Finding practical solution to reduce the effect of fungicides coating crop seeds on bacterial bio-inoculants

Document Type : Original Article


1 Microbiology Dept., Soils, Water and Environment Research Inst., ARC, Egypt

2 Maize and sugar Crops Dis. Dept., Plant Pathol. Res. Inst., Agric. Res. Center, Giza, Egypt.

3 aAgricultural microbiology department, Soils, Water and Environment Research Institute (SWERI), Agriculture Research Center (ARC), Giza, Egypt.


Seed coating is the most frequently used method in application of bio-fertilizers in different crops. The treatment of seeds with fungicides for storage purposes or protection during germination represents a challenge for application of bio-fertilizers by seed coating. In the current work, the antibacterial properties of five commercial fungicides known to be used in seed protection were screened against ten bacterial strains used as bio-fertilizers (Azotobacter salinestris, Azospirillum brasilense, Azospirillum lipoferum, Enterobacter cloacae, Rhizobium leguminosarum , Rhizobium phaseoli, Bacillus subtilis, Bacillus amyloliquefaciens, Paenibacillus polymyxa, Bacillus aryabhattai ) in addition, commercial sugar beet seeds dressed with unknown fungicids were also tested and the fungicide with antibacterial activity was selected and identified using gas chromatography (GC) to be used in further work. Sugar beet Seeds treated with selected fungicide were coated with different materials (Talc powder, Biochar, Charcoal, Polyvinylpyrrolidone (PVP), Beet moss) with expected adsorption properties and the effect of this materials in protection of bio-fertilizes was studied in agar plates. The most promising treatments were applied in a pot experiment using sugar beet (Beta vulgaris) seeds. The growth of most bacterial strains was not inhibited by already known fungicides except Rhizobium phaseoli which was inhibited by Tebuconasole 2.5% while one unknown fungicide showed a remarkable antibacterial activity against most bacterial strains under study. The GC-MS identification revealed that this fungicide is thiram. The most effective material in protection of microbial strain was charcoal.


Main Subjects

Volume 6, Issue 2022
Pages 1-8
  • Receive Date: 16 January 2022
  • Revise Date: 26 January 2022
  • Accept Date: 02 February 2022
  • First Publish Date: 02 February 2022