Effect of Seed Pelleting with Methyl Hydroxylethyl Cellulose and Carboxymethyl Cellulose on Physical Characteristics and Seed Quality of Lettuce (Lactuca sativa)

Abstract

     Lettuce seeds are small and less food accumulated in the seed. When being grown, seedlings have low germination rate and vigor. Therefore, lettuce farmers import pelleted seeds from other countries instead. Creating a pelleting substance formula for farmers’ own use is an important step to improve lettuce cultivation in Thailand. This study aims to find an appropriate type and a concentration level of binder material for lettuce seed pelleting. A randomized complete block design with four replications was used as the experimental design. Seeds were put in two main groups, which were those pelleted with five concentration levels of methyl hydroxyethyl cellulose (MHEC) which were 0.3%, 0.4%, 0.6%, 0.8%, and 1.0% (w/v) and those pelleted with the same five concentration levels of carboxyl methyl cellulose (CMC) as in the first seed groups. 130 grams of zeolite were used as a pelleting material per 10 grams of lettuce seeds. The experiment results showed that the pelleted seed with 0.3% and 0.4% (w/v) were the concentration levels of MHEC and CMC that made pellet forming the easiest and easy, respectively. After testing the quality of the pelleted lettuce seeds, it was found that the seeds pelleted with 0.4%, 0.6%, and 0.8% (w/v) of CMC had higher speed of germination and the differences were statistically significant when compared to other seed pelleting methods under laboratory conditions. At the same time, under the laboratory conditions, seeds pelleted with 0.4% (w/v) of CMC had higher root length and shoot length when compared to seeds that were not pelleted. Those differences were found statistically significant. Hence, after considering the experimental results from all seed pelleting methods, it can be concluded that pelleting red oak lettuce seeds with 0.4% (w/v) of CMC is the most proper concentration level.