摘要:

AbstractChanges occurred in leaf cells following treatment of glasshouse grown wheat seedlings with triadimefon by foliar application, root drench and vapour action. The effects were limited to cells adjacent to stomata, and included damage to the tonoplast and plasmalemma followed by breakdown of chloroplasts. These effects probably resulted from changes in membrane sterols induced by triadimefon treatment. They were severe local reactions, distinct from modification of gibberellin biosynthesis.

ISSN:0031-613X    

DOI:10.1002/ps.2780170402

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe hydrolysis kinetics of iprodione in alkaline solutions of pH 8.3 to 12 at 25°C have been determined by ultraviolet spectrophotometry. Under these conditions, iprodione leads quantitatively and irreversibly toN‐(3,5‐dichloroanilinocarbonyl)‐N‐(isopropylaminocarbonyl)glycine. The reaction is not subject to a general basic catalysis and the rate law takes the form Kobs= KOH‐ [OH−1]. The activation entropy of ‐77 J mol−1deg−1, the value of the kinetic solvent isotope effectkOH−/kOD−of 0.79 and the value of 0.60 for the Hammett parameter σ, obtained for the hydrolysis of a series of 3‐aryl‐N‐isopropyl‐2,4‐dioxoimidazolidine‐1‐carboxamides are all in agreement with the rate‐determining attack by the hydroxyl ion on the carbonyl in the 4‐positi

ISSN:0031-613X    

DOI:10.1002/ps.2780170403

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractPP969 is a novel 1,4‐ketol compound containing the 1,2,4‐triazole ring which has high systemic activity against a variety of fungal pathogens. It is a single diastereoisomer whose absolute configuration has been determined by X‐ray analysis. The fungicidal activities of the structurally related 1,4‐dione and 1,4‐diols were found to be much less than that of PP969. Its biological potential as a systemic compound for controlling foliar fungal diseases either by soil or stem application is being

ISSN:0031-613X    

DOI:10.1002/ps.2780170404

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractFluazifop‐butyl was incubated with two soils under aerobic conditions at 20°C. Hydrolysis of the racemic herbicidal ester yielded a residue of the corresponding carboxylic acid, fluazifop, in which theR‐enantiomer predominated. Further studies involving the treatment of soil with the separate enantiomers of fluazifop‐butyl showed that the two enantiomers were each hydrolysed with retention of their optical configuration. However, the hydrolysis product with theS‐configuration was inverted (50% inversion in 1‐2 days) to yield, ultimately, a residue of theR‐enantiomer with a high op

ISSN:0031-613X    

DOI:10.1002/ps.2780170405

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

Abstract2‐Butyl‐2‐(4 chlorophenyl)‐3‐(1H‐1,2,4‐triazol‐1‐yl)propanenitrile, RH 3866, a new broad‐spectrum fungicide was particularly effective against fungi in the subclass loculoascomycetidae and against powdery mildews and rusts. Some activity against fungi in the generaFusarium, MoniliniaandRhizoctoniawas also observed. The compound was translocated upwards when applied as a soil drench to control wheat‐leaf rust caused byPuccinia reconditaf.sp.tritici. Fenarimol‐resistantAspergillus nidulanswas cross‐resistant to RH 3866. Using a cell‐free yeast enzyme extract RH 3866 strongly inhibited

ISSN:0031-613X    

DOI:10.1002/ps.2780170406

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractIn the presence of mineral acids or bases the cyano group is the primary point of hydrolysis of cyanazine. However, in solutions of weak acids, carboxylic acids or phenols, the chloro group becomes labile even in essentially neutral solutions. The rates of this catalysed hydrolysis reaction have been determined with a number of carboxylic acids and 2,4‐dinitrophenol. The calculated rates of catalysis follow the Brönsted relationship with a value of ∼0.7. The reaction with 2,4‐dinitrophenol produces an isolatable ether intermediate. Comparison of the rates of hydrolysis catalysed by crotonic acid in deuterium oxide and in water suggests that the mechanism may be of the type specific acid/general base (or nucleophilic) catalysis rather than general acid cat

ISSN:0031-613X    

DOI:10.1002/ps.2780170407

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractSeedlings ofSolanum scabrumMill. andSolanum ptycanthumDun. were treated with [14C]ethalfluralin (N‐ethyl‐α,α,α‐trifluoro‐N‐(methylallyl)‐2,6‐dinitro‐p‐toluidine) and [14C]trifluralin (α,α,α‐trifluoro‐2,6‐dinitro‐N,N‐dipropyl‐p‐toluidine) supplied in nutrient solution to determine the basis for differences in response by these two species to these two herbicides. Plants ofS. scabrumabsorbed more [14C]ethalfluralin and [14C]trifluralin than plants ofS. ptycanthum. During the first 24 h,S. scabrumseedlings, but notS. ptycanthumseedlings absorbed more [14C]ethalfluralin than did plants treated with [14C]trifluralin. More [14C]ethalfluralin than [14C]trifluralin was found in the shoots of plants of both species. Seventy‐two hours after treatment with [14C]herbicides, the conversion to water‐soluble metabolites was greater for [14C]ethalfluralin than for [14C]trifluralin. In the shoots of plants from both species an average of nearly 55% of the14C recovered was found in the water‐soluble fraction following [14C]ethalfluralin treatment whereas an average of only 40% was found in the water‐soluble

ISSN:0031-613X    

DOI:10.1002/ps.2780170408

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractAn improved method for the determination of phosphine residues in a range of stored foodstuffs with a limit of detection better than 0.1, μg kg−1is described. The method has been used to obtain data on the amount of phosphine which remains in these commodities after treatment at typical dosage levels and on its persistence during storage. Results show that in cereal grains and nuts residues fall quickly to below internationally recommended levels although trace amounts of phosphine could be detected several months after treatment in all commodities examin

ISSN:0031-613X    

DOI:10.1002/ps.2780170409

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractA number of 2,6‐dibromophenols with different substituents in the 4‐position have been synthesised and their effect on the whole electron transport chain and on photosystem II have been determined. A study was made to relate the chemical characteristics of the 4‐substituent group and the inhibition of the uncoupled electron transport of isolated chloroplasts from spinach plants. The chemical nature of the 4‐substituent group varies greatly in the active compounds and it is therefore suggested that this group does not participate in the inhibitor‐receptor interaction. The results indicated that the inhibiting power of these compounds increased with the electron‐attracting capacity of the 4‐substituent group, decreased with increase in its size and that there was no correlation with its hydro

ISSN:0031-613X    

DOI:10.1002/ps.2780170410

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY

摘要:

AbstractThe fate of 4‐chlorophenylurea in soils was studied with two preparations: one labelled with14C in the phenyl ring and the other in the carbonyl group. The initial dose of 1 mg kg−1decreased to 50% in about 5 weeks in aerobic sandy clay and in about 16 weeks in anaerobic hydrosoil. Soil treatment with each of the preparations resulted in the release of [14C]carbon dioxide, pointing to decarbonylation and ring opening. The fraction of non‐extractable (soil‐bound) radioactivity increased during incubation. Quantities of ring‐14C‐labelled and carbonyl‐14C‐labelled bound residues differed strongly in the aerobic soil but only slightly in the anaerobic hydrosoil. It is assumed that two sorts of bound residues are formed from 4‐chlorophenylurea: one is fairly stable and might consist of bound 4‐chloroaniline or its transformation products, whereas the other is presumed to be a degradable derivative of

ISSN:0031-613X    

DOI:10.1002/ps.2780170411

出版商:John Wiley&Sons, Ltd    

年代:1986

数据来源: WILEY