A farmer may begin producing illicit narcotic plants under the threat of violence from criminal traffickers or as a means of supplementing farm income. Cultivation of drug plants is financially more rewarding than for most food crops. As a consequence, increased illegal crop growing may contribute to shortages in food crops in a given region, create an artificially based cash economy, and foster a close relationship between farmers and drug traffickers, placing them in an adversary position to the Government and forcing them to become dependent on criminal activity as a means of survival.
The coca bush may be cultivated under strict control for the production of cocaine required for medical purposes. However, such use of cocaine is very limited. Large scale cultivation of the coca bush serves no legitimate purpose. The cannabis plant can be cultivated for industrial (fibre and seed) or horticultural purposes. The use of cannabis in modern medicine is negligible and the cultivation of the plant to obtain drugs is therefore universally illegal. The opium poppy, which is the sources of morphine and codeine, can be cultivated to a limited degree under strictly controlled conditions, with any other growth being illegal.
Opium production is carried on in the Golden Triangle (border area of Burma, Laos and Thailand), in the Golden Crescent (parts of Afghanistan, Iran, Pakistan), Turkey and Mexico. The difficulties in trafficking opium help account for the extremely high use of the drug in territories and lands adjacent to the poppy-growing areas. Opium is bulky and has a characteristic odour; for this reason it is usually converted to heroin for trafficking internationally. Coca, from which cocaine is processed, is grown in western South America, chiefly in Peru and Bolivia, which also grow cannabis or marijuana. Ganja or cannabis from Jamaica, Mexico and the Andes is trafficked to the USA by the tonne.
The cultivation of drug crops gives a poor farmer a chance to make money. Government subsidies for sugar, vegetables, fruits, grains, wine and tobacco to farmers in industrial countries effectively leave many farmers in developing countries with the need to grow poppies, coca leaf and marijuana to survive. The markets of legal crops are unstable, blocked with protectionist measures and often offering prices below production costs. Illegal crops have guaranteed markets, high profits, and little risk to farmers.