IJERD – International Journal of Environmental and Rural Development (2012) 3-2

Research article
erd

Validated Rice Cultivars for Rice-Based Systems of theNorthern Mountainous Region, Lao PDR
KHAMDOK SONGIYKHANGSUTHOR*
Northern Agriculture and Forestry Research Center (NAFReC), Luang Prabang province,
Lao PDR
Email: khamdoks@yahoo.com and khamdok.s@gmail.com

HOUMCHITSAVATH SODARAKNorthern Agriculture and Forestry Research Center, Luang Prabang province, Lao PDR

KOUANG DOUANGSILA
National Rice Research Program, Vientiane, Lao PDR

BENJAMIN K. SAMSONInternational Rice Research Institute (IRRI), Lao PDR
Received 14 December 2011

Accepted 2 April 2012(*: Corresponding Author)

Abstracts This study aimed to identify and evaluate appropriate introduced and improved
sloping upland rice cultivars for the northern region of Lao PDR (Bokeo, Houphanh, Luangnamtha, Luangprabang, Oudomxai, Phongsaly, Sayabuly, and Xiengkhuang). The
study was designed to detect genotype by environment for seven cultivars: 1) Makhinsoung, 2) Nok, 3) Non, 4) Laboun, 5) IR55423-1, 6) B6144F-MR-6 and 7) IR6008046A  in  the  farmer’s  field  with  farmer  practices  and  farmer’s  preferences  analysis.  The  results showed that both introduced and improved rice varieties consistently produced higher
grain yield compared to local varieties, from 157 to 381 kg/ha over years that the experiments were conducted. Local varieties yielded an average of 1700 kg/ha. Most of the varieties were suitable for Oudomxai, Sayabuly and Xiengkhuang provinces. Some varieties
were specifically appropriate for some provinces: Non (Bokeo), IR60080-46A (Houaphanh and Luangnamtha). Yield data of all tested varieties were generally significantly
different from that of local variety. However, grain yield differences of entries in Luangprabang and Phongsaly were not significant, but almost all the entries cultivars produced more grain than local checks.
Keywords plant characteristics, rice cultivar validation, northern mountainous and uplandcultivation

INTRODUCTION
Rice is the primary staple crop of Lao PDR. It accounts for 70% of the diet and supplies about 70%
of caloric requirement. Among Lao people, rice self-sufficiency is equated to food self-sufficiency(Linquist et al., 2007). Laos achieved rice self-sufficiency in 1999; upland farmers and households
are still rice-deficient.
The uplands of Lao PDR are located in northern part of the country and along the LaosVietnamese border in the central and southern regions. The northern uplands form the largest upland environment in Lao PDR, comprising seven, out of eighteen provinces that make up the wholeof Laos. It is predominantly mountainous, but there are a number of minor plains and numerous flat
intermountain basins and narrow river valleys where water is available year-round, allowing for
full or partial irrigated agriculture. Upland farmers grow rice in the intermountain basin, and rivervalleys as transplanted wetland or lowland paddy rice, and on the sloping uplands as direct-seededⒸISERD140

