DE1088758B - Means for the selective control of monocotyledon weeds - Google Patents

Description

Means for selective control of monocotyledon weeds The elimination grassy weeds in crops by chemical means are known per se. Salts of trichloroacetic acid, especially that, are used to great advantage Sodium salt, for the selective control of grasses, e.g. B. in sugar cane p # gen, and can keep the soil between the perennials free of grass for a long time until through appropriate leaf stand prevents further weeds sprouting. the However, application is not limited to this sector only; z. B. is used the sodium salt of trichloroacetic acid with good success to combat the very widespread couch grass (Agropyron repens). However, it is necessary here to go through Soil tillage to expose the couch grass roots.

However, it can be general when using the known means find that overdoses, as they occur through incorrect use can very easily lead to damage to crops.

It has now been found that monocotyledons can be combated with halogenated adipic acid with much greater certainty. You can z. B. can be used in the form of their salts, nitriles or esters alone or in combination with other herbicides or fertilizers. It succeeds z. B. with a, a, ä , ä , -Tetrachloradipinsäure in the form of the disodium salt, the Que c ke z u destroy without having to perform the very annoying cultivation of the soil when using the trichloroacetic acid.

Compared to dichloropropionic acid, which is also suitable for this purpose the claimed compounds have the advantage of significantly greater selectivity, as can be seen from the examples below.

Another field of application of the weed control compositions claimed according to the invention is the control of weeds in potato plantations, which is useful here is carried out in the pre-emergence method. The grasses are safely destroyed here, without impairment of the potato plants can be observed.

You can use the claimed chlorinated adipic acid z. B. in the form of their Combine alkali, ammonium or amine salts with other weed killers, in order to obtain total herbicide in this way or the effect against Selectively increase weed species.

The weed control compositions claimed can be produced by processes known per se. So you get z. B. to a, a, ä , ä- tetrachloroadipic acid either by direct chlorination of the acid in the presence of iodine or iron chloride with the exclusion of ultraviolet light or by chlorination of the corresponding nitrile, with the last method only a-chlorination occurs.

In contrast to that by the means claimed. scored purely -selective action against monocots are z. B. by diethyl 2,2,2-trichloroethylidene malonate according to U.S. Patent 2,617,722, both monocots and dicots herbicid affects; z. B. grain and cucumber plants are damaged in growth. The effect is compared with that of 2,4-dichlorophenoxyacetic acid. The same applies to the malononitriles according to US Pat. No. 2,683,659. Also those in the post-emergence process Dialkyl chloromaleate of the USA patent which is effective against monocot weeds 2,683,660 act e.g. B. pre-emergence against broad-leaved plants.

The following examples illustrate some possible uses of the claimed weed killers described in more detail. Example 1 If you put from a, a, ä, ä -Tetrachloradipinsäure-disodium an 85 ° laiges wettable powder in one Application rate of 7 kg / ha, dissolved in 800 l of water, 4 agropyron for combating mercury repens) in autumn on unploughed and unprocessed, but greened couch grass one gets an excellent quince-destroying effect.

In contrast to the use of sodium trichloroacetate (50 kg / ha) is no tillage - i.e. exposure of the couch grass roots - required.

EXAMPLE 2 If 4 kg / ha, dissolved in 600 to 800 l of water, of an 85% wettable powder of a, a, a, a'-tetrachloradipic acid disodium are sprayed pre-emergence before the potatoes are planted on fields that are weed with grass species, the result is a safe destruction of the 1-year-old grass species without reducing the yield or damaging the potatoes. A similar effect as with potatoes can be achieved with a smaller amount, namely with 2 kg / ha, also with sugar beets in the pre-emergence method. Example 3 If a, a, ä , a = tetrachloradipic acid is sprayed as a 15m / o sprays in the pre-emergence method against mustard and oats in the greenhouse, with 4 to 0.5 g of active ingredient per square meter the monocots die off after some time, while the dicots remain undamaged . Active ingredient tetradiloradipic acid Comparative agent: Na salt of trichloroacetic acid g / sqm - dicots monocots Dicots monocots 4 normally dead, partly dead, the rest very dead damaged 2 normal dead severely damaged dead 1 normal dead clearly damaged dead 0.5 normal dead slightly damaged dead Untreated: normal normal Example 4 In the pre-emergence treatment of oats and sugar beets indicated in the greenhouse test, a 15 "/ oiges wettable powder of the a, a, a, ä -Tetrachloradipinsäure with excellent activity against monocot a striking conservation of dicots: Active ingredient tetradiloradipic acid Comparative agent: Na salt of dichloropropionic acid g / sqm Dicots I monocots dicots monocots 8 almost normal dead dead dead 4 normal dead dead dead 2 normal dead dead dead 1 normal dead dead dead 0.5 normally dead, partly dead, the rest very dead damaged Untreated: normal normal Example s In a spray test (80 ccm of broth on 1 square meter) against oats and sugar beets in the greenhouse, a 15% wettable powder of a, a, a, a -tetrachloradipic acid killed the monocots, while the beets made no difference even at the highest application rate the untreated controls showed: Active ingredient tetradiloradipic acid lubricant: pentachlorophenol g / sqm Dicots I monocots Dicots 1 monocots 1.6 normal dead dead dead 0.8 normal dead very badly damaged dead 0.4 normal dead severely damaged dead Untreated: normal I normal

Claims (3)

PATENT CLAIMS: 1. Means for the selective control of monocotyledons Weeds, characterized by their halogenated adipic acid content, if appropriate in the form of their derivatives, e.g. B. their salts, nitriles or esters, as an active ingredient. 2. Agent according to Claim 1, characterized in that the active ingredient a, a, ä, ä-tetrachloroadipic acid or their salts are included. 3. Composition according to claim 1, characterized in that a, a, ä, ci-tetrachloroadiponitrile is contained as active ingredient. - Publications considered: German Patent No. 886147; U.S. Patent Nos. 2,617,722, 2,683,660, 2683659.