Antagonistic effect of Arachis pintoi on Meloidogyne paranensis and M. incognita

Abstract

The antagonist effect of Arachis pintoi to Aleloidogyne paranaensis and M. incognita races 1, 2, 3, and 4 was examined in two glasshouse experiments. In the first, seedlings of four A. pintoi accessions and "Rutgers" tomato were planted in pots containing a sterilized substrate infested with 10,000 nematode eggs and/or juveniles. In the second, finely chopped A. pintoi tissue was incorporated in the substrate of the pots used in the first experiment, which were then re-infested with the remaining nematode population. Examination of A. pintoi root stained in B Floxine revealed that no penetration by M. incognita and M. pcll'cznaensis juveniles had occurred and hence there was no gall or egg mass formation. On the other hand, tomato favored the increase of the nematode population, mainly of the M. paranaensis and M. incognita race 2, which showed the largest population means densities. Acessions 1 and 4 of A. pili tal displayed the largest and the smallest root weight, respectively. The roots of the tomato plant sharing the pots with A. pintol accession 4 had larger galls and more egg masses than those sharing pots with accession 1. The incorporation of the non-infested Arachis tissues significantly reduced the number of galls and egg masses in the tomato plant roots. In general, the A. pintoi accessions had an antagonist effect on the nematodes, suggesting that they could be used as an intercalated crop or cover crop to reduce M. paranaensis and M. incognita populations.