Development of a picking and dropping mechanism for protray grown vegetable seedlings

Abstract

In India, manual transplanting of vegetable seedlings was the commonly adopted method for raising vegetable crops, but it is laborious, time-consuming and costly. Therefore, mechanical transplanters are developed to overcome the problems in manual transplanting. The present work was to develop multiple seedlings picking and transferring mechanism for protray grown vegetable seedlings. Tomato (Solanum lycopersicum), chilli (Capsicum annuum) and brinjal (Solanum melongena) seedlings were raised in portrays with coir pith as a growth media and used for transplanting operation. The mechanism was to pick seven numbers of seedlings in one row at a time and transfer them into lateral conveying system, which could deliver the seedlings one by one on to the ground at regular interval. Programmable Logic Controller was used to controlling entire operations of seedlings picking and dropping. At the time of evaluation, a totally 196 number of seedlings were used with 98 cell protray. From the test results, the success rate of 89.28 per cent, missing seedling of 3.57 per cent, damaged seedling of 4.08 per cent, seedling delivering failure of 3.06 per cent were recorded for tomato seedlings. Similarly, in chilli and brinjal the success rate of 95.40 and 91.83 per cent, the missing seedling of 2.04 and 2.55 per cent, damaged seedling of 1.53 and 3.06 per cent and seedling delivering failure of 1.02 and 2.55 per cent respectively were observed. Transplanting frequency of developed mechanism was 2520 seedlings h-1.   As a whole, this work was able to develop a working model of vegetable seedling transplanting mechanism, which can eject seven seedlings at a time from portray cell and transfer them into the slotted conveyor.