There's a lot of info about traditional practices available at your fingertips via a quick search, but here's a little info for your research: (from Jim Hogshire's guide on erowid)
It is noteworthy that the dominant ethnic groups of Mainland Southeast Asia are not poppy cultivators. The Burmans and Shan of Burma, the Lao of Laos, the Thai of Thailand, the Han Chinese of Yunnan, China, and the Vietnamese of Vietnam are lowlanders and do not traditionally cultivate opium poppies. Rather, it is the ethnic minority highlander groups, such as the Wa, Pa-0, Palaung, Lahu, Lisu, Hmong, and Akha who grow poppies in the highlands of the countries of Southeast Asia.
A typical nuclear family of Mainland Southeast Asian highlanders ranges between five and ten persons,including two to five adults. An average household of poppy farmers can cultivate and harvest about one acre of opium poppy per year. Most of the better fields can support opium poppy cultivation for ten years or more without fertilization, irrigation, or insecticides, before the soil is depleted and new fields must be cleared. In choosing a field to grow opium poppy, soil quality and acidity are critical factors and experienced poppy farmers choose their fields carefully. In Southeast Asia, westerly orientations are typically preferred to optimize sun exposure. Most fields are on mountain slopes at elevations of 1,000 meters (3,000 feet) or more above sea level. Slope gradients of 20 degrees to 40 degrees are considered best for drainage of rain water.
In Mainland Southeast Asia, virgin land is prepared by cutting and piling all brush, vines and small trees in the field during March, at the end of the dry season. After allowing the brush to dry in the hot sun for several days, the field is set afire. This method, called 'slash-and burn' or 'swidden' agriculture, is commonly practiced by dry field farmers - both highland and lowland - throughout Mainland Southeast Asia in order to ready the land for a variety of field crops. The slash-and-burn method is also used to clear fields for poppy cultivation. Before the rainy season in April, fields by the hundreds of thousands all over the region are set ablaze. A fog-like yellow haze hangs over the area for weeks, reducing visibility for hundreds of miles. In the mountains, the dense haze blocks out the sun and stings the eyes.
A typical highlander family will plant an area of two or three rai in opium poppy (2.53 rai is equivalent to one acre). In August or September, toward the end of the rainy season, highland farmers in Southeast Asia prepare fields selected for opium poppy planting. By this time, the ash resulting from the burn-off of the previous dry season has settled into the soil, providing additional nutrients, especially potash. The soil is turned with long-handled hoes after it is softened by the rains. The farmers then break up the large clumps of soil. Weeds and stones are tossed aside and the ground is leveled off.
Traditionally, most highland and upland farmers in Southeast Asia do not use fertilizer for any of their crops, including the opium poppy, but in recent years opium poppy farmers have started using both natural and chemical fertilizers to increase opium poppy yields. Chicken manure, human feces or the regions' abundant bat droppings are often mixed into the planting soil before the opium poppy seed is planted.
The planting must be completed by the end of October in order to take advantage of the region's 'long days' in November and December.
The opium poppy seed can be sown several ways: broadcast (tossed by hand); or fix-dropped by hand into shallow holes dug with a metal-tipped dibble stick. About one pound of opium poppy seed is needed to sow one acre of land. The seeds may be white, yellow, coffee-color, gray, black, or blue. Seed color is not related to the color of the flower petals. Beans, cabbages, cotton, parsley, spinach, squash and tobacco are crops typically planted with the opium poppy. These crops neither help nor hinder the cultivation of the opium poppy, but are planted for personal consumption or as a cash crop.
In the highlands of Southeast Asia, it is a common practice to plant maize and opium poppies in the same fields each year. The maize keeps down excessive weeds and provides feed for the farmer's pigs and ponies. It is grown from April to August. After harvesting the maize, and with the stalks still standing in the fields, the ground is weeded and pulverized. Just before the end of the rainy season, in successive sowings throughout September and October, the poppy seed is broadcast among the maize stalks. These stalks can protect young opium poppy plants from heavy rains.
The opium poppy plants form leaves in the first growth stage, called the 'cabbage' or 'lettuce' stage. After a month of growth, when the opium poppy is about a foot high, some of the plants are removed (called 'thinning') to allow the other plants more room to grow. The ideal spacing between plants is believed to be 20 to 40 centimeters, or about eight to twelve plants per square meter, although some researchers in northern Thailand have reported as many as 18 plants per square meter.
