Field and laboratory investigations into the effectiveness of Rhodotorula glutinis (isolate 10391) against Botrytis cinerea Pers. ex Fr. in strawberry

Rhodotorula glutinis (isolate 10391) was isolated from mature strawberry fr uits and tested in laboratory and Field investigations for antagonistic act ivity against Botrytis cinerea, the causal agent of grey mould in strawberr ies. The cell suspension of R. glutinis effectively reduced germination rat e and germ tube growth of conidia of B. cinerea in aqueous strawberry fruit pulp suspension (1 %) by 53.2 % and 68.8 %, respectively. The antagonistic activity of R. glutinis on detached strawberry leaf disks strongly depende d on temperature and cell density of the antagonist. Highest effectiveness was observed at 10 degreesC, which has major importance for field applicati ons. The effectiveness of R. glutinis treatments in Field trials carried ou t during blossom to control grey mould in fruits was 12.8 % in 1996 (with a rtificial inoculation) and 33.2 % in 1999 as compared to the control. The a ddition of CaCl2 (1 %) to the antagonist preparation (in 1999) had no posit ive influence on the effectiveness of R. glutinis.