Tolerance of AR1 <i>Neotyphodium</i> endophyte to fungicides used in perennial ryegrass seed production

Abstract

Perennial ryegrass (Lolium perenne) with the elite new AR1 endophyte (Neotyphodium lolii strain AR1) was treated with fungicides used for stem rust (Puccina graminis) control during head emergence flowering and seed development Field trials were carried out over two seasons evaluating triazole and strobilurin fungicides and mixtures of these two groups of fungicides applied either one or two times (Trial 1) or two or three times (Trial 2) Seed yields were measured and endophyte viability tested with growout tests of freshly harvested seed Seed yields were increased by 76 to 83 with double applications but not by single applications of azoxystrobin and epoiconazole in Trial 1 In the second year (Trial 2) seed yields were increased by between 13 and 27 with triple applications of these two fungicides and their mixtures Endophyte viability was not affected by any of the fungicide treatments