Application of some fungal bioformulations for controlling garlic white rot disease in the field conditions

Two field experiments were conducted and executed during 2015 and 2016 to evaluate the effectiveness of six newly developed fungal bioformulations in controlling garlic white rot disease caused by Sclerotium cepivorum. The bioformulations were developed using three antagonistic fungi including Trichoderma harzianum, T. asperellum and Talaromyces flavus and rice bran as an organic carrier. They were selected based on their performance in the greenhouse conditions in a previous study, where they effectively controlled and reduced the garlic white rot disease. Field trials were conducted in a randomized complete blocks design with eight treatments (six bioformulations, an untreated control and a Carbendazim fungicide) each with four replicates. The garlic seeds (bulbs) were coated with each bioformulation and were sown in the field soil preinoculated with S. cepivorum. The incidence and the index of white rot disease severity were then determined in different treatments 90 days after sowing. Results showed that in the first year field experiment, most bioformulations were effective and reduced both disease factors significantly in comparison with the untreated control. The biofomulations R.B-T.h-1 and R.B-T.h-2, with 9.11% and 13.50% disease incidence, respectively, reduced the disease significantly and were as effective as the fungicide. However, in the second year due to the higher soil inoculum density, four out of the six applied bioformulations performed effectively in controlling the disease. The overall results of this study suggest that these newly developed bioformulations could replace harmful chemical fungicides in managing white rot disease in the garlic fields.