bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of total nitrogen in youngest fully expanded blades for assessing the nitrogen status of onion (Allium cepa L.) crops
Authors: Maier NA , Dahlenburg AP , Twigden TK
Published: March 2005

This paper describes the derivation of critical total nitrogen (N) concentrations in youngest fully expanded blades (YFEB), to assess the N status of onion crops. Five rates of N, from 0 to 390 kg/ha, were applied in randomised block experiments to cv. Cream Gold at 2 sites in 1988 and 1989. YFEB were sampled 5 times between the 3- and 9-leaf stages (41-108 days after the 'hook' stage). Marketable yield significantly (P<0.01) increased as the rate of N increased at both sites. Nitrogen rates required for 95% of maximum yield were 230 and 210 kg/ha at sites 1 and 2, respectively. Sensitivity of YFEB total N concentrations to variation in N supply depended on sampling time. For example, at site 2, the increases in total N concentrations due to application of N ranged from 6.3% at 42 days to 36.3% at 93 days. Because of low sensitivity, sampling at the 3-leaf stage may be too early to detect N deficiency reliably. Mean � s.e. increases in total N concentration were 30.6 � 6.1 and 20.3 � 4.9% at sites 1 and 2, respectively. At early sampling times the relationships between relative marketable yield and total N concentration showed a marked Piper-Steenbjerg effect. Critical total N concentrations derived from these relationships decreased from 3.7-40% at 41-42 days to 1.8-1.9% at 106-108 days. This decrease highlights the importance of carefully defining sampling time to ensure correct interpretation of plant test data.
Nutritive value of Albizia lebbek supplements for growing sheep
Authors: Dwatmadj i , Teleni E , Bird AR , Lowry JB
Published: March 2005

This study was undertaken to evaluate the effect of supplements of siris (Albizia lebbeck) flowers and leaves on Merino wethers fed Mitchell grass hay (Astrebla spp.). Three groups, each of 6 sheep, were fed the following diets: hammermilled Mitchell grass hay ad libitum (M); M + 181 g DM/day of siris flowers (MF), and M + 216 g DM/day of siris leaves (ML). The experiment, conducted over 17 days, measured feed intake and digestibility, nitrogen (N) retention, and plasma glucose and urea concentrations. The total DM intakes by MF and ML sheep were significantly (P<0.01) higher than those in M sheep. As a result of the supplement of siris flowers, the digestibility of the MF diet was highest (P<0.01). Sheep fed the M diet showed negative N retention, while MF and ML sheep showed positive N retention. The increased (P<0.01) N retention in the MF and ML sheep was associated with increased (P<0.01) urinary N excretion. The improved nutritional state of MF and ML sheep was associated with increases in plasma glucose and urea concentrations. Environmental temperature, which reached a mean daily maximum of 31.3�C, did not interact with the dietary treatments.
Maize silage for the pasture-fed dairy cow. 1. Effect of level of silage feeding, and responses to cottonseed meal while grazing perennial pastures in the spring
Authors: Moran JB , Stockdale CR
Published: March 2005

Dairy cows in early lactation were fed a maize-silage-based supplement at either 3 or 8 kg DM/cow.day, while grazing irrigated perennial pastures at 45 or 30 kg pasture DM/cow.day. The supplement consisted of maize silage, alone or with 16% DM replaced by cottonseed meal. A fifth group grazed at the higher pasture allocation with no supplements. Milk yield and composition, liveweight and body condition, and pasture intake were monitored over 10 weeks during late spring-early summer. Samples of pre- and post-grazed pasture, supplement, rumen fluid, and faeces were collected for chemical analyses. Supplemention increased total feed intake and milk yield of grazing cows, except at the higher level of silage without cottonseed meal. From data on nitrogen content of the grazed pasture and the supplement, together with rumen ammonia concentrations, it was concluded that low dietary protein levels limited milk yield in cows supplemented with 8 kg maize silage DM/day without the additional cottonseed meal. Liveweight and body condition score increases were greater in supplemented animals, while their rumen volatile fatty acid profiles suggested greater partitioning of nutrients towards lipogenesis in body tissue. Pasture was substituted at the rate of 0.67 kg DM for every kg maize silage DM consumed.
Maize silage for the pasture-fed dairy cow. 3. A comparison with greenchop maize grazing perennial pasture in late summer
Authors: Moran JB
Published: March 2005

Dairy cows in mid lactation were pen-fed ad libitum maize silage, ad libitum maize greenchop, or restricted maize greenchop. A cottonseed meal supplement was also fed at 20% forage maize DM. The maize greenchop was harvested daily over 5 weeks during February and March. Both forms of forage maize were fed to sheep in metabolism cages. Digestibility was always higher with maize silage. Digestibility of maize greenchop improved with time until 34-36% DM, after which it declined, this being associated with changes in structural carbohydrates in the crop. Cows fed maize silage produced more milk and gained less weight than cows fed both greenchop diets. In a concurrent field trial, cows grazed irrigated perennial pastures in late summer and were offered 7-8 kg DM/day of the silage or greenchop. Additional cows were allocated extra pasture with no supplement. Treatment differences in milk production and liveweight change were not significant. There were differences in rumen metabolism between diets in both pen-fed and grazed cows; rumen ammonia levels increased during the day in cows fed maize silage, but they decreased or remained constant when maize greenchop was fed. There was more maize grain in greenchop at physiological maturity than in silage, and this could have contributed to observed differences in performance and rumen metabolism. The low rumen ammonia levels, and the fact that forage maize was higher in energy than the pasture on offer, suggest that milk response would have improved with the inclusion of a rumen-degradable nitrogen source such as urea with the forage maize supplements.
Effect of ensilation of lucerne on voluntary intake, digestibility, and eating and rumination behaviour in sheep
Authors: Etheridge MO , Stockdale CR , Cranwell PD
Published: March 2005

