BIOLOGICAL CONTROL OF STRAWBERRY ROOT ROT THROUGH NON-PATHOGENIC ISOLATE OF RHIZOCTONIA FRAGARIAE HUSSAIN AND MCKEEN

Rhizoctonia solani Kuhn and R. fragariae play a very important role in strawberry root rot.
This survey was carried out to investigate the possibility of limiting the damage caused by R. fragariae (RF) by a non-pathogenic isolate of the same species.
The trials were carried out with strawberry micropropagated plantlets (cv.
Gorella). Five experiments were planned: 1) the plants were inoculated with pathogenic isolate RF93 and placed in sterile sand; 2) the plants were inoculated with non-pathogenic isolate RF94 and placed in sterile sand; 3) the plants inoculated with RF94 were transplanted in sand inoculated 12 hours before with RF93; 4) the plants inoculated with RF93 were transplanted in sand inoculated 12 hours before with RF94; 5) the plants were treated with distilled water and placed in sterile sand.
Thirty plants for each thesis were used.

The assay was carried out in a phytotronic room at 24C, 70% humidity and 12 h-photoperiod.
The results were collected after 40 days; the root rot intensity was estimated (0–3). The plants of Treatment 1 were the most damaged (D.I. = 2.66). The plants of Treatment 2 were healthy (D.I. = 0.4). Treatment 3 plants resulted moderately infected (D.I. = 0.8). The protective activity of the non-pathogenic isolate RF94 versus the pathogenic isolate RF93 was largely shown.
This result can be explained by root mycrorrization and a faster colonization by the non-pathogenic isolate.

II International Strawberry Symposium

N. D’Ercole

https://doi.org/10.17660/ActaHortic.1993.348.107