An integrated approach to developing nutrient management schemes for container-grown nursery crops

An integrated approach to developing nutrient management schemes for container-grown nursery crops

Summary

The selected nursery growers tested the use of mycorrhizae as part of the cultural practices. The growers found the use of natural mycorrhizae for Echinacea, Bigleaf Hydrangea and azalea increased their biomass, and flower numbers in Echinacea. Although the addition of mycorrhizae increased slightly but not significantly the biomass of each of Oakleaf Hydrangea and chamaecyparis, there were additional benefits such as increased nutritional levels were found in these plant species and all tested ones have gained. The tissue N and P concentrations were higher in Echinacea plants inoculated with natural mycorrhiza, only P in chamaecyparis. However, there was no significant difference in macronutrients levels was found in Oakleaf Hydrangea, Bigleaf Hydrangea, and azalea, However, tissue Cu, Fe, Mn, and Zn concentration were higher in Echinacea with mycorrhizal inoculation. Copper and Fe concentration were higher Bigleaf Hydrangea inoculated plants. Similarly, there was an increase in chamaecyparis tissue Cu and Zn concentration by 27% and 16%, respectively, in mycorrhizal-treated plants. For azalea, tissue Cu, Mn, and Fe concentrations were higher in mycorrhizal plants. These tested plants varied also in their response to root mycorrhizal colonization. The arbuscular index was almost twice in mycorrhizae-treated echinacea plants and significantly different from non-inoculated plants. Although the overall RMCI was not significant among treatments for Oakleaf Hydrangea, spore index was significantly different and was 3-fold higher in mycorrhizal plants. The overall RMCI and hyphal index were significantly higher for mycorrhizal-treated chamaecyparis plants when compared to control. Root mycorrhizal colonization index was significantly higher in inoculated azalea plants than in the control. The overall RMCI was not significant among treatments for Bigleaf Hydrangea.

Accomplishments/Milestones

Milestone 4 and performance target: Six nursery growers will implement and integrate nutrient management schemes in container nursery production practices after the third year of the project and continue to use these methods to increase sustainability of nursery production, profitability and protection of the environment. These six nursery growers will be the nucleus to demonstrate the practical application of mycorrhizae and exemplary stewards for their community.

Impacts and Contributions/Outcomes

We followed up with the selected six nursery growers and we found they became very interested in using the natural mycorrhizae and started to consider including natural mycorrhizae as part of the crop production system especially after they have learned, experienced, and observed the beneficial effects of using mycorrhizae. The Christmas and forestry growers were especially interested in adding the mycorrhizae to their seedlings especially at planting in field soils. The growers learned about the impact of using mycorrhizae for growing different plant species and how each plant could differ in its reaction to same source of mycorrhizae. While certain plant species could show visual and statistical increases in biomass, the data from tissue nutrition, root colonization, spore index, and hyphal index showed that additional benefits can be gained by using mycorrhiza and such benefits could also be extrapolated especially when plants are out-planted in landscapes. Spores and hyphal colonization are two important structures that aid in inoculating new soils and new roots. Except for Bigleaf Hydrangea, all tested plants showed root colonization and increase in either arbuscular, hyphal, or spore index. While mycorrhizal inoculated plants had higher levels of micronutrients than non-inoculated plants, it was interesting to find that the tested plant species varied in their Cu, Zn, Fe, and Mn tissue concentration.
One-on-one visitations to these nursery operations were made to explain further the uses of mycorrhizae and how to establish their own source of natural mycorrhizae on their operations.
We are currently working on collected data and running statistical analyses and preparing publications on the results gained in this project.
Presentations:

Zinati, G. M. and J. Dighton. 2009. Integration of natural mycorrhizae in production of container-grown nursery crops. Presented at the 2009 ASHS Annual Conference, St. Louis, MO July 28, 2009. (presentation was chosen for podcast recording at ASHS conference)

Abstracts:

Zinati, G. M. and J. Dighton. 2009. Integration of natural mycorrhizae in production of container-grown nursery crops. HortScience 44(4):1063-1064.