Development of attachments for four-wheel riding type rice transplanter

Abstract

Rice is the most important cereal food crop of the world providing major source of the food energy for more than half of the human population. Manual transplanting of paddy is being replaced by machine transplanting due to the drudgery and increased labour cost of the former. Four wheel riding type transplanters are getting popular as they can ensure speedy operation. These costly machines require an agro-economic analysis for their proper management. Another handicap in the use of these machines is that they need to be transported in another vehicle even to nearby areas, which results in increased cost of operation. The development of a suitable transport wheel system is also needed to reduce the cost of hire charges spent for transportation. The application of bio fungicides like pseudomonas and the foliar application of micro-nutrients on the mat nursery loaded in the seedling tray of these four-wheel transplanters will be a boon to farmers as this can reduce the labour cost simultaneously boosting the yield. Hence the development of an applicator attachment for spraying liquid formulations of bio-fungicides and micronutrients on the mat nursery loaded in the seedling tray of the machine, immediately before transplanting was also attempted. Economic parameters of three types of four-wheel riding type rice transplanters, viz. Yanmar Vp8D (TR 1 ), Yanmar Vp6D (TR 2 ) and Kubota NSPU- 68C (TR 3 ) were estimated considering the agronomic requirements of common rice varieties Uma, Jyothi and Prathyasha. For developing transport wheel system, 6-row Kubota make transplanter was selected. The wheel hub assembly was fabricated according to the design considerations. An electrically operated applicator attachment suitable for all makes of 6-row four wheel riding type transplanters were developed and successfully field tested. From the agro economic analysis, it was found that the annual fixed cost, annual variable cost and hourly operational cost were maximum for TR 1 , followed by TR 2 and the TR 3 respectively. The Unit Area Operating Cost (UAOC) was dependent on hourly operational costs and field capacities of the machines. TR 1 had the highest field capacity (0.4 ha h -1 ) followed by TR 2 (0.38 ha h -1 ) and TR 3(0.33 ha h -1 ). TR 1 had more UAOC than that of TR 2 and TR 3 up to the Annual Operating Hours (AOH) of 395 h. At 395 h UAOC of both TR 1 and TR 2 were equal. Beyond 395 h TR 2 had the maximum cost of operation among the three machines. Manual transplanting by labour contract required a cost of Rs. 10000 per ha and using these transplanters is economical than manual transplanting whenever the AOH is more than 102 h. The pneumatic wheels of 680 mm diameter and width of 100 mm were selected for front wheel. The front wheel has wheel track of 1.29 m. For rear wheel it has diameter of 720 mm and 130 mm width. The rear wheel track was 1.37 m. The maximum and minimum speeds possible using these wheels are 1.14 to 9.88 km h -1 . The applicator attachment had a 12 V electrically operated diaphragm pump, LDPE pipes as conduit, five solid cone nozzles fitted on a LDPE boom. The pressure developed by the pump was 620 kPa with a discharge of 1.89 l min -1 . The nozzles were selected based on the patternator studies. Five nozzles were placed at an equal distance of 35 cm on the boom of 1.8 m, with a spray span overlap of 14 cm. The droplet size was measured using bromide photo papers with pigmented spray solution and IMAGE-J image analyzing computer software. The droplet size at 50 cm height was in the range of 200 - 300 microns. The field studies on effect of pseudomonas fluorescence application revealed the enhanced growth of rice plants. No fungal attack was observed in the plots which were treated with pseudomonas. The plants subjected to application of ‘Sampoorna- KAU mutimix’ had increased plant height, more number of tillers per unit area, more productive tillers, more number of grains per panicle, higher paddy yield and increased grain weight.