Twelve wether sheep were used in a 2 x 2 factorial experiment in which voluntary intake, diet digestibility, and eating and ruminating behaviour were compared when sheep were offered lucerne (Medicago sativa) as either wilted silage or hay. Chemical characteristics suggested that the lucerne silage was well fermented, and chemical compositions of the silage and hay were similar. Voluntary intakes were not significantly (P<0.05) different and were 1201 and 1220 g/day for silage and hay, respectively. Digestibilities of dry matter and organic matter were similar for both feeds, as were chewing behaviour and rumen physical function. Apparent crude protein digestibility was significantly (P<0.05) higher for silage than for hay (73.8 v. 70.3%). It was concluded that well-preserved lucerne silage has at least as high a feeding value as well-made lucerne hay.
Long-term patterns of seed softening in some annual pasture legumes in a low rainfall environment
Authors: Taylor GB , Ewing MA
Published: March 2005

Annual rates of seed softening were determined from 4 lines of burr medic (Medicago polymorpha), 1 barrel medic (M. truncatula), and 1 subterranean clover (Trifolium subterraneum) grown at Merredin in the 1 year. Measurements were also made on one of the lines of burr medic grown in 2 other environments, Gnowangerup and Eneabba, in the same year. Burrs were placed on the soil surface at Merredin and the numbers of residual hard seeds determined each year for up to 5 years in this one environment. Patterns of softening of seeds from the same seed populations were also determined in a laboratory oven with a diurnal temperature fluctuation of 60/15�C. In the field, the softening rates of the 5 medics grown at Merredin were similar, averaging 21% of the original seeds each year for the first 4 years. Seeds of the burr medic grown in a more favourable environment at Eneabba were much slower to soften (averaging 14%); hence, hardseededness in these medics was influenced more by the growing environment than by genotype. More than half of the seeds of subterranean clover softened in the field over the first summer, with declining annual proportions thereafter. There were clear differences between the clover and medics in both pattern and rate of seed softening. The lower seed-softening rate of medics than of subterranean clover was more favourable for ley systems involving frequent cropping, especially in low rainfall areas. Treatment of seeds at 60/15�C simulated field softening for subterranean clover well but produced misleading results for the medics.
Fertiliser responses of wheat sown into conventionally cultivated seedbeds and direct-drilled into previously uncultivated seedbeds
Authors: Dann PR , Fischer RA
Published: March 2005

In 4 consecutive years (1980-83) on a red earth near Yass, New South Wales, 9 fertilizer treatments were applied annually to wheat which was either sown into conventionally cultivated seedbeds or direct-drilled into previously uncultivated seedbeds sprayed with herbicide. Treatments comprised 1 unfertilized control, 4 levels of P and at a moderate rate of P, 2 levels of S and 2 of N. The same fertilizer treatments were applied to each plot throughout the 4 years. The response to P was substantial, with yield increases up to the maximum rate of 37 kg of P/hathinyear. Average grain yield over 4 years was 3.2 t/ha at 37 kg P/ha and 0.5 t/ha without P. With fertilizer and grain prices that applied over the 4 years, these responses were highly profitable. There was a response to N in 1983 only (18 kg of grain/kg N) and a small response to S in 3 of the years. Yields were 17% higher under direct drilling in 1980, probably because of grassy weeds in the conventional cultivation plots. In 1981 there was no difference between the 2 tillage treatments, and in 1982-83 yields averaged 15% less under direct drilling. Although the difference between the yield of direct-drilled and conventional cultivation treatments were relatively greater without or at low P than at the highest P level, this interaction was not statistically significant.
The efficacy of a range of sulfur dioxide generating pads against Botrytis cinerea infection and on out-turn quality of Calmeria table grapes.
Authors: Mustonen HM
Published: March 2005

A postharvest storage trial was undertaken to test the efficacy of 3 brands of dual-release sulfur dioxide (SO2) generating pads against Botrytis cinerea in stored table grapes (Vitis vinifera cv. Calmeria) and to determine if there were any detrimental effects (bleaching, SO2 residues) of the pads on table grape quality. The UVAGAS and UVAS Quality Grape Guard pads slowed decay development and the spread of botrytis rot, prevented naturally occurring infections, and retained stem freshness better than the SYS pad which is commonly used in the Swan Hill area. A properly working SO2 pad placed in the top of a 10-kg box was sufficient to control botrytis rot in table grapes even when moderate levels of initial inoculum were present. The results indicate that increased SO2 residues in fruit and bleaching of berries over time are more likely with increasing damage caused by B. cinerea. After 10 weeks, both inoculated and non-inoculated grapes stored with UVAGAS or UVAS pads were in sound and commercially acceptable condition. In contrast, SYS SO2 pads did not provide acceptable control of B. cinerea in Calmeria grapes.
The effect of excluding insect pollinators on seediness of Imperial mandarin fruits
Authors: Sykes SR , Possingham JV
Published: March 2005

