Field Evaluation of Using the Nematophagus Fungus Dactylaria brochopaga for the Management of Root-Knot Nematode, Meloidogyne incognita Infecting Soybean, Glycine max

Abstract

A field experiment was carried out during 2020 growing season in a soybean field naturally infested with the root-knot nematode Meloidogyne incognita for evaluating the use of the nematophagus fungus, Dacylaria brochopaga, against nematode infection, compared with the chemical nematicide Furadan (Carbofuran). The fungus was prepared in two forms, as liquid (DBL) and granules (DBG) biocide. DBG and Furadan treatments were applied once at planting date, whereas DBL was applied once after seed germination. Results obtained indicated that DBG and Furadan treatments significantly reduced nematode final population (P_f) in soil by 32.4 and 36.5%, respectively, when soybean cv. Giza-22 was used, and by 47.1 and 48.2% when cv. Giza-111 was used, compared to the control treatment. DBL had no significant effect on P_f for both soybean cultivars. The root-gall index (RGI) at mid-season was not significantly influenced by DBG and DBL treatments, whereas Furadan treatment reduced RGI by 30.6% for cv. Giza 111 and 22.5% for cv. Giza-22. At harvest, RGI was significantly reduced with DBG and Furadan treatments by 31.6% and 33.3%, respectively, in case of cv. Giza-22 and by 39.3 and 42.9% in case of cv. Giza-111, respectively, compared to the control treatment. Whereas, no significant effect on RGI was obtained by the DBL treatment for both soybean cultivars, either at mid-season or at harvest, compared to the control. Soybean seed yield of cv. Giza 22 was significantly increased by DBG treatment (10.9%), and 12.3% in case of cv. Giza -111, compared to the control. DBL and Furadan treatments had no significant effect on seed yield of both cultivars.

Keywords:

Soybean, root-knot nematodes, predacious fungi, formulation, biological control.