Research Plant Pathologist
Daniel K. Inouye U.S. Pacific Basin Agricultural Research Center
64 Nowelo St.
Hilo, Hawaii 96720
Ph: (808) 959-4314
Fx: (808) 959-5470
via ARIS System
via ARIS System
via ARIS System
Host plant resistance is an effective management strategy for improving yields in nematode infested conditions. Coffea arabica cv. Typica in Kona, Hawaii experiences coffee decline and a reduction in yields due to widespread infestation of root-knot nematodes, Meloidogyne konaensis. Grafting nematode tolerant rootstocks such as C. liberica var. dewevrei and C .canephora cv. Nemaya is an effective way to withstand damage from these pests. Plants grafted on these cultivars showed increased growth and healthier root systems. We also found differences in susceptibility to root-knot nematodes among edible ginger and turmeric cultivars grown in Hawaii. With nematodes causing yield reductions of up to 50% in ginger and 80% in turmeric, growers should consider planting those cultivars with the highest yields under heavily infested conditions.
Rotylenchulus reniformis, is considered a Class A quarantine pest by the state of California due to its wide host range and ability to greatly reduce yields in infested crops. When inspectors intercept plants from Hawaii contaminated with reniform nematode, the shipments are rejected at a loss to the grower and future exports are banned. We tested a large scale steam sterilization system developed by the University of Hawaii to eradicate plant-parasitic nematodes in volcanic cinder used as growing media. Steam sterilization was found to be an effective and practical solution for nematode eradication in potting media and greenhouse beds. We continued to test smaller steam sterilization systems and offer training to growers on how to use this effective technology in their operations.>
Continuous hot water drenches are an effective way to disinfest potted plant material of plant-parasitic nematodes. Modifications to the University of Hawaii hot water shower container allowed us to evaluate the optimal time and temperature needed to eradicate reniform nematodes in potted dracaena. A continuous flow of hot water at 50°C for 10 minutes was ideal for disinfesting plant roots and media as well as eliminating weeds in potted plants with no thermal damage.
Predatory nematodes have shown potential as biological control agents against damaging plant-parasitic nematode pests. Limited research exists on these organisms and a better understanding of their feeding behavior is needed before mass rearing can be investigated. We developed an efficient technique for analyzing the gut contents of predatory nematodes using a PCR-based approach. Species specific primers for economically important plant-parasitic nematodes were used to examine prey preferences. Our results indicated that predators were specific in prey choices and suggested that selecting a predatory nematode for mass rearing as a biological control agent would be dependent on the targeted plant-parasitic nematode species. Neoactinolaimus spp. was determined to be an efficient predator of reniform nematode and amenable to in vitro rearing.