Efficacy of Seed Priming With Cucurbitacin Phytonematicides Against Meloidogyne incognita on Pea

The cost and environment concerns of existing drench-application technologies of cucurbitacin phytonematicides resulted in conceptualization of the priming-and-drying (PAD) technology of seeds with hypogeal germination. The preliminary observations suggested that the PAD technology improved seed germination, plant growth, and vigor in pea (Pisum sativa), with limited information on suppression of root-knot (Meloidogyne species) nematodes. Post-soaking pea seeds in geometric concentrations of Nemarioc-AL and Nemafric-BL phytonematicides, seedlings were raised in greenhouse and on microplot experiments during 2019 and validated in 2020. At 60 days after inoculation with 300 eggs + second-stage juveniles (J2) of M. incognita seasonal data were pooled. Gall rating, eggs in root, and J2 in root vs. Nemarioc-AL phyto nematicide in greenhouse and on microplot exhibited negative quadratic relations, with models explained by 80-85% and 89-94% associations, respectively. Similarly, for the respective sites negative quadratic models for nematode variables vs. Nemafric-BL phytonematicide were explained by 82-93% and 90-94% associations, respectively. In conclusion, pea seed remnants belowground gradually released cucurbitacins into the rhizosphere throughout the growing period, thereby suppressing nematode population densities, and therefore, the PAD technology has the potential for assessment in a large-scale application of cucurbitacin phytonematicides for pea production.