bluuebunny/crossref_metadata_2025 huggingface dataset:
A Centrosymmetrical Di-thiolato-bridged Dinuclear Nickel(II) Compound; Bis-µ-S-(7-amino-2,4-dimethyl-5-azahept-4-ene-2-thiolato)dinickel(II) Perchlorate
Authors: Curtis Neil F. , Gladhikh Olga P. , Morgan Keith R. , Heath Sarah L.
Published: August 2004

The title compound, formed by reaction of 4-mercapto-4-methylpentan-2-one with
bis(ethane-1,2-diamine)nickel(II) perchlorate, has a centrosymmetrical
dinuclear cation. Each singlet ground-state nickel(II) ion is in tetrahedrally
twisted square-planar coordination by the primary amine and imine nitrogen
atoms and the thiolato sulfur atom of one molecule of
7-amino-2,4-dimethyl-5-azahept-4-ene-2-thiolate (adet¯), and the sulfur
atom of another molecule, with the sulfur atoms of two ligands forming a
planar Ni2S2 bridging group
{[Ni2-µ-(adet)2]
(ClO4)2,
C16H34C12N4Ni2O8S2,
Mr 662·9, monoclinic,
P21/c, a 8·267(1),
b 9·952(1), c
16·234(2) Å, β 103·010(2)°,
R1 0·033 for 2531
reflections}.
Synthesis and Crystal Structures of Two Monomeric Zinc(II) Complexes Containing Carboxylate and Aqua Ligands
Authors: Chen Xiao-Ming , Huang Xiao-Chun , Tong Ming-Liang , Tong Ye-Xiang , Ng Seik Weng
Published: August 2004

Two monomeric zinc(II) complexes of betaine
(Me3N+CH2CO2¯
= bet),
[Zn(bet)2(H2O)Cl]
(ClO4) (1) and
[Zn(bet)3(H2O)]
(ClO4)2 (2), have been prepared
and characterized by single-crystal structural analysis. The zinc atom in both
complexes is coordinated in a distorted tetrahedral geometry: the zinc atom in
complex (1) is surrounded by one aqua ligand (Zn–O 1·979(3)
Å), one chloro ligand (Zn–Cl 2·218(1) Å ) and two
monodentate carboxylate groups (Zn–O 1·946(2) Å); the zinc
atom in complex (2) is ligated by one aqua ligand (Zn–O 1·997(6)
Å) and three monodentate carboxylategroups (Zn–O
1·943(5)–2·106(8) Å). In both complexes, the aqua
ligand forms strong donor hydrogenbonds with adjacent carboxylate oxygens (for
complex (1), O · · · O is 2·689(2) Å; for
complex (2), O · · · O are 2·67(1) and
2·709(8) Å); these interactions are discussed in the context of
zinc complexesand enzyme active sites.
A Neutral Donor-Acceptor p-Stack: Solid-State Structures of 1 : 1 Pyromellitic Diimide-Dialkoxynaphthalene Cocrystals
Authors: Hamilton Darren G. , Lynch Daniel E. , Byriel Karl A. , Kennard Colin H. L.
Published: August 2004

Pyromellitic diimide forms orange-coloured cocrystals of 1 : 1 stoichiometry
with dialkoxynaphthalene derivatives. The solid-state structures of two
examples are presented. The cocrystal formed with 2,6-dimethoxynaphthalene
presents vertical stacks of alternating π-rich and π-deficient
subunits with the long axes of the respective components approximately
parallel. Investigation of the packing in the cocrystal also reveals a
stabilizing array of hydrogen bonds between the components of adjacent stacks.
Cocrystallization with 1,5-[2-(2-hydroxyethoxy)ethoxy]naphthalene, a
derivative bearing hydroxy terminated ethyleneoxy chains, gives rise to an
altered structural arrangement. Alternating donor- acceptor stacks once again
dominate the structure but adopt a geometry where the long axes of the
constituents are essentially perpendicular. Hydrogen-bonding interactions
result in the formation of continuous non-covalently linked columns of donor
and acceptor subunits by linking the terminal hydroxy functions of the
naphthalene component to the imide protons. The structural preferences
revealed by these solid-state analyses indicate that these complexes are
useful prototypes of more complex neutral supramolecular assemblies.
Synthesis and Absolute Configuration of Axially Chiral Binaphthoquinones
Authors: Baker Robert W. , Liu Song , Sargent Melvyn V.
Published: August 2004

The synthesis of
(+)-(S)-1′,4-dihydroxy-2,3′-dimethyl-1,2′-binaphthalene-5,5′,8,8′-tetrone
(62) and
(+)-(S)-4,5′,8′-trihydroxy-2,3′-dimethyl-1,2′-binaphthalene-1′,4′,5,8-tetrone
(55), compounds which are atrop-isomeric with the naturally occurring
binaphthoquinones (–)-isodiospyrin and
(–)-8′-hydroxyisodiospyrin, respectively, is described. The
binaphthyl linkages in these compounds were stereoselectively constructed by
using oxazoline chemistry. The stereochemical assignments were based on X-ray
crystal structure determination and circular dichroic spectroscopy.
Environmentally Benign Procedures for the Preparation and Isolation of 3-Methylcyclopent-2-en-1-one
Authors: Bagnell Laurence , Bliese Marianne , Cablewski Teresa , Strauss Christopher R. , Tsanaktsidis John
Published: August 2004

A moderately yielding (50±4%) method for obtaining
3-methylcyclopent-2-en-1-one from hexane-2,5-dione in ≥99·5%
purity was developed, using 2·1% (w/v) of aqueous KOH at
reflux. However, the yield was increased to 80±5% by using
considerably lower concentrations of base (<0·1%) and higher
temperature (200°C) with a conventionally heated autoclave or a microwave
batch reactor. The preparation was scaled up with a larger autoclave and also
with a continuous flow microwave reactor. The dione impurity was removed from
the enone by preferential adsorption on an anion-exchange resin in the
bisulfite form. The product was recovered from the aqueous phase with a
hydrophobic resin. This environmentally benign, non-extractive isolation
method has potential for broad applicability in cleaner production.
Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. II 4-Nitrophenoxides of Group 1
Authors: Harrowfield Jack M. , Sharma Raj Pal , Skelton Brian W. , White Allan H.
Published: August 2004

