Botrytis in blackcurrant: additional effects

Find information on the role of Botrytis in blocking filters in the processing of juice, and the effects of high nitrogen on fruit susceptibility to Botrytis

The role of Botrytis in blocking filters in the juice making process

It has been suggested that the blocking of filters during the processing of blackcurrant juice may be caused by Botrytis cinerea mycelium within ripe fruits.

A study in this project assessed whether fungal Botrytis increases substantially while latent inside infected fruits.

Inoculated

Molecular quantification of fungal biomass in fruits (Ben Hope) inoculated three to four weeks after flowering, revealed that the fungal DNA did not appreciably increase over time from inoculation to harvest.

It was concluded that mycelia inside latently infected fruit are unlikely to be responsible for blocking filters.

Effects of high nitrogen

An experiment investigated the effects of high nitrogen on fruit susceptibility to Botrytis cinerea, using a range of genotypes including commercial varieties and advanced lines.

These received a standard nitrogen treatment or high nitrogen treatment (additional top dressing during the flowering period) and were inoculated with Botrytis cinerea about two to three weeks after full bloom.

High incidence of Botrytis

Results suggested that there is some evidence that high nitrogen may lead to a high incidence of Botrytis.

However, the incidence of total rotting did not differ between the nitrogen treatments.

Authors

These pages were originally authored by Michelle Fountain, Angela Berrie and Scott Raffle (NIAB) in 2015.