LW-R-5: Use of pesticides

 The picture shows a man standing in a maize field examining the leaves of a maize plant. Click to enlarge
In the case of more unpredictable infestations with pests,careful stock checks become more important
Source: Photograph: © Bits and Splitzs / stock.adobe.com

2019 Monitoring Report on the German Strategy for Adaptation to Climate Change

Table of Contents

 

LW-R-5: Use of pesticides

Climate change will entail major uncertainties in terms of plant protection. These uncertainties should not result in increased distribution of pesticides or intensified plant protection. Regarding the total of domestic distribution, a rising trend was observed for the overall period covered.

The line graph represents the sum of domestic sales of herbicides, fungicides, insecticides (excluding inert gases) from 1991 to 2017 in active ingredient quantities in thousand tonnes. Use increased significantly during the observation period. Further lines also show the treatment index for winter wheat and winter barley, both without trend, and for winter rape from 2007 onwards. For the latter, there is also a significantly increasing trend.
LW-R-5: Use of pesticides

The line graph represents the sum of domestic sales of herbicides, fungicides, insecticides (excluding inert gases) from 1991 to 2017 in active ingredient quantities in thousand tonnes. Use increased significantly during the observation period. Further lines also show the treatment index for winter wheat and winter barley, both without trend, and for winter rape from 2007 onwards. For the latter, there is also a significantly increasing trend.

Source: Bundesamt für Verbraucherschutz und Lebensmittelsicherheit (reports according to § 19 Plant Protection Act) / Julius Kühn Institut; Plant protection services of the federal states (network reference farms plant protection)
 

Targeted application of pesticides

It is not yet possible to make any tangible forecasts regarding the impacts of climate and weather patterns on the pest infestation or infection with pathogens of agricultural crops. It is undeniable, however, that pests can respond very sensitively and spontaneously to changed weather conditions; this requires farmers and horticulturists to respond flexibly and with utmost speed in order to get problems with pest infestations under control.

It is therefore ever more important for farmers to keep a close eye on their own stocks in order to ensure integrated plant protection. This involves taking precautionary measures in order to buffer any extreme weather events or latent infestations by cultivating healthy and resilient plants. Furthermore, it is necessary to monitor crops and to ensure resistance management when using chemical pesticides by giving priority to non-chemical measures.

The National Action Plan on Sustainable Use of Plant Protection Products (NAP) adopted by the Federal Government and the German Länder aims to further limit the potential risks posed by the application of pesticides and to limit the application of chemical pesticides to what is absolutely necessary. Climate change can result in changing the first occurrence and development as well as the infection or infestation conditions of various pests. The appropriate response proposed is the targeted monitoring of crops and the observation and, where necessary, adaptation of reference values as required for effective control.

In practice this means that production systems will have to be adapted and that increased investments will be required in up-to-date and enhanced systems for forecasting and assistance in decision-making.

When interpreting long-term data series on the distribution and the intensity of pesticides, it should be borne in mind that, apart from weather-related causes, developments are influenced by a considerable number of other factors. For example, increasing specialisation of a farming business can entail an increase in problems associated with plant protection. It is also important to remember that decisions to minimise tillage in the interest of soil protection and humus production can result in increased weed growth competing with crop plants.

In other words, management decisions can bring about an increased use of herbicides if their use is the last resort left in the arsenal of plant protection. Another point to be taken into account in interpreting the data on distributed amounts of pesticides and intensities of plant protection, is the fact that modern highly effective pesticides may make it possible to use smaller quantities of these agents if they are known to provide, at least in part, stronger eco-toxicological effects. Nevertheless, from an ecotoxicological angle, it is true to say that these agents, albeit to lesser extents, are saddled with the same risk potential as older types of agents which were used in larger amounts, thus making it possible that the overall risk potential increases even if the amount distributed remains the same.

The chart shows the domestic distribution of pesticides. The illustration provides only a rough guideline for the amounts distributed in Germany, partly because pesticides are also traded beyond Germany’s borders. This trade is not covered in the chart. In the course of the past twenty years, the distributed amounts have settled around a certain level. If the spectrum of pests or pathogens changes as a result of climate change, for instance because weeds and weed grasses as well as insects benefit particularly from warmer weather, it is conceivable that this may also be reflected in the proportions of areas targeted by pesticides (herbicides, fungicides, insecticides) for the total domestic distribution covered in this chart. It is of interest to note that no such shifts have been identified for the past twenty years.

The treatment index makes it possible to make statements on the intensity of pesticides. It offsets the number of applications made per annum by the amounts used per spraying operation in relation to the highest permitted application quantity for the respective crop and indication. Any increase or decrease in the application intensity of pesticides is expressed in terms of rising or falling treatment indices. Despite any challenges associated with climate change, this should not result in an increased intensity of plant protection.

 

Interfaces

LW-I-4: Infestation with harmful organisms

 

Objectives

Reducing the dependence on the application of chemical pesticides including the introduction of further development of alternative plant protection procedures, breeding of resistant and resilient crops and expansion of cultivated areas for ecological farming (National Action Plan on Sustainable Use of Plant Protection Products 2013, e.g. ch. 5.1 and 6.1.2; the UBA’s 5-point programme for sustainable plant protection, ch. III)

Further development and systematic implementation of integrated plant protection with the objective to limit the use of pesticides to what is absolutely essential (National Action Plan on Sustainable Use of Plant Protection Products 2013, ch. 4.9 and 5.1)

Reduction of and compensation for risks which might be caused by the application of chemical pesticides (5-point programme for sustainable plant protection, ch. III)