Chemical and nonchemical options for the management of Heterodera schachtii in Northern Spain


  • E. Iturritxa
  • M. D. Romero


The susceptible sugarbeet cultivar Acord and the resistant cultivar Nemadie were sown in a field infested with Heterodera schachtii. The nematicide fenamiphos was applied to the susceptible cultivar in three different ways: at sowing, 11 weeks after sowing or both times. Differences in eggs and second stage juveniles per cyst at harvest were very marked between the different treatments. Nematode multiplication rates varied from 0.3 to 0.6, in the treatment with two applications of nematicide and for resistant cultivar respectively, to 2.1 and 2.2 for the untreated susceptible cultivar and the nematicide application at sowing. The post-emergence nematicide application led to an intermediate multiplication rate of 1.2. Regression analyses of log-transformed final and initial infestation data showed that the relative efficacy of the treatments changed depending on the initial infestation, the double application of nematicide being the only treatment that prevented nematode multiplication. Yields between the treatments from the susceptible cultivar varied significantly depending on the application of granular nematicide.