bluuebunny/crossref_metadata_2025 huggingface dataset:
Yield and persistence of irrigated lucernes cut at different frequencies, at Tamworth, New South Wales.
Authors: Lodge GM
Published: March 2005

Three irrigated lucerne cultivars, Pioneer Brand 545 (winter dormant), Condura 73 Brand (semiwinter dormant), and CUF 101 (highly winter active), were harvested at fixed cutting intervals of either 25, 28 ,35, 42 or 48 days from September to April in each of four years. This paper reports the effects of these cutting frequencies on the dry matter yield, leaf to stem ratio and persistence of these cultivars. The effect of cutting frequency on mean total yield (the sum of the mean yields for each harvest) was significant (P<0.05) in each year of the experiment, except year 3. Yields were highest in the 35-day cutting frequency in years 1 and 2. In the fourth year of the experiment the mean total yield of Pioneer Brand 545 and Condura 73 Brand was 29% higher (P<0.05) than CUF 101. By the fourth year substantial amounts of grass were present in the 25- and 28-day cutting interval plots. The contrasts between dormant and active cultivars for the dry matter yield of each of the individual harvests were not consistent in the first two years. In the third and fourth years the active initially outyielded the dormant cultivars at all cutting intervals, but yields of both were generally similar at the end of the season. Increasing the interval between successive harvests generally decreased the mean leaf to stem ratio. The ratio of leaf to stem for CUF 101 was significantly lower (P<0.05) than that for Pioneer Brand 545, with Condura 73 Brand tending to be intermediate. Within cutting intervals, mean declines in plant persistence were similar for cultivars from the different dormancy groups. Largest changes in plant frequency occurred in the fourth year when the mean frequency for the 25- and 28-day plots decreased from 69 to 12% compared with a mean decline from 74 to 65% for the 42- and 48-day cutting intervals. Productive stand life in this experiment was 3 years, even though disease was negligible. Under these conditions grass invasion was mainly related to harvest interval and much less to cultivar dormancy.
Salt tolerance of some tropical pasture legumes with potential adaptation to cracking clay soils.
Authors: Keating BA , Strickland RW , Fisher MJ
Published: March 2005

Cracking clay soils or vertisols occur in large areas of the subhumid regions of north-eastern Australia and frequently contain appreciable levels of salt in their subsoils. The comparative salt tolerance of some tropical pasture legumes was studied in pots with NaCl added to a clay soil to achieve electrical conductivities (saturated extract, ECe) over the range 2.0- 20.0 dS m-1. Tolerance, based on EC, at 50% of maximum growth (in parentheses) was in the order: Macroptilium atropurpureum cv. Siratro (10.6)> Macroptilium lathyroides cv. Murray (9.9) > Vigna trilobata (9.7) > Indigofera spicata (9.5) > Desmanthus subulatus (9.3) > Arachis pintoi (7.9) > Clitoria ternatea (6.4) > Stylosanthes scabra (5.6) > Indigofera schimperi (5.4) > Psoralea tenax (5.3) > Rhynchosia minima (5.1). The grass Panicum coloratum cv. Bambatsi was markedly more tolerant than any of the legumes studied, with 50% yield at an EC, of 16.4 dS m-1. Patterns of Na+ and Cl- uptake with increasing level of salt differed between species, but were not related to the degree oftolerance observed. The results are discussed in terms of the reported salinity tolerance of legumes generally and their implications to the search for persistent legumes for clay soils.
Effect of water content of soil at tillage on size-distribution of aggregates and infiltration.
Authors: Tisdall JM , Adem HH
Published: March 2005

In beds of a silty soil in northern Victoria, the wetter the soil (up to a water content of 24 g/100 g soil) when tilled, the less dust (i.e. particles (0.5 mm diameter) and the more clods (particles >20 mm diameter) were formed. Almost no water infiltrated into the beds tilled at a water content of 24% (w/w). In the remaining beds, tilled at water contents ranging from 11 to 22%, infiltration from water confined to 8 cm depth in the furrow was inversely related to the percentage of dust (r2 = 0.57, P< 0.01), and directly related percentage of clods >20 mm diameter (r2 = 0.42, P< 0.01).
Effect of type of seedbed, type of irrigation, and of a mulch on seedling emergence, growth and yield of maize (Zea mays).
Authors: Tisdall JM , Adem HH
Published: March 2005

A field experiment is described where maize was grown on flat bays or raised beds of Lemnos loam, with or without a mulch, and irrigated by flood, spinklers or furrows. Mulched beds irrigated by furrow dried more slowly after irrigation than did unmulched soils or soils irrigated with sprinklers. Sprinklers hastened emergence and increased plant height and yield, when compared with irrigation by capillarity from shallow water in furrows. Also, with unmulched treatments irrigated by sprinklers, the yield was higher with raised beds than with a flat bay.
Screening for resistance to powdery scab disease of potatoes.
Authors: Kirkham RP
Published: March 2005

