SE Asia

Lower costs and favorable environmental effects when using paraquat: these were the key conclusions from a four-year comparison of weed control methods in bananas, recently completed by the University of the Philippines.
The trial was conducted on a commercial plantation on Mindanao, the large southern island of the country. Bananas make a significant contribution to the economy of the Philippines being a major fruit export. New plantations are being established on more sloping land where soil erosion poses a real threat to sustainable production. Filipino authorities estimate that 623 million tonnes of soil are lost annually from 28 million hectares of land.
Erosion can be reduced by maintaining a vegetative cover on the soil. So, it is important to manage weeds so that they give as much cover as possible to help avoid erosion, but not to allow them to compete with the crop. Two weed control programs were compared. In the field trial, traditional methods of hand weeding and slashing with a machete called a bolo were compared to a monthly spray program in a sequence of two applications of paraquat followed by one of glyphosate. In the latter two years of the trial, these regimes were modified to match changing patterns of weed growth, and weeds were controlled only by paraquat when a threshold of 30% ground cover was breached.
“Time and tide wait for no man”, so they say. Rice farmers living in coastal areas of South Sumatra, and Central and East Kalimantan in Indonesia know this only too well. Their paddy fields are flooded by river water pushed back up the deltas by each incoming tide. Preparing the land is especially difficult. Not only do weeds grow incredibly vigorously under the swampy conditions, but plowing the land too deeply can result in crop failure. Although the high organic matter topsoil is fertile, below lies a yellow layer of toxic iron pyrite. This is phytotoxic to the rice if disturbed.
Farmers in the mountains of Vietnam can plant maize crops more than two weeks early by using paraquat in a conservation tillage system. Timely operations are essential in growing all crops and paraquat’s unprecedented speed of action is often a huge help to farmers up against the weather or looking for earlier harvests to get the best prices.
Results of research conducted by The Northern Mountainous Agriculture and Forestry Science Institute (NOMAFSI) show that using paraquat for weed control increased maize yields by more than 50%1. Early planting was crucial to good yields – land preparation with slow acting glyphosate herbicide resulted in much lower yields.
In the Philippines, more successful results from a project using paraquat to control weeds and prevent soil erosion have been announced. Since 2005, researchers from several universities and other organisations have been collaborating to study approaches to reducing the serious threat posed by soil erosion to food production and the environment.
Professor Gil Magsino from the University of the Philippines presented the results and conclusions from the Sagip-Lupa project’s 4th Annual Report at the University of Benguet recently.
Prof. Magsino noted that an annual loss of 2 – 4 cm of topsoil from fields in the Philippines has become commonplace, but with the imperative of achieving sufficient levels of food production this cannot be sustained.
Benefits of paraquat-based agronomy Less soil lost
Higher yields
Lower input costs
Time savings
Plants and soil organic matter are key to reducing soil erosion. Living or dead mulches of plants covering the soil resist the impact of rain, and roots and organic matter bind soil particles together. Traditional methods of weed control such as hand hoeing and plowing remove unwanted plant material, ie weeds, and disturb the soil, encouraging erosion.
The first weed species to develop resistance to the non-selective herbicide glufosinate has been recorded by researchers in Malaysia.
Preliminary experiments have confirmed concerns that an aggressive grass weed is developing populations which are no longer controlled by glufosinate.
Weed scientists from the University of Malaya have been investigating reports of weed control problems in an oil palm nursery in the state of Pahang. The weed in question is goosegrass (Eleusine indica), a globally important weed of many warm climate crops.
In Malaysia it is a particularly serious problem in oil palm and rubber plantations, and on smallholdings growing fruit and vegetables.
Goosegrass has already developed resistance to several herbicide modes of action (MOA) in a number of countries around the world. It was the second weed species to be recorded as becoming resistant to glyphosate, also in Malaysia1. To keep weed resistance at bay, and avert the threat it poses to food production, it is vital to use integrated weed management practices. These involve using herbicides with different MOA. Like paraquat and glyphosate, glufosinate has a very distinctive MOA. However, as experience with glyphosate has shown, intensive use of a single MOA herbicide regime will ultimately result in weeds becoming resistant.
