DE1905469B2 - COMBINATION OF UNWANTED GROWTH IN CONIFERCULAR CULTURES WITH 2,4,5- TRICHLOROPHENOXY ACID SALTS - Google Patents

Description

2 (i

The invention relates to the use of amine jo salts of 2,4,5-trichlorophenoxyacetic acid in particular mixed with a phosphate for the selective control of unwanted growth in coniferous wood crops.

To combat undesirable dicotyledonous injuries grew in conifers, some active ingredients are already used, but they have the following disadvantages:

Preparations based on esters of 2,4,5-trichlorophenoxyacetic acid Can be used in coniferous wood crops with the exception of larch - only after the cultivated plants have completely finished growing in late summer so that various weeds such. B. Birch surcharges, because of also already completed Growth are difficult to grasp. Furthermore, the objective determination of this date encounters difficulties in practice, due to climatic and location differences. In addition, the required removal of larch unsatisfactory.

Preparations based on l, l'-dimethyl-4,4'-bipyridi- > On the other hand, sodium dichloride is sprayed using flat-jet nozzles or a shield. However, since the agent kills all the green parts of the plant that have been hit, cultivated plants must be used before Spraying must be adequately covered, which, however, is due to the often difficult accessibility of the forest cultivated areas and is hardly possible with higher vegetation.

In contrast, preparations based on 2,6-dichlorothio-benzamide are scattered around. The application takes place in early spring, however Kiefernkulwi doors are excluded. The time limit for use and the exclusion of an important type of wood, of the pines, as well as the need for very precise dosing, pose considerable difficulties for the use of these preparations. tv>

There has therefore been a great need for a chemical herbicide which does not contain Use of technical protective devices with full protection of the very sensitive softwood control of the woody and herbaceous weeds that predominate there during vegetation, such as birch cushions, raspberries, blackberries, ragwort, thistles, nettles and others, enables more.

The agents that act selectively in cereal crops are based on so-called growth substance herbicides, such as 2-methyl-4-chlorophenoxyacetic acid (MCPA), 2,4-dichlorophenoxyacetic acid (2,4-D), 2,4,5-trichlorophynoxyacetic acid (2,4,5-T), α- (2-methyl-4-chlorophenoxy) propionic acid (CMPP) or their mixtures with water-soluble salts of phosphoric acids (see German Patent 10 94 524) did not seem to be suitable for this purpose. From these show namely z. B. MCPA, 2,4-D and their mixtures have no effect against woody weeds in coniferous crops, while others, e.g. B. 2,4,5-T-esters, their mixtures with MCPA and the mixture of 2,4,5-T with CMPP, cannot be tolerated by crops during vegetation. From a mission the amine salts, of which the same direction of action, but one compared to the ester preparations is known to have a reduced effect, it was only to be expected that they would have to be used in larger quantities, but then would also damage the timber excessively, and thus no opportunities for improvement Could offer selective use.

It has been found, however, that by using at least one amine salt of 2,4,5-trichlorophenoxyacetic acid selective control, especially when mixed with a water-soluble phosphate of undesired growth in coniferous wood crops is surprisingly possible.

Even with application rates of 12-15 kg / ha, the conifers are not damaged during control of weeds only 6 kg / ha are required.

In the use according to the invention, in particular birch cakes, broom, dogwood, Burdock, blackberry, ragwort, goldenrod, hackrose, elder and willow fights which are not or only insignificantly damaged by the other growth substance herbicides. Coniferous crops of the species Picea spec., Pinus spec., Abies spec. and Douglas fir, on the other hand, are completely spared, see above that in these cultures, for the first time during vegetation, the entire surface control of unwanted growth is made possible. However, taking into account the current economic situation of the Forestry is a decisive factor for successful softwood cultivation and therefore an essential one Enrichment of the state of the art.

Particularly suitable amine salts of 2,4,5-trichlorophenoxyacetic acid are lower dialkylamine salts, preferably the diethylamine salt.

It has also been shown that particularly good results can be achieved with a mixture which in addition to the amine salt of 2,4,5-trichlorophenoxyacetic acid, a water-soluble phosphate, preferably tetrapotassium pyrophosphate, contains, preferably in a weight ratio of the components of about 1: 1.

It is expediently used in the form of a customary aqueous spray with the addition of surface-active agents Substances, e.g. B. of polyethoxylated polyoxypropylene.

The following experimental example explains the invention.

Experimental example

In various tests, 6 kg / ha of a mixture of the following composition were used in each case

47.5% 2,4,5-T-diethylamine salt
47.5% tetrapotassium pyrophosphate
5% wetting agent based on polyethoxylated polyoxypropylene

dissolved in about 300-400 l water / ha in coniferous wood crops.

Spruce dominated, followed by fir, Douglas fir, pine and larch. It was found, that these types of coniferous wood are treated with the mixture according to the invention without hesitation can. Even softwood natural regeneration has been released with great success, and annuals too Seedlings of spruce, fir, Douglas fir and pine showed good tolerance.

In individual experiments, application rates of up to 10 kg / ha and more of the conifers were used well tolerated. There was a certain sensitivity in larches, but also a pleasant one Regeneration capacity observed, so that occasional drive curvatures quickly grow together. The following tables show the effect of the mixture according to the invention against silvicultural issues ο the most important weed species (a) and unwood species (b) listed, namely in average values on several attempts. For assessment the effect was based on 3 value groups.

^{1 (1} value number

1-2 = very good to well combinable.

2-2.5 = can be adequately combated from a silvicultural point of view.

2.6-3 = moderate to silvicultural not sufficient

can be combated.

Also means

F = spring treatment.

S = summer treatment.

Z = number of attempts.

W = average value figure.

Table a)

Effect of the mixture according to the invention at 6 kg / ha against the most important silvicultural weed species

Stinging nettle
ZW

Thistle species
ZW

thimble
ZW

Ragwort

Z W

Goldenrod
ZW

Balsam
ZW

Willowherb

Z W

F 7 1.95 9 2.83

S 43 1.29 43 2.06

2 2.5 6 2.35 40 2

12 5 2

2.3 4 1.85 39 1.44

Table b)

Effect of the mixture according to the invention at 6 kg / ha against the most important non-wood species from a silvicultural point of view

Weed Birch Broom Broom Blackberry Hazel Raspberry

ZW ZW ZW ZWZWZW

Elder willow
ZW ZW

11 2.23

1.5
1.39

17 1.33

7th 2 13th 1 2 18th 2 7th 2.35 113 2, 4th 2 159 1.55 47 2.17

15 2.17

Claims (4)

Patent claims: 1. Control of unwanted growth in coniferous wood crops durrri use of at least a derivative of 2,4,5-trichlorophenoxyacetic acid, characterized in that an amine salt of the same, in particular as a mixture with a water-soluble phosphate, is used. 2. Combating unwanted growth in coniferous wood crops according to claim 1, characterized in that that the amine salt of 2,4,5-trichlorophenoxyacetic acid is a lower dialkylamine salt, preferably the diethylamine salt is used. 3. Combating unwanted growth in coniferous wood crops according to claim 1, characterized in that that tetrapotassium pyrophosphate is used as the water-soluble phosphate. 4. Combating unwanted growth in coniferous wood cultures according to claims 1 to 3, thereby characterized in that a mixture of an amine salt of 2,4,5-trichlorophenoxyacetic acid with a water-soluble phosphate in a weight ratio of about 1: 1. 13th