Powdery scab disease of potatoes, caused by the fungus Spongospora subterranea, has developed as an important disease of potatoes in Victoria because of changes in agronomic practices, such as increased supplementary irrigation, earlier planting and increased use of the highly susceptible cultivar Kennebec. Different reactions to the disease between potato cultivars and breeding lines were found in trials on a commercial potato property and at a trial site inoculated with the causal organism. In the commercial field trial 96% of tubers of the cultivar Nooksack had no powdery scab compared with 1% of scab-free tubers for Kennebec. Of the 24 potato lines tested in the inoculated trial, two had more than half of their produce free of scab while Kennebec had 1.6% of produce in the scab-free category. Kennebec, the cultivar most commonly grown in Victoria, was the most susceptible cultivar tested in the inoculated trial. Results from these trials show the potential for selecting potato lines that are resistant to S. subterranea.
Effect of cincturing on growth and flowering of lychee: preliminary observations in subtropical Queensland.
Authors: Menzel CM , Paxton BF
Published: March 2005

The effect of cincturing on growth and flowering of three lychee (Litchi chinensis) cultivars (Bengal, Brewster and Tai So) was investigated at four sites in subtropical southern Queensland. Cultivars at these sites displayed a range in the level of natural vegetative dormancy in winter (38-95% of terminal branches) and flowering in spring (25-100% of terminal branches). There was an inverse relation (r= 0.093; P< 0.005) between the flowering response to cincturing and potential flowering as indicated by the flowering of the control trees; cincturing reduced flowering in those trees that would otherwise have flowered profusely in spring (70-100%). This occurred when the cincture healed prematurely to allow vegetative flushing in winter. Since these preliminary results suggest that some loss of yield may occur in years and cultivars with good flowering, further work is required before cincturing can be recommended as a standard horticultural practice in lychee cultivation.
Perennial pasture production after irrigation with saline ground water in the Goulburn Valley, Victoria
Authors: Mehanni AH , Repsys AP
Published: March 2005

Irrigation water with nominal salinities of 100,300,700,1500 or 3000 mg/litre and superimposed yearly gypsum treatment (5 t/ha) were applied for 2 years on established white clover, ryegrass and paspalum pasture grown on a red-brown earth soil type, and for another 6 years after the pasture was sod-seeded with strawberry clover. Initially pasture dry matter production was reduced at all salinities above the control, predominantly because of a decline in white clover growth. However, after strawberry clover was added to the sward, pasture yield was not significantly affected by water with salinities up to 700 mg/litre in any one year and only reduced by about 25 and 50% at 1500 and 3000 mg/litre respectively. Soil salinities had largely reached equilibrium after 4 years and relative pasture yields remained relatively stable from then to the end of the experiment and it is not expected to change greatly in the longer term. Pasture mineral composition was within the recommended range for animal diet requirements.
Establishing surface-sown pastures in a Poa labillardieri-Themeda australis association
Authors: Campbell MH , Keys MJ , Murison RD , Dellow JJ
Published: March 2005

The effects of time and rate of application of glyphosate, 2,2-DPA and tetrapion on Poa labillardieri and Themeda australis were measured in seven experiments carried out 55 km south of Braidwood, on the southern tablelands of New South Wales between 1980 and 1982. In an eighth experiment (1981) and in a 35-ha demonstration (1983), at the same site, the effects of applying herbicides (before and after the autumn break) and surface-sowing Phalaris aquatica, Festuca arundinacea and Trifiolium repens with fertiliser on the control of P. labillardieri were ascertained. All three herbicides proved effective in reducing the ground cover of P. labillardieri from applications at any time of the year. For T. australis, tetrapion proved effective when applied at any time of the year, while glyphosate and 2,2-DPA were effective in all seasons except winter. Glyphosate at rates between 0.72 and 1.44 kg/ha a.i. was more cost effective than 2,2-DPA (11.1 kg/ha a.i.) and tetrapion (3.75 kg/ha a.i.). Best establishment and development of sown grasses and legumes was attained by applying herbicides after the autumn break but before heavy frosts, and then surface-sowing 1-3 months later. Control of P. labillardieri was best where P. aquatica and F. arundinacea established most densely.
Nitrogen availability in a Darling Downs soil following cereal, oilseed and grain legume crops. 1. Soil nitrogen accumulation
Authors: Strong WM , Harbison J , Nielsen RGH , Hall BD , Best EK
Published: March 2005

Available soil mineral nitrogen (N) was determined in a Darling Downs clay at intervals of 4-6 weeks throughout summer and autumn after harvest of two cereals (wheat and oats), two oilseeds (rapeseed and linseed), and four grain legumes (chickpea, fieldpea, lupin and lathyrus). Soil mineral N (0-1.2 m) at 40,68, 107, 150 and 185 days after harvest was affected (P < 0.05) by the prior crop. At 40 days it was generally higher following grain legumes (34-76 kg/ha N) than following oilseeds or cereals (16-30 kg/ha N). Net increase during the next 145 days was in the order of cereals (2 1-27 kg/ha N) < oilseeds (40 kg/ha N) <grain legumes (53-85 kg/ha N). These differences are partly accounted for by differences in the quantities of N removed in the grain of these crops. However, a large quantity of mineral N accumulated following lupin even though a large quantity (80 kg/ha) was removed in the grain.
A re-evaluation of chlormequat application to wheat in Western Australia
Authors: Perry MW , Miers DJ
Published: March 2005

