Mr Farrell attended the international conference on, "The Impact of Agricultural Research for Development in Southeast Asia", in Phnom Penh, Cambodia, October 24-26, 2000. The conference included 200 participants, with the majority coming from Cambodia, Laos, Philippines (IRRI), Thailand, Vietnam and Australia. Mr Farrell's attendance at the conference was valuable for international interaction on very relevant areas of research on cold tolerance and soil fertility.
Mr Farrell then participated in an ACIAR workshop on, "Productivity of Lowland Rice in Southeast Asia -Overcoming Environmental Constraints", in Vientiane, Laos, from October 30th to November 1st. The workshop included approximately 100 scientists primarily from Laos, Cambodia, IRRI and Australia. During this visit he made contact with a number of rice scientists working in three key areas of research including drought tolerance, cold tolerance and soil fertility.
The specific aim of attending this conference was to participate as a scientist in the CARDI conference and the ACIAR workshop.
Mr Farrell attended the conference on, "The Impact of Agricultural Research for Development in Southeast Asia" and an ACIAR workshop on, "Productivity of Lowland Rice in Southeast Asia -Overcoming Environmental Constraints" October 24- November 1, 2000.
Cambodia has a population of approximately 12 million, with 80% of people located in rural areas. Poverty is a major problem, related to poor education levels, low incomes and landlessness. Cambodia is still in a rebuilding phase following the rule of Pol Pot and the Khmer Rouge. Agriculture has been identified as the first priority in Government policy, and this has led to the establishment of Cambodian Agricultural Research and Development Institute (CARDI) in August, 1999. CARDI is a semi-autonomous institution working with stakeholders to improve the living standards of all Cambodia's people, especially farmers, through agricultural research, training and technology transfer. Agricultural production in Cambodia contributes 40% of the GNP. However, Cambodia's economy is still weak compared to other southeast Asian countries. Cambodia was an exporter of rice until the late 60's and has been in a food deficit for the past three decades. Returns from agriculture are primarily derived from rice (3000 tonnes of rice produced in 2000) and, to a lesser extent, corn, beans, fisheries and livestock. Mem Sarom, the director of CARDI is confident that "there are opportunities for increased production in Cambodia".
Vietnam has significantly increased its rice productivity in the past 20 years and has become a model for countries such as Cambodia and Laos to follow. Two major reasons for increases in Vietnam's yield are increases in government funding and support, and collaboration with IRRI and developed countries (eg China) in the advance of hybrid rice production. Vietnamese scientists attended the international conference at Phnom Penh and offered the CARDI continued support in the drive for rice productivity and sustainability.
Agricultural research in Cambodia is targeting:
Constraints to rice production in Cambodia include:
Drought and flood are the key constraints to rice production in Cambodia. Depending on the region, drought or flood is the major limitation to yield. Floods can occur in the uplands as well as the lowlands, due to heavy rainfall in the mountains. There is a need to characterise the extent of both drought and flooding. Drought can occur any time during the growing season. In 1998 there was a very long drought, with 30-40% of the crops under threat, but late rains resulted in reasonable yields. Droughts generally occur every year, with early and late season drought the most common. Drought can completely damage seedlings, which may result in a delay in transplanting. Late-season drought begins in November and there has been a shift from late to medium varieties to escape from end-of-season drought.
The population of Laos is 5 million. Rice is the most important crop in the Lao PDR, accounting for 86% of the cropped land. The rice area in Laos is 650,000 ha, producing average yields of 2.7 t/ha, with the highest yields reaching 4 t/ha. Currently 84% of all rice grown in Laos (85% of total production is glutinous) is consumed by producers. Historically, the majority of rice production in Laos has been produced during the wet season as upland and lowland crops. With the advent of irrigation, rice production in the dry season has increased from 13,600ha in 1995 to 87,000ha in 1999 (NAFRI, 2000). The wet season crop is transplanted into the field in June and harvested in October, while the dry season crop is transplanted between November and January and harvested in May. Additionally, the Lao PDR is divided into the northern, central and southern regions, each having different temperature regimes due to variations in altitude and latitude. Laos has a distinct wet and dry season. Of the rice produced in Laos in 1998, the rainfed lowlands accounted for 74%, the rainfed uplands 13% and 13% was irrigated (IRRI 1999). The total rice yield in the Lao PDR was around 2.1 million tonnes in 1999, and this has made the country self-sufficient. Over the past two decades the total harvest has doubled. Most of this increase has come from the rainy lowland environment, more than doubling from 705,000 tonnes in 1980 to 1.5 million tonnes last year. The long-term aim for Laos rice production is to reduce the area of rainfed upland rice and increase irrigated rice. Almost all of the rice in Laos is transplanted by hand and harvested by non-mechanised methods.
