NEMATICIDAL EFFECT OF CHESTNUT TANNIN SOLUTIONS ON POTATO CYST AND ROOT-KNOT NEMATODES Nicola Sasanelli(1), Marek Renčo(2), Lara Maistrello(2), Ingrid Papajová(2) 1Institute for Plant Protection, C.N.R., Via G. Amendola 122/D, 70126 Bari, Italy, *Corresponding author: n.sasanelli@ba.ipp.cnr.it; 2Parasitological Institute of Slovak Academy of Sciences, Hlinkova, 3, 040 01, Košice, Slovak Republic, 3Department of Life Sciences, University of Modena and Reggio Emilia, Area S. Lazzaro, Pad. Besta, Via G. Amendola 2, 42100 Reggio Emilia, Italy The highest reduction of nematological parameters was recorded in soil treated with tannin at dose of 450 g/m2 applied at sowing and at sowing and 2 weeks later, although this treatment was not significantly different from that applied twice at 250 g/m2. Tannin treatments at different doses did not significantly affect number of eggs/cyst (Fig 1C). No significant differences, in all nematological parameters, were found between the tannin applications at sowing and at sowing and 2 weeks later for all the three tested concentrations (100, 250 and 450 g/m2) (Fig 1). Objectives of work To evaluate the potential use of chestnut tannins in the control of the potato cyst nematode Globodera rostochiensis and the root-knot nematode Meloidogyne javanica Materials and methods The population of G. rostochiensis pathotype Ro1, was obtained from an infested soil at Avezzano (province of L’Aquila, Italy) The population of M. javanica was obtained from Torchia-rolo (Province of Brindisi, southern Italy) from infested tomato roots (Solanum lycopersicum L.) Chestnut tannin powder– Agrostar s.r.l. (Cavriago, RE, Italy Tannin treatments at different concentrations were considered: 1) 100 g/m2; 2) 250 g/m2 and 3) 450 g/m2, applied at sowing or at sowing and two weeks later, with a total of six tannin treatments. Tannins were applied as aqueous solutions (400 ml/pot), calibrated on the holding capacity of the soil. Nematode infested and untreated soil was used as control. Number of cysts/100 g soil, number of eggs and second stage juveniles/g soil and reproduction rate (r = Pf/Pi) of the potato cyst nematode G. rostochiensis and number of eggs and juveniles/g root, the final population/ml soil, reproduction rate and Root gall index of the root-knot nematode M. javanica were estimated Fig. 1 – continue Effect of chesnut tannin at different doses applied at sowing and at sowing and two weeks later on nematological parameters induced by the potato cyst nematode Globodera rostochiensis on potato C) eggs and J2/g soil and D) reproduction ratio Pf/Pi. bc cd d a b C a b bc cd d D Insert two pictures J2 of M javanica and root gals javanica Results – M. javanica All tannin doses (100, 250 and 450 g/m2) reduced number of eggs and juveniles/g root, the final population/ml soil and reproduction rate of the root-knot nematode M. javanica in comparison to infested and untreated control (Fig. 2 A, B, C) In particular, a significant reduction of RGI was obtained by the use of tannins at 250 g/m2 applied two times, at transplant and two weeks later, demonstrating the protective and positive effect of repeated treatments (Fig 2 D). Fig. 2. Effect of chesnut tannin at different doses applied at transplant and at transplant and two weeks later on nematological parameters induced by the root-knot nematode Meloidogyne javanica on tomato.; A) eggs and J2/g root; B) final population/ml soil; C) reproduction ratio Pf/Pi and D) Root gall index Results – G. rostochiensis The number of cysts/100 g soil, number of eggs and second stage juveniles/g soil and reproduction rate (r = Pf/Pi) of the potato cyst nematode G. rostochiensis were significantly reduced by all tannin treatments (100, 250 and 450 g/m2) in comparison to the untreated control (Fig 1 – A,B,C,D) a b bc c d A b bc a c B a Fig. 1. Effect of chesnut tannin at different doses applied at sowing and at sowing and two weeks later on nematological parameters induced by the potato cyst nematode Globodera rostochiensis on potato. A) N. of cysts/100 g soil; B) eggs and J2/g cyst a b bc cd d A a B a C bc b c a b c ab D Acknowledgements: The present investigation was promoted and financed by AGROSTAR S.r.l. (Cavriago, Reggio Emilia), after foreseeing the applicative potential of tannins in plant protection. The research was undertaken within the framework of a bilateral project between the Italian National Council of Research (CNR) and the Slovak Academy of Sciences (SAS).