The effect of chlormequat on the grain yield of wheat was investigated in 24 field experiments between 1981 and 1983. Two times of application (at the 3.5- and 6-leaf growth stages-Zadoks decimal score 13.5 and 16.0) and rates of application up to 0.75 kg/ha a.i. were tested with two chlormequat formulations, Cycocel 750 and Bettaquat. Chlormequat application reduced crop height in all trials, but crop lodging did not occur in any trial. Statistically significant yield responses to rate of application alone were obtained in only three of 24 trials, with maximum yield occurring at 0.19-0.37 kg/ha a.i. and with some indication of a yield depression at 0.75 kg/ha a.i. A significant effect of time of application was observed in only two trials, but the results conflicted. In one trial there was a significant interaction between rate and time, with a response to rate of chlormequat only at the 6-leaf stage. No differences were detected between chlormequat formulations. In individual trials, the mean grain yield from the chlormequat treatments ranged from 92.9 to 116.5% of the control. However, averaging over all trials in each year, chlormequat treatments yielded 102.5, 99.3 and 100.0% of the control, respectively, in the three years. Our results confirm that low application rates of chlormequat, applied early in crop development, can increase grain yield. However, over the 24 trials, the effects of chlormequat were too small and inconsistent to warrant its use to increase wheat grain yields under natural rainfall in south-western Australia.
Seasonal variation in the nutrient composition of the foliage of pecan (Carya illinoensis)
Authors: Cresswell GC , Wickson RJ
Published: March 2005

Leaves were sampled every 2 weeks throughout the 1980-81 and 1981-82 growing seasons from a commercial pecan orchard in New South Wales. Leaf concentrations of nitrogen, phosphorus and potassium were highest at leaf emergence and decreased with time. Concentrations of calcium, magnesium and boron were lowest early in the season and increased with time. There was no true seasonal pattern in leaf zinc which varied in apparent response to foliar zinc spray use. These trends were similar for the cultivars Witchita and Western Schley. Minimum seasonal variation in nitrogen, phosphorus, and potassium, the main fertiliser nutrients, occurred between 1 February and 21 March. This period is therefore the most suitable for general diagnostic purposes such as the evaluation of fertiliser programs and surveys of crop nutrient status.
Effect of dietary nutrient concentration on the performance of hens beginning lay in early summer
Authors: Pell AS , Polkinghorne RW
Published: March 2005

Hens of 2 laying strains were fed ad libitum from 20 to 72 weeks of age on 3 diets of different nutrient concentration. The start of lay coincided with the onset of the hot summer. During summer, birds on the diet with high nutrient concentration (HNC, 19% protein, 12.6 MJ metabolisable energy (ME)/kg) had significantly higher intakes of ME (3% higher) and other nutrients than did those on the diets of medium (MNC, 18% protein, 11.7 MJ ME/kg) and low (LNC, 16% protein, 11.4 MJ ME/kg) nutrient concentration. Egg weight. egg mass and feed efficiency were greater on the HNC diet than on the MNC and LNC diets. Birds on the HNC diet produced more eggs (10% more) than those on the LNC diet. Over the cooler periods, feed intakes were inversely related to energy level, with no dietary effects on egg production. It is concluded that grain- and meat meal-based diets of low nutrient concentrations are unlikely to support maximum performance in early lay in hot conditions and that increased dietary nutrient concentrations can improve performance via increased nutrient intake.
Herbivore diet in a semi-arid Eucalyptus populnea woodland. 1. Merino sheep
Authors: Harrington GN
Published: March 2005

The diet of sheep was recorded by direct observation in a shrub-dominated Eucalyptus populnea woodland between Nyngan and Bourke, N.S.W., on 7 occasions over a 2-year period. Different nutritional opportunities were provided by the effects of rainfall on 3 contrasting grazing treatments. The sheep did not graze equally over the whole area available but foraged selectively so that they encountered unacceptable plants rarely. In particular variable spear grass (Stipa variabilis) was avoided once the inflorescence had emerged and only extreme hunger pressured sheep into foraging in dead stands of this grass.matured, sheep ate firstly increasing quantities of perennial forbs and then mulga (Acacia aneura). When these foods were depleted, sheep subsisted on dead perennial grass, tree litter and broad leaf hopbush (Dodonaea vlscosa). All other shrub species were unacceptable. The ability of sheep to forage successfully during dry periods put excessive pressure on perennial grass, causing it to die out. I suggest this has contributed to the increased frequency of shrub establishment in the poplar box woodlands since they have been used for pastoral production.
Herbivore diet in a semi-arid Eucalyptus populnea woodland. 2. Feral goats
Authors: Harrington GN
Published: March 2005