Rice is the single most important crop in Laos. The unpredictable nature of environmental conditions is the major problem for agricultural production in Laos and throughout the world. There is a wide variety of ongoing research, including:
The Lao workshop coincided with the commencement of a new ACIAR rice project, Increased production of rice-based cropping systems in Lao PDR, Cambodia, and Australia, which is being run by the University of Queensland. Other participating organisations include:
There were approximately 100 delegates representing 10 countries. The workshop included presentations by scientists from Laos, Australia, Japan, Korea, Cambodia, Thailand and the Philippines. The workshop consisted of six sections in addition to the opening and discussion session, in which a description of the new ACIAR Rice Project in Lao PDR and Cambodia was given.
The 5 sub-projects of the ACIAR Rice Project 99-048 include:
The major goal of the ACIAR project is to increase the productivity of the rice-based cropping systems in Lao PDR, Cambodia and Australia through:
The objectives of the workshop include:
"Alongside this research, CARDI has helped to build research capacity by teaching and training Lao personnel," said Agriculture and Forestry Minister Dr Siene Saphangthong in his opening address. The wet-season lowlands will continue to produce most rice for the foreseeable future. Higher yields and reduced year-to-year yield variability can be expected with further intensification of lowland production systems. Further production improvement will depend on higher inputs and further alleviation of production constraints. The uplands will become less important for rice as alternative, more sustainable technologies are developed to replace the "slash-and-burn" shifting cultivation.
Minister Siene Saphangthong said: "The current national socio-economic development plan stresses agro-forestry expansion and development, linking this to the processing and services industries. In this way, we are attempting to change from nature dependency production to commodity production. Nevertheless, rice remains important for Lao people. We are
striving to produce at least enough rice for domestic consumption, and if possible we hope to have a rice surplus in case of natural disaster.
"Each year, unfavourable events like drought, flood and pests damage 100,000 ha of our crops (some 20 per cent of the rice area). One solution is to switch from semi-dependency on nature to use of modern technology appropriate for Laos, switching from small and scattered production to a market commodity production approach," he added.
Dr Siene Saphangthong said that in the past five years, the Lao government has been addressing foodstuff security by expanding irrigation for agriculture. To date, some 20 per cent of farmland are irrigated, but intensive farming techniques have not been applied as much as it should have been.
"Research into and experiments on seeds are important priorities. At the same time, attention has been paid to adapting appropriate technology and mechanisation to increase the production cycles. In the past year, northern Laos experienced unusually cold weather, which affected some agricultural production and animal husbandry. If we introduce an appropriate scientific approach to farming, coupled with local expertise and support from international institutions, we believe that some time in the future, we will be able to overcome food shortages in our country," the Minister concluded.
The Lao government is set on increasing agricultural production to achieve food self-sufficiency in the short term, and to export food in the long-term. This calls for construction of hydraulic works for irrigation and drainage as soon as possible, which is why this project plays an important role in economic development and national security not only for the Vientiane province and municipality, but for the whole country.
The ACIAR project focuses on the development of plant breeding strategies for rainfed lowland rice, but also addresses other important issues associated with productivity of rice-based cropping systems in Laos and Cambodia. These issues include the development of sound direct seeding technology, intensification of rice-based cropping systems, agroecological characterisation of environments for increased crop production, and minimising constraints for dry season irrigated rice production. The main objective of the workshop was to exchange available information that would assist development of rice-based cropping systems in Southeast Asia, particularly in the Lao PDR and Cambodia. The workshop focused on:
The three major areas of research included the impact of drought, the impact of low temperature, and low soil fertility. The workshop also provided information on the new ACIAR project, and the project partners encouraged feedback on the project from the workshop participants. There was an opportunity to visit ACIAR, NAFRI, and Lao-IRRI experiments following the workshop.
