Effects of Chemical Fertilizers and New Fertilizers on Antagonism between Beneficial Fungi and Fusarium

In this study, the effect of chemical fertilizers (urea, ammonium sulfate, diammonium phosphate, potassium dihydrogen phosphate, potassium chloride and potassium sulfate) and new fertilizers (ferment fertilizer, fulvic acid and poly γ-glutamic acid) on the growth and antagonistic effects of beneficial fungi and Fusarium was explored by plate confrontation method and interaction analysis, with no fertilizer addition as control. The results showed that under the single inoculation condition, potassium chloride significantly promoted the growth of beneficial and pathogenic bacteria, while diammonium phosphate significantly inhibited the growth of beneficial fungus Chaetomium truncatulum F8. Urea and ammonium sulfate inhibited the growth of beneficial fungus Gongronella butleri F4. The growth of Fusarium was inhibited by poly γ-glutamic acid and potassium sulfate. The interaction analysis showed that both fertilization and beneficial fungi inoculation significantly influenced the growth of Fusarium, and the two factors showed obvious interaction effects. Under antagonistic conditions, potassium dihydrogen phosphate significantly inhibited the growth of Fusarium sp. Y56, Fusarium fujikuroi Y1 and Fusarium oxysporum F2, and poly γ-glutamic acid significantly suppressed Fusarium oxysporum F33 and Fusarium fujikuroi Y1. In agricultural areas where Fusarium disease occurs frequently, potassium dihydrogen phosphate and potassium sulfate are suitable fertilizers. It is recommended to combine the application of poly γ-glutamic acid with urea and ammonium sulfate.