DE2316162A1 - Plant growth regulators - contg. fluorene-9-carboxylic acid derivs and 1-(4-chlorophenyl)-1,2-dihydro-4,6-dimethyl-2-oxonicotinic acid salts - Google Patents

Abstract

The fluorene derivs are of formula (I) (where R1 is H or OH; R2 is 1-4C alkyl or a cation; R3 and R4 are independently H or Cl); the wt. ratio between (I) and the oxonicotinates being 10:1 to 1:10. Pref. fluorene deriv. is methyl 2-chloro-9-hydroxyfluorene-9-carboxlate, and the prefd. oxonicotinate is the Na salt. The compsns. are esp. useful for controlling the growth of grasses in decorative lawns and golf courses, a good appearance is maintained, and mowing may not be required for a period of several weeks to several months. They are also useful for the control of rye grass. They are pref. applied at the rate of 0.5-6 (esp. 1-4) kg active ingredient/ha.

Description

Agents for Regulating Plant Growth The invention relates to new means for regulating plant growth, in particular for inhibiting growth for grasses and for shortening and stabilizing the stalk in cereals.

There is already a large number of chemical compounds regulating it of plant growth has been proposed. However, none of the known active ingredients and with no previously described combination of active ingredients completely satisfactory results in all possible fields of application regulate the growth of grasses. The purpose of this growth regulation, to make mowing and trimming the lawn unnecessary or to save sewing length and To bring about a haline shortening and stalk stabilization in cereals is not possible reached to a sufficient extent and / or there must be symptoms of intolerance be accepted.

Only for extensive locations, e.g. edges and median strips By highways and country roads, the desired purpose can be achieved with known growth retardants Achieve means in general. The frequent discoloration, damage and uneven effects can mostly be tolerated in such areas of application will.

For high-quality ornamental lawns and lawns in sports facilities, e.g.

Golf courses, however, the effect of the known means proves as unsuitable. Apart from the inadequate tolerance, this is mainly due to the fact because none of the known agents has a sufficiently broad spectrum of activity shows.

So far, growth regulators derived from fluorene-9-carboxylic acid9, in particular the compounds of the formula, have been of particular practical importance where R1 is hydrogen or the hydroxyl group, R2 is an alkyl radical having 1 to 4 carbon atoms or a cation and R3 and R4, which can be identical or different, denote hydrogen or chlorine, and among these above all those esters in which R1 is the hydroxyl group and R3 Is hydrogen. If R2 is a cation, an alkaline cation, in particular a sodium cation, comes into consideration.

However, the above-mentioned disadvantages also occur with these compounds on.

The most important compound of the formula I, methyl 2-chloro-9-hydroxyfluorene-9-carboxylate (Chlorflurenol), for example, has a stronger effect on broad-leaved weeds than on Grasses. With an increased application rate, the growth of most types of grass is inhibited, however, tolerance is then critical (the leaf tips become temporarily yellow).

There is also a significant impact gap with respect to the important German ryegrass (Lolium perenne, perennial ryegrass).

The compounds of another group of practically important growth regulators, the 1- (4-chlorophenyl) -l, 2-dihydro-4,6-dimethyl-2-oxonicotinate also have significant gaps in effectiveness, especially against German ryegrass. Even they only inhibit the leaf growth of the grass, but not the formation of panicles. In addition, the active ingredients have no suppressive inhibitory effect on broad-leaved weeds in the lawn.

As has now been found, surprisingly have mixtures of compounds of the formula I with salts of 1- (4-chlorophenyl) -1,2-dihydro-4,6-dimethyl-2-oxonicotinic acid a spectrum of activity that is particularly favorable in practice, while at the same time being good Tolerance and uniform effect.

Combinations of chlorofluenol and salts of the 1- (4-chlorophenyl) -1,2-dihydro-4,6-dimethyl-2-oxonicotinic acid, especially the sodium salt. It is particularly important that the active ingredient combinations according to the invention Show synergism and the growth of German ryegrass is sufficient inhibit.

With the active ingredient combinations according to the invention, in particular Lawns, also high-quality decorative and golf turf, with a good appearance for several Weeks to several months are so inhibited in growth that the treated Areas do not have to be mowed or only rarely have to be mowed.

The active ingredient combinations according to the invention can also serve to to inhibit the growth in length of the stalks and to stabilize the stalks; through this the storage of the grain can be prevented.

According to the invention, the two active ingredients are in a weight ratio 10: 1 to 1: 10 used. A ratio of 6: 1 to 1: 6 is preferred, especially 4: 1 to 1: 4.

For the application, the active ingredients can be formulated separately and in Can be applied together in the form of a tank mix.

However, it is also possible to use both active ingredients together with customary auxiliaries and carriers for customary formulations, for example To process suspension powders, dusts, granulates, emulsion concentrates. If necessary, the concentrated formulations

by diluting with water spray liquors containing an active ingredient from about 0.025 to 1 weight percent.

