. PROCEDURE AND' DEVICE FOR THE PROTECTION OF PLANTS FROM FROST AND FOR THE REPRESSION OF VERMIN BY ARTIFICIAL FOG
Ulrich Muller Kiel Germany
Application April 11 1931 Serial No. 529 530 and
in Germany August 2 1930
8 Claims. (Cl. 47—2)
The protection of growing plants from destruction by night frosts in Spring has been known for a long time. Many plans of operation have been tried for this purpose but have
5 proved more or less complicated and expensive in their application as well as only partly effective. Frost-protection by means of linen covers or mats is known. These covers or mats being spread over the exposed plants are to
10 form an obstacle for the heat rays radiating from the soil. It is obvious that such form of protection is very expensive and requires employing a large number of hands and even then is only applicable for very small cultivated sur-
15 faces. The generation of heat in such plant-cultivation by means of stoves or briquettes is subject to similar objections requiring expensive and difficult attendance and offering a very small effective protection: The procedure of smoking
20 out the frost presents much greater possibilities and is based on laying a dense smoke screen over the surfaces to be protected during the periods of frost menace. The dense smoke is generated with stoves by burning materials which develop
25 smoke densely such as crude naphthalene and prevents as an artificial cloud screen the high radiation of heat from the soil. A disadvantage of this procedure however lies in the high costs which hinder a wide application of the appara-
30 tus pertaining to it and it is consequently only applicable for the protection of high class cultivations. The manipulation of the apparatus is also very expensive; as a large number of trained hands is necessary.. Another disad-
35 vantage of smoking the frost consists in the fact that the smoke screen by incomplete combustion of the materials developing smoke carries soot particles along which are deposited on the plants and affect their respiratory action.
40 On account of the rising heat resulting from the combustion undesirable air movements are caused. Cold air currents enter from the side and the inconstancy of the smoke clouds arising from this makes the desired protection from
45 frost ineffective.
The various disadvantages in the prior suggestions for the protection of plants from destruction by night frosts are avoided by the procedure and the apparatus of the present in-
50 vention.
According to the invention a screen of artifi-
cial fog is spread over the plants instead of the
smoke screen which then forms an effective
protection against the heat radiation. The ar-
55 tificial fog may be produced for example in
the known manner by spraying materials forming dense fog for example fog acid in finely distributed form or allowing it to drip on large surface bodies. As fog acid sulphur trioxide chloro-sulfo acid sulphur trioxide dissolved in 60 chioro-sulfo acid etc. can for example be employed as answering the purpose. Detailed experiments have shown that the fog formed by the evaporation of fog acid exercises no detrimental effects on the plants in the low con- 65 centration found in the extremely fine distribution of the fog particles. No detrimental de-posits whatever on the plants take place by precipitation of the fog in the procedure according to the present invention so that injury to the 70 respiratory action and consequently to the growth of the plants does not occur. Besides this the fog screen is quite stable as there is no heat source to cause rising air currents and consequently an effective prevention of heat radia- T5 tion from the soil during frost nights is made possible.
Furthermore according to the invention the generated fog can besides being employed as a frost protection medium also be used for the 80 destruction of certain animal and vegetable parasites. It has been ascertained by detailed experiments that the uredo for example can-not thrive on sour fostering soil so that consequently by means of the fog in very finely dis- 85 tributed form an effective protection of the plant cultivations from this evil is also attained thus naturally yielding considerably superior and more valuable returns.
According to the invention one can go still fur- 90 ther in the employment of the artificial fog and use the fog particles as bearers of specifically vermin-destroying materials for example fluor-combinations which develop a remarkable germ-killing effect. For example fluorsulfo acid 95 (HFSO3) in which sulphur trioxide dissolves is according to the invention 'especially qualified for this purpose. By evaporation of this mixture one succeeds in carrying fluor-combinations over extensive districts in much finer particles than 100 is possible in the distribution of the hitherto employed powder-formed vermin-destroying mediums.
