M.E. Gartshore’s scientific contributions

Because of the need to find plants that suppress root lesion nematodes for use in rotation or cover-crops, 16 native sand-prairie species were evaluated for host status for 6 years. Plants were grown on a Fox sand soil at a local prairie plant nursery. Soil cores were taken in the spring, summer, and fall and assayed for plant parasitic nematodes. Five species supported very low numbers (less than 100/kg soil) of root lesion nematodes. Brown-eyed Susan ( Rudbeckia hirta ) had no detectable nematodes for the duration. Switchgrass ( Panicum virgatum L.) and Indiangrass ( Sorghastrum nutans L., Nash) samples produced detectable nematodes on only two sampling dates over the 6 years and were statistically not different from brown-eyed Susan. Butterfly weed ( Asclepias tuberosa L.) also had very low detectable nematodes as did sand dropseed [ Sporobolus cryptandrus (Torr.) Gray.]. New Jersey tea ( Ceanothus americanus L.), little bluestem [ Schizachyrium scoparium (Michx.) Nash], and big bluestem ( Andropogon gerardi Vitman) were poor hosts with <200 nematodes/kg soil. Mountain mint ( Pycnanthemum virginianum L), wild bergamont ( Monarda fistulosa L), horsemint ( Monarda punctata L), and dwarf blazing star ( Liatris cylindracea L) all had root lesion populations over 3000/kg soil. Horsemint and wild bergamont plants died out, possibly as a result of nematode infestation. Root lesion nematodes have an extremely wide host range in current agronomic and horticultural crops, and weeds and are difficult to manage using nonchemical means. Indiangrass, switchgrass, big bluestem, and little bluestem have all been used agriculturally for pastures and consequently have potential as beneficial long-term rotation crops for nematode management and soil building.

Le nematode des lesions des racines (Pratylenchus penetrans), le nematode phytoparasite le plus important du sud de l'Ontario, possede une gamme d'hotes extremement large. A cause de la necessite de reprimer ces parasites avec des cultures recouvrantes qui sont peu ou pas hotes, plusieurs especes indigenes des prairies sablonneuses ont ete evaluees pour leur susceptibilite au nematode des lesions. Onze especes appartenant a quatre familles (Asclepiadaceae, Asteraceae, Poaceae et Fabaceae) ont ete identifiees commes des hotes faibles. Les populations tres faibles de P. penetrans sur ces especes indiquent qu'elles pourraient avantageusement servir comme cultures recouvrantes.