The effect of caging trees to exclude insect visitors on the fruit density, seediness, and quality of Imperial mandarin in north-western Victoria was investigated during 1990-91.The major effect of caging was a reduction in fruit seediness, with open trees having 5-16% of fruit seedless and caged trees 80-95%. The number of seeds per fruit ranged from 0-18 and 0-5 for open and caged trees, respectively. Caging trees had no effect on mean fruit density, mean fruit weight, fruit juiciness, soluble solids and percentage citric acid. These results provided further evidence for parthenocarpic fruit development by Imperial mandarin.
Productivity of Hereford, highgrade Simmental and Belmont Red beef herds in central Queensland. 2. Liveweight of the breeding herd and progeny up to weaning
Authors: Tierney TJ , Rudder TH , Webber RJ , Burns BM , Knights PT , Howitt CJ
Published: March 2005

Liveweights of Hereford, highgrade Simmental and Belmont Red calves and cows, between calving and weaning, were compared at Brigalow Research Station, Theodore, Queensland. These cattle grazed predominantly improved pastures growing on cleared brigalow country. Over the 4 calf crops, highgrade Simmental calves were heavier (P<0.05) at birth, 50, 126 and 205 (weaning) days of age (41, 83, 166, 220 kg, respectively) than Belmont Red (33, 72, 141, 191 kg) and Hereford (36, 71, 138, 184 kg) calves. Belmont Red calves were significantly heavier (P<0.05) than Hereford calves at 205 days but not at other ages, while Hereford calves were heavier (P<0.05) than Belmont Red at birth. The advantage to highgrade Simmental calves was greatest during above average seasonal conditions and under these conditions Hereford calves were similar to Belmont Red calves. Conversely, under adverse seasonal conditions Belmont Red calves were heavier than Hereford calves. The 4-year average May liveweight of highgrade Simmental cows (519 kg) was heavier (P<0.05) than Belmont Red (481 kg) which was heavier (P<0.05) than Hereford (465 kg). Highgrade Simrnental breeders were always heavier than Hereford and Belmont Red. While these differences varied according to year, highgrade Simmental were always at least 41 kg heavier than Hereford and 17 kg heavier than Belmont Red. Differences between Belmont Red and Hereford were small and not commercially significant during average to above average years, but favoured the Belmont Red by up to 30 kg following below average seasonal conditions. Production of weaner liveweight per breeder was 125, 132 and 155 kg for Hereford, highgrade Simmental and Belmont Red, respectively. These weights represented 27, 25 and 32 kg weaner production respectively per 100 kg breeder liveweight supported.
Effect of dry or hydrated bentonite on the wool growth and liveweight gain of sheep fed wheat chaff
Authors: Murray PJ , Winslow SG , Rowe JB
Published: March 2005

Many reports on the use of bentonite to increase wool growth indicate variable responses and it is often claimed that this variability is related to the chemical characteristics or the form in which the bentonite is fed. This paper describes 3 experiments in which there was consistency in the type and form of the clay. There was also comparison of the effects of dry and hydrated bentonite. In the first experiment, 64 sheep were individually penned and fed wheat chaff ad libitum. Thirty sheep were fed chaff only, 17 sheep received dry bentonite added to their chaff (20 g/kg chaff) and another 17 sheep had 23.7 g/day of bentonite added to their drinking water. Inclusion of bentonite in the drinking water significantly increased wool growth (P<0.05, 14.8%) and increased chaff intake (P = 0.08, 6%). In the second experiment, 105 sheep were penned in groups of 7 and each pen fed wheat chaff ad libitum. Five pens of sheep had dry bentonite added to their chaff (20 g/kg chaff) while another 5 pens had bentonite added to their drinking water (23.7 g/sheep.day). There were 5 pens of sheep which received no bentonite. Inclusion of bentonite either in the drinking water or in the chaff, significantly increased chaff intake (P<0.05, 6%), but had no effect on wool growth. In the third experiment, 60 sheep were divided into 12 groups and each group grazed individual 0.7 ha of cereal stubble. All groups were supplemented with the equivalent of 200 g of lupin grain/sheep.day fed twice weekly and 6 of the groups were watered by buckets containing hydrated bentonite (11.8 g bentonite/L). In experiments 2 and 3, inclusion of bentonite in the diet or in the drinking water had no effect on wool growth (P>0.05) but liveweight gain was significantly increased (P<0.05). It was concluded that the variability in the response to bentonite was not related to its chemical composition or the form in which it is administered and that, on balance, bentonite does not offer a practical or reliable means of increasing wool growth in sheep.
Use of oxytocin to measure milk output in Merino ewes and its effect on fat content
Authors: Bencini R , Martin GB , Purvis IW , Hartmann PE
Published: March 2005