The diet of feral goats was recorded by direct observation in a shrub-dominated Eucalyptus populnea woodland between Nyngan and Bourke, N.S.W., on 7 sampling occasions over 2 years. Different nutritional opportunities were provided by the effects of rainfall on 4 contrasting grazing treatments. The goats foraged evenly over the paddocks and encountered most foods with the same frequency as they occurred. With unlimited quantities of forage available the goats spent 63% of their time grazing and only 28% browsing. Most browsing took place under dry conditions when pasture quality was low. When forage was in short supply the goats accepted some shrubs not normally eaten, and these plants died; other woody plants were consumed erratically or not at all. Acacia aneura was the only woody plant which was both palatable and resilient to goat browsing. Goats mostly ate the same plant species as sheep and with the same preference, but tended to eat more browse and less forbs than sheep in dry times. The browse consumed was principally the same as consumed by sheep, demonstrating sequential competition for dry-season fodder. Goats demonstrated a potential for overgrazing in dry times, indicating that stocking rates must be adjusted at such times to avoid pastures becoming extinct.
Effect of different phosphatic fertilisers applied at sowing on the survival of inoculated Rhizobium trifolii and on the nodulation of clover
Authors: Jones HR
Published: March 2005

Dical-super, a new phosphatic fertiliser, had little or no effect on the survival of rhizobia when the fertiliser was mixed with inoculated seed of subterranean clover. Superphosphate reduced rhizobial survival when the inoculated seed was not protected by a seed coating of lime. When dical-super was sown in rows with inoculated clover seed into very acid soil (pH 4.6, 1:5, soil:water) additional lime (in the form of a lime coating on the seed) was needed to ensure good nodulation of the clover. When sown in a less acid soil (pH 5.3) no lime was needed. When superphosphate was the fertiliser applied at sowing, additional lime, as fertiliser and/or lime pelleting of the seed, was needed to obtain a high number of nodulated plants in the very acid soil. Lime pelleting only was needed in a less acid soil to obtain good crown nodulation.
Nutrition of irrigated crops on an alkaline brown clay soil at Trangie, New South Wales. 1. Lucerne
Authors: Muldoon DK
Published: March 2005

The elements nitrogen, phosphorus, potassium, sulfur and zinc were sequentially omitted from a 'complete' fertiliser applied to plots on an alkaline soil, and lucerne (Medicago sativa) was sown immediately afterwards. The dry matter production of lucerne was measured in repeated cuts over 2 years; its mineral composition was determined periodically. In a second experiment 4 rates of phosphorus were applied to a l -year-old stand of lucerne and dry matter production recorded for 1 year. Lucerne yields in the first year were reduced from 17-1 8 t/ha to less than 14 t/ha by omitting phosphorus. Yields universally decreased in the second year as the 50 kg/ha P applied at sowing was depleted through the removal of 40 kg/ha P in forage. Following this depletion a linear yield response up to 80 kg/ha P was found (experiment 2). Omitting phosphorus fertiliser reduced the plant phosphorus concentration from 0.23 to 0.21% when sampled 15 months after sowing. The plant phosphorus concentration decreased with time in all treatments. The available soil phosphorus level decreased from an initial 12 to 6-7 �g/g after 6 months and further to 2 �g/g after 30 months. Fertiliser phosphorus raised the soil phosphorus level but this also was depleted to 2-3 �g/g in 30 months. Omitting zinc reduced the plant zinc concentration. However, neither the omission of nitrogen, potassium, sulfur nor zinc from the fertiliser had any effect on lucerne yields.
Fungicide treatment of sunflower seed to inhibit germination of admixed sclerotia of Sclerotinia sclerotiorum
Authors: Kochman JK , Langdon PW
Published: March 2005

Sunflower seed lots infected with sclerotia of Sclerotinia sclerotiorum provide a means of dispersal of the fungus. To find a chemical control, sclerotia were dusted or dipped with 19 chemical formulations. Eight of these (benomyl 50%, benomyl 15% plus lindane 1%, thiabendazole wettable powder, thiabendazole 45% water-based flowable, iprodione 50%, dithianon 75%, omadine 50% and thiophanatemethyl 70%) completely inhibited germination of sclerotia when in direct contact with and covering the organism. Sclerotia were able to germinate if these chemicals were removed by washing, but germination was significantly lower for those sclerotia which had been treated with benomyl 50%, benomyl 15% plus lindane 1% (Bennel 13, thiabendazole 90% and 45%, iprodione 50% and thiophanate-methyl 70% than for dithianon 75% and omadine 50%. When sclerotia were buried in moist soil for 1 month those treated with formulations of benomyl, thiabendazole and iprodione did not germinate on potato dextrose agar, while the germination percentages of those treated with dithianon, ornadine and thiophanate-methyl were not significantly different from that for germination of sclerotia which had not been treated. When thiabendazole, benomyl and iprodione were used at 3 rates to treat sunflower seed infested with sclerotia, thiabendazole was the most effective fungicide in preventing germination of sclerotia. This result was confirmed when the fungicide was used commercially to treat lots of sunflower seed containing sclerotia. As thiabendazole had no apparent effect on gerrnination of sunflower seed it could be used to treat sunflower seed containing low levels of sclerotia to prevent previously uninfested areas being contaminated with S. sclerotlorum during sowing operations.
Effects of plant density and sowing date on grain yield of faba beans (Vicia faba L.) in northern New South Wales
Authors: Marcellos H , Constable GA
Published: March 2005

