Optimization of the performance of a metering unit for precision seeding of Coriander seeds (Coriandrum sativum L.) using Box-Behnken Design

Abstract

Objective: The objective of this study was to find out the seed spacing performance of a vacuum type precision metering unit for seeding coriander seeds (Coriandrum sativum L.). Materials and Method: In order to meet this objective, experiments were conducted in the laboratory conditions and a vacuum type precision seeder was used. Box-Behnken design based experiments with three independent variables, with three levels for each was conducted in the laboratory. These variables were considered to be the hole diameter on vacuum plate, forward speed of the seeder and the vacuum. The data obtained were evaluated for five different performance indicators for defining the seed spacing quality. The performance indices were selected to be quality of feed (Iqf), multiple (Imulti) and miss index (Imiss), precision (Ip) and coefficient of precision (CP3). Results: Polynomial functions were tried to develop for each indicator. As a result of regression analysis for all indices, only one polynomial function for Iqf was obtained without lack of fit. From the polynomial function, the optimum diameter of the hole on vacuum plate, forward speed of the seeder and vacuum was found to be 1.75 mm, 1.5 ms-1 and 47.7 mbar, respectively. Conclusions: The Iqf value at these optimum points was calculated to be 94.7 % while the verification tests of these optimums experimentally resulted in an average value of 97.3%.