Some performance aspects of seed maize processing operations

Abstract

The processing of seed maize includes such activities like drying, shelling, cleaning, sizing or grading, chemical treatment and bagging. Most of these unit operations are capable of affecting the quality of seed if proper control is not instituted. The objective of this thesis is to analyse some performance aspects of an existing commercial seed maize processing plant of the Kenya Seed Company Limited. A good portion of this work has dealt with drying and damage to seed during shelling since it was felt that the two areas are more critical in the present situation. Various recommendations are suggested that can further improve the performance of the seed processing plant. The field tests were carried out at Seed Driers Limited in Kitale between November 1989 to September 1990. The parameters used in the analysis include the germination capacity of dried seeds, grain damage through mechanical shelling and performance factors of cleaning and sizing operations. The results obtained show that maize ears dried at the top and those dried at the bottom of the bin behave differently when their drying curves and germination are compared. No statistical significance was found when the effect of sheller speed on grain damage was considered even though certain varieties tend to generate more damaged seeds after processing. Hybrid variety number 512 produced the largest amount of chipped grains, while varieties H625 and H614 generated more screenings.