Summary
This is the third survey of pesticide usage practices conducted in the arable sector in Northern Ireland, providing comparative data to that obtained in the previous surveys in 1990 (Jess et al., 1992) and 1992 (Jess et al., 1995). Information on all aspects of pesticide usage was collected from 338 holdings throughout the Province, representing 17% of the total area of arable crops grown. Quantitative data has been adjusted to provide estimates of total pesticide usage. The area of arable crops grown in Northern Ireland in 1994 was 51,718 hectares, representing an 11% reduction to that recorded in 1992.

Comparing 1994 with 1992, the quantity of pesticides applied declined by 26% to 242 tonnes, while the pesticide-treated area remained approximately the same at 245,971 spray hectares. An increase of 8% in the fungicide-treated area was recorded, while the quantity of fungicide active ingredients applied declined by 11%. The use of herbicides and desiccants decreased in both area treated and quantity applied by 5% and 37%, respectively. Although there was a 2% reduction in the insecticide-treated area between 1992 and 1994, the area treated represented a 25% increase to that recorded in 1990. The quantity of insecticide active ingredients applied increased by 25% in the two year period 1992 to 1994 resulting in an overall increase of 67% when compared with that recorded in 1990. The area treated with organophosphates declined from that recorded in 1992 by 13%, while the data showed a 17% increase in the use of pyrethroid insecticides during the same period. In the two year period 1990 to 1992 the molluscicide-treated area remained relatively constant, while the quantity of active ingredients applied declined by 18%. Comparing 1994 with 1992, molluscicide usage has declined by 72% and 63% of the treated area and quantity applied, respectively. The area treated with growth regulators increased steadily by 48% in the four year period 1990 to 1994, while the weight of active ingredients applied increased by only 3%, demonstrating the use of reduced treatment rates for this pesticide group. When compared with 1990, a reduction of applications of formulations with mixed pesticide activity of approximately 42% in both area treated and quantity applied was observed. While the area of arable crops sown or planted with treated seed decreased by 13% in the two year period 1992 to 1994, the weight of active ingredients used increased by 35%. The latter is due to higher concentrations of alternative active ingredients in seed treatment products, replacing the organomercury seed dressings.

In 1994 regional pesticide usage closely approximated to the areas of arable crops grown in each county. Pesticides were applied to 99% of the total of arable crops grown in Northern Ireland in 1994, with a mean of three applications.

Fungicides were applied to 47% of the pesticide-treated area accounting for 38% of the total quantity of pesticides used. Herbicides and desiccants accounted for 30% of the pesticide-treated area and 55% of the total quantity of pesticide used. Insecticides, applied to 2% of the pesticide-treated area, accounted for 1% of the total quantity of pesticides used. Growth regulators, applied primarily to winter cereals, accounted for 5% of the pesticide-treated area, representing 4% of the weight of active ingredients used. Seed treatments applied to arable crops grown in 1994 accounted for 16% of the pesticide-treated area, representing 2% of the quantity of active ingredients applied. Collectively, molluscicides and pesticides with mixed activity, accounted for less than 1% of both the total pesticide-treated area and quantity of pesticides applied to arable crops grown in Northern Ireland in 1994.

Potato crops received 84% of the total weight of fungicides applied, representing 63% of the area treated with fungicides. The single most commonly used fungicide active ingredient was mancozeb accounting for 39% of the fungicide-treated area and 69% the weight of fungicide active ingredients applied.

Cereals accounted for 77% of the area treated with herbicides/desiccants and 27% of the weight of herbicide/desiccant active ingredients applied. Treatments to spring barley crops represented 34% of the herbicide/desiccant-treated area, representing 7% of the weight of herbicide/desiccant active ingredients applied. Metsulfuron-methyl, accounting for 27% of the herbicide/desiccant-treated area, was the herbicide most commonly applied to cereal crops, in particular spring barley.

Cypermethrin was the most commonly used insecticide active ingredient and was applied to 43% of the insecticide-treated area to control aphids in cereal crops. Pyrethroid and organophosphate insecticides accounted for 89% of the insecticide-treated area.

A total of 196 products, comprising 108 active ingredients, were recorded used on field crops in the survey.

In addition to information concerning field applications of pesticides to crops, data relating to post-harvest/storage treatments applied to farm stored potatoes were collected. It was estimated that 119,447 tonnes of potatoes were stored, on-farm, following the 1994 growing season. Ware potatoes accounted for 71% of the total quantity of stored potatoes, seed potatoes 20% and mixed seed and ware storage 9%. While County Antrim accounted for 35% of the potato crops grown in Northern Ireland in 1994, the quantity stored in County Antrim represented 51% of all potatoes and 60% of ware crops. An estimated 1,852 kilograms of pesticides were applied to 26,580 tonnes of stored potatoes. With reference to quantities of active ingredients applied, tecnazene was the most extensively used pesticide accounting for 43% of the total weight of pesticides used. However, thiabendazole, as a single active ingredient or in formulation with tecnazene, represented the most widely applied pesticide, accounting for 53% of treated stored potatoes.

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