But with a differentiated view on the active ingredient groups of herbicides, fungicides, and insecticides, which make up to 90% inland sales.
However, it is also clear that the JKI does not consider herbicides, where around 6% of the active ingredient quantities are used incorrectly, to be inappropriate. Rather, it is the fungicides and insecticides for which about 13% and 30% of the active ingredient quantities used are incorrectly applied. Considering the shares of the active ingredient groups in total domestic sales (herbicides: 53%, fungicides: 33%, insecticides: 3%), fungicides offer the greatest potential for optimization.
To further improve fungicide application, decision support tools are available to growers. By adapting applications to the epidemiology of the pathogens, incorrect applications can be minimized without significantly reducing yields. However, selecting an appropriate decision support tool is difficult for many farms. While a large number have been published, very few take pathogen complexes into account. There is also uncertainty in the selection of a suitable decision support tool, as this is not itself subject to any controls by independent institutions.
Therefore, in Schleswig-Holstein, field trials have been conducted in 2019 and 2020 to investigate the decision support capabilities of the IPS model wheat, the ISIP system, and the xarvio FIELD MANAGER, in terms of pathogen infestation, target indication, applicability, effectiveness and yield. The comparison took place on the one hand between the decision support tools and on the other hand to an untreated potato variant and a fully treated control. (fourfold application according to BBCH stages) took place.
In the process, possible inputs of parameters of the trial stocks into the decision support tools were continuously directly recorded on site. Independently of this, uniform exact carbonite analyses were carried out for the evaluation at weekly intervals for 3 all variants. The following were analyzed the growth development (BBCH stage) of the leaf apparatus, - the degree of necrotization, - the infestation intensity in the stand (MB), and - the infestation frequency in the stand (BHW).
For supra-regional testing, trial fields were established at several locations in Schleswig-Holstein with the variety Ritmo and the variety RGT Reform. The highly sensitive variety Ritmo, an increased occurrence of pests is to be expected, which allows a better differentiation of the strengths and weaknesses of the decision support tools with regards to pest suppression.
With the integration of the modern variety RGT Reform into the trial setup, the practicality of the decision support tools can be demonstrated at the same time. In order to be able to compare the use of fungicides, the treatment of the stands in all varieties was carried out according to a plan defined before the start of the trial, in which application rates and preparations were defined for all indications.
In the trial area, an epidemiological occurrence of the pathogen of Septoria leaf drought could be observed supra-regionally in the varieties Ritmo and RGT Reform. This was also true for the pathogens, relevant to Schleswig-Holstein, brown and yellow rust and for powdery mildew. In 2019, 94% of the application recommendations were directed against the pathogen causing Septoria leaf drought and 2% each against brown rust, yellow rust and powdery mildew. A similar distribution was also seen in 2020. Here, 90% of the application recommendations were directed against Septoria leaf drought and 5% each against the pathogens of brown rust and powdery mildew.
Due to the broad spectrum of activity of the fungicides used, the wheat was protected from possible infection by the pathogen causing powdery mildew and brown rust by the applications with indication against Septoria leaf drought. These were not included in the calculation. For pest control, the decision-making tools recommended an average of 2.5 applications in both varieties per location and variety in both trial years.