We examined the influence of the dose of oxytocin i n measurement of milk production in Merino ewes and its effect on fat content. Eight ewes were milked after an intra-venous injection of 2.0 International Units (I.U.) of oxytocin, then milked again after a further intra-venous injection of 0, 0.5, 1.0 and 5.0 I.U. of oxytocin, with the treatments allocated to a double Latin square design. The milk yielded at each treatment was recorded and samples of the milk were analysed for fat content. All oxytocin treatments significantly increased the amount of milk extracted (P<0.01), but did not affect the fat content of the milk. The dose-response curve showed a plateau at the 1 I.U. level. It was therefore concluded that 1 I.U. is the most suitable dose for measuring milk output in Merino ewes and that, within the range of doses tested, oxytocin does not affect the fat content of the milk withdrawn.
The effects of sowing time, sowing technique and grazing on tall fescue (Festuca arundinacea Schreb.) establishment
Authors: Charles GW , Blair GJ , Andrews AC
Published: March 2005

The effects of sowing time (autumn and spring) and technique (conventional cultivation, inverted T direct drill, triple disc direct drill and aerial seeding), on the establishment of tall fescue into a weed infested pasture on the Northern Tablelands of New South Wales were examined. A pre-sowing herbicide treatment was included in the 2 direct drilling treatments, and heavy pre-sowing grazing was used in the autumn sowing. The design used 38 plots of 0.12 ha, analysed as 2 separate, complete block experiments, with some common treatments. Tall fescue establishment, 120 days after the autumn sowing, averaged 48 seedlingslm2 on the inverted T treatment (16% establishment). Establishment was improved by 63%, to 78 seedlings/m2, with herbicide and 46%, to 70 seedlings/m2, by heavy grazing. These effects were additive, giving 105 seedlings/m2 for the combined treatments. Only 52 seedlings/m2 established on the triple disc treatment with heavy grazing and herbicide, while establishment on the cultivated seedbed was not different from the inverted T (93 seedlings/m2). There was no establishment after the aerial seeding at either sowing. Fescue establishment showed the same trends in the spring sowing, with 140 seedlings/m2 on the inverted T treatment with pre-sowing herbicide, which was higher than the establishment of 107 seedlings/m2 on the cultivated seedbed. The fescue yield, 18 months after the autumn sowing, was highest in the autumn sown, inverted T treatment with pre-sowing herbicide and heavy grazing (123 kg/ha). In the spring sowing, fescue was recorded only on the cultivated treatment (84 kg/ha) and on the inverted T treatment with pre-sowing herbicide (39 kg/ha). These results show that tall fescue can be re-established into weed dominated pastures on the Northern Tablelands with direct drilling, in either autumn or spring, and that heavy, pre-sowing grazing and herbicide increase fescue establishment.
Forage production from hedges of tagasaste in a high rainfall temperate environment, and the effects of plant spacing and frequency of harvesting
Authors: McGowan AA , Mathews GL
Published: March 2005

The effect of spacing between plants (1,2 and 4 plants/m) and frequency of harvesting (2,3 and 4 times/year) on the production of tagasaste grown in hedges, was measured for 4 years following establishment. In the first 2 years, yield per metre of hedge increased with reduced spacing between plants; in the third and fourth years, however, there was little difference in the yields of the 2 closest plantings which still out-yielded the sparsest planting (1 plant/m). Total annual yields of both dry matter and 'edible' dry matter were greatest with only 2 harvests per year, but there was very little difference between yields from 3 or 4 harvests per year. With a spacing of 4 plants/m and 2 harvests per year, total annual dry matter yields of over 4.5 kg/m of hedge were achieved in the third and fourth years after establishment. Approximately 66% of the forage harvested was considered edible with this level of production. Pasture production adjacent to the hedges was generally unaffected by the tagasaste hedges. The protein content, digestibility and production of the tagasaste warrants further testing of its performance in larger scale plantations, rather than in isolated hedges.
Fusarium oxysporum associated with wilt and root rot of tomato in Queensland; races and vegetative compatibility groups
Authors: Ramsey MD , O'Brien RG , Pegg KG
Published: March 2005

Twenty-two isolates of Fusarium oxysporum, from Queensland's major tomato growing areas, were studied in glasshouse pathogenicity tests and assessed for vegetative compatibility. Isolates of Fusarium oxysporum f. sp. lycopersici were identified to race using pathogenicity tests with 4 differential tomato cultivars: Grosse Lisse, Scorpio, moradade and Delta Tristar. The occurrence of race 3 in the Bundaberg district in 1988 was established. In glasshouse experiments, Fusarium wilt severity was influenced by inoculum concentration (1 x 106 v. 5 x 106 conidia/ml). Pathogenic and non-pathogenic isolates were distinguished by vegetative compatibility group analysis. However, all races were in a single vegetative compatibility group and could not be differentiated using this technique. Isolates collected from discoloured vascular tissue in the lower stems of plants with severe root rot (Pythium spp. associated), were non-pathogenic to tomato, bean and pea, although some isolates caused slight damage to cucumber. These isolates were distinctly different from Fusarium oxysporum f. sp. radicis-lycopersici, the cause of root and crown rot.
Growth and carcass characteristics of three-way Africander multiply Simmental multiply Hereford crossbreds in south-western Queensland
Authors: Cavaye JM , Knight JL , Tierney TJ , Kelly AM
Published: March 2005