The effects of varying plant density and sowing date on grain yield of faba beans (Vicia faba L.) were determined in 6 experiments at Tamworth and Narrabri in northern New South Wales. The graph of grain yield rose to an asymptote as plant density was increased. Under conditions favouring high yields, a plant density of 20 m-2 gave near maximum grain yields, but for a wider range of circumstances a plant density of 30-35 m-2 was appropriate. If sowing was delayed after the end of April, grain yield was reduced as was dry matter yield and the duration of pod-filling. Late sowing also lowered the height of the first pod above ground, and increased the likelihood of yield loss through foliar disease.
Effect of sowing time on the once-over harvest yield of broccoli cultivars in north-west Tasmania
Authors: Chung B , Strickland HL
Published: March 2005

The effect of sowing times between November and May on the maturity and once-over harvest yield of broccoli (Brassica oleracea L. var. italica Plenck) was studied on the north-west coast of Tasmania. Sowing times between November and January had little effect on the plant size and marketable spear yield of the cultivar Futura. However, delaying sowing from January to March reduced the plant size and marketable spear yield of 10 cultivars of different maturity types. The length of the growing period of all cultivars was increased for sowings after February. A continuous production of broccoli for once-over harvest can be maintained for March-August by a combination of cultivars and sowings from January to March. However, yields of less than 5 t/ha can be expected for the mid-May-August harvests compared with yields in excess of 10 t/ha for March and April harvests.
Relationship between predicted energy requirements and measured energy intake of dairy cattle at pasture
Authors: Fulkerson WJ , Dobos RC , Michell PJ
Published: March 2005

Intakes of metabolisable energy (ME) in grazed herbage, silage, hay and grain were measured in dairy cows on 2 farmlets during 2 consecutive 12-month periods. Measured intakes were compared with predicted 'requirements' for ME, calculated by using values for liveweight and milk production measured during the 2 periods. These results validate the use of standard energy allowances to predict ME requirements of dairy cattle grazing in an environment similar to that described here. The measured (mean � s.d.) ME intake was 95 � 6.7% of predicted requirements using standard energy allowances.
Selecting for nutritive value in Digitaria milanjiana. 2. Intake and digestibility of divergently selected full-sibs compared with Digitaria decumbens
Authors: Minson DJ , Hacker JB
Published: March 2005

We compare the voluntary intake and digestibility of 6 genotypes selected from 3 F1 families of Digitaria milanjiana for high or low leaf digestibility, and D. decumbens (pangola grass). Swards were harvested on 6 occasions (4 by 4-week regrowths, 1 by 10-week and 1 by 14-week regrowth) and fed to sheep in metabolism cages. Averaged over families and regrowths, high digestibility selections were significantly superior to low digestibility selections in digestibility, voluntary dry matter intake and intake of metabolisable energy. There was a large range in leafiness of the genotypes. Correlations between leafiness and in vivo digestibility, dry matter (DM) intake and intake of metabolisable energy were positive and statistically significant. Comparison of full-sibs at the same percentage stem (80 and 100%) suggested a higher DM intake, digestibility and intake of metabolisable energy of stem from genotypes selected for high leaf digestibility. Averaged over harvests, none of the selected genotypes was significantly superior to pangola grass in digestibility but all were superior in DM intake and 5 in intake of metabolisable energy. The best selected genotype was 35% better than pangola grass in terms of intake of metabolisable energy. Differences in in vitro digestibility of young leaves from vegetative tillers of full sibs, the characteristic on which the genotypes had been selected, were maintained under sward conditions, although differences were reduced.
Lucerne irrigation and soil water use during bloom and seed set on a red-brown earth in south-eastern Australia
Authors: Taylor AJ , Marble VL
Published: March 2005

Lucerne (Medicago sativa L.) cv. WL45 1, grown on a shallow red-brown earth, was subjected to different irrigation frequencies during bloom to determine the effect on seed yield. The highest yield of 1105 kg ha-1 was produced when the crop was irrigated at an accumulated Epan of 75 mm between irrigations. Yields declined to 528 kg ha-1 as the interval between irrigations increased and the total amount of water applied during bloom was reduced as a consequence. Seed yield was positively correlated with total top growth, number of stems, number of racemes with pods and number of seeds per pod. Neither individual seed weight nor number of pods per raceme was influenced by the irrigation treatments. Soil water extraction by the crop was confined mainly to the 0-1.2 m depth. However, highest seed yields were produced when soil water extraction was confined to the 0-0.6 m depth by regular irrigation. About 16% of the available water in the 0.6-1.2 m depth and 89% of the available water in the 1.2-1.8 m depth could not be extracted by the crop. Failure to extract water from the lower subsoil was attributed to soil physical restrictions and lack of adequate root density.
The relationship between average annual rainfall and exchangeable aluminium in soils of south-eastern New South Wales
Authors: Conyers M
Published: March 2005

