BAAN KHLONG KHOO, Thailand >> During 18 years living across the road from rice paddies, Malinee Khammon has never planted a single seedling. The daughter of farmers who is in her last year of high school, she has become adept at deflecting increasingly desperate pleas from her parents for help on the farm.

“It’s hot and exhausting — I don’t like it,” Malinee said recently as she downloaded photos from her camera onto a computer at the local community center. “I’d rather stay indoors.”

Backbreaking and muddy, rice farming in Thailand has long been the domain of the young and able-bodied who had the strength to stoop for hours in the searing sun, transplanting rows of rice plants, one seedling at a time.

But in Thailand today, rice farming is the preserve of the old as young people stay in school longer and as the vast metropolis of Bangkok lures the country’s best and brightest to careers in air-conditioned workplaces.

“All they can do with their hands is use a cellphone,” said Sudarat Khammon, who at 33 is the youngest farmer in Baan Khlong Khoo, a small village of stilt houses outside the central Thai city of Phitsanulok.

Only 12 percent of Thai farmers today are younger than 25, down from 35 percent in 1985, according to government statistics, and their average age increased to 42 in 2010 from 31 in 1985.

The move away from the rice paddies is not altogether surprising. Thailand and other rice-growing countries in Asia are following patterns of industrialization seen elsewhere.

But the transition is especially challenging for Thailand, where the growing of rice — notably the prized jasmine variety — is entwined with the country’s identity, and its livelihood. Thailand has been the world’s leading rice exporter since 1983, according to the U.S. Department of Agriculture, and rice exports amounted to more than $6 billion last year.

Rice is highly politicized in Thailand, and this year, partly to appease disgruntled farmers, the government put in place a price guarantee system that has hurt competitiveness, leading to stockpiles of unsold rice.

In the long term, as the older generation of farmers dies off, experts worry that Thailand may have trouble finding people to work its 32 million acres of rice paddies.

Beyond the basic question of who will take up the plow, some Thais see a more immediate but less tangible threat to the society as a whole. The fertile soils of central Thailand, fed by rivers draining from the Himalayas, are the heartland of Thai culture and one of the reasons that Siam, as the country was formerly known, thrived.

As young people flee the farms, the values and knowledge of rice farming and the countryside are fading, including the tradition of long kek, helping neighbors plant, harvest, or build a house, said Iam Thongdee, who grew up in a farming family and became a professor of humanities at Mahidol University in Bangkok.

“This has alarmed me for a long time,” said Iam, clutching an ancient manuscript handed down through generations in his family and used to instruct farmers in the rituals of village life. “We are losing what we call Thai-ness, the values of being kind, helping each other, having mercy and gratefulness.”

In Baan Khlong Khoo, there are two visible signs of the abandonment of rice farming. When farmers meet to discuss prices or other rice-related issues, the room is filled with men and women in their 50s, said Nongnut Apiwatnawa, a 51-year-old farmer. The other visible sign is a gaping hole in the ground near Nongnut’s home. Several of his neighbors decided to sell their topsoil to construction companies, which have hauled off the dirt to build houses.The precise reasons the young are turning from farming include some universal explanations: the belief that life in cities is easier, or at least more exciting. But some of the reasons are more specific to Thailand.

While the image of farmers in some parts of the world is bound together with thoughts of self-reliance, strength and nostalgia for the countryside, the Thai farmer is seen as “poor, stupid and unhealthy,” said Iam, who specializes in studying the culture of rice growing. “Farmers say that if I’m reincarnated 10 times, I don’t want another life as a farmer.”

Television shows regularly portray farmers as the embodiment of uncouthness. Farmers’ skin, darkened by the sun, has become a physical marker of lower social status in a country so obsessed with light skin that television and women’s magazines are packed with advertisements promoting skin-whitening creams.

But there are also economic drivers for the move away from the farm. As a group, farmers are increasingly indebted, last year owing on average 104,000 baht, or about $3,300, the equivalent of about five years of their average income, according to government statistics. The reasons for the increase in debt are rising fertilizer prices and the legacy of crop losses from flooding, drought and other natural disasters.

The debt figures may be inflated, said Robert M. Townsend, a professor at the Massachusetts Institute of Technology who has led a project surveying Thai villagers every month for the past 15 years. The farmers he has studied have debt levels that on average are equivalent to less than one year of their income. But it is also increasingly rare to find families who do nothing but farm, Townsend said. The Thai countryside is filled with small entrepreneurs who open grocery shops, hair salons and other businesses.

Robert Zeigler, director general of the International Rice Research Institute in the Philippines, said that he expected the declining number of rice farmers to cause “stresses” in the short term, but that labor shortages were usually catalysts for the increased use of efficient machines, like those that transplant rice. 1/4

For now in Thailand, the problem is acute enough — and the farmers who make up about a third of the population are still a strong enough political constituency — that the government is taking measures beyond the price guarantee system.

The Rice Department of the Thai Ministry of Agriculture is devising a Farmers’ Welfare Fund that seeks to give farmers pensions, workers’ compensation for disabilities and subsidized equipment. The goal is to make rice farming more “honorable and secure,” the ministry said.

The transition in Thailand from a rural and feudal society to one that is now one of the foremost producers of computer hard drives and a hub for Japanese and American car companies has been abrupt.

That is causing a stark generational divide between parents who had no other choice but farming and children who are exposed to a range of possibilities in high school and at universities.

Boonmee Khammon, 41, the father of Malinee, the high school student, spoke bitterly about his two daughters’ refusal to help him in the rice fields. He complained that they came home from school, played computer games and talked on the phone.

“They live in their own world,” Boonmee said. “They’re not interested in working on the farm. I’ve tried to force them. It’s difficult.”

Malinee said her dream is to become a teacher. Her friends at school, some of them also farmers’ children, want to be doctors, pharmacists and engineers. She seemed slightly embarrassed about her farming roots.

“She’s afraid of getting dark!” offered Namaoi Taengbang, a friend.

Kwanchai Gomez, the executive director of the Thai Rice Foundation, a research center financed by the Thai royal family, believes the decline in interest in such hard work is inevitable. A decade ago she set up an annual summer camp to keep at least some young people engaged in the ancient skill of coaxing rice from the ground. They meet with experts and spend time in laboratories experimenting with new rice strains.

But the effort has met with limited success. “Many people who came to the camp,” Kwanchai said, “want to further their studies.”