Host-status and host-sensitivity of sweet potato cultivar ‘Blesbok’ to Meloidogyne javanica

Sweet potato (Ipomoea batatas L.) is an important staple crop valued for its high nutritional content and adaptability to adverse environmental conditions. However, its production is constrained by root-knot nematodes (Meloidogyne species), particularly Meloidogyne javanica (Treub [Chitwood]) which significantly reduce yield and quality in various crops. This study evaluated the host-status and host-sensitivity of the sweet potato cv. ‘Blesbok’ to M. javanica in a pot experiment, conducted at the Green Biotechnologies Research Centre of Excellence, University of Limpopo. A randomized complete block design with seven inoculation levels (0, 5, 25, 125, 625, 3125 and 15625 eggs + second-stage juveniles (J2) and six replications were used. Validation was done over two growing seasons. Nematode reproductive factor (RF), root galls and key plant variables were assessed at 56 days after inoculation. Meloidogyne javanica was able to establish and reproduce on ‘Blesbok’ at low inoculation levels, with RF exceeding 1, but declined to below 1 at higher inoculation levels. Variable RF values, the absence of root galls and plant variables which were not affected by nematode infection, but all suggested a degree of tolerance rather than resistance. The findings suggest that while ‘Blesbok’ can be cultivated in nematode-infested fields, integrated pest management strategies may be necessary to mitigate nematode pressure in high-density infestation areas. Future research should focus on alternative control measures to enhance the sustainability of sweet potato production in nematode-prone environments.