Cobweb disease in white button mushroom (Agaricus bisporus) is a newly identified disease caused by Cladobotryum mycophilum in China. Currently, there are few highly effective and safe fungicides for controlling this disease in the field. This study assessed the fungicidal effect of prochloraz–manganese chloride complex and seboctylamine acetate against C. mycophilum, as well as their ability to control cobweb disease. Additionally, the residues of these fungicides in the mycelium and the mushroom were evaluated. The extent of the fungicidal effect against the pathogen was determined based on the efficiency of crop production. The results revealed that, in addition to the potent inhibitory effect of prochloraz–manganese chloride complex on the hyphae of C. mycophilum, the domestically developed seboctylamine acetate exhibited high toxicity, inhibiting both mycelial growth and spore germination of C. mycophilum, with EC₅₀ values of 0.990 mg/L and 0.652 mg/L, respectively. Furthermore, the application of the two chemical agents had no adverse effects on the mycelial growth and fruiting body growth of A. bisporus, and the residual amount of chemical agent was lower than the maximum residue limit standard. The field application results showed that 400 mg/L of prochloraz–manganese chloride complex and 6 mg/L of seboctylamine acetate resulted in 61.38% and 81.17% disease control respectively. This study presents efficient and safe fungicides for controlling cobweb disease in white button mushroom. Additionally, a residue determination analysis of the fungicide seboctylamine acetate in mushroom crops is described.

The yellow spot disease of Pleurotus ostreatus, caused by the bacterium Pseudomonas tolaasii, poses a threat to both the yield and quality of oyster mushrooms due to the limited availability of effective bactericides and the insufficient comprehensive safety assessments for the chemicals applied in the field. In this study, we performed greenhouse toxicity tests to identify highly effective bactericides against P. tolaasii, while simultaneously assessing their safety for P. ostreatus. Subsequently, we verified the field efficacy of the selected bactericide and its impact on mushroom yield through field experiments. Additionally, we established detection methods for the selected highly effective and safe bactericides in P. ostreatus and measured their residue levels during the evaluation. Our findings indicated that kasugamycin and seboctylamine acetate displayed potent inhibitory effects against P. tolaasii. The field application results showed that 1.8% seboctylamine acetate AS with concentrations of 3 mg/L exhibited good disease control, achieving 83.00%, which is comparable to the efficacy of the registered kasugamycin. Furthermore, the application of seboctylamine acetate did not adversely affect the yield of P. ostreatus, and the detected chemical residues were below the maximum residue limit. Seboctylamine acetate is anticipated to serve as a viable substitute for the currently registered fungicides, holding the promise of offering comparable or superior performance while potentially addressing concerns related to environmental impact and sustainability.