This section included papers on the current rice production systems in Laos and Cambodia and highlighted the limitations and environmental constraints to present systems. The problem of low soil fertility and fertiliser requirements was included in this section. Examples from the neighbouring countries of Thailand and Vietnam were also included. A major objective was to determine the benefit and risks associated with various rice-based double cropping systems. Methods need to be developed to determine the probability of success of double cropping, and to estimate the water balance components in different environments. Insect pests (gall midge and brown plant hopper), rodents, weeds and disease (eg brown spot) provide major constraints to rice production. There are many constraints to rice production systems in southeast Asia that researchers are attempting to alleviate, minimise or manage (Tables 1 and 2).
The magnitude of constraints to rice production systems in Cambodia, Laos And Thailand
Types of constraints |
Magnitude | ||
Cambodia |
Laos |
Thailand | |
N |
all soils |
most soils |
most soils |
P |
most low in P |
most soils |
most soils |
K |
sandy soils / not used |
20-30% soils |
sandy soils |
S |
sandy soils |
20-30% soils |
sandy soils |
Fertiliser quality |
erratic |
OK |
OK |
Bronzing |
sandy stagnant water |
sandy stagnant water |
? |
Sandy soils |
10% poor fert response |
limited |
extensive |
Microtopography |
most areas |
most areas |
most areas |
Wetting and drying |
most soils |
most soils |
most soils |
Al toxicity |
acid soils 5% of soils |
? |
? |
Low fertiliser use |
low income |
low income |
low income |
Straw removal |
most farms |
most farms |
most farms |
Fertiliser response |
variable |
mod-consistent |
poor |
The management options, cultivars and future research to counter major constraints to rice production
Types of constraints |
Management options |
Cultivars |
Future research |
N |
fertiliser, balanced nutrients, K fertility residue mgt, GM |
breeding |
long term cropping systems research on nutrient cycling |
P | |||
K | |||
S | |||
Fertiliser quality |
regulations |
NA |
NA |
Bronzing |
K, varieties |
breeding |
identify cause |
Sandy soils |
regular OM |
alternative use? | |
Microtopography |
site specific fertiliser |
breeding |
nutrient x water interactions |
Wetting and drying |
risk magt | ||
Al toxicity |
straw, varieties |
breeding |
role of OM |
OM available |
residue, FYM |
? |
role of OM |
Low fertiliser use |
tactical use |
efficient cultivars |
Optimise efficiency |
Straw removal |
collect FYM, alt feeds |
||
Fertiliser response |
efficient cultivars |
efficient cultivars |
water x nutrient interaactions, roots, OM |
Other management options include:
Some ways to develop adapted cultivars for poor soil conditions include:
Future research is required, including
generic:
Fifteen papers on water and drought tolerance were presented. Genetic, physiological, agronomic and breeding approaches to combating drought in Laos, Thailand, Cambodia and Indonesia were discussed in these papers. A number of papers on statistical approaches to genotype by environment (GxE) interaction were also presented.
This section examines the drought problems and technologies available to minimise the effect of water shortages. The main emphasis in this section was to characterise the pattern of drought development in rainfed lowland rice and to consider how drought resistant cultivars may be developed.
Drought is the major environmental constraint to rice production in Laos. Variety selection and avoidance will contribute to reducing the losses related to drought. Grienggrai Pantuwan highlighted the potential successes of screening for drought tolerance in Thailand. He has found that tall varieties stress more during drought. He also discovered that a large root system is a disadvantage during a short severe drought. Greengrai is successfully screening 1200 lines each year. Leaf yellowing is highly correlated with drought tolerance and growers have had good success with drought escape.
