Morpho-Molecular Characterization of Ditylenchus dipsaci and Alternatives for Its Management in Green Onion Allium fistulosum Crops from Colombia

Green onion is one of the most consumed vegetables in Colombia. However, its production is negatively affected by the nematode Ditylenchus. To determine the species of the nematode, as well as to propose management strategies for its control, in the present study the morphological, morphometric, and molecular characterization of the phytonematode was carried out and was used to evaluate the effect of immersion of the propagation material in water hot, application of a commercial strain of Purpureocillium lilacinum and the application of an agrochemical with insecticidal-nematicidal action to control the phytosanitary problem under field conditions. The morphological and morphometric characteristics of the nematode were similar to those reported for the type and reference populations of D. dipsaci. Based on sequences of the D2-D3 segment and Internal Transcribed Spacer-ITS of the rRNA, the presence of D. dipsaci in green onion crops in Colombia was confirmed. The application of P. lilacinum statistically showed an efficient control of D. dipsaci, at the same time that presented the highest yield, in relation to the other evaluated treatments (P ≤ 0.05).