Application of Ascophyllum nodosum extract and its nutrient components for the management of Meloidogyne javanica in soybean

Luanna Karoline Rinaldi1*, Angélica Calandrelli1, Angélica Miamoto1, Monique Thiara Rodrigues e Silva1, and Cláudia Regina Dias-Arieira2
Nematodes of the Meloidogyne genus are among the main limiting factors of world agricultural productivity. Its management is quite complex and alternative methods such as the use of extracts have been widely studied. This study aimed to evaluate the penetration and development of M. javanica in soybean (Glycine max (L.) Merr.) treated with Ascophyllum nodosum extract and assess this algal product and its nutrient components in nematode management. Experiment 1 comprised five sampling times (5, 10, 15, 20, and 25 d after nematode inoculation) and three application methods (planting hole, foliar spraying, and untreated control). Soybean plants were inoculated with 2000 eggs+second-stage juveniles of M. javanica and treated with algal extract. Total nematode number, number of nematodes per developmental stage, and population density (nematodes g-1 root) were determined. Experiment 2 consisted of 11 treatments: Algal extract, N, K, P, Ca, Mg, Cu, Zn, Mn, Fe, combined nutrients, and untreated control. Soybean crops were evaluated for total nematode number, population density, gall index, plant height, root fresh weight, shoot fresh weight, and shoot dry weight. In Experiment 1, algal extract reduced nematode penetration, regardless of application method. There was a decrease in the total number of nematodes and number of nematode g-1 root by 83% and 56% in the application via furrow and 68% and 70% via foliar application, respectively. In Experiment 2, all nutrient treatments reduced at least one nematode parameter, with P, Ca, Mg, Fe, and combined nutrients (Trial 1) and algal extract, P, Ca, Mg, Cu, Zn, Mn, Fe and combined nutrients (Trial 2) achieving 83% to 95% reductions in population density. Nutrient treatments positively influenced vegetative development, as a 20% increase in height for the nutrients A. nodosum, N, K, P, Ca, Mg, Cu and Fe. Ascophyllum nodosum and its nutrient components have potential in the management of M. javanica in soybean.
Keywords: Alternative control, Glycine max, nutrition, root-knot nematode, seaweed.
1Universidade Estadual de Maringá, Pós-Graduação em Agronomia, 87020-900, Maringá-Paraná, Brasil.2Universidade Estadual de Maringá, Departamento de Ciências Agrárias, 87020-900, Umuarama-Paraná, Brasil.*Correspondence author (lu.rinaldi@hotmail.com).