment had a significant 1% with CV=10.89% andP-value=0.0035, treatment which be heaviest was T3=98.25 g/plant and lightest treatments was
T1=51.25 g/plant. For weight per plant of each treatment had a significant 1% with CV=4.71%,
heaviest treatment of weight per plant was T2=129.85 g per plant and lightest weight per plant was
T0=95.45 g per plant. Furthermore, total weight of all treatments were significant 0.1% with
CV=10.56% and P-value = 0.0034, which be heaviest was T3 = 18.30 t/ha and lightest was T1 =9.10 t/ha. Otherwise, number of leaf and weight of weed were not significant.
Refer to data calculation in Table 3 was shown that income of each treatment are opened-type(US$ 5.94/bed), net house (US$ 7.74/bed), and covered-ridge is US$ 10.98/bed. In addition,
treatment which be more profit is T3 (US$ 7.93/bed), next is net-house (US$ 4.50) and lasttreatment is opened-type got US$ 3.88/bed.
According to compare on the growth rate of Chinese mustard (Table 2), we were recorded onsome data such as plant height, leaf area. ANOVA of these factors had shown that three factor were
not same on some reasons such as soil of experiment plots, closing net-house doors and wind flow.
Total weight had obtained by grower be good thing to get such weight of Chinese mustard, soafter ANOVA Table 2 and total weight of all treatments were significant 0.1% with CV=10.56%
and P-value = 0.0034, which be heaviest was T3 = 18.30 t/ha and lightest was T1 = 9.10 t/ha (Fig.
3). After this research, result observation was proved that some reasons can be good for this study
such as soil moisture on covered-bed treatment. we have observed some frogs and yellow tree frogsⒸ ISERD

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those are nearby covered-bed treatment. According optimal condition of frog lifecycle is shownthat proper humidity to live is 97.80% and temperature is 27.5 0C (Lannoo et al, 2005).
CONCLUSION
For the net-house and outside application in two seasons on Chinese mustard yield be effective andwell than another treatment no need net. It makes Chinese mustard grow well and obtain high yieldas well. Covered-bed application can keep humidity in soil, reduced pest on vegetable, reduce soil
erosion and prevent the crop from heavy rain and insects destroying. And according to the results,
where the criterion for net-house selection and its application rate is based on total yield as total
weight, then the following net regimes can be recommended: T3=18.30 t/ha stand for covered-bed
net-house was obtained highest yield and got highest profit (US$ 7.93 per bed) in this experimentand next suitable was T5=4.50 t/ha with profit was US$ 3.88 per bed.
ACKNOWLEDGEMENTS
It is a great opportunity for me to write about this subject like effectiveness of different net-houseon production yield of Chinese mustard at Royal University of Agriculture (RUA).
I acknowledge with gratitude to leader and leader assistant and Winrock Organization withUSAID, and Feed the Future had supported research fund for Pest Exclusive Net Trial project.
Especially, apart from me, this manuscript will certainly be immense importance for those who areinteresting to know about this subject. I hope they will find it comprehensible.
I have tried hard and soul to gather all relevant documents regarding this subject. I do notknow how far I am able to do that. Furthermore, I do not claim all the information in thismanuscript is included perfectly. There may be shortcoming, factual error, mistaken opinion which
are all mine and I alone am responsible for those but I will try to give a better volume in future.
REFERENCES
Chanchhaya, K., 2006. The comparison of organic fertilizers on Chinese mustard at crop station in Royal
University of Agriculture, Cambodia. Royal University of Agriculture, Cambodia.
Dany, H., 2010. The comparison of four different Chinese kales in net-house, Royal University ofAgriculture, Cambodia.
Farris, P.W., Neil T., Bendle, P.E., Pfeifer., D.J. and Reibstein, 2010. The definitive guide to measuringmarketing performance, Upper saddle river, New Jersey, Person Education Inc, ISBN 0-13-705829-2.
Lannoo, M.J. 2005. The conservation status of the United States species. Berkeley and Los Angeles,California, University of California Press, ISBN 0-520-23592-4, 463-465.
MAFF Cambodia. 2016. Soil analysis results in the national agriculture laboratory. General Directorate ofAgriculture (GDA), Lab. ID 12/16, MAFF, Cambodia.
Nai, K. 2005. The efficiency of liquid compost fertilizers on Chinese mustard in Royal University ofAgriculture, Cambodia. Royal University of Agriculture, Cambodia.
Vanarith, K., 2005. The comparison of compost fertilizer on Chinese mustard growth rate at Royal
University of Agriculture. Cambodia. Royal University of Agriculture, Cambodia.

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