Room-temperature single-crystal X-ray studies are recorded for
4-nitrophenoxide (4-np¯) salts, variously hydrated, of the Group 1
metals, M(4-np-).χH2O, for M
= Li, Na (redetermination), K (already recorded), Rb and Cs.
Li(4-np).3H2O is monoclinic, space group
Pc, a 11·359(3),
b 7·518(3), c
10·855(4) Å, β 90·56(3)°, Z
= 4; conventional R on
|F| was 0·056 for
No 2098 independent
`observed" (I >
3σ(I)) reflections. Na(4-np).2H2O is orthorhombic,
Ima2, a 6·888(6),
b 19·699(8), c
6·436(8) Å, Z = 4,
R 0·031 for
No 664.
Rb(4-np).H2O is orthorhombic,
Pbca, a 11·82(3),
b 19·724(7), c
7·199(1) Å, Z = 8,
R 0·036 for
No 1465.
Cs(4-np).3H2O is monoclinic, P
21/c, a
13·337(2), b 12·770(5),
c 6·311(2) Å, β 100·56(3)°,
Z = 4, R 0·031 for
No 2636. Whereas the lithium
compound is essentially a discrete mononuclear neutral molecular complex
[(4-np-O)Li(OH2)3]
with four-coordinate lithium, the other compounds exhibit two- or
three-dimensional sheet polymer structures with 4-nitrophenoxide moieties
providing
O-C6H4-NO2
head-tail connecting motifs between successive metal atoms.
Structural Systematics of 2/4-Nitrophenoxide Complexes of Closed-Shell Metal Ions. III 2/4-Nitrophenoxides of Univalent Heavy Metals
Authors: Harrowfield Jack M. , Sharma Raj Pal , Skelton Brian W. , White Allan H.
Published: August 2004

Room-temperature single-crystal X-ray studies are recorded for 2- and
4-nitrophenoxide salts of silver(I) and thallium(I), M(2-np) and Tl(4-np)
(anhydrous), and Ag(4-np).H2O. Ag(2-np) is monoclinic,
P21/c,
a 9·012(4), b
5·743(5), c 12·594(5) Å, β
104·34(4)°, Z = 4; conventional
R on |F| was
0·042 for No 1378
independent ‘observed’ (I >
3σ(I)) reflections. Tl(2-np) is monoclinic,
C2/c, a
27·250(3), b 3·712(1),
c 15·147(3) Å, β 114·41(1)°,
Z = 8, R 0·025 for
No 1346.
Ag(4-np).H2O is monoclinic,
P21/a,
a 5·613(6), b
13·191(7), c 9·844(5) Å, β
92·50(6)°, Z = 4,
R 0 ·033 for
No 622. Tl(4-np) is tetragonal,
I 41/a,
a 18·037(8), c
8·979(8) Å, Z = 16,
R 0·043 for
No 924. An acid salt of the
latter, Tl(4-np).(4-npH)3, triclinic,
P-1, a
11·861(8), b 11·45(1),
c 11· 423(1) Å, α 114·00(6),
β 109·78(5), γ 96·87(7)°, Z
= 2, R 0·042 for
No 3814, is isomorphous with its
rubidium analogue. These comprise a novel array of structures: although the
structures of the silver(I) complexes are two-dimensional sheets with familiar
head-tail connecting ligands, a strong silver-aromatic carbon interaction is
found in Ag(2-np) (Ag–C 2·496(5) Å). Tl(2-np) and Tl(4-np)
both present unusual forms related to the stair-polymer and cubane adducts
found in 1 : 1 coinage metal(I)/halide-unidentate nitrogen base adducts;
Tl(2-np) is a double-stranded stair-polymer array, with the phenoxide oxygen
atoms incorporated in the stair and the nitro oxygen atoms linking successive
thallium atoms. The structure of Tl(4-np) is based on a tetranuclear cubane
motif of -4 symmetry,
[Tl(O-phenoxide)]4,
these being linked into a three-dimensional network by further Tl ·
· · O-nitro interactions from adjacent
units. The structure of silver(I) picrate monohydrate, isomorphous with its
sodium counterpart, is also recorded: monoclinic, C
2/m, a 12·818(7),
b 20·208(8), c 3·
741(1) Å, β 88·25(3)°, Z =
4, R 0·047 for
No 1042, void of any significant
Ag · · · C contacts.
Synthesis and Structural Characterization of Copper(I) and Copper(II) Complexes with an Ambivalent Phenanthroline-Type Ligand
Authors: Collin Jean-Paul , Gaviña Pablo , Sauvage Jean-Pierre , Cian André De , Fischer Jean
Published: August 2004

The new phenanthroline ligand
2-(p-methoxyphenyl)-9-(5′-methylpyridin-2′-yl)-1,10-phenanthroline
L has been synthesized and shown to form four-coordinate
CuI(L)2 (1) and six-coordinate
CuII(L)2 (2) complexes. Their
structures have been determined by X-ray crystallography: (1)
C50H38CuN6O2.BF4,
triclinic, space group P -1,
a12·924(3), b
14·567(4), c 12·649(3) Å , α
105·57(2), β 107·68(2), γ 104·00(2)°; (2)
C50H38CuN6O2.2PF6,
monoclinic, space group P
21/c, a
17·701(5), b 19·285(5),
c 14·93(4) Å, β 98·20(2)°.
In solution, cyclic voltammetry measurements indicate for the copper(I) and
copper(II) complexes a very fast rearrangement of the pyridine substituent
with the change of the oxidation state. Surprisingly, the X-ray data show two
different coordination modes for the ligand around the copper(I) ion, the
1,10-phenanthroline nucleus being either mono- or bi-dentate. In solution,
since the 1H n.m.r. spectra obtained even at several
temperatures display only one set of signals, it is proposed that a fast
equilibrium takes place between two coordination modes of the phenanthroline
Synthesis and Binding Studies of a New DNA Minor Groove Binder
Authors: Clark Christopher I. , Kelly David P. , Martin Roger F. , White Jonathan M. , Lobachevsky Pavel
Published: August 2004