Laos
In 1993, experiments were undertaken to study drought in Laos. The occurrence and timing of drought is variable, with droughts occurring during the early-season (2 in 8 years), the late-season (4 in 8 years) and sometimes no drought occurring (2 in 8 years). Early-season drought is a problem when there is not enough standing water for transplanting. Late-season drought is a problem in some provinces such as Vientiane and Savenekhet. Approximately 100,000 ha of rainfed area are affected by drought. Average yields are approximately 1 t/ha, ranging from 0 to 2 t/ha. Therefore, drought can reduce yield by more than 1 t/ha. Direct seeding in Vientiane is becoming more important because it requires less labour.
Thailand
In Northeast Thailand approximately one million hectares (56.4% of the area) is drought-prone. Bi-model rainfall patterns exist in northeast Thailand. Early and late season drought are common. Direct seeding of rice is sometimes adopted to escape end of season drought. Less labour is required for direct seeding which also assists in improved midge resistance. Direct seeding of rice is soil and season dependent. A new breeding method for Thailand has been recently established which estimates genotype by environment interactions using multi-location trials. Environmental characterisation has enabled the use of water balance for estimation of drought patterns. Thailand breeders are successfully improving drought tolerance by wet season direct screening using yield.
Management options for combating drought have been identified and recommendations and observations include:
Screening for drought tolerance in Laos (Vientiane, Savenelkhat) include:
Multi-environment trials to identify genotype by environment interactions have been established involving:
In this section, low temperature problems in rice were examined. This included a review of the present understanding of the effect on yield of low temperature during the establishment and reproductive phases. Examples of experiences in minimising the low temperature problem were given. Genotypic variation in low temperature tolerance was also reviewed. Results of recent work in identifying low temperature problems in Laos were also presented.
There has been a 7.6-fold increase in yield from dry season lowland irrigated areas over the past decade (41 000 tonnes in 1990, 354 000 tonnes in 1999). Now there are plans for the development of further small-scale irrigation schemes to achieve a total dry season irrigated area of around 180 000 ha by 2005. Increasing productivity of dry season irrigated rice is a major objective of the ACIAR project. This can only be done by first identifying the climatic constraints and cultivar requirements of low temperature tolerance and high yield in the dry season in Laos. This includes an investigation of mechanisms for genotypic adaptation to low temperature and determining the magnitude of GxE interaction across seasons and countries.
Dr Moon He Lee, a rice physiologist, showed the success of the low temperature screening in Korea. Wind (including typhoons) is also a major problem in Korea. The expected yield is approximately 5 t/ha, but can be reduced dramatically by wind damage. In 1993, 10% or the rice area was damaged, reducing the yield to 4.2 t/ha. In 1980, the yield was nearly halved to 2.8 t/ha when 80% of the rice area was damaged by wind. However, the Korean physiologists have had good success with outstations in cooler areas. Dr Lee highlighted the impact of cooler temperatures at the vegetative stage including the inhibition of rooting, growth and tillering as well as delayed panicle initiation. He summarised the impacts of low temperature on reproductive growth including inhibited panicle development, degeneration of spikelets, disturbed meiosis and pollen formation and delayed heading. He confirmed that the critical microspore stage occurred 10 days before heading which is similar to what Mr Farrell has found in Australia. They have had success screening at 23/10oC for 10 days at reproductive development.
One of the major limitations to current rice practices in Laos is that the traditional varieties have a duration that is too long for double cropping (170 days). Currently the magnitude of low temperature stress is large affecting:
Avoiding the risk to encounter sub-optimal temperature is a shortcut some countries like Japan have used for establishing a stable cultivation system. Upon avoiding the extreme temperatures as much as possible, improving the level of tolerance needs to be considered. To avoid the risk of cold damage, selection of adequate varieties and planting time is imperative. Protecting the nursery at the seedling stage and in the main paddy from cooler conditions is the key to improved establishment and vegetative growth. For example, there were some lessons to be learned from the Japanese experience based on multi-location testing. Average air temperature requirements at transplanting varied between the different types of nurseries, such as upland nursery with vinyl cover (13.5-14oC) and semi-irrigated nursery with vinyl cover (14-15oC). Japanese researchers have also found seedlings that have a higher content of nitrogen and starch show faster rooting in the main paddy. Seedlings transplanted at 5-6th leaf stage have shown the best performance in cooler climates of Japan.
