Antagonistic bacteria for biospace control of roselle spot (Corynespora cassiicola) of Hibiscus sabdariffa

In recent years, Corynespora cassiicola induced spotted of roselle threatens calyx production. The objective was to determine if some bacterial strains inhibit the development of C. cassiicola in vitro and under biospace conditions. The inhibition of development was due to the dual confrontation of the bacteria: food (20), amphibian skin (41), tailings (22), air (seven) and rhizosphere (10) against the fungus. Plants of jamaican “Creole” variety were sown and artificially inoculated with C. cassiicola . From the beginning of symptoms of the disease, the selected bacterial strains with the highest percentage of inhibition were inoculated. AUDPC was evaluated. Only seven strains inhibited the development of the fungus in vitro from 62.7 to 100%: Klebsiella pneumoniae (M10-1 and M10-10), Acinetobacter lwoffii (A5), Sphingomonas paucimobilis (NF21), Serratia marcescens (M13ACD), S. liquefaciens (M8ACD) and Acinetobacter sp. (5H2). Regarding leaf severity, the M10-1 and M10-10 strains reduced AUDPC by 9.5 and 12.6%, respectively, followed by NF21 (AUDPC 14.5), the control registered the highest levels (AUDPC 45.7). For the severity in calyces, the AUDPC analyzes of all the strains exercised control by reducing severity levels (17.1-8.6 AUDPC).