Pesticide usage report: Mushroom crops 2011

Summary

This report presents information from a survey of pesticide usage practices on mushroom crops (Agaricus bisporus) in Northern Ireland in 2011. It is the fifth survey of pesticide usage practices conducted on the mushroom sector in this region. Results from the previous surveys, which reported on pesticide usage practices on mushroom production in 1991 (Kidd et al; 1994), 1995 (Kidd et al; 1998), 1999 (Kearns et al; 2002) and 2007 (Kearns et al; 2008), are included in the report for comparative purposes. Data were collected from 35 growers, representing 92% of all mushroom holdings in Northern Ireland, with counties Armagh and Tyrone accounting for 94% of all mushroom crops grown in Northern Ireland in 2011.

When compared with the previous survey in 2007, the number of growers decreased by 31%, the area treated with pesticides decreased by 13% and the quantity of pesticides used decreased by 58%. Conversely, during the same period, the cropping area increased by approximately 10% to 105,000 m². A total of 231 kilograms of pesticides and 1,700 kilograms of disinfectant chemicals were applied to mushroom production and spawn-running houses in 2011.

In common with previous surveys, fungicides accounted for the majority (91%) of the weight of pesticides used and were applied to 33% of the pesticide-treated area. Prochloraz was the only fungicide active ingredient recorded during this survey period, primarily for „general disease‟ control.

Insecticides were principally used for the control of phorid (Diptera: Phoridae) and sciarid (Diptera:Sciaridae) flies. Applications of bendiocarb to the interior walls and structure of the mushroom houses, primarily at the pre-fill house treatment stage, accounted for 59% of the insecticide-treated area and 83% of the weight of insecticides applied. Bendiocarb does not have approval for use during mushroom cultivation, however, it does have approval for use on structures in which mushrooms are grown, i.e. on internal walls and frames of mushroom houses prior to compost being placed in them.

The only biopesticide recorded in this survey was the insect-pathogenic nematode Steinernema feltiaewhich was applied to 38% of the pesticide-treated area. Proportionately, biopesticides have increased in use from less than 5% of total area treated in 1999 to almost 40% in 2011 (Figure 12).

Disinfectant usage on yard areas outside the mushroom houses and as part of the house sterilisation process increased by 34% in area compared with 2007, making it comparable to the area treated in both 1995 and 1999 at approximately 3,180 spray metres squared (sp m²). However, the quantity of disinfectants used decreased by 70% compared with 2007, possibly due to the increased use of steam sterilisation and commercial pressure from the marketplace to reduce pesticide inputs and residues.

A total of ten products, comprising four pesticide active ingredients, three disinfectant active ingredients and one biopesticide were recorded in this survey.

For further information on this work please contact: Pesticide usage monitoring group