Increasing water temperatures (by using a warming pond, canal or plastic tubes) may assist growers to improve growth. Increasing water depth at the critical reproductive stage will provide warmth to the developing panicle. It is vital for researchers to get an improved understanding of the thermal conditions to identify potential risks. It is important to establish the nursery system to compare different types of protected nursery and conventional nursery. Efforts need to be made in exploring the adequate time of planting in combination with phenology of the cultivars (by means of cropping season experiments and the crop growth model). Breeding effort for suitable phenology (90-130 days) is the first priority. Screening varieties for tolerance to low temperatures at the vegetative stage is vital, and may include using cool water screening of genotypes from INGER and southeast Asia. Screening varieties for tolerance at the reproductive stage is important for some provinces (eg, Oudomxay).
Low temperature problems in rice is a shared problem throughout the world and researchers in this area from Northern Laos, Australia, Korea and Japan were represented. Cold tolerant cultivars are required for northern areas of Laos. Mr Farrell had previously sent approximately ten varieties including cold tolerant cultivars that he had identified in recent glasshouse experiments. These varieties will assist researchers and breeders to develop cultivars adapted to dry season rice production in Northern Laos. Researchers were given the opportunity to discuss best agronomic practices.
Breeding strategies for sub-optimum conditions were examined in this section, including presentations on the description of rice breeding programs in Laos and Cambodia, as well as a description of irrigated conditions highlighting the challenges for the future. Breeding strategies in rainfed lowland rice in Thailand were also included. Experimental work to examine genotype and environment interaction in rainfed lowland rice was presented, and possible modifications to the Lao and Cambodian programs were also discussed.
This last presentation section examines methods of integrating information using GIS and simulation models. Experiences in Thailand and other countries were also presented as a model for Laos. The success of applying these techniques in Laos and Cambodia was also presented
On-farm level micro-ecology is important to capture the large variability in water and nutrient availability. Application of GIS technology to agroeceological map development is important to assist the integration of environmental information. Collecting reliable data in Laos and in neighbouring countries is vital for the success of agroecological characterisation, which will contribute to the development of sound cultural practices and breeding program.
The Australian Centre for International Agricultural Research (ACIAR) and the International Rice Research Institute (IRRI) presented a summary of different production systems and possible solutions for increasing rice productivity, which will contribute to addressing food shortages. The Lao Ministry has been working with ACIAR, and the results have enabled them to draw up a rice production development plan for food production in the Lao PDR.
This discussion section helped to consider the application of the knowledge, experience and skills available to us to minimise environmental constraints on production of rice based cropping systems in Laos, Cambodia and neighbouring countries. Recommendations were made to scientists in Laos and Cambodia on their future research activities.
The production systems in Laos, Cambodia and Thailand are similar in having large areas of rainfed lowland rice, low population density, subsistence agricultural and major problems relating to drought, low soil fertility and floods. However there is a unique nature of rice production in each country, with recession rice in Cambodia, irrigated rice in Laos and rice of good grain quality in Thailand
The ACIAR international workshop contributed to understanding the productions systems in Laos, specifically the rainfed lowland and irrigated dry season rice environments. Laos has many similarities to Cambodia and Thailand with extensive lowland rice, low population density and subsistence agriculture. They share common constraints to rice production (primarily drought, low soil fertility and flooding). Low temperature problems in rice are a shared problem throughout the world, including areas such as Northern Laos, Australia, Korea and Japan. Agro-ecological characterisation will contribute to an improved understanding of the environment in Laos. Breeding strategies for stress environments (eg drought, low soil fertility, and low temperature) need to be implemented to improve the productivity of rice growing in Laos and other southeast Asian countries. Improvement to production systems depends on the success of scientific research, of technology transfer and of international cooperation.
Technology transfer is vital to improvements to rice productivity throughout southeast Asia. In Laos, improved nursery protection from low temperatures is vital to superior establishment growth. Also, screening against drought in rainfed lowlands is crucial to variety development. Direct seeding technology (including land levelling) and wet seeding research needs to be delivered to growers. Germplasm transfer and evaluation is vital to reducing environmental constraints to rice production. The INGER network contributes to the ease of international germplasm exchange. Exchanging promising lines between Laos, Australia, IRRI and Cambodia is underway.