Liveweight and carcass traits of 3-way Africander (A) x Simmental (S) x Hereford (H) crossbreds and purebred Herefords were monitored predominately on native pastures at Dirranbandi, Queensland, for 2 calf crops over 6 years. The relative breed compositions of the crossbreds were A4S2H2, A4S 1 H3 and A4H4. The mean liveweight of the A4S2H2 cattle ranked highest from about 250 days post-weaning to slaughter (520 days post-weaning) for steers, and at first joining for heifers (560 days post-weaning). Differences in liveweight were not significant at all times. The A4S2H2 and A4SlH3 steers had the highest (P<0.05) post-weaning average daily gains. Differences in weaning weight between crossbreds were carried through to slaughter for steers and to joining for heifers. The A4S2H2 steers had the highest (P<0.05) mean final liveweight (433 kg) and mean carcass weight (232 kg). There was no difference in carcass weight between the other crossbreds and Herefords. Fat depth at the P8 rump site of A4H4 crossbreds (8.5 mm) was higher (P<0.05) than that of Herefords (5.5 mm) and other crossbreds. Dressing percentages were similar for all breed types. The A4S2H2 maiden heifers had higher (P<0.05) liveweights at first joining (369 kg) than the A4S1H3 (353 kg) and A4H4 (337 kg) heifers. These data show that beef producers in southwestern Queensland can increase carcass weights with A4S2H2 crossbreds and produce carcasses that primarily meet the Korean-EC market and the requirements of domestic supermarket outlets.
Seasonal growth and carcass characteristics of grazing steers implanted with trenbolone acetate and oestradiol
Authors: Tudor GD , James T , Hunter RA
Published: March 2005

Measurements were made of the effects of Revalor on the seasonal growth, carcass weight and fatness of Zebu crossbred steers in central Queensland. Ninety-three steers were grazed on improved pastures for 15 months prior to slaughter. Half the animals were implanted with Revalor (140 mg trenbolone acetate plus 28 mg oestradiol-17B mixed with cholesterol) for the first 25 weeks (September-March) and the balance left as controls. During this period, treated steers gained weight significantly (P<0.001) faster than untreated steers (0.57 v. 0.42 kg/day). In March, the 2 groups were further divided into 2 subgroups and 1 subgroup from each group was either implanted for the first time or reimplanted with Revalor. The animals implanted in March were reimplanted again 4 months later. The other subgroups were not implanted. After implantation in March, steers implanted for the first time gained weight significantly (P<0.001) faster (1.27 kg/day) than all other treatment groups. Steers implanted at the beginning of the experiment in September, but not reimplanted in March, continued to gain significantly (P<0.05) faster in the period March-May than steers which had never been implanted (1.01 v. 0.85 kg/day). This suggests that the implant was still having an anabolic action at least 6 months after implantation. The experiment ended with the slaughter of the steers in December. Animals treated with Revalor at some time during the experiment were significantly (P<0.05) heavier at slaughter (about 22 kg) and had significantly (P<0.001) heavier carcasses (about 13 kg) than those left untreated. Steers implanted throughout the experiment and those implanted for the 9 months before slaughter had significantly (P<0.001) less subcutaneous fat at the P8 rump site than those either not treated or implanted earlier than 9 months prior to slaughter.
Monitoring the toxicity of lupin (Lupinus angustifolius) stubbles has limited value in the prevention of lupinosis
Authors: Morcombe PW , Allen JG , Hancock GR , Jacob RH , Hopkins DL
Published: March 2005

Lupin (Lupinus angustifolius) stubbles at 3 'sentinel' sites in the Midlands Region of Western Australia were monitored throughout the summer of 1985-86 to assess the level of infection of the stems by the fungus Phomopsis leptostromiformis, and to measure the concentration of its toxic product, phomopsin A. These parameters were found to have little value as predictors of fungal infection and of the toxicity of lupin stubbles on farms in surrounding districts. It was found also that visual rating of the level of P. leptostromiforrnis infection of lupin stems was unrelated to the concentration of phomopsin A in those stems or to the liver damage in sheep grazing stubble from which the stems were sampled. It is suggested that these ratings should not be used to advise farmers on the 'lupinosis risk' of a lupin stubble. Monitoring the phomopsin A concentration in lupin stems collected throughout a summer confirmed that rain, associated with cloudy days, was the primary environmental stimulus to a significant increase in the phomopsin A concentration.
Early sowing with wheat cultivars of suitable maturity increases grain yield of spring wheat in a short season environment
Authors: Kerr NJ , Siddique KHM , Delane RJ
Published: March 2005

Eleven field trials were sown in the northeastern wheatbelt of Western Australia to test the hypothesis that if wheat cultivars with suitable maturity are sown earlier than current practice, then higher grain yields will be achieved. The experiments included time of sowing treatments that ranged from early May to late June in 1988, 1989 and 1990. Seven commercial cultivars with a wide range of developmental patterns and maturities were used. Sowing between mid May and early June produced the highest grain yields. For plantings after early June, yields declined by approximately 250 kg/ha (15%) per week. Delayed sowing caused a decrease in dry matter and kernel number (per m2). In general this reduction in kernel number was not compensated by an improvement in kernel weight. At early times of sowing, the medium-long season cultivars generally had higher yields than short season cultivars. The short season cultivars were the highest yielding cultivars at the late times of sowing. These results suggest that cultivars should be chosen to suit the seasonal break, which may vary from late April to mid June. As a consequence, farmers should be encouraged to retain a number of cultivars with differing maturities suited to a range of planting times.
Impact of genotype multiply environment interaction on response to selection in sugarcane
Authors: Bull JK , Hogarth DM , Basford KE
Published: March 2005

