Effects of seed pelleting formulae on seed germination and vigor of tobacco seeds (Nicotiana tabacum L.)

Abstract

The tobacco (Nicotiana tabacum L.) seeds are very small: the size of seed is about 0.4-1.3 mm. One gram of tobacco seeds contains about 10,000-12,000 seeds. The very small size of tobacco seeds makes it so difficult to produce seedlings. The pelleting of seeds can solve this problem because it can improve a tobacco seed’s size and weight. The objective of this experiment was to find out suitable methods and best formulations of seed pelleting for tobacco seeds. The experiment was conducted at the Seed Processing Plant, Faculty of Agriculture, Khon Kaen University; and was arranged in a completely randomized design with 4 replications. Seven formulations of seed pelleting were pelleted with tobacco seeds. Each formulation used 150 g of the following per 3 g of seeds: calcium carbonate, talcum, limestone, bentonite, zeolite, pumice and no pelleting (control). Hydroxylpropyl methylcellulose (HPMC) was used as adhesive with concentration of 4 percent by weight. The results showed that seeds pelleted with pumice can form a suitable pellet with high seed uniformity. The pelleted seeds had about 3.61% more weight when compared with that non-pelleted seeds. After pelleting, the seeds with pumice contained 1-2 seeds per pellet, and had the best solubility in water when compared with that of other formulations. Moreover, pumice had the highest adhesive binding percentage of about 97 percent, and the lowest pelleting friability of about 0.57 percent. Concerning the quality of tobacco seeds after pelleting with pumice, they had higher germination percentages and speeds of germination under laboratory and greenhouse conditions than those of other treatments, but not significantly different from those of the seeds pelleted with talcum. After testing seed vigor of pelleted seeds by accelerated aging, pumice showed the highest germination percentages and speeds of germination in both conditions. In conclusion, this experiment showed that pumice is the most suitable material for pelleting tobacco seeds as they give the highest seed vigor and germination.