Nematicidal effect of chestnut tannin solutions on the potato cyst nematode Globodera rostochiensis (Woll.) Barhens

Recently, tannins have been reported for their nematicidal activity against the root-knot nematode Meloidogyne javanica both in vitro and in pot experiments in addition to a biocidal effect on a wide range of fungi, bacteria and yeasts. However, no information is available on the effect of these polyphenols on plant parasitic cyst nematodes. Therefore, an in vitro and a pot experiments on potato were undertaken to investigate the nematicidal activity of tannin aqueous solutions at different concentrations on the potato cyst nematode Globodera rostochiensis. In the in vitro experiment different tannin concentrations in a geometric scale (from 0.32 to 20.48 g/l) were tested for their effect on the egg hatch of the nematode. All tested tannin concentrations were effective to reduce egg viability from 56 to 87%, in comparison to the untreated control. In the pot experiment, tannins, as aqueous solutions at rates of 100, 250 and 450 g/m(2), were applied to soil at two different application times (at sowing and at sowing and two weeks later). All tested doses were effective to reduce the number of cyst/100 g soil, eggs and juveniles/g soil and reproduction rate in comparison to untreated control. The number of eggs and juveniles/cyst was not influenced by the different applied rates of tannins.