Fields of purple opium poppy stretch across the pastures and peaks of mountainous eastern Myanmar, with many farmers reluctant to give up the profitable cash crop in spite of incentives offered.Myanmar is the second biggest source of opium in the world after Afghanistan, with Shan state its main production hub.AFP hiked up the steep mountainside towering over the small town of Hopong, just a few dozen kilometres from tourist hotspot Inle Lake. The farmland closest to the town boasts fields of coffee, potatoes and corn, and provides a lifeline for the scattered villages.But scale the ridge and the far side exposes a blanket of purple reaching up to an altitude of some 2,400 metres (8,000 feet). Each day men and women from the surrounding villages, home to the Pa-O and other Shan ethnic minority groups, take to the fields of the illegal flower.They harvest its addictive sap into cans that can fetch up to $100 each, sums that far exceed the profits possible from other produce.The fight has been on for decades to eradicate the drugs production, with a mixture of carrot-and-stick tactics.Anti-drugs police destroyed more than 600 hectares (1500 acres) of poppy fields in Hopong in the last year.Meanwhile, the government and NGOs have offered Myanmar farmers incentives to switch to other cash crops -- with some success.In 2018, the area of opium poppy cultivation in the country dropped by 10 per cent to 37,300 hectares from the previous year, according to the UN Office on Drugs and Crime. The agency acknowledges, however, that this is partly due to a strong shift by drug gangs toward synthetic drugs, especially methamphetamine. For many farmers -- among Myanmars poorest people -- their crop choice simply comes down to money.After trying to cultivate coffee, one farm worker, preferring not to be named, said he switched back to growing opium three years ago.We know that its not good for our country, he said, looking up from the opium poppy in his hand to survey the purple-shrouded mountainsides around him. But we have no choice because its very difficult to make a living from other crops.