Morphological and Mechanical Characteristics of Onion Seedlings Insight to Mechanized Transplantation

Abstract

Background: Onion is a widely accepted as vegetable as well as spice crop, sharing a 14.31 lakh ha area with 267.3 lakh MT production in 2020. Improved management structure and healthy seedling are important factors in overcoming the cause and even developing effective transplanter. The information of morphological properties is essential before designing modern farming equipment. Methods: Present study focuses on the properties and age of seedlings for automated transplanting, five majorly cultivated varieties of onion Light red gavran, N-53 Nasik red, AFDR, KSP-117 and Nafed were selected. The morphological (height, weight, diameter) and mechanical (compressive strength and static coefficient of friction) properties were measured under 10 days intervals to compare 30-70 days seedling. Result: Bulb and stem diameter were in the range from 2.82 to 3.82 mm and 0.86 to 2.12 mm, respectively. The model was found significantly different with concerning days. Plywood and aluminium had less influence on the seedling’s outer surface moisture content. The morphological parameters and compressive strength increased while a static coefficient of friction reduced with an increase in the age of the seedling. Regression and ANN (using FFBP method) models were developed for the prediction of compressive strength of seedling stem as well as a bulb with respect to the age and diameter. The ANN model was found best with the coefficient of determination of 0.76. It is concluded that 60 and 70 days, seedling is best suited for mechanical or automated transplanting.