In Asia alone, more than two billion people obtain over 60% of their calories from rice. It is the most rapidly growing source of food in Africa and is critical to food security. Long grain rices are typically of the indica race and include the fragrant Jasmine rice from Thailand and Basmati rice from India. Short grain rice, typically japonica, is usually more sticky than long grain and is favoured in Japan. Saki rice is grown in Japan to make rice wine, and in Indonesia there are red and black grained varieties. About 80% of the world's rice is grown by smallholders in these places. In Asia, women are often responsible for rice farming as men have moved to work in the cities.
Efficient and productive rice-based production systems are essential for economic development and for improved quality of life for much of the world's population. Plant breeding, crop protection, water management and fertilization have increased productivity and reduced the costs of production.
In September 2008, after an evaluation by the Thai Toxicology Evaluation Committee, paraquat was approved for continued sale in Thailand and scheduled to enter the new re-registration process.
As of May 2009, the final approval of the re-registration procedure by the Ministry of Agriculture and Cooperatives is still pending, but paraquat has been included in the first stage of the review program which is expected to start in July 2009.  The current registration will expire in August 2011.
Following a major revision of the regulatory system for crop protection products, the Ministry is working through nearly 27,000 dossiers for re-registration.  CropLife International, the global federation representing the plant science industry, has been working with Thai regulatory officials to strengthen the country’s regulation of herbicides, fungicides, insecticides and other crop protection products used on its 18 million hectares of crops.
Farming Facts about Thailand 1st - Thailand's position as a rice exporter 
10 million ha of rice grown
11% of Thailand's GDP comes from farming
43% of Thai workforce engaged in agriculture
Rice is the staple food for more than half the world. In Asia alone, more than two billion people obtain over 60% of their calories from rice. It is the most rapidly growing source of food in Africa and is critical to food security.
Rice-based production systems and the operations processing the grain for food employ nearly one billion people in rural areas of developing countries. About 80% of the world's rice is grown by smallholders in these places. In Asia, women are often left to conduct many of the rice farming tasks as men have moved to work in the cities. Efficient and productive rice-based production systems are essential for economic development and for improved quality of life for much of the world's population.
For thousands of years, cultivating rice has meant that people have had to work together, and the need for standing water in rice farming has shaped the landscape. Festivals are dedicated to rice and the crop was considered divine by many ancient Asian emperors and kings. Even today, the Japanese refer to rice as their ‘mother’ and regard rice farmers as the guardians of their culture and countryside.
Paraquat and no-till methods are minimizing soil erosion and increasing productivity for corn farmers in Northern Vietnam. Corn (maize) is an important crop for the Vietnamese - especially for those living in the hilly northwest region.  180,000 hectares (ha) of corn are grown on hillside fields during the rainy season.
Traditional but time-consuming “slash and burn” farming practices limit crops to one per year and often result in low yields and high soil erosion.
Paraquat applied pre-planting and inter-row reduced soil erosion by 34% and shortened growing time by more than 20 days per season*. This represents a savings of VND **750,000 per ha in manpower costs compared to manual hand-weeding methods.
Paraquat allows rice planting in currently non-productive land and reduces the time between rice crop cycles in Indonesia.
The population of Indonesia is increasing at 2% per year and its government is desperately trying to achieve self-sufficiency in rice to feed this population. They hope to achieve this by bringing currently non-productive land like the tidal areas of Kalimantan into cropping and by increasing the number of rice crops grown each year.
There are currently 1 million hectares of tidal rice, mainly in Kalimantan, but the potential is close to 10 million hectares. Approximately 60% of this area is influenced by tides. Inundation is caused when the incoming tide forms a barrier to rivers flowing into the sea, which then flood areas with fresh, but somewhat brackish water. Much of the area has an underlying layer of iron pyrites, and while rice can be grown on these soils there is a danger of soil erosion.
The manual preparation of rice paddy fields is not only very arduous, but it also a major cause of soil erosion. In contrast, the development of no-till systems has minimized this erosion.