Summary
This is the third survey of pesticide usage practices conducted in the mushroom sector in Northern Ireland, providing comparative data to that obtained in the previous surveys in 1991 (Kidd et al., 1994) and 1995 (Kidd et al., 1998). Information was collected from 96 growers, representing 33% of the total grower population. A total of 191 hectares and 1489 growing houses were recorded in the region for this year.

By comparison with 1995, the pesticide-treated area in 1999 decreased by 3%, while the total quantity of pesticide used decreased by 19% to 3.9 tonnes of pesticide active ingredients. The quantity of disinfectant used in 1999 increased by 18% compared with 1995, to 4.9 tonnes of disinfectant chemicals, with only a marginal (2%) increase in the disinfectant treated area.

A combined 8.8 tonne of pesticide active ingredients and disinfectant chemicals were applied to 595 and 263 spray hectares of mushroom production houses, respectively.

Overall, regional pesticide usage approximated to the areas of mushroom crops grown in each country. County Tyrone represented 37% of the area grown, accounting for 43% of the total area treated with pesticide. Counties Tyrone and Armagh comprised approximately 68% of the total area of mushroom production in Northern Ireland.

Fungicide usage remained similar to that recorded in the previous survey in 1995. Fungicides, applied to 58% of the pesticide-treated area, accounted for 89% of the total quantity of pesticides used. The active ingredient prochloraz represented 70% of the fungicide-treated area, while accounting for only 25% of the quantity of fungicide used. Formaldehyde accounted for 72% of the quantity of fungicides used, representing only 23% of the fungicide-treated area, with 86% of its usage being applied for house sterilisation.

There was a marked reduction in the usage of insecticides in 1999 with a 76% decrease in the quantity used and a 28% decrease in the insecticide-treated area when compared with 1995. Insecticides were applied to 38% of the pesticide-treated area, accounting for 11% of the total pesticide usage by weight. Formulations containing pyrethrin/resmethrin and diflubenzuron were the most frequently applied insecticides, collectively accounting for 91% of the insecticide-treated area. Diflubenzuron represented 76% of the quantity of insecticides compared with 19% in 1995, with diazinon only representing 1% of the quantity of insecticides used compared with 70% in 1995. Approval of the use of diazinon was revoked in September 2000.

A total of 22 pesticide products, comprising of 12 active ingredients, six disinfectants and one registered biological control agent were recorded in this survey.

A full list of published reports is available together with abstracts from other relevant published work.

For further information on this work please contact:

Pesticide Usage Survey Group
Agri-food and Biosciences Institute
Newforge Lane
Belfast BT9 5PX

Email: pesticide.science@afbini.gov.uk
Tel: +44 (0)28 90 255689
Fax: +44 (0)28 90 255035