A soybean
cyst nematode
sex pheromone (
vanillic acid), chemical analogs of the
pheromone, and the fungus Verticillium lecanii were applied in
alginate prills (340 kg/ha) to microplots and small-scale field plots as potential management agents for Heterodera glycines on soybean. In 1991 microplot tests, treatment with V. lecanii,
vanillic acid,
syringic acid plus V. lecanii, or
vanillic acid plus V. lecanii lowered midseason
cyst numbers compared with the untreated susceptible cultivar control, autoclaved V. lecanii treatment, or
aldicarb treatment, At-harvest
cyst numbers were lowest with V. lecanii and with
vanillic acid treatments.
Aldicarb treatment reduced midseason
cyst numbers in 1992. There were no differences among seed yields either year. In the field trials, numbers of
cysts were reduced one or both years with
aldicarb,
ferulic acid,
syringic acid,
vanillic acid, or 4-hydroxy-3-methoxybenzonitfile treatments, or with a resistant cultivar, compared to an untreated susceptible cultivar. Highest yields were recorded
after treatment with 4-hydroxy-3-methoxybenzonitrile (1991),
methyl vanillate (1992), and
aldicarb (1992). These studies indicate that some chemical analogs of
vanillic acid have potential for use in soybean
cyst nematode management schemes.