Gooseberry survey to determine the incidence and cause of branch and bush dieback or death

A serious problem for commercial growers for many years has been unexplained dieback of either single or multiple branches or death of gooseberry bushes, with symptoms often occurring around the first full cropping year. This occurs throughout the UK on all current commercial gooseberry cultivars apparently regardless of plant type or husbandry. Some growers have thus held back from expanding their crop area, despite good demand for the fruit from all markets. Growers have struggled to control losses, often not knowing what pathogen is involved, with both soil (e.g. Phytophthora or Verticillium) and air-borne infection (e.g. Eutypa or Phomopsis) being potential causes.

At least five gooseberry plantations containing one or more of the current major commercial cultivars will be visited in order to determine the incidence and severity of dieback or death and to sample for diagnosis. A husbandry survey will be carried out in each plantation and the distribution of bushes with symptoms recorded. Symptom development in two of these plantations will then be monitored over a further growing season.

Information on techniques and products used by growers that may have reduced losses to dieback will be provided. Areas for further research including the need for Extension of Authorisations for minor use in the UK will be noted.

Overall aim of the project

To determine the incidence, severity and causal pathogens of the dieback of branches or the sudden death of gooseberry plants in commercial fruiting plantations and provide information towards managing the losses.

Objective 1

• To evaluate the extent of loss of branches and/or bushes in a sample of established commercial fruiting plantation
• To note the locations, varieties and husbandry of affected and unaffected gooseberry plants and the nature of the symptom
• To follow the development of symptoms over a year on a selection of bushes
• To sample affected tissue, record the symptoms and damage distribution on the bush, and determine the fungal pathogens present

Objective 2

• To carry out surveys of plantation management

Objective 3

• To utilise site sample and survey information to produce guidance on where changes in management or awareness of site conditions could lead to reduced dieback and bush death