Pesticide usage report: Arable crops 2004

Summary

This is the eighth survey of pesticide usage practices on arable crops in Northern Ireland, providing comparative data to that obtained in the previous surveys in 1990, (Jess et al., 1992), 1992 (Jess et al., 1995), 1994 (Jess et al., 1997), 1996 (Jess et al., 2000), 1998 (Jess et al., 2002), 2000 (Withers et al., 2004) and 2002 (Withers et al., 2004).

Information on all aspects of pesticide usage was collected from 293 holdings throughout the Province, representing 24% of the total area of arable crops grown. Quantitative data has been adjusted to provide estimates of total pesticide usage.

The total area of arable crops grown in Northern Ireland in 2004 was 48,541 hectares, an increase of less than 1% compared to that recorded in 2002. Approximately 44% of the arable cropping area was in County Down, 23% in County Londonderry, 16% in County Antrim, 8% in County Tyrone and 9% in County Armagh. There was no significant area of arable cropping in County Fermanagh.

During the period 2002 to 2004, the area of arable crops treated with pesticides increased by 13%, to 325,299 spray-hectares. The most notable increase was recorded in the use of insecticides (57%) which was mainly due to increased applications of the pyrethroid insecticides, principally lambda-cyhalothrin, esfenvalerate, deltamethrin and cypermethrin, along with the organophosphate, chlorpyrifos. Applications of fungicides (9%) and herbicides/desiccants (21%) also increased since 2002. However, the weight applied of these pesticide groups decreased by 17% and 35% respectively. This reflects the relatively low dose rates of current pesticide applications. Molluscicide applications reduced by 82% for both treated area and weight applied. This was the result of fewer applications principally to potatoes but also to cereals. Growth regulators were applied primarily to spring barley, winter barley and, most frequently, to winter wheat. The use of growth regulators on cereal crops reduced by 5% when compared with 2002. The principal growth regulator used in 2004 was chlormequat, which is consistent with previous surveys in 1998, 2000 and 2002. The total weight of pesticides applied to arable crops in 2004 decreased to 341 tonnes of active ingredients, a reduction of 31% compared with 2002. The single active ingredients fludioxonil and imazalil, were the  most commonly used seed treatments applied to cereals and potatoes, respectively

During 2004, regional pesticide usage was related to the area of arable crops grown in each county. Pesticides were applied to 82% of the total area of arable crops grown in Northern Ireland in 2004 with a range of  1.0 - 8.6 applications per crop.

Fungicides were applied to 43% of the pesticide-treated area, accounting for 21% of the total weight of pesticides used. Herbicides and desiccants were applied to 32% of the pesticide-treated area, representing 75% of the total weight of pesticides used. Insecticides accounted for 10% of the pesticide-treated area of arable crops, representing less than 1% of the weight of pesticides used.  Molluscicide treatments represented less than 1% of both area of application and weight of pesticides applied. Growth regulator usage accounted for 5% of the pesticide-treated area and 3% of the weight of active ingredients applied. Seed treatments were applied to 10% of the area of arable crops grown in 2004, representing less than 1% of the weight of active ingredients applied.

Potato crops comprised 13% of the area of arable crops grown in Northern Ireland in 2004, while accounting for 25% of the total pesticide-treated area. However, the weight of pesticides applied to potato crops represented 77% of the total weight of pesticides used on all arable crops. The total area of potatoes grown comprised 74% maincrop, 19% seed and 7% early potatoes. Potato crops accounted for 37% of the area of arable crops treated with fungicides and received 72% of the total weight of fungicides applied. Furthermore, applications of herbicides and desiccants to potato crops represented 19% and 83% of the area treated and weight applied of this pesticide group, respectively. The most commonly recorded fungicide was mancozeb, applied to arable crops as a single active ingredient and in formulation with other compounds. Mancozeb was used on 21% of the fungicide-treated area and accounted for 54% of the weight of fungicide active ingredients applied. Mancozeb was used primarily in maincrop potatoes to control blight (Phytophthora infestans). Spring and winter barley crops accounted for 54% of the herbicide and desiccant-treated area, but only 10% of the weight applied of active ingredients from this pesticide group. The most commonly applied herbicide, used almost exclusively on cereal crops, principally spring barley, was metsulfuron-methyl. Owing to the low application rate of this active ingredient, the weight applied represented less than 1% of the total weight of herbicides and desiccants used.

This was the fourth survey where the cultivation of pea and bean crops was recorded .

A total of 221 products, comprising 119 active ingredients, was recorded in use 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 155,669 tonnes of potatoes were stored on-farm following the 2004 growing season. This represented a 158% increase compared with 1998. Ware potatoes accounted for 79% of the total quantity of stored potatoes, with seed potatoes accounting for the remainder. County Down and County Antrim accounted for 40% and 34% of all potatoes stored respectively. An estimated 78% of all potatoes receiving treatments in storage were held in County Down and treatments to these potatoes accounted for 95% of the weight of pesticides applied. Overall, 2% of stored potatoes received pesticide treatment. Two active ingredients were recorded as applied, with an estimated 154kg of pesticide active ingredients applied to 3,772 tonnes of stored potatoes in Northern Ireland in 2004. Approximately 42% of all potatoes in 2004 were stored in barn stores.  Overall, 63% of potatoes were stored on-farm in boxes, while 23% were stored in bulk.

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