Submitted to: International Congress of Nematology
Publication Type: Abstract Only
Publication Acceptance Date: 5/1/2008
Publication Date: 7/13/2008
Citation: Halbrendt, J.M., Lamondia, J.A., Zasada, I.A. 2008. Evaluation of millet and rapeseed as rotation or green manure crops to control nematodes in orchard replant . International Congress of Nematology. Meeting Abstracts. Interpretive Summary:
Technical Abstract: Four annual crops, including Canadian forage pearl millet (Pennisetum glaucum) hybrid 101, velvetbean (Mucuna spp. ), rapeseed (Brassica napus) cv. Dwarf Essex, and buckwheat (Fagopyrum spp.), were evaluated as rotation or green manure crops for suppression of dagger (Xiphinema americanum) and lesion (Pratylenchus spp.) nematodes. Two sets of field plots (3 m × 3 m) were established in Pennsylvania and one in Connecticut, and four replications per treatment were arranged in a randomized complete block design. All plots were planted with seed from the same seed lot to eliminate variability. Nematode population levels were determined three times for each treatment in each set of plots: pre-plant, end of season and three weeks after the crops were incorporated as green manure. Canadian forage pearl millet suppressed lesion nematodes but was a good host for dagger nematodes. Dwarf Essex rapeseed reduced populations of dagger nematodes only after incorporation as green manure but did not suppress lesion nematode populations. All sites had similar results although the dagger nematode data was not statistically different at one location in Pennsylvania. Buckwheat was included as a susceptible control and the data showed that it was a good host for both lesion and dagger nematodes. Velvetbean has been reported to have nematicidal activity, but our results showed that the variety used in these experiments appeared to be a good host for both lesion and dagger nematodes and was not nematicidal as a green manure. Many old orchard sites are infested with lesion and dagger nematodes, and both nematodes have the potential to cause problems on young trees in replant sites. Rotation crops offer an environmentally friendly alternative to chemicals for nematode control, but as this research demonstrates, it is important to know which nematodes are present and what effect a rotation crop may have on the population.