Distribución y abundancia de nematodos fitoparásitos asociados al cultivo de yerba mate en Itapúa: un riesgo potencial e inminente

Abstract

Yerba mate (Ilex paraguariensis St. Hil.) has in recent years become a culturally and socially important crop for Paraguay. Moreover, it has also stood out economically, prompting an expansion of production at international levels due to increased exports. The department of Itapúa in Paraguay is responsible for 65% of the national production. Its profitability and productivity can be affected by organisms such as nematodes, but so far in Paraguay there have been no scientific reports of presence of these animals in the crop. To identify the presence of phytonematodes in the yerba mate of the department of Itapúa, soil samples were obtained from the districts of Tomás Romero Pereira and Carlos Antonio López, which were processed in the Plant Clinic of the San Carlos University, for their subsequent taxonomic gender identification and quantification. The data obtained were subjected to descriptive statistics and the analysis of ecological indices: Simpson's Dominance Index and Shannon's Diversity and Equity Index. The phytoparasitic nematodes identified were Criconemella, Helicotylenchus, Meloidogyne, Pratylenchus, Scutellonema, Tylenchorhynchus, Trichodorus, Xiphidorus and nematodes of the Tylenchida group. In addition, beneficial nematodes such as Aphelenchoides, Predators, Bacteriophages and Dorylaimida were identified. On the other hand, Helicotylenchus was the most frequent, abundant and dominant genus species in the analyzed samples, followed by Meloidogyne and Scutellonema. The nematode community of the studied localities was not very diverse and were relatively uniform. This research is the first report of nematodes associated with yerba mate crops in Paraguay and is a call to attention to reduce the potential risk that these organisms present to the production of yerba mate.