Investigating Possible Causes of Concord Grape Replant Disorder

A green house experiment  was conducted  for 5 months (March 2013) . Warden silt loam soil was collected from 8 different sites for use as treatments. Two sites were selected that have not been used for crop production as “control” treatments (virgin soils). In production agriculture sites, two types of samples were collected: 1) In row samples - to reflect the biological and chemical conditions existing during plant production: 2) Between row samples - where, in theory, the biology and chemistry of the soils is not reflective of Concord or tree fruit production A total  of  14 soils were collected from vineyards or orchards with and without a replant disorder history.  Each soil was  planted with own rooted, certified Concord vines in 10 replicate pots. Shoot presence or length and leaf area was measured on each vine throughout the growing season to assess growth and health. In the first 6 weeks total shoot number and leaves per plant were recorded twice weekly.  Thereafter, weekly measurements were collected on a single shoot, recording: total leaf area and shoot length.  To evaluate potential causal factors  of concord grape replant disorder (RPD), soil samples were collected from each location (soil treatment) and evaluated for nematodes (species and population), and for soil chemical properties .  This paper will report vine growth and survival rates as well as any differences in soil biological and chemical properties.