สถานภาพการผลิต พันธุ์ และแนวทางพัฒนาลำไยเพื่ออุตสาหกรรมในเขตภาคเหนือ

Abstract

The objective of this study is to investigate the situation of longan production, indigenous knowledge, varieties as well as longan industry in Northern Thailand.

The data for this study are obtained from the survey of 170 farmers including 109 house-wife farmers 'groups who process dried longan less than 100 ton / season in Chiang Mai and Lumphun and 33 enterprises who process dried longan more than 100 ton / season in Chiang Mai, Lumphun, Chiang Rai, and Lumpang.

From the research finding, it is found that at present farmers especially in Chiang Mai and Lumphun has planted longan extensively. In the past decade, dried longan has exported 20 folds both in quantity and cost. The important variety is Daw. The reason is that it is an early type (early harvesting), can be consumed both fresh and dried and accepted by processing plants.

Farmers make their own decision on planting longan and use their own indigenous knowledge / technology with household labours. They own their land with the average of 10 rai. Most of the land are lowland or old paddy field with sufficient water. For cultural practices, the appropriate type of soil for longan is loamy soil, good drainage with the pH 7.7 and sufficient organic matter. Planting duration is from May to August (beginning of rainy season). Farmers buy their seedlings from the best orchard. After planting they do mulching in order to keep moisture and decrease the weed. Most of farmers use furrow system for watering. They use both organic and inorganic fertilizers with the formula of 15-15-15 or 16-16-16. Most of them do not pruning the longan trees to control the canopy but they use bamboo trunk to support the tree to prevent the strong wind.

After 4 years the longan will begin to bear fruits. Farmers will stop watering since November until flower buds are formed then they start to water a little at the time. Some of them fumigate the longan a few times in December in order to stimulate bud initiation. Practices during fruit setting and harvesting, farmers will apply fertilizers and water. Some of them may apply plant hormone to prevent fruit dropped off. Farmers taste the sweetness of the fruit and feel the smooth of the longan peel for fruit ripening. In addition, some of them may count the date from flowering to harvesting periods. Hired labour are supplemented during harvesting time. The labour wage costs 120-200 Baht / day depended on kind of works. Plastic baskets are the most favoured container for fresh longan with the weight of 15-25 kg / basket. Some of them may use paper carton with 12-15 kg.

After harvesting, farmers manage to prune the trees to repair damage followed by applying 15-15-15 fertilizer to encourage leaf bud. Witches 'Broom disease is the most popular disease of longan as well as leaf minor.

The most popular pattern of sale longan are green sales or advanced sales. The condition for selling depends on agreement. Longan can be classified into 3-4 grades for fresh market.

At present longan processing is carried out by both small and large industries which include farmers' house wife groups, household industry and private companies. Small processing employs oven imported from Taiwan and the machine is mainly diesel engine which is facilitated by government's supports, i.e. Department of Agricultural Extension, Department of Agricultural Cooperatives, Ministry of Agriculture and Cooperatives and Department of Internal Trade, Ministry of Commerce.

Both small and large industries have the same process to produce dry-longan. The raw material will be graded. Oven drying is normally spent about 40-50 hrs. Only large industry regrades its product before pack in the plastic bags to ensure high quality. Paper carton is used for bulk handling for export.

For canning factory, only large companies have capacity to invest. Grading is made before process the raw materials to ensure uniformity of the products.