Use of the opium poppy antedates written history. It was the first active alkaloid extracted from the opium poppy. The primary source of morphine is isolation from poppy straw of the opium poppy. Etorphine was synthesized in 1960, from the oripavine in opium poppy straw. In 2003, a comprehensive ban on the cultivation of the opium poppy came into effect. Plants such as tobacco, cannabis, opium poppy, and coca yield psychotropic chemicals. In northern Burma bans have ended a century-old tradition of growing the opium poppy. Poppy seed is an oilseed obtained from the opium poppy ("Papaver somniferum"). Opiates are alkaloid compounds naturally found in the opium poppy plant "Papaver somniferum". Morphine-containing honey has been reported in areas where opium poppy cultivation is widespread. Morphine is biosynthesized in the opium poppy from the tetrahydroisoquinoline reticuline. In South Korea, the cultivation of the opium poppy is strictly prohibited. Farmers in unprecedented numbers began planting cash crops such as opium poppy, tobacco, and cotton. Two of the following three growing seasons saw record levels of opium poppy cultivation. In the opium poppy, the alkaloids are bound to meconic acid.