Mexico and the UN announced the results of a new study that estimates opium poppies were planted on about 61,000 acres last year.
The study is the first of its kind in Mexico, so authorities can't compare the results with past years to determine whether opium growing has expanded.
The head of the UN Office on Drugs and Crime in Mexico, Antonio Mazzitelli, yesterday said a second part of the study will try to estimate what the crop yield is in Mexico.
Mazzitelli said production is concentrated in nine states along Mexico's Pacific coast, including Guerrero, Sinaloa and Nayarit.
US authorities estimate that about half of the heroin seized there came from Mexico. Most of the rest of US heroin comes from South America.
The Drug Enforcement Administration has said poppy cultivation in Mexico is on the rise, with 17,000 hectares in 2014 and an estimated potential production of 42 metric tons of heroin.
