Phytoparasitic nematodes associated with Guava (Psidium guajava L.) crop in agroecologically managed plots

Abstract

Phytoparasitic nematodes cause necrosis, bark splitting, and soft rot in the cortical tissues (root system) of various economically, socially, and environmentally important crops. The objective of this study was to identify the genera of phytoparasitic nematodes associated with guava cultivation in an agroecologically managed plot. This research was conducted at the Universidad Nacional Agraria, in Managua, Nicaragua. In the agroecological plot, soil and root sampling were performed to identify the nematode genera. Soil and root samples were collected using a graduated auger at a depth of 0 cm to 15 cm. Ten random sub-samples were taken per tree within the drip area, and these sub-samples were homogenized to obtain a composite sample of 1 kg of soil and 10 grams of roots. Soil nematodes were extracted using the centrifugation-flotation method, while root nematodes were extracted using the Berman funnel method. Nematodes were identified at the genus level using light microscopy, morphological characters, and taxonomic keys proposed by S’ Jacob and Bezooijen (1984). Data were entered into a Microsoft Excel spreadsheet, where absolute and relative frequencies were determined. Populations were assessed through individual counts. Five families and ten genera of nematodes were identified in soil and root samples, predominantly as ectoparasitic species associated with guava cultivation.