2-[2′-(4′′-Ethoxyphenyl)-1H-indol-6′-yl]-5-(4′′′-methylpiperazin-1′′′-yl)-1H-benzimidazole
(1) has been synthesized from
2-(4′-ethoxyphenyl)-1H-indole-6-carbaldehyde (4b)
and 4-(4′-methylpiperazin-1′-yl)benzene-1,2-diamine (3b). The
aldehyde (4b) was prepared in five steps by using a modified
Leimgruber–Batcho indole synthesis. Evaluation of (1) as a DNA ligand is
described.
Mono- and Bi-nuclear Complexes of the Doubly Bidentate, Bridging Ligand 4,6-Di(2-pyridyl)pyrimidine.
Authors: Phillips Ian G. , Steel Peter J.
Published: August 2004

Thirteen mononuclear, homobinuclear and heterobinuclear transition metal
complexes of 4,6-di(2- pyridyl)pyrimidine have been prepared. Assignments of
the 1H n.m.r. spectra of the molybdenum(0) and
ruthenium(II) complexes were achieved by a combination of one- and
two-dimensional n.m.r. techniques, especially 1D-TOCSY. For the ruthenium
complexes, electronic absorption spectroscopy and cyclic voltammetry were used
to probe the nature of the metal{ligand and, for the binuclear complexes,
metal-metal interactions. The complexes have low HOMO−LUMO energy gaps.
Meta-metal interactions are shown to be of similar magnitude to those in
complexes of the better-studied ligands 2,2′-bipyrimidine and
2,3-di(2-pyridyl)pyrazine.
The Preparation and Biological Activity of Lactam-Based, Non-Steroidal, Inhibitors of Human Type-1 Steroid 5α-Reductase.
Authors: Abell Andrew D. , Phillips Andrew J. , Budhia Sangeeta , McNulty Ann M. , Neubauer Blake L.
Published: August 2004

A Beckmann rearrangement of cis- and
trans-fused
3,4,4a,9,10,10a-hexahydrophenanthren-1(2H)-one oximes
has yielded three azepines. An in vitro assay of the
azepines and
(3aSR,9bSR)-6-methoxy-3-methyl-1,3,3a,4,5,9b-hexahydro-2H-benz[e]indol-2-one,
prepared in four steps from naphthalene-1,6-diol, against human type-1 steroid
5α-reductase, revealed the tricyclic five-membered lactam to be a potent
inhibitor (IC50 733 nM).
Dimethyl (±)-2,3-Dimethylcubane-1,4-dicarboxylate
Authors: Bliese Marianne , Cristiano Domenico , Tsanaktsidis John
Published: August 2004

The preparation of dimethyl (±)-2,3-dimethylcubane-1,4-dicarboxylate
(2), in multigram quantities, from 3-methylcyclopent-2-en-1-one (3), in an
overall yield of c. 26%, is presented.
Coupling of 1,3-Diynes on Metal Centres: Molecular Structure of Ru2{µ:µ-PhCC(C≡CPh)C[C2Ph{Co2(µ-dppm)(CO)4}]CPh}(CO)6
Authors: Bruce Michael I. , Zaitseva Natasha N. , Skelton Brian W. , White Allan H.
Published: August 2004

The reaction between
Ru3(µ3-PhC2C≡CPh)(µ-CO)(CO)9
and Co2(µ-dppm)(CO)6
afforded the title complex, in which a
Co2(µ-dppm)(CO)4 unit is
attached to one of the C≡C triple bonds of a
µ-2η1:η4-PhCC(C≡CPh)C(C≡CPh)CPh
ligand bonded to an Ru2(CO)6
fragment.
Pentakis(methoxycarbonyl)cyclopentadiene Chemistry. Some Ruthenium, Osmium and Rhenium Complexes
Authors: Bruce, Michael I. , Humphrey Paul A. , Williams Michael L.
Published: August 2004

The reaction between
Ru(O2CMe)2(PPh3)2
and
HC5(CO2Me)5
affrded orange Ru(O2CMe)-{
C5(CO2Me)5}(PPh3)2,
which on standing in methanolic solution in air lost
PPh3 and was converted into purple
{Ru(µO2CMe)[C5(CO2Me)5](PPh3)}2O.
The
C5(CO2Me)5
ligands chelate the ruthenium atoms via two ester carbonyl oxygens. The
reaction of
RuCl(O2CMe)(CO)(PPh3)2
with
Tl[C5(CO2Me)5]
in MeCN gave cream
[Ru(O2CMe)(CO)(NCMe)(PPh3)2]
[C5(CO2Me)5].
The syntheses of
[C5(CO2Me)5]¯
salts of the
[Ru(C=CHPh)(PPh3)2Cp]+,
[Ru3H(CO)12]+,
[Os(NCMe)(PPh3)2Cp]+,
[OsH2(PPh3)2Cp]+
and
[Re(CO)3(NCMe)3]+
cations are also reported.
Intramolecular Michael Addition of N- and O-Centred Nucleophiles to Tethered Acrylates. The Role of Double-Bond Geometry in Controlling the Diastereo- selectivity of Cyclizations Leading to 2,6-Disubstituted Tetrahydropyrans and Piperidines.
Authors: Banwell Martin G. , Bissett Brett D. , Bui Chinh T. , Pham Ha T. T. , Simpson Gregory W.
Published: August 2004

The oxyanion derived from hydroxyacrylate E-(5)
undergoes smooth intramolecular Michael addition to give the
trans-2,6-disubstituted tetrahydropyran (7) as the major
product of reaction. In contrast, the oxyanion obtained from isomer
Z-(5) cyclizes to give the
cis-2,6-disubstituted tetrahydropyran (6) as the major
product. Such chemistry has been extended to the enantioselective synthesis of
(+)-(6) the acquisition of which constitutes a formal total synthesis of
acid (+)-(2), a constituent of the glandular secretion from the civet cat
(Viverra civetta). Reductive amination of keto acrylate
(12) affords an intermediate amine which cyclizes,
in situ, to give the
cis-2,6-disubstituted piperidine (26). Analogous
treatment of compound (13) delivers the isomeric
trans-2,6-disubstituted piperidine (27) as the exclusive
product of reaction. Transition state structures have been proposed to account
for the diastereoselectivities observed in all of the cyclization reactions.
Molecular Cocrystals of Carboxylic Acids. XXXII The Crystal Structures of the Adducts of 2-Aminobenzothiazole with 3,5-Dinitrobenzoic Acid (Adduct Hydrate) and 3-Aminobenzoic Acid, and 2-Amino-2-thiazoline with 2-Aminobenzoic Acid
Authors: Lynch Daniel E. , Smith Graham , Byriel Karl A. , Kennard Colin H. L.
Published: August 2004

