After the final spraying run, work on the sprayer is not yet over. Residual spray solution remains in the tank, pump and pipes; traces of crop protection products cling to the outside. Rinse water can carry them out of the vineyard and, if cleaning and disposal are poorly organised, into sewers or surface waters.
The water protection symposium on 5 November 2026 at DLR Rheinpfalz in Neustadt an der Weinstraße will focus on equipment cleaning and wash water treatment. The specialist event promises practical demonstrations. The programme alone does not reveal which procedures winegrowers actually use in their day-to-day work or what obstacles they encounter. The available recommendations do, however, highlight the points at which post-application routines become crucial.
Avoid leftovers in the first place
The first step comes before spraying: calculate the required volume as accurately as possible so that little or no spray mixture is left at the end. The DLR booklet on professional competence in viticulture describes a procedure for unavoidable leftovers in which the liquid is diluted and applied to an area of vineyard that has already been treated. Emptying leftovers onto tracks, bare ground, into watercourses or into sewers is not a permissible alternative. The product’s instructions for use and specific conditions of application remain the determining factors.
Internal cleaning serves a purpose too: residues in the tank, pump and pipes should be diluted and applied to the vineyard area in a controlled manner, rather than allowed to drain away unchecked. The DLR booklet describes repeated rinsing for this purpose. This means more than briefly directing a jet of water into the tank: liquid must pass through the parts of the equipment where residues may remain.
External washing needs a suitable site
For external cleaning, the DLR recommendations identify two options: the area where the product was applied or a purpose-built cleaning area. When cleaning in the vineyard, the ground should be unpaved and preferably covered with vegetation. Contaminated water can quickly run off paved surfaces; rain also brings the risk of it being washed into ditches and watercourses. The Aufsichts- und Dienstleistungsdirektion, the supervisory and service authority for Rheinland-Pfalz, explicitly lists the location and proper execution of equipment cleaning as matters that may be inspected.
For businesses that need to clean equipment regularly, collection and treatment systems may offer another option. The DLR framework recommendations describe systems in which residual spray solution and wash water are collected and trickled through substrate containers, where microorganisms break down crop protection products. According to DLR, building regulations must be checked and specialist advisers consulted before construction. This is not a solution that can simply be adopted without considering the site, system capacity and operating obligations.
From guidance notes to everyday practice
A cleaning area, collection tanks and treatment facilities require space and organisation. For smaller businesses in particular, this raises the practical question of whether shared or easily accessible infrastructure is available. The sources document such options, but not how widespread they are or what specific support winegrowers need. Establishing that would require discussions with businesses and advisory services.
Hochschule Geisenheim University’s water protection advisory service illustrates how advice and analysis can be organised within a regional programme: participating businesses receive services including testing and fertiliser advice. The scheme primarily concerns nutrient management and does not demonstrate that comprehensive advice on equipment cleaning is available. It does, however, show that protecting water involves more than regulations alone: businesses need clear procedures and accessible advice tailored to their land and working practices.
After spraying, then, it is not only the product used and the accuracy of its application that matter. Where residual liquid and wash water end up is crucial too. The symposium focuses precisely on this often invisible stage — work whose success is measured by residues not reaching places where they do not belong.
Original reviewed by the editors · 5 November 2026
