Biostimulation of lettuce growth with rhizobacteria in order to produce seedlings in seedbed

Abstract

Plant growth-promoting rhizobacteria (PGPR) are an alternative for optimizing resources in agricultural crops. Therefore, the effect of five bacterial strains on the growth of lettuce seedlings in seedbeds was evaluated using a 20% Stainer nutrient solution. The experiment included five strains and a control, with four replicates of 20 plants each one. Seedlings were inoculated 3 days after emergence. They were watered with a 20% Stainer nutrient solution. Harvesting took place after 35 days, and the variables evaluated were leaf area, dry weight, and nitrogen (N), phosphorus (P), and potassium (K) content. Paenibacillus BSP1.1 and Bacillus licheniformis JP13 were the strains that showed the greatest effects; particularly BSP1.1 increased leaf area by 124.3%, dry weight by 112.5%, and N content by 74.6% compared to the control. The other strains showed lower effects, without statistically outperforming the control. Inoculating seedlings with rhizobacteria such as BSP1.1 and JP13 to stimulate growth can be very useful in obtaining vigorous lettuce seedlings that lead to successful transplanting in the field or in hydroponic systems, considering that lettuce is one of the most consumed leafy vegetables in the world.