Two adducts of 2-aminobenzothiazole and one of 2-amino-2-thiazoline with
aromatic carboxylic acids have been synthesized and their X-ray crystal
structures determined. These are 2-aminobenzothiazole with 3,5-dinitrobenzoic
acid (the 1 : 1 adduct hydrate) (1), and 3-aminobenzoic acid (1 : 1) (2), and
2-amino-2-thiazoline with 2-aminobenzoic acid (1 : 1) (3). Compound (1) is a
non-centrosymmetric proton-transfer complex and gave a signal of 0·30
relative to urea when tested for second-order non-linear optical properties.
Compound (3) is also a proton-transfer complex but (2) is not.
Some Transformations of Adducts of 3,6-Dimethoxy-4,5-methylenedioxy-1,2-didehydrobenzene and Furans. An Approach to the 5,8-Dimethoxy-6,7-methylenedioxynaphtho[2,3-c]furan-4,9-dione Ring System of Ventilone A
Authors: Buttery Jarrod H. , Wege Dieter
Published: August 2004

Adducts derived from the aryne
3,6-dimethoxy-4,5-methylenedioxy-1,2-didehydrobenzene (19) with furan and
2-methoxyfuran have been converted into
5,8-dimethoxy-6,7-methylenedioxy-1,2-naphthoquinone (22) and
5,8-dimethoxy-6,7-methylenedioxy-1,4-naphthoquinone (24) respectively. The
trapping of (19) with
1H,3H-furo[3,4-c]furan
(38) yielded an unstable adduct (37), which on acid-catalysed ring opening and
subsequent oxidation was transformed into
5,8-dimethoxy-6,7-methylenedioxynaphtho[2,3-c]furan-4,9-dione
(36), a compound possessing the ring system of the naturally occurring quinone
ventilone A.
Synthesis of Highly Oxygenated Anthraquinones from Chamaecrista greggii
Authors: Cameron Donald W. , Gan Chee-Yong , Griffiths Peter G. , Pattermann Judy A.
Published: August 2004

Four isomeric anthraquinones (2)–(5) have been synthesized for the first
time, by cycloaddition involving the new dienes (8) and (9). Their
spectroscopic properties have been compared together and with data for two
natural anthraquinones reported from
Chamaecrista greggii. The assigned structure (2) was
thereby supported for one of the natural isomers. The other isomer, previously
formulated as (3), did not correspond to any of the synthesized compounds
[(2)–(5)].
Correlation Between the Lever Parameter and Electronic Properties of Nitrosyl Ruthenium(II) Complexes
Authors: Lopes Luiz G. F. , Gomes Maria G. , Borges Simone S. S. , Franco Douglas W.
Published: August 2004

The Lever parameter (EL), for a
series of ruthenium nitrosyl complexes of the type
[Ru(NH3)4NOL]
n+, where ligand L = nicotinamide (nic),
isonicotinamide (isn), pyrazine (pz), pyridine (py), imidazole (imN),
L-histidine (L-hist), NH3, trimethyl phosphite
[P(OMe)3] and triethyl phosphite
[P(OEt)3], is correlated to
Epc1 (the potential for the reduction
RuNO++e- → RuNO
0) and v(NO) data. A correlation
is observed between ∑EL and
Epc1, and between
∑EL and
v(NO), since these parameters are dependent on
electronic characteristics of the nitrosyl group. For
∑EL v.
Epc1, the slope,
SL, and intercept,
IL, of the linear correlation are
related to interligand coupling through the metal centre and to the extent of
the Ru → NO back bonding.
A Hydrogen Electrode Study of Concentrated Alkaline Aluminate Solutions
Authors: Sipos Pal , Hefter Glenn , May Peter M.
Published: August 2004

A detailed study of highly concentrated aqueous alkaline aluminate solutions
has been made by hydrogen electrode potentiometry in cells with liquid
junction at 25°C in 8 M Na(ClO4) media. Measurements
were performed over the total concentration ranges 0·1 M <
[NaOH]T < 4·0 M and 0·02 M
< [AlIII]T <
3·2 M, and at total concentration ratios of 6·92 ≥
[OH-]T/[AlIII]T
≥ 4·3. Nernstian electrode behaviour was observed at
[NaOH]T ≤ c. 2 M in
pure NaOH/NaClO4 mixtures. At low
[AlIII]T the data were
consistent with the formation of only the well known
Al(OH)4-(aq) species but there is
clear evidence of a systematic release of hydroxide as
[AlIII]T and
[NaOH]T increase. The data are consistent with
the formation of polymeric aluminate complexes having a stoichiometry of
Alq(OH)3q - rr+
(q = 4–7, q + r = 1 or 2). However, unequivocal
identification of these species is difficult on account of strong correlations
in the data and the possible effects of ion-pairing.
Acid-Promoted Fries Rearrangements of Benzannulated Lactones
Authors: Cambie Richard C. , Mitchell Lorna H. , Rutledge Peter S.
Published: August 2004

The scope of acid-promoted Fries rearrangements of benzannulated lactones has
been examined. The reaction is applicable to seven-membered lactones
possessing a sufficiently activated aromatic ring but not to six-membered
lactones, and it proceeds in higher yield for diterpenoid lactones than for
lower molecular weight lactones. The structures of the 2,6-methano-bridged
benzoxocin side products (23), (24), and (25) from rearrangement of the
diterpenoid lactone (11) have been assigned.
Flash Vacuum Pyrolysis of Some N-Benzylbenzotriazoles and N-Benzylbenzisoxazolones
Authors: Khalafy Jabbar , Prager Rolf H
Published: August 2004

The flash vacuum pyrolysis products of
2-(benzotriazol-1-ylmethyl)benzonitrile, methyl
2-(benzotriazol-1-ylmethyl)benzoate and the corresponding benzisoxazolones
have been characterized. The benzotriazoles lose nitrogen to give diradicals
which undergo intramolecular hydrogen-atom transfer or cyclization, while the
benzisoxazolones rearrange initially to the corresponding benzaldehyde
N-(2-carboxyphenyl)imines which undergo subsequent
intramolecular addition reactions.
Stomatal response of grapevines to wind
Authors: Campbell-Clause J. M.
Published: August 2004