The impact of genotype x environment interaction on the response to 3 methods of selection in sugarcane was assessed over 3 locations and 3 cropyears. The 3 selection methods considered were 2 previously used procedures, mass (individual) selection using a visual appraisal of clonal performance and family selection using selection rate, and a new procedure, family selection using a net merit grade (NMG) derived from weighing family plots. Within the 2 forms of family selection, light mass selection based on a visual appraisal of clonal performance was used to reject the poorest clones. The gains from selection, cdculated as the deviation in performance of the select groups from the performance of a group of randomly chosen clones, were assessed for each of these 3 methods. All 3 selection methods gave similar gains over the random group when averaged over all locations and crop-years. Family selection based on NMG is recommended for routine use as it is the least labour-intensive and most cost-effective. Genotype x environment interaction, on both a family and clonal basis, was large enough to affect the gains made from selection. These effects provided some support for location-specific selection. Furthermore, selections based on the results from the central experiment station produced relatively poor gains when assessed over all locations and crop-years. This indicates that the experiment station may be a poor location for centralised selection. The use of at least 1 other location may provide a buffer against infrequent environmental factors rendering worthless family or clonal discrimination at any particular location.
Improving fruit size and packout of Late Valencia oranges with ethephon fruit-thinning sprays
Authors: Hutton RJ
Published: March 2005

This study set out to establish concentrations of ethephon sprays that could reliably thin alternate cropping orange trees in a heavy set year to improve fruit quality for fresh marketing. An optimum concentration of ethephon as a thinning agent was identified for the practical control of alternate cropping in Late Valencia oranges. A single, high volume spray of ethephon (as Ethrel, 42-60 mL/100 L water), applied in a heavy-set year at 6-8 weeks post bloom when fruitlet size was 10-15 mm diameter, induced a 15-20% reduction in fruit number. This resulted in significantly improved fruit size and marketable outturn with negligible yield penalty. In the 2 successive harvests following spray treatment, the cropping pattern remained uniform and a 14% improvement in packout (marketable fruit size <100 counts per carton) was maintained. Internal fruit quality was unaffected. Control of alternate bearing was carried forward for at least 2 seasons with relatively stable yields following a single spray treatment.
Effect of plant spacing on tea (Camellia sinensis L.) yield at Wollongbar, New South Wales
Authors: Trochoulias T , Dettmann EB
Published: March 2005

Tea yields were compared from single-row plots (2 m apart, 63-cm spacing within rows) and double-row plots planted at 2 different row spacings (2 m between row centres, rows 90 cm apart, plant spacing of 83 or 56 cm within rows), giving plant densities of 8 000, 12 000 and 18 000 bushes/ha. Over a 6-year period total dry weight yields from double-row plots (10.70 t/ha) were significantly higher than from single-row plots (8.21 t/ha), but there was no significant difference between yields from double-row plots with different within-row spacing.
Dryland mediterranean farming systems in Australia
Authors: Rovira AD
Published: March 2005

The mediterranean region of Australia extends from Geraldton in Western Australia across southern Australia into western and northern Victoria. This region experiences hot, dry summers and cool, wet winters, with 300-600 mm annual rainfall. In the dryland farming zone, the cereal-livestock farming system dominates and produces 30-35% of Australia's total agricultural production. The major soils in the region are deep, coarse-textured sands and sandy loams, duplex soils with coarse-textured sands over clay (generally low in nutrients and organic matter), and fine-textured red-brown earths of low hydraulic conductivity. Major soil problems in the region include sodicity, salinity, soil structural degradation, nutrient deficiencies, boron toxicity, acidity, waterlogging, inadequate nitrogen nutrition, water-repellence, and root diseases. These problems have been exacerbated by excessive clearing of trees, increased frequency of cropping, reduced area sown to pastures, declining pasture production, and a decline in nutrient levels. With improved soil management there is potential for increased productivity from dryland farming areas of the region and improved ecological sustainability.
Physical and chemical characteristics of duplex soils and their distribution in the south-west of Western Australia
Authors: Tennant D , Scholz G , Dixon J , Purdie B
Published: March 2005

Duplex soils are widespread in Western Australia and occupy about 60% of the south-west agricultural area. The physical and chemical properties of these soils reflect their origin as erosional surfaces of old laterite profiles and the predominance of underlying, quartz-rich, granitic materials. The resulting combination of high contents of quartz sand, kaolin clay, and iron and aluminium oxides has important consequences on water-holding capacity, fertility, nutrient leaching, phosphate fixation, anion and cation exchange capacity, and buffering capacity. These soils are generally held to have a number of physical and chemical problems. Among these, low fertility and low permeability of the clay B horizon have greatest effect. While data on the chemical properties of these soils are limited, significant data sets on the physical properties of duplex soils are available from several studies of catchment hydrology. These studies reflect concern with runoff, waterlogging, and the development of secondary salinisation. Depth to clay varies from 5 to >100 cm. The shallower depths (10-40 cm) predominate and, in medium and high rainfall areas, combine with low permeability in the clay to result in widespread waterlogging. Commonly, the sand surface can be hardsetting and can have high strength from structural decline, from the presence of cementing agents, and from traffic effects. Sodicity is widespread and has effects on hardsetting in the A horizon and on permeability of the B horizon. Management strategies are available to treat some of these problems, but generally, much has yet to be done to develop sustainable agricultural systems on these soils.
Management of excess water in duplex soils
Authors: McFarlane DJ , Cox JW
Published: March 2005

