RESEARCH ON THE ROOT ROT COMPLEX OF STRAWBERRY PLANTS.

Fungal diseases of the root system of the strawberry constitute the most difficult problems of this plant's pathology. Symptoms differ according to which parasite prevails. The problem most feared by strawberry growers, however, is that of the death of the plant after summer-autumn transplanting.

The results were grouped into three periods on the basis of the appearance of post-transplant decline symptoms: (I) appearance after 10-15 days; (II) appearance after 50–60 days; (III) appearance in the following spring. Mycological analyses of the root system, leafstalks and peduncles of each group were conducted.

The results are presented according to the abovementioned scheme. The in vitro analyses showed results that differed greatly. In group (I) mainly saprophytic fungi (Penicillium, Aspergillus and Rhizopus) were isolated. Phytophthora cactorum, Verticillium dahliae, Rhizoctonia fragariae, Rhizoctonia solani, Idriella lunata etc. were isolated with relative ease from group (II). Group (III) showed the same fungi as in group (II) with a prevalence of Rhizoctoniae and Verticillium.

Experimental results are also reported for a reduction in post-transplant summer death with the use of Trichoderma viride.

A discussion of all results follows.