Effects of plant-growth-promoting microorganisms and fertilizers on growth of cabbage and tomato and Spodoptera litura performance

Fertilizer and plant-growth-promoting microorganisms (PGPMs) both benefit crop growth; however, little is known about the interaction effects when they are combined. This study assessed the effect of PGPMs and fertilizer on plant growth, foliar chemistry, and subsequent insect feeding. Cabbage and tomato plants were inoculated with PGPMs (fungi and bacteria) and various levels of fertilization. Plant growth parameters (fresh weight, dry weight, and leaf area) and foliar chemistry (water content, protein content, and polyphenol oxidase activity) were then analyzed. In addition, foliage was also fed to the third instar larvae of Spodoptera litura to evaluate foliage quality. The results indicated that plant performance differed significantly among treatments, and the combined fungi Meyerozyma guilliermondii and fertilizer treatment promoted the greatest plant growth. In summary, PGPMs and fertilization can have their own effect; their interaction effect, however, need to be clarified. (C) 2014 Korean Society of Applied Entomology, Taiwan Entomological Society and Malaysian Plant Protection Society. Published by Elsevier B.V. All rights reserved.