Picrolonic Acid as a Hatching Agent for the Potato Cyst Nematode, Heterodera rosto-chiensis Woll.

Abstract

Calam, Todd and Waring¹ reported that almost as many eggs of the potato cyst-nematode, Heterodera rostochiensis, were stimulated to hatch by a 3 mM aqueous solution of anhydrotetronic acid as by potato root diffusate; other tetronic acid derivatives they synthesized did not stimulate hatching. Marrian, Russell and Todd² synthesized various compounds based on an α-arylidene-Δ^β:γ-butenolide skeleton and reported that two of these, α-(p-hydroxybenzylidene)-γ-methyl-Δ^β:γ-butenolide and α-(3-methoxy-4-hydroxybenzylidene)-γ-methyl-Δ^β:γ-butenolide, “showed definite activity” at a concentration of 0.1–0.5 mM, whereas the rest were inactive or only slightly active. That anhydrotetronic acid is a good synthetic hatching agent has been confirmed^4–6, and in our tests, at 3 mM concentration, its hatch rating³ was 90 (potato root diffusate = 100, water = 0), whereas 0.1–0.05 mM α-(p-hydroxybenzylidene) -γ-methyl-Δ^β:γ-butenolide was only slightly active (hatch rating 7).