Management of Crown and Root Rot Diseases in Strawberry Commercial Fields in Egypt

Abstract

Surveyed strawberry fields at three different districts (Abo Swar, EL-Kassasin and El-Manayef) in Ismailia Governorate during 2014 -2016 growing seasons showed that 13 fungal species belonging to 13 genera were isolated from infected roots, runners and crowns segments of strawberry plants. The most frequent isolated fungi were; Macrophomina phaseolina (53.33%) and Colletotrichum acutatum (33.33%). These two pathogenic fungi were used in this study. Biological and chemical control experiments were conducted and significant differences in diseases incidence (DI%) and disease severity (DS%) were found among treatments of bioagents and chemical fungicides compared with control treatments. DI and DS percentages reached 0% when Bacillus subtilis or Rizolex were applied in plots of artificial infested soil with M. phaseolina and C. acutatum. Trichoderma harzianum occupied the second rank after B. subtilis, Rizolex (15 and 7.4% for DI) for M. phaseolina , (10 and 6.5% for DS)for C. acutatum, T. viride (16 and 16% for DI), (26 and 11% for DS) and Streptomyces canescens (20 and 21% for DI), (25 and 26% for DS), respectively. Moreover; Rizolex gave best results in pathogens control more than Topsin-M fungicide. In field experiment; the effect of soil disinfection using three treatments; two fumigants (Methyl bromide and Agrocelhone) and solar heating solarization applied on two strawberry cultivars (Festival and N-70) during 2015 and 2016 seasons were studied. Soil fumigation with Agrocelhone™ compound and Methyl bromide (MB) led to the best results for soil disinfection on both Festival and N70Strawberry cultivars during two seasons. Percentage DI and DS of crown and root rot diseases occurred were (9.4, 9.0%) and (8.4, 7.5%) for both cultivars, respectively in 2015 it was very low (2.9, 3.0%) and (2.5 and 3.0%); respectively when applied again in 2016.