Pesticide usage report: Arable crops 2010

Summary

This is the eleventh 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), 2002 (Withers et al., 2004), 2004 (Withers et al., 2006) 2006 (Withers et al., 2007) and 2008 (Withers et al.,2009).

Information on all aspects of pesticide usage was collected from 249 holdings throughout the Province, representing 25% 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 2010 was 43,027 hectares. This represented a decrease of 7% compared to that recorded in 2008 and a 23% reduction compared to that recorded in the first pesticide usage survey of the arable sector, in 1990. Approximately 42% of the arable cropping area in 2010 was in County Down, 24% in County Londonderry, 18% in County Antrim, 9% in County Armagh and 7% in County Tyrone. This distribution is similar to that recorded in 2008 and 2006. There was no significant area of arable cropping in County Fermanagh.

A total of 297 products, comprising 101 active ingredients were recorded in use on field crops in the survey.

During the period 2008 to 2010, the area of arable crops treated with pesticides decreased by 10%, to 337,336 spray hectares. Applications of pesticide groups mainly decreased with the exception of a synthetic latex application to oilseed rape to minimise seed loss at harvest time and growth regulator applications which increased by 7% when compared to 2008. The principal growth regulator used in 2010 was chlormequat which is consistent with previous surveys conducted in 1998 to 2008. Similar to 2008 data, in 2010 growth regulators were applied primarily to spring barley, winter barley and most frequently to winter wheat. Fungicide applications decreased by 7% and herbicides and desiccants by 12%. Insecticide applications decreased by 26% when compared with 2008 and the weight applied decreased by 21%. Pyrethroids were the most frequently applied insecticides representing 95% of all insecticide applications. Esfenvalerate was the most frequently applied insecticide primarily to spring barley crops to control aphids. Molluscicide applications decreased by 36% and were similar to levels first recorded in 1990. An estimated 60% of molluscicide applications were to control slugs on potato crops. The total weight of pesticides applied to arable crops in 2010 decreased to 136 tonnes of active ingredients, a reduction of 19% compared with 2008 and 43% compared with 2006. Seed treatment applications decreased by 7%. However, the weight applied increased by 15%. In keeping with 2008 data, the formulation prochloraz/triticonazole was the most commonly applied cereal seed treatment in 2010. This contrasted with 2004 and 2006 where the single active ingredient fludioxonil was the most commonly applied to these crops. The formulation imazalil/pencycuron was the most commonly used seed treatment on potatoes.

During 2010, regional pesticide usage was related to the area of arable crops grown in each county. Pesticides were applied to 97% of the total area of arable crops grown in Northern Ireland in 2010 with a range of 1.0 – 10 applications per crop.

Fungicides were applied to 44% of the pesticide-treated area, accounting for 50% of the total weight of pesticides used. Herbicides and desiccants were applied to 31% of the pesticide-treated area, representing 37% of the total weight of pesticides used. Insecticides accounted for 8% of the pesticidetreated 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 7% of the pesticide-treated area and 10% of the weight of active ingredients applied. Seed treatments were applied to 10% of the area of arable crops grown in 2010, representing 2% of the weight of active ingredients applied.

Potato crops comprised 9% of the area of arable crops grown in Northern Ireland in 2010, accounting for 23% of the total pesticide-treated area. However, the weight of pesticides applied to potato crops represented 39% of the total weight of pesticides used on all arable crops. The total area of potatoes grown comprised 82% maincrop, 14% seed and 4% early potatoes. Potato crops accounted for 37% of the area of arable crops treated with fungicides and received 59% of the total weight of fungicides applied. Furthermore, applications of herbicides and desiccants to potato crops represented 17% of the area treated and 23% of the weight applied of this pesticide group. The most commonly recorded fungicide applied to potato crops was fluazinam, applied mainly as a single active ingredient but also in formulation with metalaxyl-M. Fluazinam was used on 31% of the fungicide-treated area and accounted for 7% of the weight of fungicide active ingredients applied. It was used primarily in maincrop potatoes to control blight (Phytophthora infestans) and for general disease control. Chlorothalonil, applied mainly as a single active ingredient but also in formulation, was the most frequently applied fungicide to cereal crops. The most frequently applied herbicide and desiccant used on cereal crops, principally spring barley, was glyphosate. It accounted for 21% of the area of arable crops treated with herbicides and desiccants and 31% of the total weight of herbicides and desiccants applied.

This was the seventh survey in which the cultivation of pea and bean crops was recorded.

In addition to information concerning field applications of pesticides to crops, data relating to postharvest/storage treatments applied to farm stored potatoes were collected. It was estimated that 111,028 tonnes of potatoes were stored on-farm following the 2010 growing season. This represented a 52% increase compared with 2008. Ware potatoes accounted for 85% of the total quantity of stored potatoes, with seed potatoes representing the remainder. No early potatoes were recorded as stored. County Down and County Londonderry accounted for 43% and 35% of all potatoes stored, respectively. All potatoes receiving treatments in storage were in County Londonderry. Overall, approximately 9% of stored potatoes received pesticide treatment. The sprout suppressant chlorpropham was the only pesticide used with an estimated 203 kg applied to 9,644 tonnes of stored ware potatoes in Northern Ireland in 2010. Approximately 40% of all potatoes in 2010 were stored in ‘refrigerated’ buildings and 34% in ‘barns’. Overall, 76% 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