Tall fescue (Lolium arundinaceum ) forms a mutualistic symbiosis with Neotyphodium coenophialum , which increases host plant fitness. Livestock consuming tall fescue containing the wild-type endophyte suffer from fescue toxicosis. The removal of the endophyte eliminates the symptoms of fescue toxicosis in livestock, but stands do not persist as well, especially during periods of summer drought stress. Novel endophyte strains are selected to maintain stand persistence and to eliminate the occurrence of animal disorders. Novel strains may differ in the mechanism by which they influence host desiccation and survival patterns. The objective of this study was to compare novel endophyte strains for their effect on the sensitivity of host tiller survival in terms of tiller-base desiccation tolerance and desiccation postponement. Six novel endophyte strains inoculated into a common host of ‘Kentucky-31’ were planted into pots 15 cm in diameter by 76 cm tall. After establishment, water was withheld for at least 23 days, after which pots were sequentially rewatered approximately every 3 days until 100% tiller mortality. Regression analysis was conducted using the Proc Genmod (SAS Institute, version 9.1) function to determine the lethal tiller-base water content (LWC ₅₀) and lethal duration (LD₅₀) associated with 50% tiller mortality. LWC₅₀ and LD₅₀ for all novel endophyte strains were not significantly different from the wild-type. Novel endophyte strains 4 and 16 had the highest LWC₅₀ (avg. 0.282 g H₂O/g DW). Strain 15 had the lowest LWC₅₀ (0.179 g/g), suggesting enhanced host tolerance to shoot desiccation. Strains 4 and 15 had the highest LD₅₀ (avg. 57.5 d), suggesting greater postponement of shoot desiccation. Novel endophytes apparently differ in their effects on shoot desiccation patterns.