IJERD – International Journal of Environmental and Rural Development (2012) 3-2

upland rice. The uplands also provide a range of agro-ecological environments that enable farmers
to grow cash crops, paper mulberry, cassava, and beans, among other crops.
Surveys of upland households show that livelihoods are overwhelmingly agricultural in nature.
Farmers with more lowland had better food security than farmers who raised their crops purely on
upland sloping environments. Seventy three percent of households reported at least 1 year of ricedeficiency in 10 years (1995-2005). In contrast, only 17% of households with lowland reported atleast one year of rice deficiency during the same period.
The major constraints to improve rice production in the uplands are low productivity of rice
varieties, lack of high quality seeds and livestock diseases, inadequate extension services, limitedaccess to public services and advanced technologies, poorly developed transport, irrigation andmarketing infrastructures (Roder, 2001).
This paper aims to describe the process and results of a long-term effort to evaluate and identify appropriate rice germplasm for the uplands of Lao PDR through multi-environment yield trials.
METHODOLOGY
Multi-environment   yield   trials   were   conducted   on   farmers’   fields,   with   farmer   participation,   in  eight provinces of the northern region of Lao PDR: Sayabuly, LuangPrabang, Oudomxai, LuangNamtha, Bokeo, Phongsaly, Houaphanh, and Xiengkhuang. The field research sites were selected
to represent the northern region of Lao PDR. Oudomxai and Sayabuly provinces had more farmer
participants from 2005 to 2009. Elevation of field sites ranged from 300m to 1300m. Fields wereselected to be representative of upland environments.
Seven lines and cultivars were used in the trials. Laboun, Non, Nok, and Makhinsoung are
traditional cultivars which have been identified from a series of screening trials to perform wellunder a range of upland conditions. These cultivars have been purified so that each variety is distinctive, recognizable and produce uniform crop stands in the field. IR55423-1, B6144F-MR-6,
IR60080-46A are improved, stable, non-glutinous rice lines which perform well in upland environments. Seeds were direct-seeded on dry soil. Crops were managed according to local practice.
Neither fertilizer nor other agricultural chemicals were used on the crop. At the time of harvest,
crop cuts were taken to determine grain production of the lines and cultivars. Data from 2003 to2009 were included in the analysis. Data were tabulated and graphically evaluated.
Preference analyses by farmers were conducted prior to harvest. Farmers were asked to identify the reasons why they liked or disliked particular varieties. These data were tabulated and graphically evaluated.
RESULTS
Table 1 shows the mean grain yield of seven rice cultivars in eight northern Lao PDR provinces.
Under farmer management practices, grain yields of test cultivars were significantly better thanthose of local check varieties. Yield advantage of rice lines and selected and purified glutinous
landrace varieties ranged from 157-381 kg/ha (9-22%). Improved non-glutinous varieties (IR55423-1, B 6144F-MR-6, IR 60080-46A) produced 167-334 kg/ha (10-20%) more grain than local
checks. Selected and purified traditional cultivars (Laboun, Non, Nok, and Makhinsoung) produced
157-381 kg/ha (9-22%) more grain than checks.
Sites where the trials were conducted were significantly different in mean rice production
across the years examined (Table 2). Bokeo had the highest mean annual rice production (2,309 kg/ha) among eight provinces, while Phongsaly and Xiengkuang had the lowest (1,615 kg/ha).
Table 2 also shows that mean rice production, across sites, was more than 1,800 kg/ha from2003 to 2007. Production declined in 2008 and 2009. The trend of production is shown in Figure 1.
IR60080-46A  exhibited  the  best  yields  in  2003  and  2004,  during  the  “good”  years  for rice production. However, B6144F-MR-6 did best in 2006 and 2008. Laboun performed best in 2005, 2007
and 2009. These observations may indicate that these lines and cultivars are highly adaptable toboth  “good”  and  “bad”  rice  growing  years.
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Table 1 Mean grain yield of seven test lines and cultivars and their yield advantage
over local varieties
Varieties

Grain yield (kg/ha)

LabounNon
IR60080-46A
B6144F-MR-6
Nok
IR55423-1
Makhinsoung
Local
SE(N= 9)5%LSD 780DF
PR>F

2080
2038
2034
2017
1887
1867
1857
1700

Grain yield advantage (kg/ha)

Grain yield advantage (%)

381
339
334
318
188
167
157
0

122
120
120
119
111
110
109
100

a
ab
ab
ab
abc
bc
bc
c
76
210
0.0001

Table 2 Mean annual rice grain yield in eight northern Lao PDR provinces
Provinces
Luangprabang
Oudomxai
Houphanh
Luangnamtha
Phongsaly
Sayabuly
XiengKuang
Bokeo
Mean (kg)SE(N=99)
5%LSD 780DF
PR>F

