In 1940, Mexican government officials requested from US Vice President Henry A. Wallace assistance in developing a program to train a new generation of Mexican agricultural scientists. The agrarian reforms following the Mexican Revolution of 1910 had resulted in much lower yields, and the Mexican government feared their agricultural industry was being left behind. The US government passed the program on to the Rockefeller Foundation. The Rockefeller Foundation contacted E.C. Stakman and two other leading agronomists. They developed a proposal for a new organization, the Office of Special Studies, as part of the Mexican Government, but directed by the Rockefeller Foundation. It was to be staffed with both US and Mexican scientists, focusing on soil development, maize and wheat production, and plant pathology.

Stakman chose Dr. J. George "Dutch" Harrar as project leader. Harrar immediately set out to hire Borlaug as head of the newly-established Cooperative Wheat Research and Production Program in Mexico; Borlaug declined, choosing to finish his war service at DuPont.Davidson, M.G. 1997. An Abundant Harvest: Interview with Norman Borlaug, Recipient, Nobel Peace Prize, 1970, Common Ground, August 12
In July 1944, after rejecting DuPont's offer to double his salary, and temporarily leaving behind his pregnant wife and 14-month old daughter, he flew to Mexico City to head the new program as a geneticist and plant pathologist.

In 1964, he was made the director of the International Wheat Improvement Program at El Batán, Texcoco, on the eastern fringes of Mexico City, as part of the newly-established Consultative Group on International Agricultural Research's International Maize and Wheat Improvement Center (Centro Internacional de Mejoramiento de Maíz y Trigo, or CIMMYT), an autonomous international research training institute developed from the Cooperative Wheat Research Production Program, with funding jointly undertaken by the Ford and Rockefeller Foundations and the Mexican government.

Borlaug officially retired from the position in 1979. But he remains a senior consultant at the CIMMYT and has continued to be involved in plant research at CIMMYT with wheat, triticale, barley, maize, and high-altitude sorghum, in addition to taking up charitable and educational roles.

Wheat research in Mexico

Borlaug said that his first couple of years in Mexico was difficult. He lacked trained scientists and equipment. Native farmers were hostile toward the wheat program because of serious crop losses from 1939 to 1941 due to stem rust. "It often appeared to me that I had made a dreadful mistake in accepting the position in Mexico," he wrote in the epilogue to his book, Norman Borlaug on World Hunger. He spent the first 10 years breeding wheat cultivars resistant to disease, including rust. In that time, his group made 6,000 individual crossings of wheat.University of Minnesota. 2005. Borlaug's Work in Mexico

Double wheat season

His boss, George Harrar, was against this expansion. Besides the extra costs of doubling the work, Borlaug's plan went against a then-held principle of agronomy that has since been disproved. It was believed that seeds needed a rest period after harvesting, in order to store energy for germination before being planted. Harrar vetoed his plan, causing Borlaug to resign. Elvin Stakman, who was visiting the project, calmed the situation, talking Borlaug into withdrawing his resignation and Harrar into allowing the double wheat season. As of 1945, wheat would then be bred at locations 700 miles (1000 km) apart, 10 degrees apart in latitude, and 8500 feet (2600 m) apart in altitude. This was called "shuttle breeding".

As an unexpected benefit of the double wheat season, the new breeds did not have problems with photoperiodism. Normally, wheat varieties cannot adapt to new environments, due to the changing periods of sunlight. Borlaug later recalled, "As it worked out, in the north, we were planting when the days were getting shorter, at low elevation and high temperature. Then we'd take the seed from the best plants south and plant it at high elevation, when days were getting longer and there was lots of rain. Soon we had varieties that fit the whole range of conditions. That wasn't supposed to happen by the books". This meant that the project wouldn't need to start separate breeding programs for each geographic region of the planet.

