Fungicides for the control of take-all disease of plants

Abstract

A method of controlling Take-All disease of plants by applying a fungicide of the formula wherein Z1 and Z2 are C and are part of an aromatic ring which is [benzothiophene]thiophene; and A is [selected from] -C(X)-amine [wherein the amine is an unsubstituted, monosubstituted or disubstituted amino radical]wherein the amine is a monosubstituted or a disubstituted amine, wherein one of the substituents has a cyclic moiety, said cyclic moiety which is chosen from the group consisting of thienyl, furanyl, and a non-heterocyclic substituent, wherein when the amine is disubstituted, the second substituent is a non-cyclic substituent, -C(O)-SR3, -NH-C(X)R4, [and] or -C(=NR3)-XR7; B is -Wm-Q(R2)3 or selected from [O-tolyl]o-tolyl, 1-naphthyl, 2-naphthyl, and 9-phenanthryl, each optionally substituted with halogen or R4; Q is C, Si, Ge, or Sn; W is -C(R3)pH(2-p)-; or when Q is C, W is selected from [-C(R3)pH(2-p),[-C(R3)pH(2-p)-, -N(R3)mH(1-m)-, [-S(O)p-,] -S(O)p-, and -O-, X is [0] O or S; n is [0, 1, 2, or 3]2; m is 0 or 1; p is 0, 1, or 2; wherein the two R groups are combined with the thiophene ring to form a fused ring which is benzothiophene; each R and R2 is independently defined herein; R3 is C1-C4 alkyl; R4 is C1-C4 alkyl, haloalkyl, alkoxy, alkylthio, alkylamino, or dialkylamino; and R7 is C1-C4 alkyl, haloalkyl, or phenyl, optionally substituted with halo, nitro, or R4; or an agronomic salt thereof.

Description

FIELD OF THE INVENTIONThis invention relates to a method for the control of Take-All disease in plants, particularly cereals, by the use of certain substituted aryl compounds, some of which are novel, and fungicidal compositions for carrying out the method.BACKGROUND OF THE INVENTIONTake-All disease is a serious problem in the production of cereals, particularly wheat and barley. It is caused by the soil-borne fungus Gaeumannomyces graminis (Gg). The fungus infects the roots of the plant, and grows throughout the root tissue, causing a black rot. The growth of the fungus in the roots and lower stem prevents the plant from obtaining sufficient water and / or nutrients from the soil, and is manifested as poor plant vigor and, in severe instances of disease, by the formation of "whiteheads," which are barren or contain few, shriveled grains. Yield losses result. Gaeumannomyces species also infect other cereal crops, for example, rice and oats; and turf.Currently the primary means of avoi...

AI Technical Summary

Benefits of technology

The present invention provides a method of controlling disease caused by Gaeumannomyces species in plants comprising applying to the plant locus, that is, the plant itself, its seed, or the soil, a fungicidally effect

Problems solved by technology

Take-All disease is a serious problem in the production of cereals, particularly wheat and barley.

The fungus infects the roots of the plant, and grows throughout the root tissue, causing a black rot.

The growth of the fungus in the roots and lower stem prevents the plant from obtaining sufficient water and / or nutrients from the soil, and is manifested as poor plant vigor and, in severe instances of disease, by the formation of "whiteheads," which are barren or contain few, shriveled grains.

However, in areas where the primary crops are cereals, rotation is not a desirable practice, and an effective control agent is greatly desired.