Molecular Confirmation of Figs Root-Knot Nematode Meloidogyne incognita and its Chemical Control Integrated with Fungal and Bacterial Formulation

Abstract

This study was conducted in one of figs orchards in Bani Muslim region of Babil, central Iraq, for the seasons of 2022 and 2023, to evaluate the efficiency of the single treatment with Oxamyl, Imicyfose or the Biohealth fertilizer in reducing root-knot nematode (RKN) Meloidogyne incognita infection and improving figs yield compared to the same treatments followed foliar Oxamyl during the growing season. The nematode was characterized by the adult female perineal pattern, which was confirmed by molecular identification by PCR, which was successful in amplifying the DNA even with a small concentration of one J2 juvenile DNA. The results of amplified DNA sequence showed 100% genetic sequence similarity with M. incognita registered in the GenBank database compared with reference accession number# NC-024097.1 according to the NCBI. The results of the field experiment show the efficiency of all treatments in reducing nematodes density despite the differences among treatments. The highest reduction in M. incognita density in figs roots and soil combined was recorded in the treatment of Biohealth by 58 and 67% where applied alone or followed by foliar Oxamyl during the first season, which increased to 66 and 78% in the second season, respectively. Ground treatment with Oxamyl decreased nematode density by 55.9% in the single treatment to 73.4% where followed by foliar Oxamyl in the second season. It is generally noted that Imicyfose was relatively less efficient, but it also reduced M. incognita density by 54 to 56% in the single treatment and by 59 and 70% with the following foliar Oxamyl respectively. All the treatments lead to a relative increase in the weight of 100 fruits, at least by 28 and 32% in Imicyfose to the highest by 42 and 45% in Biohealth treatments enhanced with foliar Oxamyl for the two seasons, respectively.

Keywords:

Root-knot, plant nematodes, biological control, figs.