Increasing disease resistance through multiline varieties

In 1953, Borlaug extended this technique by suggesting that several purelines with different resistance genes should be developed through backcross methods using one recurrent parent.Borlaug, N.E. 1953. New approach to the breeding of wheat varieties resistant to Puccinia griminis tritici. Phytopathology, 43:467
Backcrossing involves crossing a hybrid and subsequent generations with a recurrent parent. As a result, the genotype of the backcrossed progeny becomes increasingly similar to that of the recurrent parent. Borlaug's method would allow the various different disease-resistant genes from several donor parents to be transferred into a single recurrent parent. To make sure each line has different resistant genes, each donor parent is used in a separate backcross program. Between five and ten of these lines may then be mixed depending upon the races of pathogen present in the region. As this process is repeated, some lines will become susceptible to the pathogen. These lines can easily be replaced with new resistant lines. As new sources of resistance become available, new lines are developed. In this way, the loss of crops is kept to a minimum, because only one or a few lines become susceptible to a pathogen within a given season, and all other crops are unaffected by the disease. Because the disease would spread more slowly than if the entire population were susceptible, this also reduces the damage to susceptible lines. There is still the possibility that a new race of pathogen will develop to which all lines are susceptible, however.AGB 301: Principles and Methods of Plant Breeding. Tamil Nadu Agricultural University.

Dwarfing

Borlaug's new semi-dwarf, disease-resistant varieties, called Pitic 62 and Penjamo 62, changed the potential yield of wheat dramatically. By 1963, 95% of Mexico's wheat crops used the semi-dwarf varieties developed by Borlaug. That year, the harvest was six times larger than in 1944, the year Borlaug arrived in Mexico. Mexico had become fully self-sufficient in wheat production, and a net exporter of wheat.University of Minnesota. 2005. The Beginning of the Green Revolution
Four other high yield varieties were also released, in 1964: Lerma Rojo 64, Siete Cerros, Sonora 64, and Super X.

Expansion to South Asia: The Green Revolution

In 1961 to 1962, Borlaug's dwarf spring wheat strains were sent for multilocation testing in the International Wheat Rust Nursery, organized by the US Department of Agriculture. In March 1962, a few of these strains were grown in the fields of the Indian Agricultural Research Institute in Pune, New Delhi, India. In May 1962, M. S. Swaminathan, a member of IARI's wheat program, requested of Dr. B.P. Pal, Director of IARI, to arrange for the visit of Borlaug to India and to obtain a wide range of dwarf wheat seed possessing the Norin 10 dwarfing genes. The letter was forwarded to the Indian Ministry of Agriculture, which arranged with the Rockefeller Foundation for Borlaug's visit. In March 1963, the Rockefeller Foundation and the Mexican government sent Borlaug to India to continue his work. He supplied 100 kg (220 lb) of seed from each of the four most promising strains and 630 promising selections in advanced generations to the IARI in October 1963, and test plots were subsequently planted at Delhi, Ludhiana, Pant Nagar, Kanpur, Pune and Indore.

During the mid-1960s, the Indian subcontinent was at war, and experiencing widespread famine and starvation, even though the US was making emergency shipments of millions of tons of grain, including over one fifth of its total wheat, to the region. The Indian and Pakistani bureaucracies and the region's cultural opposition to new agricultural techniques initially prevented Borlaug from fulfilling his desire to immediately plant the new wheat strains there. By the summer of 1965, the famine became so acute that the governments stepped in and allowed his projects to go forward.

In the late 1960s, most experts said that global famines in which billions would die would soon occur. Biologist Paul R. Ehrlich wrote in his 1968 bestseller The Population Bomb, "The battle to feed all of humanity is over... In the 1970s and 1980s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now." Ehrlich also said, "I have yet to meet anyone familiar with the situation who thinks India will be self-sufficient in food by 1971," and "India couldn't possibly feed two hundred million more people by 1980."

