Dec. 6, 2016
1. Thailand is one of world top 10 rice countries
Regarding global production, it was found in 2013/14 that harvested areas amounted to 6,248 million hectares, producing 476.96 million tons of rice, with an average yield of 4,418.75 kilograms per hectare. Harvested area and production had increased from the 6,178.5 million hectares and 471.88 million tons registered respectively in 2012/13, marking a 1.71 percent and 1.08 percent increase respectively. Yield decreased by some 0.70 percent from 4,450 kilograms produced in 2012/13.
Countries showing increases in productivity between the two periods were India, Bangladesh, Vietnam, Myanmar, Philippines, Brazil, Japan, Nigeria, Pakistan, Cambodia, and Thailand, among others. In contrast, the countries with lowered productivity were China and Indonesia.
Figure 1: Rice harvested area, production and yield/ha of world top 6 countries in 2014
2. Rice cultivation in Thailand
Thailand's planting area from 2011 to 2014, by region, saw a major decline in the rice planting area due to changes in government policy, declining prices, and the farmers’ decision to switch to planting sugarcane, which provided higher returns and market certainty. However, the yield slightly increased because the level of rainfall was sufficient for it to thrive.
The cultivation of rice has, over the centuries, shaped the landscapes, cultures, languages, and characters of Asian peoples. Many believe that the Thais were the first to cultivate rice and the first to focus on the suitability of land for such cultivation when deciding where to settle. Evidence has been found that the Thais have cultivated rice for thousands of years.
Figure 2: Thailand Rice Cultivation and Percentage of Area Planting Year 2014
3. Thai rice: Quality over quantity
Figure 3: Rice Planting Management
While Thailand retains its position as one of the world's major producers and exporters of rice, a comparison of the nation's output with that of other major rice growing countries reveals relatively low production. This is primarily because rice in Thailand is still grown in the traditional way, with a strong focus on producing high-quality, long-grain white rice, such as the famous perfumed jasmine rice. These strains are deemed to be far superior in taste than those of the higher yield varieties, and most Thai rice farmers prefer to maintain this reputation for quality, especially as higher prices may be achieved for a superior final product.
4. Method of cultivation of rice in Thailand
Thailand is divided geographically into four main regions: northern, northeastern, central plain, and southern. The total area planted with rice is 9.87 million hectares. Northern Thailand, with some 23.5% of the total rice area, contributes nearly 31.8% of the total rice production.
Northeastern Thailand has 59.7% of the total area, and 45.5% of total production. In the central plain, the rice planting area and rice production are 15% and 21.25% of the total, respectively, while in southern Thailand, the corresponding percentages are only 5% each.
Some 92% of the total rice-planting area in northeastern Thailand falls under rain-fed conditions, compared with 70% in the northern region, 27% in the central plain, and 69% in the southern region. The average grain yield of rain-fed lowland rice in the northeast during the 2013-2014 crop season was 2.21 hectares, compared with 2.22 hectares for irrigated lowland rice.
Among the four regions, the rice yield in the northeast is the lowest. It is negatively affected by very poor soil conditions and unreliable rainfall.
4.1 Pre-Germinated Direct Seeded Rice
Figure 4.1: Crop stage and application timing of pesticide apply in Pre germinated Direct Seeded Rice
Under the pre-germinated direct seeded rice broadcasting method, in areas where irrigation or water control is possible or the fields have some standing water, the farmers can direct-seed into the soil with wetland preparation. Germinated rice seeds (soaked 24 hours and incubated 24 hours) are broadcast onto the well-puddled soil.
The field is thoroughly prepared in advance, and if it has been flooded, the soil particles are allowed to settle down and the field is drained before seeding.
4.2 Dry Direct Seeded Rice
Figure 4.2: Crop stage and application timing of pesticide apply in Dry Direct Seeded Rice
As soon as the rainfall has moistened the soil enough to make ploughing possible, the land is ploughed (in late April, May, or early June). In the heavy clay soils of the central plain, the seed is broadcast within a few days of ploughing, before the next shower. Much of the seed falls into cracks between, around, or under the overhang of large clods. When the next shower comes, the heavy clay clods slake down, so that the clod fragments cover most of the seed. In irrigated areas, the field will be irrigated after seeding to promote germination.
In light-textured soil, such as loamy sand, sandy loam, and sandy clay loam, in the lowland rice areas of northeastern Thailand, the method of land preparation differs between farmers. Many farmers plough the field only once, but some plough twice before broadcasting the seed. The second ploughing is done just before broadcasting the seed, and then the field is harrowed so that the loosened soil covers the seeds to retain moisture and protect them from birds.
4.3 Transplanting Rice
Figure 4.3: Crop stage and application timing of pesticide apply in Transplanting Rice
Transplanting is a method of growing rice. For transplanting, seedlings are first grown in a seedbed for a month while the main fields are being ploughed along the bunds surrounding each paddy.
When each field has been prepared, the seedlings are pulled from the seedbed and then transplanted in the field by hand.
This growing method is Thai Farmer called “Na Damh”
5. Rice: Main herbicides, insecticides, and fungicides
5.1 Major Rice Weeds in Thailand
Weeds flourish in the humid climates of rice fields in Thailand. Without any control, weeds can completely overwhelm the rice crop. The traditional method for weed control in rice fields is hand-weeding. Weeding rice adequately requires 30-120 man-days/hectare. Typically, two to three hand weeders are recommended for optimal weed control. However, especially during the time of peak periods of labor demand, weeding is either done late or skipped, causing drastic losses in rice yield. Some farmers abandon weeding due to heavy infestations, particularly after the rains.
5.2 Major Rice Insecticide in Thailand
In Thailand, rice is grown in warm, humid environments conducive to the survival and proliferation of key insect pests: the yellow stemborer, leaffolders, brown plant hoppers (BPH), and green leafhoppers. Stemborers are ubiquitous throughout rice fields in Asia and cause some damage in every rice field every year. The larvae bore into the stems and eat their way down to the base of the plant hollowing out the stem. Losses from borer damage can reach up to 95%. Leaffolder larvae fold the leaves by stitching the leaf margins and feed by scraping green leaf tissue. Yield losses attributable to leaffolders range from 63% to 80%. BPH suck sap from the rice plant, causing the plant to dry out, turn brown, and die.
5.3 Major Rice Fungicide in Thailand
Sheath blight is caused by a fungus that lives in the soil; the fungus floats to the top when fields are flooded, contacts rice plants, and spreads to adjacent plants. The spread of sheath blight is thus favored by dense crop canopies.
The flow of water and nutrients in the rice plant is interrupted, and the leaf dies, reducing rice yield. Sheath blight has developed into a major disease only since the intensification of the rice-cropping system, with new short-statured, profuse tilling varieties; high planting densities; and an increase in nitrogen fertilization inducing a favorable microclimate for the pathogen.