Summary
The mushroom industry in Northern Ireland employs the 'Satellite Bag-growing System' and in 1995 generated an output value of £30.4 million. A total of 272 growers and 1,252 growing houses comprising 129 hectares were recorded.

This is the second survey of pesticide usage practices conducted in the mushroom sector in Northern Ireland, providing comparative data to that obtained in 1991 (Kidd et al., 1994). Results indicate that while the total quantity of pesticides used remained constant, there was a 54% increase in the pesticide-treated area. In contrast, the quantity of disinfectant used in 1995 had increased by 40% since 1991, with a two-fold increase in the disinfectant-treated area. This suggests a greater emphasis on preventative hygiene practices as a means of disease control in mushroom production.

The survey indicated that 4.8 tonnes of pesticide active ingredients and 3.6 tonnes of disinfectant chemicals were applied to 614 and 226 spray hectares of mushroom production houses, respectively. Data were collected from 150 growers representing 55% of mushroom growers in Northern Ireland in 1995. Counties Armagh and Tyrone collectively accounted for 63% of the total area of mushroom production.

Overall, regional pesticide usage approximated to the areas of mushroom crops grown in each county. However, County Armagh represented 28% of the area grown, while accounting for 33% of the total area treated with pesticides. The total growing area was treated with pesticide and disinfectant with a mean of five and two applications, respectively.

Insecticides were applied to 51% of the pesticide-treated area, accounting for 37% of the total pesticide usage by weight. Formulations containing pyrethrins/resmethrin and diflubenzuron were the most frequently applied insecticides, collectively accounting for 68% of the insecticide-treated area. By comparison with the 1991 survey, a 17% decrease in the quantity of insecticides used and a 41% increase in the insecticide-treated area was recorded. In the current survey diazinon represented 70% of the quantity of insecticides compared with 81% in 1991.

Fungicides, applied to 49% of the pesticide-treated area, accounted for 63% of the total quantity of pesticides used. Treatments of prochloraz represented 80% of the fungicide-treated area, while accounting for only 35% of the quantity of fungicide active ingredients applied. Formaldehyde represented only 15% of the fungicide-treated area, but 60% of the quantity of fungicides used. Approximately 98% of the quantity of formaldehyde applied was used either in pre- or post- crop house disinfection. The fungicide active ingredients, benomyl, carbendazim and chlorothalonil were also used. Carbendazim and chlorothalonil had not previously been recorded on mushroom crops.

A total of 20 pesticide products, including two registered biological control agents, and 8 disinfectants, comprising 17 and 13 active ingredients, respectively, 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