Danfoil sprayers and the enviroment
In recent years, the environment has received more and more attention. This is illustrated partly by the public debate, partly through national and international regulations and through technical standards based on protection of the surrounding environment.
Interest is high for drift reducing equipment and a lot of time is spent with testing sprayer’s efficiency. Globally[J1] , there is an interest in drift reduction and the development of need-adjusted use of chemicals.
Three main accounts
When talking about spraying with pesticides, it is advantageous to make a væske-regnskab with three main accounts: (1) an account for the liquid reaching the target and creates the effect, (2) an account for the liquid that does not reach the target, and (3) an account for the liquid dropped on the ground. As mentioned, the first two accounts have received a lot of interest, whereas the last account “drop on the ground” has not, in our opinion, received the necessary attention.
Danfoil sprayers, using atomizer technology and only 30-60 l/ha, eject only a small amount liquid, why there is not much to drop on the soil.
The danfoil sprayer was first sold in 1984. Since then, more than 1200 sprayers has been produced and sold, treating about four million hectare each year. The most important spraying task[J2] takes place using far fewer chemicals than conventional sprayers. The savings is a result of lower doses per spraying or as recommended dosage using reduced treatment frequency (defined as number of sprays (treatments?))
What do the experts think?
Experts in spraying technique believes that “drop on soil” is not an unimportant factor when spraying in an established crop uses a larger quantity of liquid (300 l/ha). There are reports of up to 50% loss of the ejected volume. However, using a limited quantity of liquid, and using the atomizer technique (Eurofoil technique), the account “drop on soil” will draw near to zero.
The problem is, in our opinion, of such a nature, that any savings in this account must benefit the spraying concept, if there is merely a reasonable likelihood of reducing the amount of liquid dropped on the soil. It is certain that chemical residues, which are dropped on the ground, will continue into the groundwater and pollute watercourses and lakes, to significant damage to the environment.
Danfoils contribution to improving the environment
As we have seen above, danfoil sprayers use a spraying concept, where the amount of ejected liquid is reduced, compared to conventional field sprayers. It is proven that danfoil field sprayers both deposits on the target, and that the effectiveness in both weed control, disease control, and in measured yield are better than by comparative techniques, even using less pesticides. Regarding the assessment of drift for a danfoil field sprayer, one must also take into account that there is very little pesticide to drift, due to the reduced amount of pesticides used.
In September 2010, Danfoil have completed a survey, in order to document danfoil customers experience with the use of chemicals when spraying. In the survey, 50 danfoil customers told about their experience with their danfoil field sprayers, and the main results are:
- There is a big potential for reductions in pesticide consumption, if all farmers reduce their consumption of pesticides as much as the farmers that reduces the most.
- There is a big potential for considerable environmental and economic savings
- Few negative experiences in yield as a result of chemical reductions.
- Danfoil field sprayers have a large capacity – average amount of liquid is 40-50 l/ha.
- Danfoil customers are satisfied – 90 % would recommend others to buy a danfoil sprayer.
As shown in Figure 1 there is with a danfoil sprayer a significant reduction of pesticide consumption when desiccating potatoes. This gives both the farmer and the environment an opportunity to save. If all farmers could recuce as much as the user with danfoil sprayers could, the environment would over a 10 year period be able to save 19.500 litre pesticides. Each potato farmer will over a 10 year period be able to save DKK 175.500 which per year is DKK 17.550.
As shown in Figure 2 it is possible to reduce pesticide in other crop than potatoes. The survey shows that danfoil users have been able to reduce the quantity of pesticide up to 75% - great potential.
Following this, danfoil has, through the product manual, handed out instruction on how danfoil sprayers is used most efficient and with a minimum risk of environmental contamination. We recommend that spraying is planned carefully in relation to the most appropriate time to spray, purpose of spraying, and assessment of area size, which helps the user to only bring along the needed amount of liquid. In that way there is no need to dispose of chemical residues not required.
The spray instructions also provide a recipe for how to start and complete the spraying, so that there are no chemical residues left in the sprayer. Whatever is left is heavily diluted.