Study on seed pelleting and performance of welsh onion (Allium fistulosum L.)

Seed pelleting is among the important types of seed coating. Compared with conventional seed coating, seed pelletization not only changes the seed shape and standardizes the seed appearance but also carries a larger amount of active ingredients with better compatibility. In this study, the irregular welsh onion (Allium fistulosum L.) seeds were pelletized, the performances of different fillers and binders for seed pellet granulation were investigated, and the microstructures of the prepared pellets with the optimized formulations were characterized. The results showed that the application of magnesium stearate mixed with talcum powder at a mass ratio of 1 : 2 as a filter and 1% CMC solution as a binder was favorable for the pelletizing of welsh onion seeds. The pelleted seeds were qualified in all indexes and met the standards of seed pelletization. The SEM observations of microstructures showed that there are significant differences among the pellets prepared by different fillers, and the tighter the bonding between fillers, the greater the strength of the pellets. The quality assessment of the pelletized seeds with pesticides showed that the reasonable addition of appropriate pesticides had little effect on seed germination. This study enriches the basic theory of seed pelleting via the combined evaluation of macroscopic properties and microstructures and provides a useful guideline for the improvements of precision sowing and standardized planting.