Surface soil samples (0-10 cm) from a range of soil types were collected in south-eastern New South Wales. Linear regression and analysis of variance were used to establish that, at a given pH (0.01M CaCl2), the amount of neutral salt exchangeable aluminium in surface soils tends to increase with increasing average annual rainfall. Where aluminium toxicity is a factor limiting plant growth, soils in higher rainfall areas will generally require higher pH for the removal of aluminium from the cation exchange complex.
Geographic distribution of common root rot and Bipolaris sorokiniana in Queensland wheat soils
Authors: Wildermuth GB
Published: March 2005

A survey to determine the geographic distribution of common root rot in Queensland wheatgrowing areas was conducted in 1978, 1979 and 1980. In 1980, soil populations of Bipolaris sorokiniana were determined from the areas where common rot was assessed. Common root rot was found in all areas and was most severe in the South-western Downs, Western Downs and Northern Darling Downs and least severe in the Central Highlands. Incidence of common root rot over all areas changed from 77% in 1978, to 65% in 1979, and to 56% in 1980. This was mostly due to a reduction from 91 to 44% on the Darling Downs. The lower incidence in 1979 and 1980 was thought to be associated with lower rainfall in those years and in some areas with an increase in rotation to crops other than winter cereals. Severity of common root rot was significantly lower only in 1979. In general, the severity of common root rot in Queensland was higher than that recorded in Canada and lower than that recorded in Brazil. Soil populations of B. sorokiniana varied from 0 to 320 propagules per gram of soil with an overall mean of 58. They were highest in the Western and Southwestern Downs, and lowest in the Central Highlands. In general, the size of the populations were less than those recorded elsewhere.
Growth and yield of clonal guavas in south-eastern Queensland
Authors: Chapman KR , Paxton B , Maggs DH
Published: March 2005

Five processing guava clones (GA6- 1, GA7- 12, GA8-30, GA9-35, GA11-56) were tested over 3 cropping years at Nambour, in coastal south-eastern Queensland. Mean marketable yield for the first crop at 2 years of age was 45 kg/tree or 36.23 t/ha at a density of 805 trees/ha. GA11-56, the most acceptable clone for processing, also gave the highest marketable yields of 627, 71.65 and 72.53 t/ha for the first 3 crops. Yield per unit cross sectional area of trunk was a more simple and useful index of yield efficiency than more complex parameters including a fruitfulness index and multiple regressions with yield of north-south canopy spread, number of primary branches and combinations of these and trunk girth. Similarly, trunk - - girth provided at least as good an estimate of tree size as the vigour index. Tree dimension measurements which included east-west canopy spread, north-south canopy spread, tree height, stem height, number of primary branches, crown height, crown radius, tree canopy volume, canopy surface area and an index of crown weight provided no consistent indication of tree size. They were not highly correlated with either accumulated or final yield of the guava. The GA11-56 clone because of its yield, fruit size and other desirable processing characteristics was the only clone that could be recommended for commercial plantings.
Productivity and growth of six okra cultivars
Authors: Blennerhassett RM , El-Zeftawi BM
Published: March 2005

The productivity and pod characteristic of 6 okra (Abelmoschus esculentus) cultivars were studied over 2 seasons in Sunraysia. The cultivars (Penta Green, Dwarf GLP, Clemson Spineless, Emerald, Perkins and Lee) were planted in late October and all produced continuously from mid January to mid April. Production fluctuated with cultivar and season and major peaks occurred particularly in the second season. The top yielding cultivars over the 2 years tested were Clemson Spineless, Dwarf GLP and Penta Green. All cultivars except Penta Green gave low yields in 1980-81. Yield and pod size also varied widely between the 2 seasons with greater yields and larger pods being produced in the cooler 1981-82 season. Production per cultivar varied markedly in a given year and it appears that those cultivars like Penta Green that have a greater ability to fruit on lateral branches produce more consistent yields between years. Pod length and weight increased rapidly after set whereas pod diameter increased slowly in comparison. After 8- 14 days pod moisture levels fell and pod toughness increased at a time when pod elongation had slowed or stopped. Seed oil contents varied from 11% w/w (Emerald) to 15% (Dwarf GLP and Penta Green). Germination percentages were: Emerald, 76; Dwarf GLP, 59; Penta Green, 49; Perkins, 48; Clemson Spineless, 44; and Lee, 35%. Clemson Spineless, Penta Green and Dwarf GLP appear to be high yielding and suitable cultivars for growing in Sunraysia.
Water intake of grazing Angora wether goats and Merino wether sheep
Authors: McGregor BA
Published: March 2005