2003

2004

1908
2239
1311
1783
1843
1886
2627
1942
187
518
0.000

2037
1861
1830
1351
2784
1497
2810
2024

Annual grain yield (kg/ha)
2005
2006
2007
1995
1604
1941
2035
1860
2720
1383
1523
1883

Grain yield (kg/ha)

3,000

2,500

2036
1336
2184
1341
2712
2128
1693
1919

1663
2881
1615
1957
2893
2202

2008

2009

1407
1057
1232

1610
1771
1467
1313
1187
1469

B6144F-MR-6
IR60080-46A
Local
Nok

IR55423-1
Laboun
Makhinsoung
Non

2006

2008

Mean (kg)
1808
1821
1913
1695
1615
2275
1616
2309
1882

2,000

1,500

1,000
2003

2004

2005

2007

2009

Fig. 1 Grain yield of seven rice lines and cultivars over seven years,
averaged across sites
Rice lines and cultivars performed well in Oudomxai, Sayabuly and Xiengkhuang provinces(Table 3). Some varieties performed well in specific provinces, such as Non in Bokeo province,
and IR60080-46A in Houphanh and Luangnamtha. However, none of varieties stood out in termsof grain production in Luangprabang and Phongsaly provinces. Almost all lines and cultivars in thetest set, except Makhinsoung, and the checks produced more than 2,000 kg/ha in Sayabuly province sites.
Fig. 2 gives a human dimension to the grain yield data. The graphic summarizes farmer opinions and comments on traits that they liked and disliked about the lines and cultivars in the test set.
Large panicles, big-sized grain and strong culms were the most commonly referred to positive
characteristics. Farmers did not like cultivar that produced few tillers, short and non-uniform panicles.
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Itchy seed

Few leaves

Non-uniform plant

Weed competitivenessMany leaves

Resistant to lodging

Few grain

Rapid emergence

Late duration

Positive plant characteristic

Negative plant characteristic

IJERD – International Journal of Environmental and Rural Development (2012) 3-2

Susceptible to pests
Non-uniform ripening
Growth in some soil
Poor emergence
Sterile spikelets
Small stem

Many panicle
Grows in any soil
Uniform panicle
Uniform plant height
T all plant
Early duration
More tiller

Small grain

Many grains

Non-uniform panicle

Strong stem

Short panicle

Large grain

Few tiller

Large panicle

0

5

10

15

20

25

30

35

0

40

10

20

30

40

50

60

70

80

Number of times mentioned by farmers

Number of times mentioned by farmers

Fig. 2 Positive and negative plant characteristics most mentioned by farmers
Table 3 Grain yield of rice lines and cultivars in eight northern Lao PDR provinces
Varieties

Bokeo

Houa
phanh

Luang
namthaLuang
prabangOudom
xai

Phongsaly

SayabulyXiengkhuang

B6144F-MR-6
IR55423-1
IR60080-46A
Local
Laboun
Makhinsoung
Nok
Non
SE(N=12)
5%LSD 724DF
PR>F

1710
1706
1720
1704
1688
1789
1380
2478

1659
1974
3577
1934
1954
2148
1951
1953

1887
1789
2276
1686
1807
1817
1638
1683

1814
1753
1828
1668
2040
1697
1881
1993

2511
1508
2913
1456
2680
2108
2074
2040

1458
1091
1628
1627
1470
2052
1086
2028

3748
3595
4496
2251
3160
1761
2108
2072

2233
1344
2133
1524
2294
2366
2700
1928

205
570
0.0000

Based on the preferences of farmers, six (Nok, Makhinsoung, Laboun, Non, IR55423-1 andB6144F-MR-6) were propagated. Production of seeds for distribution to farmers was ramped up
from 2005 to 2009 (Table 4). Makhinsoung and Nok distribution to farmers was more than 2 and 3
tons, respectively, in 2009. B6144F-MR-6 distribution peaked at 2 tons in 2007.
Table 4 Amount of rice seed distributed (kg) from 2005 to 2009
Varieties
Nok
Makhinsoung
LabounNon
IR55423-1
B6144F-MR-6
Total

