Bioefficacy of Trichoderma asperellum and Penicillium raperi filtrate culture consortium for suppressing bacterial stalk rot disease (Dickeya zeae) and improving the initial growth of corn seedlings

Abstract Background Dickeya zeae is an emerging cosmopolitan soil-borne pathogenic bacterium that causes corn stalk rot disease in Indonesia. Environmentally friendly control using antagonistic fungal filtrates is an effective and efficient alternative option for suppressing this pathogen’s progression. This study aims to evaluate the efficacy of the Trichoderma asperellum and Penicillium raperi filtrate culture, either singly or in consortium, in suppressing the growth and development of D. zeae and improving the initial growth of corn seedlings. Results The BusbakSR22 bacterial isolate was identified as D. zeae with a genetic distance coefficient of 0.001–0.007 and homology > 98%. There were three consortium treatments (6A-7A-9, 6A-02-10, 7A-02-10) and three single treatments (CHM01, HMRP9, HMRP10) which were significantly able to suppress the growth of D. zeae colonies on NA media with inhibition percentages ranging from 36.60 to 65.58%. The 6A-7A-9 and 7A-02-10 consortium treatments were consistently able to suppress the bacterial stalk rot disease progression inside a screen house and act as a biostimulant in improving corn seedling growth, especially maximum growth potential, growth rate, and vigor index. Conclusion The 7A-02-10 consortium treatment consistently showed better performance than the other treatments in suppressing the growth and development of D. zeae both in vitro and in planta and improving the growth of corn seedlings.