CS196538B1 - Selective herbicides - Google Patents

Abstract

Herbicidal compsns. comprise mixts. of (a) 3-cyclohexyl-5,6-trimethylene-uracil (I) and (b) a trichloroacetaldehyde deriv. of formula (II) or (III): (where R1 is alkyl substd. by OH or alkoxy (esp. by 2,2,2-trichloro-1-hydroxyethoxy) or is alkylideneamino, R2 is ureido opt. substd. by alkyl (esp. 2,2,2-trichloro-1-hydroxyethyl), cycloalkyl, aryl or acyl). The compsns. are esp. useful for selective weed control in beet crops (sugar beet turnips), they have synergistically increased activity against a wide range of brook-leafed and grassy weeds.

Description

Author of the invention SIEGHARD LANG Dr., CHRISTIAN RAINER WENZEL, CUNERSDORF, PAUL HELD Dr.,

HANFRET) 'KLEPEL Dr., MAGDEBURG, SABINA KUHNE, MAGDEBURG, LISA KRANZ. ZWEENFURI and MANFREL GROSS, Dr. MAGDEBURG (NDR) ⁵⁴ ) Selective herbicides

The invention relates to the combined use of known herbicidally active compounds in selective herbicides for controlling undesirable plants in crops of useful plants, preferably / beet crops.

Lenacil and other uracil herbicides are known to exhibit gaps in the weed spectrum, especially at grass weeds, at conventional doses and, at higher doses, produce phytotoxic side effects on the crop.

It is further known that chloral in its addition compounds with water, alcohols and carboxylic acid amides, in particular urea, have herbicidal effects on grasses with partially insufficient effects on dicotyledonous species. The proposed mixtures with Lenacil and trichloroacetaldehyde derivatives, on the other hand, show good herbicidal activity against monocotyledonous dicotyledonous weed species and are suitable for weed control in beet crops.

however, due to the different physical properties of the two components, their recipe formulation for the formulation makes some problems.

The purpose of the invention is to overcome the drawbacks of said herbicidally active compounds and mixtures thereof.

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The object of the invention is - thus. by suitable combination of known and intentional structurally-modified active substances to develop herbicides which combine a wide herbicidal spectrum at the lowest possible dosage and improved compatibility with useful plants.

It has been found that mixtures of N-cyclohexyl-N-trimethylenuracil (Lenacil) of formula I

0H ₂ * CHg CHg N-CH CHg (AND) oh ₂ ch ₂ CH2 CH ₂ . 0 N and edema trichloroacetaldehyde derivatives formulas II OH CljC-. CH OR ¹ (II)

wherein R ¹ denotes ^alkyl ZB ^{yt alkyl} with 2 ^to 8 carbon ^hlík u are u ≤ t ≤ formula --NR ^{hydroxyacetophenone Y b} not on radials

2,2,2-trichloro-1-hydroxyethoxy or C1 -C6 alkylidene, or the trichloroacetal derivatives of formula III

OH

Cl, O - CH ³ _r 2 (III), o

wherein R is a ureido group optionally substituted 2,2,2-trichloro-l-hydroxyethelovými radicals, the ratio of I to uracilu'vzorce derivative trichloroacetaldehyde general model ^of RCE II, ^or of ^p and d ^c in ^E III ^{i 1} i ^0, 5 to ^{1: 2} °, especially ^E on ¹ ι ¹ to ^{1: 10,} esp .vykazuj ^{í á} §? good herbicidal activity against monocotyledonous and dicotyledonous weed species; and are suitable for combined application in selective. herbicides for controlling undesirable plant growth in useful crops, preferably beet crops.

The trichloroacetaldehyde derivatives of the general formulas II and III (for example the compounds listed in Table 1) can be prepared by known methods by reacting the trichloroacetaldehyde with the corresponding alcohols, oximes or ureas.