The total active ingredient content in the concentrates is generally about 1 to 95 percent by weight. The application rates are between about 0.5 and 6 kg / ha, preferably 1 to 4 kg / ha. The application rates depend largely on the area of application, but also on the nature of the soil and the climatic conditions. For the Inhibition of grass growth considerably larger application rates are required than for shortening the stalk in cereals.

The formulations of the agents according to the invention can be according to the following Examples are given (quantities in percent by weight): Formulation examples 1. Wettable powder 10 ffi Chlorflurenol 20% Sodium 1- (4-chlorophenyl) -1,2-dihydro-4,6-dimethyl-2-oxonicotinate 1 * wetting agent (diisobutylnaphthalene sulfonate) 5% oleic acid-N-methyltauride 35% colloidal Silicic acid 29% kaolin 2. Wettable powder 15% Chlorflurenol 45% Sodium-1- (4-chlorophenyl) -1,2-dihydro-4,6-dimethyl-2- oxonicotinate 1% diisobutylnaphthalene sulfonate 5 ffi oleic acid-N-methyltauride 34% precipitated silica 3. Aqueous dispersion 10% chlorofurenol 30% sodium 1- (4-chlorophenyl) -1,2-dihydro-4,6-dimethyl-2-oxonicotinate 2 ffi bentonite 5% alkylphenol polyglycol ether 8% calcium lignosulfonate 45% water 4th Aqueous dispersion 20% chlorofluenol 20% sodium 1- (4-chlorophenyl) -1,2-dihydro-4,6-dimethyl-2-oxonicotinate 1% bentonite 2% carboxymethyl cellulose 3% oleyl alcohol polyglycol ether 54% water 5. Oily dispersion 15% chlorofluenol 20% sodium 1- (4-chlorophenyl) -1,2-dihydro-4,6-dimethyl-2-oxonicotinate 1% colloidal silica 10% non-ionic emulsifier 54% mineral oil The respective Mixtures of Examples 1 to 5 are processed in the usual way and diluted with water to make the spray liquid for use.

6. Tank mix a) 12.5 ffi Chlorflurenol 11.5 * dimethylformamide 6% emulsifier (mixture of anionic and non-dichogenic emulsifiers) 70% Solvent-Naphtha This concentrate is diluted with the desired amount of water.

b) The resulting broth is 0.02% isooctylphenol polyglycol ether (with 10 mol of ethylene oxide) such an amount of sodium 1- (4-chlorophenyl) -1,2-dihydro-4 dimethyl-2-oxonicotinate added that an active ingredient ratio between 10: 1 and 1:10, preferably between 4: 1 and 1: 4.

For the growth inhibition in lawn areas in particular Mixtures with about 1 part of chlorofluenol to 2 to 4 parts of the active ingredient mixture have proven successful.

Comparative experiment spectrum of the inhibitory effect and tolerance The effect of the active ingredient combinations according to the invention was compared to the Components tested on a lawn mix.

The lawn mix consisted of the species Agrostis tenuis, Agrostis stolonifera, Festuca nigrescens, Festuca rubra eurubra, Poa pratensis. The application rate is given in kg / ha (active ingredient). The evaluation of the compatibility was carried out after a 9-point rating scale, with 1 being the best grade (no findings / very good), 9 means completely incompatible.

4 stands for "still acceptable1 ?, 5 for insufficient.

The cutting height of the experimental lawn was 5-6 cm. Spraying took place 3 days after a cut at a height of 11-12 cm. A rating was carried out 4 weeks after the treatment. Active ingredient Effort- Existing level *) in cm Compatible- quantity Mixture Lolium perenne I 1 28 45 2-3 1.5 24 45 3 2 20 45 3 3 18 45 4-5 II 2 38 45 1 3 38 45 1 4 36 45 1 I + II 1.5 23 23 1-2 +2 1 26 26 1-2 +3 - - 40 45 1 (Control) I: Chlorflurenol II: Sodium 1- (4-chlorophenyl) -1,2-dihydro-4,6-dimethyl-2-oxonicotinate) The plant height (including the panicles) is given in cm.

Claims (4)

Claims Agent for regulating plant growth, characterized in that it contains a compound of the formula wherein R1 is hydrogen or the hydroxy group, R2 is an alkyl radical having 1 to 4 carbon atoms or a cation and R3 and R4, which can be identical or different, are hydrogen or chlorine, and a salt of 1- (4-chlorophenyl) -1,2 dihydro-4,6-dimethyl-2-oxonicotinic acid in a weight ratio of 10: 1 to 1:10. 2. Means according to claim 1, characterized in that the active ingredients Methyl 2-chloro-9-hydroxy-fluoro-9-carboxylate and a salt of 1- (4-chlorophenyl) -l, 2-dihydro-4,6-dimethyl-2-oxonicotinic acid are. 3. Means according to claim 1 and 2, characterized in that the Weight ratio of the active ingredients is 4: 1 to 1: 4. 4. Use of agents according to claims 1 to 3 for inhibiting growth with grasses. D. Use of agents according to claims 1 to 3 for shortening the stalk and stalk stabilization in cereals.