The effect of different fertilizer applications on stem and bulb nematode, Ditylenchus dipsaci (Kühn 1857) (Tylenchida: Anguinidae) on onion

Keywords: control, Ditylenchus dipsaci, fertilizer, onion, stem and bulb nematode, humic acid


Stem and bulb nematode, Ditylenchus dipsaci (Kühn 1857) is an important constraint of onion. The application of chemical control
methodologies due to the environmental and economical concerns is restricted and needed to develop new control strategies to keep the
nematode population under damage threshold. Considering the effects on plant development and soil biodiversity, it is aimed to investigate
control option for the stem and bulb nematode using different fertilizer combinations. The D. dipsaci susceptible onion variety Beyaz Bilek was
planted onto fresh field soil in 3x13 cm plastic tubes as one plant per tube being 8 replications for each fertilizer application and the negative
control. Fertilizer applications were 5 fertilizer applications of organic, synthetic, worm fertilizer and humic acid and sea algae. Fertilizers were
applied 4 times with 2 weeks intervals starting in sowing. Ditylenchus dipsaci was inoculated to all plants as 200 nematodes per plant after 4
weeks planting. Plants were harvested 4 weeks later nematode inoculation. At harvest time, the most frequent soil nematodes were Cephalobus
and Eucephalobus genera. Humic acit, vorm fertilizer and synthetic fertilizer increased the plant development significantly. Stem and bulb
nematode population significantly decreased in fertilizer applications, the most lower one were organic fertilizer and humic acid application.