Edible ginger and turmeric roots are important agricultural commodities for the State of Hawaii. Bacterial wilt, Ralstonia solanacearum, and root-knot nematodes, Meloidogyne spp., are major factors hindering optimum production. An evaluation of tolerance and resistance to M. incognita was undertaken with 22 commercially grown cultivars. Curcuma longa Red Hawaiian turmeric had the greatest susceptibility with the highest number of juveniles in the soil and the most eggs recovered from the roots. The population factor (Pf) of M. incognita was largest in C. longa Red Hawaiian turmeric and Alpinia galangal Blue finger. Curcuma caesia Black turmeric was the most intolerant cultivar with the lowest rhizome weights and greatest yield losses. The highest tolerance was seen in Zingiber officinale J and I, which demonstrated the greatest rhizome yields and lowest yield differences when inoculated. Zingiber officinale M had the lowest Pf value, suggesting partial resistance to M. incognita. Effective management strategies need to be investigated as significant yield reductions are occurring when cultivating ginger and turmeric in root-knot nematode infested fields.