A surprising and unpredictable from the prior art is that the combination of the invention show a considerably better herbicidal capacity than would be expected based on the EOU ^{No. EFFECTIVE} ge jednotMvých aložek. This ^p rojevuje ^eV for ^D m ^{that measurable} combine YM ^{d PLN} ová.ním spectrum efficiency. In addition, important, partly difficult to control weeds exhibit clearly synergistic effects attributable to the different mechanisms of action of the components. Ex ^AST valuable in the ^L and ^T nose kombinao ^{t s p} o e ^dl VYN ^á climb SPO ^No. lies in the fact that it reduces ^the implication zesílerá undetermined species of weeds and without compromising tolerance by useful plants, in particular the aspects and beet.

In addition, it has been found in large-scale field trials that derivatives of triohloroacetal3

196 '53B of dehyde in certain cohesive ranges increased the resistance of the useful plants to other herbicidal ingredients - in this case to Lenncil (I), apparently due to the beneficial effect of the metabolism. This finding is not predictable and underlines the importance of the beneficial properties of the herbicides according to the invention. .

The selective herbicides of the invention can be used to control weed c weed grasses such as, for example, StellcMc medic, Senecio vilgQris-starčekc. common, Anthemis ervensis, Agrostenmc githago ▼, Common Lcmium purpureum, Chenopodium clbum, White glyphum Psp. , Asperc spion-venti, Foc cnnuc *, Seric viridis, Bromus s ^ alinus- brome, Echinochloc orus-gaClí - hedgehogs corns in field c of middle cultures such as beets, beetles , sugarcane, batcte, yeasts, stone fruit, pulses, soft fruits before emergence or possibly by weeding out c weed grasses.

The compositions according to the invention are dosed with 3 to 20 kg of active substances or hectares according to the soil type. For beet, the optimum dose is 8 to 15 kg / hc.

The compositions of the present invention may be formulated in accordance with the envisaged process with suitable carriers or surfactants or surfactants or other conventional excipients according to conventional methods, such as granules, emulsified concentrates or solutions.

Compared to the known derivatives, the derivatives of the general formulas (II) and (III) have a more favorable physical properties, in particular lower vapor pressures and higher melting points. _;

The selective herbicides according to the invention can be used in conjunction with other plant protection agents or for controlling pesticides, fertilizers or egrochemicals.

The following examples illustrate the compositions of the present invention, but without the use of these additives. . 1 · cd 1% w / w _> 2,2 ₁ 2-trichloro-l-hddroyrtthyburea% hnoC] t-t-t-t-t-t-t-t-t-t-t-t-t-t-t-t) nc is based on olefinsylteurine% silicic acid silica. kaolin

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Example 2 '

In pot pot experiments, the herbicidal effect and the beet tolerance of various combinations of g 3-cyclohexyl-5,6-trimethylenurecil and the _t- trichloroacetaldehyde derivatives listed in Table 1 were investigated using the soil pre-emergence method using soil sorption capacity for water absorption.

The active ingredients were applied in the form of 50% or 20% spray powder in 1000 l of water / ha by sprayer immediately after sowing.

The following key was used to assess herbicidal activity

Signs of creditworthiness

Extent of damage

Plants completely dead

Claims (1)

Plants completely dead Traces of damage Without damage The results are shown in Table 2. Table 1 Chemical name of the active substance A 1,2-bia- (2,2,2-trichloro-1-hydro-ethyl) ethane, B 2,2-Bia- (2,2,2-trichloro-1-hydro: yethoz) diethyl ether, C 0- (2,2,2 — t richiloT · —l-hayXPyll) eoxetoxox » D 0- (2,2,2-trichloro-1-hydroxyethyl) cyclohexanone oxime, E bis - (-) - - Trichloro-1-hydroxyethoxy-hydroxy propane, F l, 8-bis (2,2,2-trichloro-hydroxyethoxy) kktan _t G 1,2,3-tris- (2 2 2 * 2-tricyclo-1-hydoxy and hooy) propene, H 1,2,2-trichloro-lthydhoxytthllhapovapn, N, N-bis- (2,2,2-trichloro-1-ylmethyl) urea, The Tetr □ tetrakis- _(2> 2,2-trichloro-l-] ЦfdroзyethoJymettyl) -metPan _t *