Can Bacteria Be Beneficial for Cut Flowers?

A gram of soil can contain billions of microorganisms. Many of these microorganisms are bacteria that live in the rhizosphere, the region of the soil near the plant roots. The bacteria feed on sugars, amino acids, and organic acids in plant root exudates, and the relationship is either beneficial, harmful (e.g. pathogens), or neutral to the plants. Beneficial bacteria can promote plant growth and enhance tolerance to both abiotic and biotic stresses. This is a dynamic relationship that is influenced by many other environmental and biotic factors. In soils where nutrients are limiting, bacteria can increase the availability of macro- and micronutrients and improve uptake efficiency. In the presence of these bacteria, plants can thrive with lower fertilizer inputs.

While the culturable bacteria in the soil are only around 1% of the population, beneficial bacteria available in both commercial products and research collections have been shown to promote plant growth and/or enhance stress tolerance. In the D.C. Kiplinger Floriculture Crop Improvement Program at The Ohio State University, we are investigating the use of beneficial bacteria to improve the production and postproduction quality of greenhouse crops. The objective of this research is to determine if beneficial bacteria applications during production can enhance vase life and flower quality of zinnias grown at reduced fertilizer levels compared to those grown with optimal fertility.

We are testing both commercial biostimulant products, and bacteria from an OSU collection. Growing media is drenched weekly with the bacterial treatments and plants are fertilized with either 1X or 0.5X fertilizer (150 or 75 ppm N) from 15N-2.2P-12.5K-2.9Ca-1.2Mg water soluble fertilizer (Jack’s Professional LX, J.R. Peters). Flower vase life and quality are assessed for all treatments. Biostimulants that contain beneficial bacteria provide cut flower growers with a tool to increase flower quality, while reducing fertilizer inputs.

We hypothesize that the improved plant health and stress tolerance we have observed with containerized plants will translate into improved flower quality and vase life for cut flowers.

Use of beneficial bacteria in cut flower production systems to enhance flower longevity when plants are grown at lower fertility levels

Michelle Jones

Professor and D.C. Kiplinger Floriculture Chair

Michelle Jones is Professor and D.C. Kiplinger Floriculture Chair, The Ohio State University. Contact her at [email protected]