Excess water in duplex soils can be removed by drains. In soils in which drainage is impractical, some success has been obtained by deep ripping and by gypsum amendment. These practices can increase profile storage or drainage. Interceptor drains are suitable for duplex soils with slopes of more than about 1.5%. On more gentle slopes, relief drains are used to remove excess water. Subsurface tube and mole drains have been used successfully to drain cereal crops in Victoria, but in Western Australia open drains are preferred because they can carry storm runoff as well as seepage waters. The greatest cost of open drains is the land removed from production. Over 35% of the rain falling during the growing season has been removed by drains in Victoria and Western Australia in wet years. Drainage was almost entirely downslope of monitored interceptor drains in Western Australia, which is not predicted from the theory. Simulation of water levels between drains and of drain flows using the DRAINMOD model indicated significant, preferred pathways for water flow to drains. The pathways explain the predominantly downslope effect of interceptor drains and the wide drain spacings which can be used. Deep ripping and the incorporation of gypsum can reduce waterlogging in some soils, but has had no effect in several others. The effect of deep ripping on recharge is unclear. Drains may decrease groundwater recharge, water and wind erosion, and soil structure decline. Their effect on phosphate export from catchments is unclear.
Yield responses of wheat and other crops to agronomic practices on duplex soils compared with other soils in Western Australia
Authors: Anderson WK , French RJ , Seymour M
Published: March 2005

A survey of experimental results relating crop management to grain yield was conducted for wheat and other crops on duplex and non-duplex soils in the wheatbelt of Western Australia. Increases in grain yield of wheat due to improved agronomic practices on duplex soils were almost as great as on other soils. Early sowing improved yield more on duplex soils than on other soils, but the response to applied nitrogen was more variable, possibly related to the reduced efficiency of uptake of applied nitrogen. The yield advantage for a semi-dwarf cultivar (Aroona) over a tall cultivar (Garnenya) was less (6%) on duplex soils than on other soils (29%). The optimum seed rate was 27% greater on duplex than on other soils. Increases in both grain yield and grain quality due to the application of potassium were large on 1 duplex soil. Water use efficiency in grain production was similar on duplex and other soils where seasonal water use did not exceed about 350 mm. At 1 location in the eastern wheatbelt, yields of wheat, barley, lupins and peas grown on a duplex soil were compared with yields on 2 other soils. Wheat was the most productive crop on the duplex soil, while barley yielded most on the other soils. All crops, except lupins, yielded less on the duplex soil. Experiments with 2 lupin cultivars grown on duplex and other soils on the south coast of Western Australia (average growing season rainfall >300 mm) showed that both cultivars yielded less on duplex soils, but 1 cultivar required slightly fewer plants to achieve its maximum yield on the duplex soils. This survey of experimental results in Western Australia shows that duplex soils are no less productive than other soils when results are averaged over all crops and locations. We conclude, however, that different management practices may be required to improve yields on duplex compared with other soils.
The importance of seed manganese content for the growth of narrow-leafed lupins in manganese-deficient conditions
Authors: Crosbie JA , Longnecker NE , Robson AD
Published: March 2005

No abstract available.
Rates of acidification of two soil types in the central wheatbelt of Western Australia
Authors: Dolling P
Published: March 2005

No abstract available.
Variability of surface runoff and seepage on a hillside duplex soil
Authors: Bligh KJ , Laing IAF , Hauck EJ , Prince JA , Ortiz HA
Published: March 2005

No abstract available.
Evaporation and transpiration components of evapotranspiration from early and late sown wheat and lupins on a duplex soil
Authors: Eastham J , Gregory PJ , Williamson D , Watson GD
Published: March 2005

No abstract available.
Productivity, persistence and response to moisture regimes of a tropical grass and lucerne on a solidic soil
Authors: Tow PG
Published: March 2005

No abstract available.
The establishment of field peas into cereal stubbles for soil erosion control on duplex soils
Authors: Russell J
Published: March 2005

No abstract available.
Nitrogen accumulation and remobilisation in wheat of 15N-urea applied to a duplex soil at seeding
Authors: Palta JA , Fillery IR
Published: March 2005

No abstract available.
Structural problems on duplex soils
Authors: Cochrane HR , Aylmore LAG
Published: March 2005

No abstract available.
Utilising the Western Australian soil profile database for research and land management
Authors: Peluso E
Published: March 2005

No abstract available.
Wynn cassia (Cassia rotundifolia cv. Wynn) improves the feed intake and liveweight gain of cattle fed poor quality native pasture
Authors: Quirk MF , Wilson RJ , Blight GW
Published: March 2005

