Effect of Seed Pelleting Application of Plant Growth Promoting Bacteria on Germination and Growth of Lettuce (Lactuca sativa)

Abstract

Plant growth-promoting bacteria (PGPB) are commonly used to pellet seeds. Different bacterial strains affect germination and plant growth in varying ways. The objective of this experiment was to study the effects of seed pelleting with three strains of bacteria on changes in germination, vigor, seedling growth, and the plant growth of lettuce. The experiment followed a completely randomized design with four repetitions and five treatments: without pelleting (T1), pelleting with CaSO4-zeolite only (T2), pelleting with 1×107 CFU/mL Stenotrophomonas sp. strain sk3 (T3), pelleting with 1×108 CFU/mL Burkholderia sp. strain 3-DB05 (T4), and pelleting with 1×108 CFU/mL Enterobacter sp. strain 4-RB05 (T5). Burkholderia sp. and Enterobacter sp. were more effective in producing indole-3-acetic acid (IAA), and pelleting seeds with these strains resulted in higher germination rates and seedling growth compared to unpelleted seeds when tested in both laboratory and greenhouse conditions. Seed pelleting with 1×108 CFU/mL Enterobacter sp. promoted plant growth and resulted in significantly higher leaf and root weight. Therefore, seed pelleting with 1×108 CFU/mL Enterobacter sp. strain 4-RB05 is recommended to improve the germination and plant growth of Red Oak Leaf lettuce seeds.