Pesticide usage report - arable crops 2002

Summary

This is the seventh 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), 1992 (Jess et al., 1995), 1994 (Jess et al., 1997), 1996 (Jess et al., 2000), 1998 (Jess et al., 2002) and 2000 (Withers et al., 2004).

Information on all aspects of pesticide usage was collected from 315 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 2002 was 48,222 hectares, representing a 9% decrease compared to that recorded in 1998. During this period, the area of crops treated with pesticides reduced by 7%, to 288,348 spray-hectares. The most notable increase was recorded in the use of molluscicides (72%). Application of methiocarb to early potatoes increased almost fourteen-fold while use on maincrop potatoes increased almost three-fold. The use of metaldehyde on seed and early potatoes was reported for the first time. The application of all other pesticides decreased, except for insecticide which remained approximately at the same level.

Fungicide usage reduced by 10%, herbicides and desiccants by 5%, growth regulators by 8%, seed treatments by 4% and mixed formulations by 33%. The use of carbamate insecticides, principally pirimicarb, showed a 100% increase in use from 1998 while the use of organophospates, principally chlorpyrifos and dimethoate, decreased by 20%. Pyrethroid insecticides accounted for 91% of all insecticides used on arable crops, with lambda-cyhalothrin and esfenvalerate the principal active ingredients. The use of growth regulators on cereals remained unchanged when compared with 2000 but reduced by 9% when compared with 1998. The principal growth regulator used in 2002 was the active ingredient chlormequat which is consistent with both 1998 and 2000.

The total quantity of pesticides applied to arable crops increased by 10% to 492 tonnes of active ingredients compared with 1998. During 2002 regional pesticide usage was related to the area of arable crops grown in each county. Pesticides were applied to 94% of the total area of arable crops grown in Northern Ireland in 2002 with a range of 1.0 - 9.9 applications depending on pesticide group and crop type. Fungicides were applied to 44% of the pesticide-treated area, accounting for 17% of the total quantity of pesticides used. Herbicides and desiccants were applied to 30% of the pesticide-treated area, representing 76% of the total quantity of pesticides used. Insecticides accounted for 7% of the pesticide-treated area of arable crops, representing less than 1% of the weight of pesticides used.

Molluscicides and mixed activity pesticide treatments represented less than 1% of both area of application and quantity of pesticides used. Growth regulator usage accounted for 6% of the pesticide-treated area and 2% of the weight of active ingredients used. Seed treatments applied to arable crops grown in 2002 accounted for 12% of the pesticide-treated area, while representing less than 1% of the quantity of active ingredients applied.

Potato crops accounted for 52% of the area of arable crops treated with fungicides and received 82% of the total weight of fungicides applied. Furthermore, applications of herbicides and desiccants to potato crops represented 17% and 91% of the area treated and quantity of this pesticide group applied, respectively. The most commonly recorded fungicide applied, as a single active ingredient, was fluazinam, used primarily in maincrop potatoes to control blight (Phytophthora infestans). Spring and winter barley crops accounted for 56% of the herbicide and desiccant-treated area, but only 6% of the weight of active ingredients applied. The most commonly applied herbicide, used almost exclusively on cereal crops, principally spring barley, was metsulfuron-methyl. Owing to the low application rate for this active ingredient, the quantity applied represented less than 1% of the total quantity of herbicides and desiccants used. This relative proportion was further diminished by the large quantities of sulphuric acid applied as a pre-harvest potato haulm desiccant, to a comparatively small area of potato crops.  This was the third survey where the cultivation of pea and bean crops was recorded .  A total of 232 products, comprising 108 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 60,353 tonnes of potatoes were stored on-farm following the 2002 growing season. This represented a 63% decrease compared with 1998. Ware potatoes accounted for 73% of the total quantity of stored potatoes, with seed potatoes accounting for the remainder. County Londonderry accounted for 37% of all potatoes stored. County Down represented 34% of all potatoes receiving treatments in storage and 78% of the quantity of pesticides applied. Overall, 22% of stored potatoes received pesticide treatment. An estimated 488kg of pesticide active ingredients were applied to 13,053 tonnes of stored potatoes. Five active ingredient formulations were recorded in use on stored potatoes in Northern Ireland in 2002. Approximately 42% of all potatoes in 2002 were stored in refrigerated stores. Overall, 61% of potatoes were stored on-farm in boxes, while 20% were stored in bulk.