Summary. A porometer study of 2 grapevine cultivars
(Vitis vinifera cvv. Italia and Ribier) was conducted in
the field to assess the effect of wind on stomatal resistance. The effect of
differing light levels was also studied. Data of the grapevines stomatal
resistance responses to wind and light were incorporated into the
Penman–Monteith equation and an estimation of the effect of wind and
light on evapotranspiration was made.
Wind increased stomatal resistance for Ribier and Italia in an exponential
manner. Both varieties showed a typical response to light with a flattening
curve of decreasing stomatal resistance with increasing light. Stomatal
resistance was similar at the upper range of light (>800
W/m2) for both Ribier and Italia. At lower light
levels stomatal resistance of Ribier increased more than that of Italia.
Stomatal resistance began to increase appreciably when the level of light fell
below 400 W/m2 . Using the Penman–Monteith
model, together with average weather data and including these responses to
wind and light, daily evapotranspiration in January for Italia was calculated
to be 4.03 mm/day (38.4% of class A pan evaporation) compared with
3.91 mm/day (37.2% of class A pan evaporation) for cv. Ribier. Wind
speeds above 4 m/s reduced estimated evapotranspiration compared with less
windy conditions (wind speed <4 m/s), more so at higher wind speeds.
Reducing wind speed using a windbreak significantly increased water use and
potential yield. Under Swan Valley conditions, a 3.6 m high, 40%
permeable windbreak would be required every 60 m to reduce wind speed below
5.5 m/s for 93% of the time. Windbreak frequency can be determined
for other areas with information on wind frequency and wind speed.
Assessment of the nitrogen status of field-grown canola (Brassica napus) by plant analysis
Authors: Hocking P. J. , Randall P. J. , Marco D. De , Bamforth I.
Published: August 2004

Summary. Field trials were conducted over 2 seasons at
Greenethorpe and Canowindra in the Cowra region of New South Wales to develop
and calibrate plant tests for assessing the nitrogen (N) status of canola
(Brassica napus). Plants were tested at 3 and 7 growth
stages up to the start of flowering at Greenethorpe and Canowindra,
respectively. The petiole of the youngest mature leaf (YML) was the most
suitable plant part to sample for tests based on nitrate-N. Suitable plant
parts for tests based on total N were the YML petiole or lamina, or the whole
shoot.
There was good agreement between the 2 sites in the just-adequate fertiliser N
rates (rates giving 90% of maximum yield) and the critical N
concentrations in the plant parts tested. Critical nitrate-N concentrations in
the fresh YML petiole for dry matter production at the time of sampling the
plants decreased from 1.62 to 0.14 mg nitrate-N/g fresh weight between the
4–5 leaf rosette stage (4–5 RS) and the start of flowering (SF).
Critical nitrate-N concentrations in the dry YML petiole decreased from 16.5
to 0.8 mg/g dry weight between 4–5 RS and SF. Critical total N
concentrations decreased from 4.5 to 2.0, 7.2 to 5.0 and 6.2 to 2.8%
dry weight, in the YML petiole, YML lamina, and whole shoot, respectively,
between 4–5 RS and SF. Critical nitrate-N and total N concentrations for
assessing potential seed yield were similar to those for dry matter production
at the time of sampling for each of the growth stages. The critical total N
concentrations obtained for the YML petiole and lamina, and the whole shoot
before the start of stem elongation are likely to be less precise than the
critical nitrate-N concentrations in the YML petiole because of the limited
response of total N concentrations to increasing rates of fertiliser N.
However, total N in the YML petiole or lamina, or in the whole shoot may be a
better indicator of N status for plants sampled after the start of stem
elongation as nitrate-N concentrations become low and more variable, and it is
harder to identify the YML. The decline in critical N concentrations must be
taken into account when interpreting the results of plant tests for diagnosing
the N status of canola, as sampling needs to correspond to the plant growth
stage for which a particular critical N concentration has been obtained.
A comparison of once- and twice-yearly weaning of an extensive herd in northern Australia
Authors: Sullivan R. M. , O'Rourke P. K.
Published: August 2004

Summary. In northern Australia, many cows conceive only
after their calves are weaned. The subsequent calves are born in the late wet
or early dry season. Where producers wean once a year these late calves stay
with the cows with resultant increased risk of cow mortality. A second weaning
may reduce this risk.
From June 1985 to June 1990 we recorded cow liveweights, mortalities and
reproductive rates from a herd of 500
Bos indicus-Bos taurus-cross cows
at Kidman Springs, Northern Territory. The herd grazed native pastures, and
was continuously mated and unsupplemented. Calves were weaned if they weighed
100 kg or more at muster in June (W1) or in either of June and October (W2).
In both groups (W1 and W2), 75% of calves were weaned at the June
muster, and a further 14% were weaned at the October muster (W2 group).
There was no difference in liveweight change, mortality or branding rates
between the 2 groups. Overall productivity was low, probably due to poor
nutrition during both dry and wet seasons. For example, average branding and
mortality rates were 51.8 and 11.8%. Forty-seven percent of all cows
were pregnant at the June muster but a quarter of these failed to rear a calf.
The low proportion of calves suitable for weaning in October indicated that
the weaning times were too close together, and did not allow enough late
calves to reach the target liveweight for weaning. Consequently, the benefit
of the second weaning was reduced. Weaning times for continuously mated herds
should be determined by the time taken for calves born late in the wet season
to reach target liveweights for weaning at the second weaning round.
Effectively, this means the first weaning should be earlier, perhaps in April,
since high temperatures and the increased likelihood of rain make mustering
after October difficult.
Factors affecting the early growth of Leucaena leucocephala
Authors: Brandon N. J. , Shelton H. M. , Peck D. M.
Published: August 2004