2005

Seeds distribution in each year (kg)
2006
2007
2008

30
20
20
20
5
10
105

230
100
250
30
20
800
1430

220
200
250
30
2000
2700

2585
1079
340
70
50
25
4149

2009
3317
2207
1145
527
163
165
7524

The number of farmers planting the lines and cultivars, and the amount of seeds they used aresummarized in Table 5. There was a steady increase in number of farmers planting the lines andcultivars and the amount of seeds that they used, except for IR55423-1. By 2008, fifty farmers were
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using Non and Nok, but larger amounts of seeds were being used by farmers using Nok, perhaps
implying that larger areas of land were being sown to his cultivar. The number of farmers tryingout B6144F-MR-6 increased to 70 by 2008 but the amount of seed used was static from 2008 to2009 at about 900 kg. This probably means that more farmers were trying out the line, but steadyuptake was not yet occurring for this rice line. It is worth noting that these data are limited to thefarmers and farm households that could be tracked by the researchers and does not include unreported seed exchanges and sales.
Table 5 Number of farmers planting selected rice lines and cultivars andamount of seed used from 2006 to 2008
Variety
Nok
Makhinsoung
LabounNon
IR55423-1
B6144F-MR-6

Farmers
5
5
5
5
5
5

2006

2007

Amount of seed
(kg)
2.5
2.5
2.5
2.5
2.5
2.5

Amount of seed
(kg)
220
200
100
100
30
900

Farmers
8
7
10
4
2
50

2008
Farmers
50
27
20
50
3
70

Amount of seed
(kg)
2585
1079
800
450
50
850

DISCUSSION
Results showed that both introduced lines, and selected / purified landraces performed better, under
the same environmental conditions, as local varieties (Asai et al., 2009). However, other reported
that only the improved rice germplasm produced higher yields in both low and high fertility conditions over a number of locations (Saito et al., 2007). The average grain yield of the test lines andcultivars was higher than that of the local varieties in all sites. This supports the findings (Atlin etal., 2006). Higher productivity may be due to high sink size of improved lines and selected/purified
landraces, manifested by their larger panicle number per unit area. Panicle number has been reported to be an essential trait for high grain yield in low as well as high soil fertile uplands in Asia andWest Africa (Saito and Futakuchi, 2009). Poor adaptation of tropical japonica rice genotypes to low
soil fertility conditions may be the result of reduced sink size and grain-filling percentage.
Our results suggest that improved indica rice and selected/purified traditional rice cultivars
can improve productivity without addition of fertilizer, even in low soil fertility conditions (short
fallow cycle). This finding is significant and important for resource-poor farmers, who have faceddifficulty in maintaining rice productivity in short-fallow slash-and-burn systems in northern Laos.
Other reasons for those select/purified traditional rice cultivars were preferred and adopted in large
areas by Laos farmers, because they were glutinous rice and big-sized  grain.  And  most  of  Laos’s  farmers preferred glutinous cultivars than non-glutinous cultivars.
The use of these genotypes should only be seen as a component for improving upland ricebased cropping systems since continuous rice cropping with such high-yielding genotypes can leadto a greater nutrient withdrawal from the soils as well as a more rapid decline of soil organic carbon
in upland conditions (Saito et al., 2006b; Asai et al., 2007). Therefore, integrated soil fertility management practices need to be developed for effective use of sustainable rice production.
CONCLUSIONSThis paper showed that indica and tropical japonica rice genotypes differed in yield response to soil
fertility conditions under rainfed uplands in northern Laos. Grain yield of rice genotypes were notstable across low and high soil fertility conditions. Grain yield of introduced improved rice lines,
and selected/purified cultivated varieties were generally significantly better than local varieties.

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