During the first two months, the opium poppies may be damaged or stunted by nature through the lack of adequate sunshine, excessive rainfall, insects, worms, hail storms, early frost, or trampling by animals. The third month of growth does not require as much care as the first two months. Three to four months after planting, from late December to early February, the opium poppies are in full bloom. Mature plants range between three to five feet in height. Most opium poppy varieties in Southeast Asia produce three to five mature pods per plant. A typical opium poppy field has 60,000 to 120,000 poppy plants per hectare, with a range of 120,000 to 275,000 opium-producing pods. The actual opium yield will depend largely on weather conditions and the precautions taken by individual farmers to safeguard the crop. The farmer and his family generally move into the field for the final two weeks, setting up a small field hut on the edge of the opium poppy field.
The scoring of the pods (also called 'lancing,' 'incising,' or 'tapping') begins about two weeks after the flower petals fall from the pods. The farmer examines the pod and the tiny crown portion on the top of the pod very carefully before scoring.
The grayish-green pod will become a dark green color as it matures and it will swell in size. If the points of the pod's crown are standing straight out or are curved upward, the pod is ready to be scored. If the crown's points turn downward, the pod is not yet fully matured. Not all the plants in a field will be ready for scoring at the same time and each pod can be tapped more than once.
A set of three or four small blades of iron, glass, or glass splinters bound tightly together on a wooden handle is used to score two or three sides of the pod in a vertical direction. If the blades cut too deep into the wall of the pod, the opium will flow too quickly and will drip to the ground. If the incisions are too shallow, the flow will be too slow and the opium will harden in the pods. A depth of about one millimeter is desired for the incision.
Using a blade-tool designed to cut to that depth, scoring ideally starts in late afternoon so the white raw opium latex can ooze out and slowly coagulate on the surface of the pod overnight. If the scoring begins too early in the afternoon, the sun will cause the opium to coagulate over the incision and block the flow. Raw opium oxidizes, darkens and thickens in the cool night air. Early the next morning, the opium gum is scraped from the surface of the pods with a short-handled, flat, iron blade three to four inches wide.
Opium harvesters work their way backwards across the field scoring the lower, mature pods before the taller pods, in order to avoid brushing up against the sticky pods. The pods continue to produce opium for several days. Farmers will return to these plants - sometimes up to five or six times - to gather additional opium until the pod is totally depleted. The opium is collected in a container which hangs from the farmer's neck or waist.
The opium yield from a single pod varies greatly, ranging from 10 to 100 milligrams of opium per pod. The average yield per pod is about 80 milligrams. The dried opium weight yield per hectare of poppies ranges from eight to fifteen kilograms.
As the farmers gather the opium, they will commonly tag the larger or more productive pods with colored string or yarn. These pods will later be cut from their stems, cut open, dried in the sun and their seeds used for the following year's planting.
The wet opium gum collected from the pods contains a relatively high percentage of water and needs to be dried for several days. High-quality raw opium will be brown (rather than black) in color and will retain its sticky texture. Experienced opium traders can quickly determine if the opium has been adulterated with tree sap, sand, or other such materials. Raw opium in Burma, Laos and Thailand is usually sun-dried, weighed in a standard 1.6 kilogram quantity (called a 'viss' in Burma; a 'choi' in Laos and Thailand), wrapped in banana leaf or plastic and then stored until ready to sell, trade, or smoke. While opium smoking is common among most adult opium poppy farmers, heavy addiction is generally limited to the older, male farmers. The average yearly consumption of cooked opium per smoker is estimated to be 1.6 kilograms.
A typical opium poppy farmer household in Southeast Asia will collect 2 to 5 choi or viss (3 to 9 kilograms) of opium from a year's harvest of a one-acre field. That opium will be dried, wrapped and stacked on a shelf by February or March. If the opium has been properly dried, it can be stored indefinitely. Excessive moisture and heat can cause the opium to deteriorate but, once dried, opium is relatively stable. In fact, as opium dries and becomes less pliable, its value increases due to the decrease in water weight per kilogram.