Summary. Slow seedling growth is a limitation to the
more widespread adoption of the tree legume, leucaena
(Leucaena leucocephala). Three glasshouse trials
examined the role of arbuscular mycorrhiza and phosphorus (P) nutrition in
determining early growth and nodulation of leucaena. Treatments included soil
types, inoculation with arbuscular mycorrhizal (AM) fungi, P application,
grass competition and fumigation with methyl bromide, an anti-fungal agent.
Plant measurements included colonisation by AM fungi, nodule weight, tissue
nitrogen (N) and P concentrations.
Slower early growth of leucaena in a soil from Mt Cotton than in soils from
Gayndah or Theodore was due to slow colonisation of roots by AM fungi.
Sequential harvests of plants revealed that rate of colonisation in the Mt
Cotton soil was only half that in the Theodore soil prior to 28 days after
planting resulting in subcritical P concentrations 21 days after sowing and an
approximate halving of top dry weight 41 days after sowing. However, following
increased infection, tissue P concentration and final plant growth 98 days
after sowing were similar in both soils.
Early seedling growth in the Mt Cotton soil was increased by inoculating the
soil with mulch containing AM fungi but not with soil collected from beneath
established leucaena added at a lower rate. Phosphorus application
significantly increased growth of leucaena seedlings, but only the highest
rate of 1200 kg P/ha was able to prevent early P deficiency. Final growth
was reduced by 50% in the presence of
Panicum maximum as a result of increased competition for
N and P and by 90% in fumigated soil as a result of P deficiency.
The results of these experiments confirm the important role of AM fungi on
early seedling growth of leucaena. However, the potential to increase early
growth using a soil or mulch inoculum containing AM fungi or P fertiliser may
be limited by the high rates of application needed. More work is needed to
determine whether slow rate of infection is a significant limitation in soils
other than the Mt Cotton soil in the field.
Hot water dipping and low temperature storage of 'Eureka' lemons
Authors: McLauchlan R. L. , Underhill S. J. , Dahler J. M. , Giles J. E.
Published: August 2004

Summary. Prestorage heat treatments at 47–53°C
for 1–3 min were investigated as a potential control of chilling injury
in cold disinfested ‘Eureka’ lemons
(Citrus limon). Hot water dips significantly reduced the
incidence of chilling injury in fruit stored at 1°C for 28 and 42 days.
Storage at 1°C for 14 days resulted in comparatively minor chilling
injury, so that hot water dips gave little additional benefit. This result is
thought to reflect the low incidence of chilling injury, rather than the lack
of effectiveness of heat treatments. Scald damage (surface browning) occurred
after 3 min at 53°C. Heat treatments had no significant effect on the
incidence of disease at all durations of storage. The rate of fruit weight
loss during 7 days at 20°C after storage for 14, 28 or 42 days at 1°C
was significantly lower in heat- treated fruit.
Effects of irrigation frequency and transient waterlogging on the production of a perennial ryegrass - white clover pasture
Authors: Dunbabin J. S. , Hume I. H. , Ireson M. E.
Published: August 2004

Summary. Perennial ryegrass–white clover swards
were irrigated for 3 years every 50, 80 and 120 mm of crop evapotranspiration
minus rainfall (ETc–R) and water ponded on the soil surface for either
4, 12 or 24 h at each irrigation. Pasture production and clover content were
highly seasonal, peaking in spring and autumn. Frequent irrigation increased
dry matter production by an average of 56%. When irrigating at 50 mm
ETc–R, dry matter production was decreased by ponding water on plots,
17% for 12 h ponding and 14% if ponded for 24 h. However, when
irrigating at an interval of 80 mm ETc–R ponding increased dry matter
production by 7% for 12 h ponding and by 25% for 24 h ponding.
Ponding also increased production at an irrigation interval of 120 mm
ETc–R by 25% for 12 h ponding but only by 2.4% for 24 h
ponding. While these increases in dry matter production are large in relative
terms the absolute increase in production is small.
More water infiltrated per irrigation at longer irrigation intervals, and at
longer ponding times. Frequently irrigated, rapidly drained swards used
irrigation water most efficiently. The small gain in dry matter production
achieved by prolonging ponding at longer irrigation intervals is an
inefficient use of water and likely to recharge regional groundwater systems.
Oxygen diffusion rate measurements suggested that ponding for as short as 4 h
was likely to cause waterlogging stresses and that these stresses were higher
when irrigating frequently. The relative increase in waterlogging stress by
extending the period of ponding from 4 to 24 h was small.
Genotypic variation of plant species to the allelopathic effects of vulpia residues
Authors: An M. , Pratley J. E. , Haig T. , Jellett P.
Published: August 2004

Summary. The germination and seedling growth of 12 plant
species and 12 cultivars from 2 plant species were tested in the presence of
aqueous extracts of vulpia dry matter residues. Concepts of whole-range
assessment and inhibition index were developed, and used, with principal
component analysis, for assessing results. Species were grouped according to
the inhibition index. Average threshold concentration, average
I50 (the extract concentration required to cause
50% inhibition in plant response) and average root and coleoptile
lengths were used as auxillary indices for each group. Marked differences in
tolerance toward the phytotoxicity of vulpia residue extracts were observed
among species and cultivars. Such differences were widespread among plant
species, with generally cocksfoot, Vulpia spp.,
subterranean clover (cv. Trikkala), phalaris, canola, medics, and oats being
relatively tolerant, while lupins, barley, and wheat (cvv. Janz, Vulcan) were
the most susceptible, and subterranean clover (cvv. Seaton Park, Karridale,
Clare, Woogenellup, Junee), field peas, and wheat (cvv. Ford, Darter,
Dollarbird, Rosella) were relatively susceptible. The findings of this study
suggest that choice of species and cultivar may be a valuable management
option for minimising the negative effects of vulpia residues. The whole-range
assessment developed in this study proved to be a statistically efficient
summary of the plant response profiles. Together with the bioassay techniques
adopted, it provides a simple and rapid screening methodology for assessing
the relative tolerance of plant species to the allelopathic effects of weed
residues.
Effects of sex and liveweight on feeding behaviour of crossbred weaner lambs receiving oaten grain supplement on lucerne pasture
Authors: Holst P. J. , Hall D. G. , Stanley D. F. , Nolan J. V.
Published: August 2004