Another great advantage as compared with the hitherto employed procedure for frost protec- 105 tion lies according to the invention in the in-expensive simple apparatus with which fog is generated. As fog source the original transport barrel in which the fog acid is sold may be used and this is laid on a suitably arranged trestle at 110
2
5 10 15 20
30 35 40 45 50
25 pends on the size of the tract of land to be
the place of employment. A drip spout projects transversely to both sides under which lime is heaped or a nozzle system is fitted directly to the discharge tap of the barrel so that the acid can be suitably distributed over the lime poured for example into a box or a wire basket or over other large surface bodies in the basket. Such apparatus is made ready for use simply by fitting a filled transport barrel on a trestle and by filling the wire basket with large surface bodies such as lime coke and other materials. When a night frost sets in or is threatened the discharge cocks of the barrels are merely opened so that the acid then flows through the nozzles or openings upon the large surface bodies and gives rise to a dense fog formation. The apparatus does not require attendance whilst in service. The manipulation of the apparatus is thus simple and inexpensive and can be taken care of by a few untrained hands so that the procedure makes the protection of large plant cultivations from destruction by night frosts pos-
sible by inexpensive and simple manipulation.
The number of apparatus units to be erected de-

screened with due regard for the direction of the wind.
Figure 1 is a perspective view of one form of fog-producing apparatus according to my invention whereas Figures 2 and 3 are front and side elevations respectively of another embodiment of the apparatus.
1 shows the transport barrel which lies on a trestle 2. According to Figure 1 the cask is provided at each of its two ends with a three armed clip 3 having the gudgeons 4 on which the cask can easily be rotated in the bearing of the trestle 2. Below the barrel there are the discharge spouts 5 for the fog-forming acid projecting to each side. Below the spouts lime for ex-ample is heaped on the surface of which the fog acid evaporates. Instead of the usual screw closure of the transport barrel 1 the barrel is provided with a screwed-in insert 16 having two distributing nozzles 17. When the transport barrel 1 is inverted these nozzles deliver the acid at a definite rate into the discharge spouts 5. For better distribution of the fog acid the spouts 5 are provided with discharge holes 5a through-out their length.
In the design represented in side and front
view in Figures 2 and 3 the cask 1 lies on two
rollers 6 and 7 by means of which together with
two rods 8 and 9 arranged thereunder the two
55 iron sheets 10 and 11 are united to form a trestle.
On the lower rods 8 and 9 a container 12 for
lime coke etc. is erected the side walls of which
preferably consist of wire gauze so that air can
sweep the container from all sides. The cask
60 1 is laid on the rollers 6 and 7 in such a manner
that the discharge cock 13 lies between the roll-
ers which besides enables a slight rotation of
the cask so that the cock 13 may lie over the
center of the box 12. The cock 13 is preferably
65
provided with two distribution pipes 14 15 Iying crosswise to one another and having a number of discharge holes on their lower side so that the acid flowing from the cask 1 is distributed over the whole surface of the lime in the container 12 in order to obtain a dense fog screen.
I claim:-
1. Process for the protection of plants from frost and for combating parasites which comprises the laying of a fog blanket over the plants by the simple volatilization of fog-forming al d parasite killing material.
2. Process for the protection of plants from frost and for combating parasites which comprises laying a fog blanket over the plants by the simple volatilization of a fog-producing acid.
3. Process for the protection of plants from frost and for combating parasites which comprises laying a fog blanket over the plants by the simple volatilization of a fog-producing acid on bodies of large surface.
4. Process for the protection of plants from frost and for combating parasites which comprises laying a fog blanket over the plants by the simple volatilization of fog-producing acid containing additions of parasite-destroying ingredients for which the fog particles serve as carriers.
5. Process for the protection of plants from frost and for combating parasites which comprises laying a fog blanket over the plants by the simple volatilization of fog-producing acid mixed with a fluor-sulfo acid.
6. Apparatus for laying a fog blanket for the protection of growing plants comprising in combination a transport container of fog-producing acid means for discharging fog-producing acid therefrom at a controlled rate and means associated therewith for receiving and effecting the simple volatilization of fog-producing acid as discharged from said transport container.
7. Apparatus for laying a fog blanket for the protection of growing plants comprising in combination a trestle having a pair of connecting rods fitted with rollers to form between them a seat a cylindrical container of fog-producing acid rotatably positioned in said seat and provided with a drainage opening and means associated with said container to effect simple volatilization of the fog-producing acid drained therefrom.
8. Apparatus for laying a fog blanket for the protection of growing plants comprising in combination a trestle having a pair of connecting rods fitted with rollers to form between them a seat a cylindrical container of fog-producing acid rotatably positioned in said seat and provided with a drainage opening and a container of bodies of large surface disposed beneath said cylindrical container and having sides permeable to air to permit the simple volatilization of fog= producing acid drained from said cylindrical container.
ULRICH MUT T F R
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