| Abstract | Presently, Thailand is one of the leading producers of pineapples. Most of the pineapple cultivation operations, excluding tillage, are carried out manually. Due to industrialization, there is a shortage of laborers for agricultural work. Pineapple planting is a time- and labor- consuming operation, which needs to be mechanized. However, there is currently no mechanical means to transplant pineapple suckers, the traditional planning material, and no details available of a transplanter suitable for the big-sized planting material. Therefore, it was aimed to design and develop a pineapple transplanter, mainly suitable for Thai planting conditions. This study was focused on creating a new planting concept for pineapple, and verify it by designing, developing, and testing the prototype. The new planting concept was started from the existing conditions that most pineapples are planted in well prepared loamy sand soil. During the moving of the furrower through loose soil, such as prepared loamy sand soil, an instantaneous hole occurs at the rear point of the furrow opener. Thus, the concept of delivering a sucker into an instantaneous hole and covering the soil simultaneously was created. This planting concept can be applied with a pineapple transplanter because of the easy occurrence of instantaneous holes as described. Base on the described planting concept, the study of pineapple planning conditions was conducted to develop a semi-automatic transplanter employing four feeders and using a tractor as the power source. The machine principle included: i) soil opener creating an instantaneous hole. ii) sucker being delivered into this hole, and iii) soil covering being done simultaneously. This principle is similar to that of row-crop seeder. During the designing and developing process, the motion economy principle was applied to increase manual feeding and refilling of suckers which significantly affect field capacity of this transplanter. This innovation was verified by the performance testing of the first prototype. The field capacity was found to be about 0.1 ha/h, and the field efficiency was 35.9%. Thus, the capacity was five times higher than by the traditional method. The man-hour requirement to use this machine was 113.5 man-h/ha or 48.8% of the traditional method. The comparison indicated that plant spacing, stand angle, and planting quality by the transplanter had rather more variation than traditional methods. However, these differences will not affect the planting quality by transplanter. The important results obtained were: standing plant 97.1%, lying plant 2.2%, missed hills 0.7% and damaged plant 0%. The planting pattern and quality by transpalanter were satisfactory. The economic analysis indicated the break-even area of 43.6% ha/yr for the assumed transplanted life of 10 years, that cause the operating cost of transplanted equal the cost of traditional method. This size of planting area needed would consist of about 2-7 households to form a user group. Thus, the developed transplanted may be accepted by farmers, especially large-scale farmers and co-operative groups of farmers. |