Summary. The response of 96 weaner, crossbred lambs to
oat grain on lucerne pasture was examined where they were fed in single sex
ewe or cryptorchid groups or in mixed sex groups. All groups had a similar
profile of weights (range 16–34 kg). Intakes of lucerne and air dry oats
fed daily in troughs at 300 g/head and later at 200 g/head were
estimated at intervals over 4 weeks commencing 4 weeks after weaning.
Overall mean (± s.e.) growth rate (cryptorchid 144 ± 6 v. female
115 ± 7 g/day) of cryptorchid or female lambs was not significantly
different when fed as a single sex group or combined.
Intake of supplement when offered up to 300 g, was not affected by sex of lamb
but was significantly (P<0.001) affected by
liveweight at the start of the experiment. Mean initial liveweight of lambs
that consistently ate least supplement was 20.0 kg compared with 26.1 kg for
the remainder and they were 12 days younger than the remainder. The behaviour
of some of these lighter lambs at feeding suggested that a form of dominance
was operating.
Cryptorchid lambs ate more lucerne pasture than female lambs at the same
liveweight (746 v. 586 g dry matter at the middle, and
904 v. 759 g dry matter at the end of the experiment).
We conclude that our weaner crossbred lambs did not need to be segregated on
sex for supplementary feeding on pasture. However, many of the lightest lambs
were shy feeders and could benefit from segregation. Shy feeders represented
11% of this flock.
Influence of energy and protein supplements on the productivity of dairy cows grazing white clover swards in spring
Authors: Stockdale C. R.
Published: August 2004

Summary. Two experiments were conducted to determine the
production responses from high-producing dairy cows grazing white clover
(Trifolium repens c v. Haifa) swards while being
supplemented with maize (Zea mays) silage with or
without additional protein and/or energ y. The white clover swards in
experiments 1 and 2 comprised 5 and 25% flowers respectively. In each
experiment, 6 groups of 4 Friesian cows were offered about 20 kg dry matter (
D M ) / c o w.day of pure white clover for 5 weeks in spring–early
summer. Each group was assigned to one of 6 supplementary feeding treatments:
(i) no supplement; (ii) 5 kg DM/cow of maize silage; (iii) 5 kg DM/cow
of maize silage with 75 g of urea; (iv) 3 kg DM/cow of maize silage plus 2
kg DM of rolled barley; (v) 3 kg DM/cow of maize silage plus 2 kg DM of
cottonseed meal; or (vi) 3 kg DM/cow of maize silage and 1 kg DM of barley
and 1 kg DM of cottonseed meal each day. All cows were individually fed
supplements but grazed pasture as separate treatment groups.
In experiment 1, milk yields averaged 22.0, 24.4, 24.5, 24.0, 25.1 and 25.5
kg/cow. d a y, respectively, for the treatments listed above. None of the
supplemented treatments were significantly different. In experiment 2,
corresponding milk yields were 17.9, 20.0, 21.1, 21.5, 22.1 and 21.3
kg/cow. d a y. Addition of urea, barley or cottonseed meal to maize silage
significantly increased milk production above that of the unsupplemented cows.
Feeding supplements in experiment 2 also significantly improved body
condition. There were no significant biological effects of supplementary
feeding treatment on rumen fermentation, although ammonia-nitrogen
concentrations were reduced when energ y supplements were fed in experiment 1.
While the responses from feeding maize silage were consistent with previous
research, the results obtained from the replacement of some of the silage with
extra e n e rgy and/or protein were inconclusive. Certainly trends in milk
yield were apparent, particularly from the addition of nitrogen/protein,
but the design of the experiments was not conducive to high experimental
precision. On the other hand, where barley was included in the ration, it was
possibly unrealistic to expect large changes in productivity, unless positive
associative effects existed, since the barley probably provided little extra
total energy.
Assessment of soil phosphorus tests for situations in Australia where reactive phosphate rock and water-soluble phosphorus fertilisers are used
Authors: Simpson P. G. , McLaughlin M. J. , Weatherley A. J. , Sale P. W. G. , Hoy V. , Lancaster P.
Published: August 2004

Summary. A selection of commonly used soil phosphorus
(P) tests, which included anion and cation exchange resin membranes, were
compared in a glasshouse experiment using subterranean clover, and evaluated
in the field at 19 sites from the National Reactive Phosphate Rock Project in
1993 and at 6 sites in 1995. The ability of the soil P tests to predict plant
response was used to evaluate the tests. In the glasshouse experiment the
resin test was less effective than the Bray 1 and Colwell tests in its ability
to assess the level of plant-available P from the different fertiliser
treatments. Seventy-one percent of the variation in total P content of the
subterranean clover shoots was explained by resin-extractable P values,
whereas the Colwell procedure accounted for 81% and the Bray 1
procedure accounted for 78%. Water and CaCl2
extracts were poor predictors of P content. In the field experiments all tests
evaluated performed poorly in describing the relationship between soil test P
and the level of P applied and relative yield and soil test P over a wide
range of soil types and environments. The Bray 1 procedure performed best but
the relationship was poor.
Adding bentonite to sorghum grain-based supplements has no effect on cow milk production
Authors: Ehrlich W. K. , Davison T. M.
Published: August 2004

Summary. Twenty-four Holstein–Friesian cows were
used in an experiment comparing milk production from cows offered rolled
sorghum grain either alone at 8 or 10 kg/head. day of air-dried grain or
with 4% sodium bentonite. The design was a 4 × 4 latin square
with a 1 week adjustment period and a 3 week treatment period. This design was
used to highlight the effects of high levels of grain feeding and changing
that level of grain or grain–bentonite every 4 weeks. Cows grazed either
ryegrass (Lolium multiflorum cv. Tetila) or oats
(Avena sativa cv. Cluan) during the day and a mixed
ration based on maize silage, lucerne hay, and meat and bone meal at night.
There was no significant effect of treatments on milk yield or composition.
Cows fed bentonite had a higher (P<0.05) rumen pH,
tended to eat less grain sorghum and have lower concentrations of rumen
ammonia and faecal starch. Faecal crude protein tended to increase with the
use of bentonite indicating cows may have substituted pasture or mixed ration
for grain and maintained a more stable rumen fermentation.
Longevity of wheat yield response to lime in south-eastern Australia
Authors: Coventry D. R. , Slattery W. J. , Burnett V. F. , Ganning G. W.
Published: August 2004

