Pesticide usage report: Grassland & fodder crops 2013

Summary

This is the seventh survey examining pesticide usage practices on grassland and fodder crops in Northern Ireland, providing data comparative to that obtained from previous surveys in 1989 (Jess et al., 1992), 1993 (Jess et al., 1995), 1997 (Jess et al., 2000), 2003 (Withers et al., 2005), 2005 (Withers et al., 2007) and 2009 (Withers et al., 2010). In this survey, information on all aspects of pesticide usage was collected from 235 enclosed grazing, 56 arable silage, 11 fodder maize and 18 other fodder crop holdings throughout the province, representing 1.9% of the total area of grassland and fodder crops grown. Quantitative data obtained were adjusted to provide estimates of total pesticide usage.

Overall, the area of grassland and fodder crops grown in 2013, 1,302,730 ha, increased by 14% when compared to 2009. The area of established grassland crops also increased by 14% throughout this period. The area of sown crops increased by 38% mainly due to the increase of grass reseeds. The area of fodder crops grown in Northern Ireland in 2013 decreased by 40% compared to that recorded in 2009. This was principally due to the decrease in fodder maize production. A fourth cut of silage was recorded for the first time in 2005 and this recurred in 2009. During 2013 the area of fourth cut silage increased by over five fold when compared to 2009.

The area of grassland and fodder crops receiving pesticide treatment, increased by 21% when compared to that recorded in 2009. A total of 87 tonnes of pesticide was applied to 123,354 spray hectares of grassland and fodder crops during 2009. This represented a 16% increase in the weight of pesticides applied compared to 2009. A total of 118 products comprising 78 active substances were recorded in use during this survey. Herbicides accounted for 78% of the pesticide-treated area, representing 85% of the weight of pesticides applied. Insecticides accounted for 12% of both the treated area and the weight of active ingredients applied. This was a five-fold increase in insecticide use compared with 2009. The weight of insecticide active substances applied increased from 176kg to 10,375kg. This was principally due to increased chlorpyrifos applications to first cut silage to control leatherjackets, although enclosed and rough grazing also received increased applications. Fungicides, growth regulators and seed treatments collectively accounted for the remainder of the total pesticide usage and were exclusively applied to arable silage crops and the nurse crop in undersown arable silage crops. No molluscicide use was recorded during this survey.

The area of established grassland crops treated with pesticides increased by 44% when compared to the 2009 survey. This was mainly due to increased areas of grass silage grown and subsequent treatment for leatherjackets and docks (Rumex spp.). Correspondingly, the weight of active substance applied to established grassland crops increased by 35%. Pesticide usage on sown grassland crops increased by 16% when compared with 2009. However, the weight of active substances applied decreased by 10%. This was mainly due to the increased area of arable silage grown and grass reseeds together with decreased application rates. The reduction in the area of fodder crops sown is mainly attributed to the 44% reduction in fodder maize crop production. However, other fodder crops reduced by 25% when compared to 2009. The pesticide-treated area of fodder crops decreased by 59% from 16,703 spray hectares (spha) to 7,040 spha and the weight of active substances applied decreased by 40%.

In keeping with data from previous years, herbicides remained the most extensively used pesticide type on grassland and fodder crops. The use of herbicides decreased by 21% between 2003 and 2005. This trend continued between 2005 and 2009, showing a 32% reduction. When comparing 2013 with 2009 there was a 2% increase in the weight of active substances applied. However, there was a 20% increase in the area treated. The formulation of fluroxypyr/triclopyr remained the most frequently-used herbicide, principally applied to the first-cut of grass silage to control docks (Rumex spp.).

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