Survey and characterization of nematode populations affecting onion and spinach crops in Karachi, Pakistan

Abstract

Vegetables are an important source of micronutrients, which can help malnourished people throughout the world and improve their health. In many countries, spinach and Onion are popular vegetables that help to overcome micronutrient deficiencies. Current technology and advances have greatly aided agricultural productivity, while most of the producers have overlooked several critical aspects that might help to reduce yield losses. Particularly, root-knot (Meloidogyne spp.) and cyst (Heterodera spp.) nematodes are thought to be among the most significant plant pests on a variety of crop plants.  They have a wide host range, a brief life cycle and a rapid rate of multiplication. This research study conducted an extensive survey of nematode populations affecting onion and spinach crops in Karachi, Pakistan. Soil samples were collected from farmers’ fields and the UBIT field at the University of Karachi. The survey identified a total of 10 different genera of plant parasitic nematodes including Longidorus elongatus, Hemicriconemoides communis, Rotylenchulus reniformis, Hoplolaimus columbus, Bitylenchus brevilineatus, Aphelenchus avenae, Pratylenchus coffeae, Seinura spp., Filenchus spp., and Helicotylenchus spp., along with free-living soil nematodes. Notably, some genera, such as Longidorus elongatus, Bitylenchus brevilineatus, Rotylenchulus reniformis, Hemicriconemoides communis, and Seinura spp., were reported for the first time in onion and spinach crops in Pakistan. The study also provided systematic information, morphometric data, and illustrations of these genera. The findings highlight the importance of understanding and managing nematode populations in onion and spinach crops to ensure sustainable agricultural practices in Karachi, Pakistan. © 2022 The Author(s)