In 1965, after extensive testing, Borlaug's team began its effort by importing about 450 tons of Lerma Rojo and Sonora 64 semi-dwarf seed varieties: 250 tons went to Pakistan and 200 to India. They encountered many obstacles. Their first shipment of wheat was held up in Mexican customs and so could not be shipped from the port at Guaymas in time for proper planting. Instead, it was sent via a 30-truck convoy from Mexico to the US port in Los Angeles (LA), encountering delays at the US-Mexico border. Once the convoy entered the US, it had to take a detour, as the US National Guard had closed the freeway due to Watts riots in LA. When the seeds reached LA, a Mexican bank refused to honor Pakistan treasury's payment of ^*]100,000 because the check contained three misspelled words. Still, the seed was loaded onto a freighter destined for Bombay, India and Karachi, Pakistan. Twelve hours into the freighter's voyage, war broke out between India and Pakistan over the Kashmir region. Borlaug received a telegraph from the Pakistani minister of agriculture, Malik Khuda Bakhsh Bucha: "I'm sorry to hear you are having trouble with my check, but I've got troubles, too. Bombs are falling on my front lawn. Be patient, the money is in the bank..."

These delays prevented Borlaug's group from conducting the germination tests needed to determine seed quality and proper seeding levels. They started planting immediately, and often worked in sight of artillery flashes. A week later, Borlaug discovered that his seeds were germinating at less than half the normal rate. It later turned out that the seeds had been damaged in a Mexican warehouse by over-fumigation with a pesticide. He immediately ordered all locations to double their seeding rates.

The initial yields of Borlaug's crops were higher than any ever harvested in South Asia. The countries subsequently committed to importing large quantities of both the Lerma Rojo 64 and Sonora 64 varieties. In 1966, India imported 18,000 tons —the largest purchase and import of any seed in the world at that time. In 1967, Pakistan imported 42,000 tons, and Turkey 21,000 tons. Pakistan's import, planted on 1.5 million acres (6,100 km²), produced enough wheat to seed the entire nation's wheatland the following year. By 1968, when Ehrlich's book was released, William Gaud of the United States Agency for International Development was calling Borlaug's work a "Green Revolution". High yields led to a shortage of various utilities: labor to harvest the crops, bullock carts to haul it to the threshing floor, jute bags, trucks, rail cars, and grain storage facilities. Some local governments were forced to close school buildings temporarily to use them for grain storage.

In Pakistan, wheat yields nearly doubled, from 4.6 million tons in 1965 to 7.3 million tons in 1970; Pakistan was self-sufficient in wheat production by 1968. Yields were over 21 million tons by 2000. In India, yields increased from 12.3 million tons in 1965 to 20.1 million tons in 1970. By 1974, India was self-sufficient in the production of all cereals. By 2000, India was harvesting a record 76.4 million tons of wheat. Since the 1960s, food production in both nations has increased faster than the rate of population growth. Paul Waggoner, of the Connecticut Agricultural Experiment Station, calculates that India's use of high-yield farming has prevented 100 million acres (400,000 km²) of virgin land from being converted into farmland—an area about the size of California, or 13.6% of the total area of India.Easterbrook, G. 1997. Forgotten Benefactor of Humanity. The Atlantic Monthly. (duplicate)
The use of these wheat varieties has also had a substantial effect on production in six Latin American countries, six countries in the Near and Middle East, and several others in Africa.

Borlaug's work with wheat led to the development of high-yield semi-dwarf indica and japonica rice cultivars at the International Rice Research Institute, started by the Ford and Rockefeller Foundations, and at China's Hunan Rice Research Institute. Borlaug's colleagues at the Consultative Group on International Agricultural Research also developed and introduced a high-yield variety of rice throughout most of Asia. Land devoted to the semi-dwarf wheat and rice varieties in Asia expanded from 200 acres (0.8 km²) in 1965 to over 40 million acres (160,000 km²) in 1970. In 1970, this land accounted for over 10% of the more productive cereal land in Asia.

Nobel Peace Prize