| Mint nematodes (Longidorus elongatus)
are also referred to as needle nematodes because of their long, slender stylet. Mint
nematodes are the largest plant-pathogenic nematodes found on any plant (5 mm=0.2 inch).
Mint nematodes are migratory ectoparasites. Mint nematode
reproduces at soil temperatues as low as 50 F and perhaps lower. Most rapid populaiton
growth occurs at soil temperatures of 75-85 F, but, as temperature increases above 85 F,
reproduction declines. Mint nematodes feed exclusively on root tips, which are transformed
into terminal galls in many plants. |
Damage to peppermint may range from
slight stunting to large barren areas. Symptoms are most evident during late spring
and early summer before mint has a chance to cover. Individual plants are generally
shorter and usually exhibit the reddish appearance often attributable to stress factors
that retard mint growth. Roots are often malformed or stubby, and feeder roots may be
absent. Plants become unthrifty and die from an inability to take up sufficent water and
nutrients. Damage causes stands to thin over time, and there is reduced growth after
harvest. Damaged areas often typically occur in localized areas or patches |
