High Soil Temperature and Water Relations of Endomycorrhizal Nursery Crops

by Steven E. Newman, and Fred T. Davies, Jr.

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 degrees C (104 to 113 degrees F) and then subsequently declined after 3 dats. Stomatal conductance (SC) was reduced at similar root-zone temperatures. Hydraulic root conductance (Lp) increased lincarly 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 degrees C (95 to 104 degrees F).

J. Environ. Hort. 5(2):93-96. June 1987