Fighting grapevine root diseases with brassica cover crops

Research Brief Publication Date: May 07, 2024
Last Updated: July 11, 2024
Researchers:
Corynne O’Farrell, Tom Forge, and Miranda M. Hart.

Introduction

This study explored the potential of four brassica cover crops to control soil borne pathogens in a no-till, vineyard setting.

Vineyards can suffer significant economic loss due to crop destruction from soil-borne root diseases. This includes fungal trunk diseases found commonly in the Okanagan such as black-foot disease and Petri disease. Parasitic nematodes, such as root-knot and ring nematode, also cause damage to grapevine roots and lead to reduced yield, stunted growth, and/or eventual death of the grapevine. 

One way of controlling fungal diseases and parasitic nematodes is the use of cover crops. Some species of cover crops, particularly in the Brassicaceae family, produce chemicals that suppress the growth of bacteria, fungi, nematodes, weeds, and insect pests. Because the chemicals are primarily released when plant tissues are broken down, cover crops are typically mixed into the soil with tillage. However, in perennial systems like vineyards, tillage can only occur in the interrow to avoid disturbing the grapevine roots. This leaves the soil closest to the grapevines un-protected from pathogens. Additionally, intensive tillage has been found to have negative impacts on soil health.

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Study site at Tantalus Vineyards. Photo by Corynne O’Farrell.

About this Brief

This brief was prepared by the BC Food Web team with the help of Corynne O’Farrell and is based on the following scientific journal article:

O’Farrell, C., Forge, T, & Hart, M. M. (2023). Using brassica cover crops as living mulch in a vineyard, changes over one growing season. International Journal of Plant Biology, 14(4), 1105-1116. https://doi.org/10.3390/ijpb14040081 

 

Key Findings

  • Brassica cover crops can provide benefits in vineyards without being incorporated with tillage.
  • Shepherd’s purse and white mustard showed potential for controlling the parasitic nematode population, lowering the odds of finding a parasitic nematode by 46% and 52%, respectively. 
  • Shepherd’s purse and rockcress, two naturally-occurring plants in BC vineyards, are viable cover crop options that have the potential to improve soil health.