Efficacy of vermicompost and/or plant growth promoting bacteria on the plant growth and development in gladiolus

The use of environmental and sustainable ornamental flower production practices with renewable resources has drawn worldwide interest. One of these renewable resources is vermicompost (earthworm castings). In recent years, increasing demand for improving environmental quality have focused on the importance of Plant Growth Promotion Bacteria (PGPBs) in agriculture. Vermicomposts also help microbial agents function effectively in soil. In this study, a total of six treatments [A: PGPB formulation, B: Not autoclaved vermicompost, C: Autoclaved vermicompost, D: Not autoclaved vermicompost+PGPBs, E: Autoclaved vermicompost+PGPBs, F: Control (untreated bacteria and vermicompost)] were tested for their effects on the plant growth and development parameters in gladiolus (Gladiolus grandiflorus L. ‘Red Beauty’) in greenhouse condition. Vermicompost was added to the related pots by dissolving in water. After the addition of vermicompost, PGPB formulation was given immediately to related pots. All the treatments were applied to soil once in three leaf stage, close to the plant root zone. Parameters in terms of yield and quality attributes of plant and corm were determined and analyzed. The treatment A increased in plant height of gladiolus of 24.55% rate. The earliest times to flowering was determined in E application (100.48 day), which also increased in corm diameter with rate of 17.41% and number of corms and cormels with rate of 151.83% according to F application. Results indicated that the treatment E promoted overall better performance as compared to other treatments diameter of flowers for number of leaves per plant, number of florets per spike, stem diameter, spike length, fresh and dry weight of flowers, the number and diameter of corm. Autoclaved vermicompost can be good choice in gladiolus cultivation but it should be enriched with PGPB.