Summary. A long-term experiment in north-eastern
Victoria has been regularly monitored for wheat yield responses to a range of
lime and fertiliser treatments, and the soil sampled for acidity attributes.
Substantial grain yield increases have been consistently obtained over a
period of 12 years with a single lime application. Lime applied at 2.5
t/ha in 1980 was still providing yield increases of 24% with an
acid-tolerant wheat (Matong, 1992 season) and 79% with an
acid-sensitive wheat (Oxley, 1993 season) relative to no lime treatment. The 2
wheat cultivars responded differently to phosphorus fertiliser, with the
acid-sensitive wheat less responsive to phosphorus fertiliser in the absence
of lime. The use of a regular lime application applied as a fertiliser (125 kg
lime/ha) with the wheat seed gave only a small grain yield increase
(8% Matong, 16% Oxley), despite 1 t/ha of lime applied over
the 12-year period. Liming the soil at a rate of 2.5 t/ha (1980) initially
raised the soil pH by about 1.0 unit and removed most soluble aluminium
(0–10 cm). However, after 12 years of crop–pasture rotation after
the initial 2.5 t lime/ha treatment the soil pH had declined by 0.7 of a
pH unit and exchangeable aluminium was substantially increased, almost to
levels prior to the initial application of lime. Given the continued yield
responsiveness obtained following the initial application of lime, this
practice, rather than regular applications of small amounts of lime, is
recommended for wheat production on strongly acidic (pHw
< 5.5) soils in south-eastern Australia.
Effect of defoliation frequency and summer irrigation on survival of perennial (Lolium perenne) and biennial (Lolium multiflorum) ryegrass in the subtropics
Authors: Donaghy D. J. , Scott J. M. , Fulkerson W. J.
Published: August 2004

Summary. The present study investigated, in a
subtropical environment, the timing of defoliation treatments in spring and
summer irrigation management on the survival of perennial
(Lolium perenne cv. Yatsyn) and biennial
(L. multiflorum cv. Noble) ryegrass in a mixed
ryegrass–white clover (Trifolium repens) pasture
over the first summer, and seedling recruitment the following autumn.
Defoliation options were related to various ryegrass plant development stages
such as the number of leaves per tiller attained during regrowth, stem
elongation and seed set. The criterion for timing of frequent defoliation was
1 leaf/tiller regrowth and infrequent defoliation 3 leaves/tiller.
Both pasture types were defoliated either frequently or infrequently at
specific times from sowing to mid summer. Half the plots were irrigated from
30 November to 6 April while the remaining plots were not irrigated over this
period.
There was no survival of biennial ryegrass plants into autumn of the second
year and pasture production was entirely from seedling recruitment of seed set
in the previous spring. The maximum seedling recruitment (plant population
89% of spring in establishment year) was achieved by infrequent
defoliation in mid spring and then cessation of defoliation until mid summer
to allow plants to set seed. However, this resulted in a production loss of
3094 kg dry matter/ha of ryegrass and clover. In contrast, production of
perennial ryegrass in the second year was reliant almost exclusively on
individual ryegrass plants surviving the summer, as there was little seed set
and virtually no seedling recruitment.
There would appear to be 2 contrasting defoliation requirements to optimise
perennial ryegrass persistence. Infrequent defoliation from sowing to early
spring (22 March–2 September) and frequent defoliation in early summer
(19 November–3 February) resulted in maximum plant survival and minimum
tropical grass incursion. Frequent, compared with infrequent, defoliation up
to 2 September decreased root dry matter in February by 45% to 1.66 g
dry matter/plant. However in early summer, frequent defoliation maximised
survival, presumably by reducing shading by tropical grasses, and preventing a
closed canopy which encourages ‘rust’ infestation of the ryegrass.
Irrigation of ryegrass over summer, in situations likely to become
waterlogged, will only be of benefit in dry years and if scheduling is
frequent enough to benefit ryegrass rather than tropical grass.
These results highlight the importance of maintaining an infrequent
defoliation interval to maximise persistence of perennial ryegrass in the
subtropics. More frequent defoliation may be necessary in late
spring/early summer to reduce the impact of leaf rust.
Influence of fungal pathogens and environmental conditions on disease severity, flower fall and desiccation of harvested Geraldton waxflower 1. Studies with model packages
Authors: Taylor M. N. , Joyce D. C. , Wearing A. H. , Simons D. H.
Published: August 2004

Summary. Flowering sprigs of Geraldton waxflower
(Chamelaucium uncinatum Schauer cv. ‘Alba’)
inoculated with Botrytis cinerea,
Alternaria alternata or left uninoculated (control
treatment) were kept in sealed plastic containers (model packages). Three
relative humidity treatments (75, 90 or 100%) by 4 temperature
treatments [5, 10, 20 or 5/20° C (alternated daily)] were
maintained. An additional treatment of ethylene absorbent (Purafil) sachets in
the model packages was included. Disease severity, flower fall and desiccation
were monitored over 22 days. Both disease severity and flower fall were
reduced in treatments with no inoculum, at lower temperatures (5, 10 and
5/20°C) and under reduced relative humidities (75 and 90%).
However, desiccation was a problem at 75 and 90% relative humidity and
at 20 and 5/20°C. Ethylene scrubbing at 100% relative humidity
did not significantly reduce disease severity or flower fall. Considered
collectively, our results show that postharvest disease severity, flower fall
and desiccation can be minimised by keeping waxflower at ≤10˚C and
≥90% relative humidity.
A review of the introduction and use of white clover (Trifolium repens L.) in Australia —significance for breeding objectives
Authors: Lane L. A. , Ayres J. F. , Lovett J. V.
Published: August 2004

Summary. White clover was introduced to Australia with
the early European settlers in the late 18th century and is now the most
valuable pasture legume in high rainfall temperate regions of Australia.
Through a process of ingress and naturalising in conjunction with pastoral
expansion during the 19th century and widespread pasture improvement in the
20th century, white clover now occupies 6 million hectares in Australia and is
of major significance for the sheep, beef cattle and dairy industries. This
paper describes these historical influences on formation of the white clover
zone in Australia and the continuing requirement for better adapted cultivars
in key agro-geographic regions, with particular close reference to the
northern tablelands of New South Wales—the most extensive dryland
region. These considerations provide a basis for defining breeding objectives
for white clover improvement in Australia.