Water intakes of Angora wether goats and Merino wether sheep grazing annual pastures were measured in summer on dry pasture and in winter on green pasture. Animals were grazed at 7.5 and 12.5 animals ha-1 in 1984 and 7.5 and 10 animals ha-1 in 1985 on unshaded paddocks. Mean maximum temperatures were 25� in summer and 13�C in winter. In summer, animals at the lower stocking rates were heavier (sheep 40.8 kg fleece free liveweight (FFLW), goats 37.3 kg FFLW) and consumed more water than animals at the higher stocking rate (sheep 33.7 kg FFLW, goats 30.2 kg FFLW). Angora goats consumed significantly more water than Merino sheep, 1.87 v. 1.37 litre day-1. Daily water intake of Angora goats was 55.6 ml (kg FFLW)-1, 50% more than Merino sheep (P<0.005). Maximum water intakes on the hottest day (35�C, maximum) were twice the average recorded intake in both species. As a result of frequent drinking, goats formed tracks which radiated from the water trough. Daily water intake in winter was 0.1 litre or 2.5 ml (kg FFLW)-1 for goats and sheep. Water in oblong metal water troughs had higher temperatures but lower evaporative losses than water in larger circular concrete water troughs. It is concluded that Angora goats grazing dry pasture in summer require water supplies and their water consumption is greater than that of similar-sized sheep.
Factors limiting the intake by sheep of the tropical legume, Calopogonium mucunoides
Authors: McSweeney CS , Wesley-Smith RN
Published: March 2005

Sheep were studied to determine whether their low intake of organic matter (400-500 g/day OM) of calopo (Calopogonium mucunoides) was due to toxic properties of the plant, factors that affect its 'acceptability', or to the mineral status of the legume. Practical methods of increasing intake of the harvested plant were also investigated. The low intake by sheep of calopo was not due to its toxicity since supplementation with 500 g/day of ground calopo via the ruminal fistula did not depress voluntary consumption of lucerne hay more than when an equivalent amount of siratro was given. Treatment of the plant with the 'taste-modifiers' monosodium glutumate (2% dry matter fed) and molasses (5%), or with sodium hydroxide 4% w/w or its molar equivalent of potassium hydroxide was associated with an immediate and sustained increase in organic matter intake of about 40%. This intake is similar to that of other tropical forages with similar digestibilities. The taste or odours of the plant therefore appear to limit intake. The low sodium (0.03%) and marginal potassium (0.55%) content of calopo induced a deficiency of these elements in the animal which did not affect intake in the short term. Treatment with molasses had the advantage of supplying extra potassium and energy.
Efficiency with which yellow serradella and subterranean clover use superphosphate on a deep sandy soil near Esperance, Western Australia
Authors: Bolland MDA
Published: March 2005

In 1984, the efficiency with which an early- and a late-flowering yellow serradella (cv. Pitman and strain DP4 respectively) and a subterranean clover (cv. Seaton Park) utilise phosphorus (P) from superphosphate was compared on a deep sandy soil near Esperance, W.A. Phosphorus applications ranged from 0 to 90 kg/ha P. For each legume there was an approximately linear relationship between the amount of P applied and either the yield of dry herbage and seed, or the P content of dry herbage. The efficiency with which each legume utilised applied P (kg/ha) was determined by calculating the slope of the relationships between dry matter production, or phosphorus content of this dry matter, and the amount of phosphorus applied; this varied according to the growth stage at which the legumes were sampled. Strain DP4 utilised P more efficiently to produce dry herbage, and Seaton Park to produce seed. Pitman was the least efficient at utilising P for dry herbage production in September, and Seaton Park in early October. For dry herbage production in September and early October, the relationship between yield and P content was similar for all 3 legumes, and yield depended on the amount of P present in the herbage. For each legume, the rate of phosphorus applied had no effect on seedling emergence, the period between sowing and commencement of flowering, senescence or the weight per seed.
Interactions of surface drying and subsurface nutrients affecting plant growth on acidic soil profiles from an old pasture
Authors: Pinkerton A , Simpson JR
Published: March 2005

Previous studies on soils from old pastures in southern New South Wales have demonstrated that nutrients have accumulated at the soil surface, but that the 40-100-mm depth layer in many profiles has become strongly acidic (e.g. pH 4.7), and high in extractable aluminium. Poor growth of subterranean clover has occurred on such soils during dry periods and may be associated with poor root growth in the acidic, nutrient-poor subsurface layers. Possible nutritional causes of these observations were investigated using reconstituted soil profiles. The root and shoot growth of subterranean clover, wheat, oats and lucerne were compared in unamended profiles and in profiles amended by applying nutrients or calcium carbonate (lime) to correct the more obvious deficiencies of the subsurface layers. Subterranean clover grew well as long as the surface soil remained moist, so that plants could utilise the nutrients potentially available within it. When the surface (0-40 mm) was allowed to dry but the subsurface layers remained moist, growth was poor unless phosphate was applied to the moist layer. Subsurface application of lime alone was ineffective. Nitrogen application increased clover growth in the presence of added phosphate or surface moisture, but nitrogen alone did little to alleviate the effects of surface drought. Wheat, and to a lesser extent oats, responded to subsurface lime when the surface was moist, and both responded to subsurface phosphate when the surface was dry. Lucerne responded to subsurface phosphate similarly to subterranean clover but the response was more than doubled in the presence of additional borate and lime. Lime without borate was not effective. When the surface was maintained moist, liming both the surface (0-40 mm) and subsurface layers improved the response over liming the subsurface layer only. The results suggest that declining fertility and productivity in old pastures developed on acid soils may not be rectified by liming alone, but that cultivation, ripping or drilling of phosphate, and in some cases addition of borate, may be required to improve the penetration of nutrients, particularly phosphorus, to greater depth.
Effect of a press wheel and depth of sowing on the establishment of semidwarf and tall wheats
Authors: Radford BJ
Published: March 2005

