High Soil Temperature and Water Relations of Endomycorrhizal Nursery Crops2
High root-zone temperatures can stress plants and reduce nursery productivity of container-grown crops. Predawn shoot water potential was initially increased (less water strain) by root-zone temperatures from 40° to 45°C (104° to 113 °F) and then subsequently declined after 3 days. Stomatal conductance (SC) was reduced at similar root-zone temperatures. Hydraulic root conductance (Lp) increased linearly in response to increasing root-zone temperatures for high temperature tolerant species, and quadratically for susceptible species. Endomycorrhizal fungi colonization enhanced high root-zone temperature stress tolerance at moderate temperatures from 35 ° to 40°C (95 ° to 104°F).
Contributor Notes
Published as Journal series number 6465 of the Mississippi Agricultural and Forestry Experiment Station, Mississippi State, MS 39762. Paper presented at the Mycorrhiza Working Group Workshop “Mycorrhizal Fungi and Host Plant-Water Relations,” during the joint XXII International Horticultural Congress and the 83rd Annual Meeting of the American Society of Horticultural Science, Davis, California, August 14, 1986.
2The findings cited herein are a condensed version of results previous ly published by Newman (33) as a portion of a PhD Dissertation. These studies were funded in part by the Center for Energy and Mineral Resources, Project 18826 and the Texas Transportation Institute, Project 31120. Plant materials were provided by Mr. Grady Wadsworth of Greenleaf Nursery, El Campo, TX and Mr. William Barr of Hines Nursery, Rosenburg, TX.
3Assistant Professor of Horticulture.
4Associate Professor of Horticulture.