Vegetable crops 1995

This is the second survey of pesticide usage practices in vegetable crops, produced for human consumption, conducted in Northern Ireland, providing comparative data to that obtained in the previous survey in 1991 (Jess et al., 1993). Information on all aspects of pesticide usage was collected from 107 holdings throughout the Province, representing 51% of the total number of growers and 76% of the total area of vegetable crops grown. Quantitative data has been adjusted to provide estimates of total pesticide usage. The area of vegetable crops grown in Northern Ireland in 1995 (1,323 hectares) was similar to that recorded 1991 (1,316 hectares).

By comparison with 1991, the pesticide-treated area increased by 26% to 7,505 spray hectares, while the quantity of pesticides applied was virtually unchanged at approximately 7 tonnes. The fungicide-treated area increased by 28%, while the quantity of fungicide active ingredients applied increased by 60%. Applications of herbicides and desiccants increased by 19%, while the weight of active ingredients applied increased by only 5%. The use of insecticides increased in both area treated and quantity applied by 47% and 46%, respectively. The area treated with organophosphates increased from that recorded in 1991 by 35%, while the data showed a two-fold increase in the use of pyrethroid insecticides during the same period. In the four year period 1991 to 1995 there was a slight increase in the molluscicide-treated area. While the area of vegetable crops sown or planted with treated seed decreased by only 9% in the four year period 1991 to 1995, the weight of active ingredients used decreased by 24%. Soil fumigants, applied to four hectares of vegetable production land in 1991, were not recorded in use in 1995.

During 1995 regional pesticide usage closely approximated to the areas of vegetable crops grown in each country. Pesticides were applied to 99% of the total area of vegetable crops grown in Northern Ireland in 1995, with a mean of two applications.

Fungicide application represented 12% of the pesticide-treated area and 19% of the total quantity of pesticides used. Herbicides and desiccants accounted for 34% of the pesticide-treated area and 53% of the total quantity of pesticides used. Insecticides, applied to 43% of the pesticide-treated area, accounted for 28% of the total quantity of pesticides used. Seed treatments applied to vegetable crops grown in 1995 accounted for 11% of the pesticide-treated area, while representing less than 1% of the quantity of active ingredients applied. Molluscicides accounted for less than 1% of both the total pesticide-treated area and the quantity of pesticides applied to vegetable crops grown in Northern Ireland in 1995.

Brassica crops received 37% of the total weight of fungicides applied, representing 49% of the area of vegetable crops treated with fungicides. The single most commonly used fungicide active ingredient applied to brassicas was chlorothalonil. Carrots, parsley and parsnips, collectively accounted for 42% of the fungicide active ingredients applied while representing 10% of the fungicide-treated area. A formulation of mancozeb/metalaxyl was most frequently used on these vegetable crops.

Propachlor was the herbicide/desiccant active ingredient most commonly applied to vegetables crops, particularly leeks, spring onions and brassicas. However, linuron was also frequently used, mainly on carrots, parsley and parnsips.

Brassicas accounted for 65% of the insecticide-treated area, while only representing 26% of the quantity of insecticide active ingredients applied. Conversely, carrots, parsley and parsnips accounted for 53% of the total weight of insecticides applied and only 22% of the insecticide-treated area. Organophosphates continued to be the most frequently used insecticide active ingredients, specifically dementon-S-methyl and chlorpyrifos.

A total of 111 products, comprising 69 active ingredients, were recorded in use on vegetable crops in the 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