Submitted to: Nematropica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/10/2017
Publication Date: 12/31/2017
Citation: Myers, R.Y., Mello, C.L., Keith, L.M. 2017. Evaluation of edible ginger and turmeric cultivars for root-knot nematode resistance. Nematropica. 47:99-105.
Interpretive Summary: Edible ginger and turmeric roots are specialty crops grown for culinary and medicinal use. An important agricultural export for the State of Hawaii, production has declined due to bacterial wilt and root-knot nematodes. Host plant resistance has potential for increasing yields if sources of tolerance or resistance can be identified. Twenty-two commercially grown ginger and turmeric cultivars were inoculated with root-knot nematodes and evaluated under greenhouse conditions. Black turmeric was found to be highly susceptible having the lowest rhizome weights and greatest yield reductions when infested. Another turmeric cultivar supported the greatest nematode reproduction. Partial tolerance and resistance were displayed in three edible ginger cultivars originating from the University of Hawaii collection. Superior rhizome weights and slight yield differences under nematode pressure suggest these cultivars can withstand damage in infested fields.
Technical Abstract: 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 BDT 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 BDT and Alpinia galangal Blue finger. Curcuma longa 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 and no yield differences under nematode pressure suggesting partial resistance and high tolerance 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.