The feeding value for cattle of Wynn cassia hay (Cassia rotundifolia cv. Wynn) was assessed by measurement of dry matter intake (DMI) and average liveweight daily gain (ADG) of yearling steers fed chaffed diets of native pasture hay (0.44% N) that included 0, 10, 25, 50, or 80% of cassia hay. The cassia hay was obtained after seed harvest and, so, was of relatively poor quality (1.10% N, 70% stem). For comparison, lucerne hay (Medicago sativa cv. Trifecta) (2.42% N) treatments were also fed with native pasture hay at the same dietary legume proportions. The experiment was conducted over an 80-day period. Cattle fed only native pasture had low DMI (2.9 kg/head.day) and ADG (0.012 kg/head). DMI increased curvilinearly and ADG increased linearly with the proportion of cassia in the diet. Both DMI and ADG were significantly (P<0.05) increased when 50% cassia was fed (to 5.24 kg/head.day and 0.210 kg/head, respectively), while only 25% lucerne was needed to obtain significant increases in both parameters (to 5.69 kg/head.day and 0.310 kg/head). The poorer response to increasing dietary legume measured with cassia diets was not unexpected given that it had been cut at a more mature stage of growth. However, when the responses were examined against a common index of feed quality (protein content), both legume hays gave similar responses. Despite its relatively poor quality, the cassia hay was readily eaten at levels up to 50% of the diet, and improved both DMI and ADG. Our results suggest that cassia successfully introduced into native pasture will improve the liveweight performance of grazing cattle.
Management of highly fecund ewe types and their lambs for 8-monthly lambing. 2. Effect of weaning age and sex on lamb growth and carcass traits
Authors: Fogarty NM , Hall DG , Atkinson WR
Published: March 2005

The effect of weaning at ages ranging from 6 to 13 weeks on growth of lambs from Booroola Merino x Poll Dorset (BD), Trangie Fertility Merino x Poll Dorset (TD), and Border Leicester x Merino (BLM) ewes was examined over 2 years as a component of management in an 8-monthly lambing system. Skin weight and carcass traits were also analysed. In the first year, there was a significant (P<0.01) difference between growth rates to 3 months of age of lambs weaned at 12, 9, and 6 weeks (222.5 � 4.4, 204.8 � 4.4, and 180.0 � 4.6 g/day, respectively). In the second year, lambs were weaned at weekly intervals from 6 to 13 weeks of age, and growth rates were higher because of better seasonal conditions. Using regression coefficients, lambs weaned at 12 and 9 weeks were estimated to have higher (P<0.01) growth rates by 17 and 8%, respectively, than lambs weaned at 6 weeks. There was no difference between lambs weaned at 6 and 9 weeks for liveweight at 5 months, but those weaned at 12 weeks were 5% heavier (P<0.01). Postweaning mortality was higher amongst early-weaned lambs. Progeny from TD and BLM ewes had 7% higher growth rates and liveweights than those from BD ewes (P<0.01). Male lambs (rams and wethers) grew faster (P<0.01) than ewes, and in the second year there was a 5% liveweight advantage of rams over wethers (P<0.01). Weaning age had no effect on any carcass trait. Carcass weight accounted for most variation in carcass traits, and its inclusion in the model removed the effect of type of rearing. There was a significant (P<0.01) crossbred type x carcass weight interaction for fat depth at the C site, due to progeny of BLM ewes being fatter than the other crossbred types at heavier carcass weights. The regression coefficients for fat depth at the C site on carcass weight were 0.39 � 0.05, 0.31 � 0.04, and 0.60 � 0.05 mm/kg for BD, TD, and BLM progeny. Carcasses of rams were leaner than those of wethers, which were leaner than those of ewes (P<0.01). There was no advantage from early weaning in management for an monthly lamb production system because lamb growth and survival were depressed.
Persistence and tolerance to soil acidity of phalaris and cocksfoot in north-eastern Victoria
Authors: Ridley AM , Windsor SM
Published: March 2005

Persistence of Phalaris aquatica L. cv. Sirosa (phalaris) and Dactylis glomerata cv. Porto (cocksfoot) was evaluated for 5 pH treatments at 2 field sites on acidic soils. At one site (Beechworth) the soil was strongly acidic [pH(CaCl2) 14.21 to depth (80 cm) and contained concentrations of CaCl2-extractable aluminium (Al) >11 �g/g. At the other site (Lake Rowan) the soil pH (0-10 cm) was 5.0 and A1 concentrations were 4 �g/g. At Beechworth, lime incorporated at 5.5 t/ha improved establishment of phalaris but plant density declined, and by 30 months after sowing, phalaris plant densities were similar to treatments receiving no lime. Establishment of cocksfoot was less affected by lime application than phalaris, and plant densities were similar to those of phalaris by 26 months after sowing. However, there were no differences between pasture species where no lime was applied. Considerable re-establishment of cocksfoot seedlings occurred regardless of soil treatment. Despite the reported relative sensitivity of phalaris to Al in solution culture experiments, at Beechworth phalaris had more root development at depth than cocksfoot or annual pasture. Although concentrations of Al in the subsoil were high, the perennial deep root system of phalaris may give it an advantage over cocksfoot in terms of survival over summer. A larger root system at depth may give phalaris greater potential than cocksfoot for reducing nitrate leaching and soil acidification. On less acidic soils at the Lake Rowan site, lime application did not affect establishment of either phalaris or cocksfoot. Phalaris had greater persistence than cocksfoot at Lake Rowan. Dry summer conditions at Lake Rowan were the likely cause of poor persistence of cocksfoot. More drought-tolerant cocksfoot cultivars are required if this species is to be a useful perennial grass for pastures in ley cropping areas of Victoria and southern New South Wales.