The effects of sowing with a press wheel on the seedling establishment of semidwarf (Banks, Cook, Shortim, 7605) and tall (Gatcher, Spica) wheats at various sowing depths (3.5-13 cm) were studied in factorial experiments in 14 sowings at 7 sites in Queensland. Establishment was generally lower with the semidwarf cultivars. A sowing depth of about 5.5 cm was optimum for wheat establishment when no rain fell between sowing and emergence. However, consistent placement of seed at the optimum depth requires level seedbeds or planting machinery with accurate depth control. Sowing with a press wheel increased the establishment of both semidwarf and tall cultivars at all depths of sowing. Semidwarf cultivars sown using the press wheel gave establishment equal to or better than tall cultivars sown without press wheel pressure. Highest establishment was obtained when tall cultivars were sown using a press wheel. The fitting of press wheels to wheat planters is recommended.
Wheat crop surveys in southern New South Wales. 4. The response by grain yield and other wheat attributes to weeds
Authors: Taylor AC , Lill WJ
Published: March 2005

Regular hand-weeding was undertaken in experiments located in 167 wheat crops in southern New South Wales from 1967 to 1970 to quantify the effect of weeds on 10 wheat attributes at flowering or maturity. Short annual grasses, skeleton weed, wild oats and annual legumes were the most widespread weeds, all of which tended to occur in mixed stands. At wheat flowering, over all sites, wheat DM, nitrogen concentration, nitrogen uptake, phosphorus uptake and number of ears were increased (P< 0.05) by 11.2, 3.3, 14.4, 13.6 and 7.8%, respectively by weeding; wheat phosphorus concentrations did not respond to weeding. At maturity, grain yield and nitrogen yield increased after weeding (P< 0.05) by 17.3 and 1 7.0%, respectively, but grain protein and kernel weight did not respond to weeding. Regression procedures were used to relate wheat responses to total weed DM and the DM of 8 weed classes. At flowering, for every 100 g of DM removed, wheat DM, nitrogen uptake, phosphorus uptake and ear number increased by 52.3 g m-2, 958 mg m-2, 92.6 mg m-2and 18.7 m-2, respectively. At maturity, grain yield and grain nitrogen yield increased by 31.9 g m-2 and 665 mg m-2, respectively, for every 100g m-2 of weed DM present at flowering. The regressions also showed that, at both flowering and maturity, fumitory, annual grasses and sundry weeds (a group made up of weeds not sufficiently widespread to consider separately) appeared to be the most aggressive weeds. Consideration of standardised responses of the wheat attributes increased by weeding showed that they all responded similarly when corrected for scale of measurement.
Potassium nutrition of irrigated potatoes in South Australia. 2. Effect on chemical composition and the prediction of tuber yield by plant analysis
Authors: Maier NA
Published: March 2005

I compared the effects of potassium sulfate and potassium chloride fertiliser, at rates up to 1280 kg/ ha K, on the concentrations in petioles of the youngest fully expanded leaves and in harvested tubers of potassium, calcium (tubers only), magnesium, phosphorus, chloride and sulfur (petioles only) and on potassium: magnesium ratios in petioles. For the sites classified as deficient and marginal according to soil test potassium concentrations, increased application rates of potassium sulfate increased the potassium and sulfur concentrations and potassium: magnesium ratios in petioles and decreased magnesium, phosphorus and chloride concentrations. In tubers both potassium and magnesium concentrations increased as potassium sulfate rates increased, while calcium and phosphorus concentrations showed negative trends. Compared with potassium sulfate, potassium chloride resulted in higher potassium, calcium and chloride concentrations and lower sulfur concentrations. Chloride concentrations in petioles from many sites were much higher than those reported in other studies and were related to high chloride concentrations in irrigation waters. Significant correlations were obtained between bicarbonate- extractable potassium concentrations in the surface (0-1 5-cm) soils and potassium concentrations in petioles (r2 = 0.75***) and tubers (r2 = 0.84***). As bicarbonate-extractable potassium concentrations in the surface soils increased from 40 to 600 mg/kg, the potassium concentrations in tubers increased from 1.69 to 2.69% compared with an increase from 5.72 to 1376% in petioles. Significant correlations were obtained between relative yields ((mean treatment yields/maximum mean treatment yie1d)x 100) and potassium concentrations (dry weight basis) in petioles and tubers and potassium:magnesium ratios in petioles. The percentage of variance in relative yield accounted for by each regression was 67.9, 31.0 and 56.9% respectively. The potassium concentration in petioles was the most effective plant index to predict yield response to potassium. For petioles and tubers prognostic critical potassium concentrations of 11.30 k 0.26% and 2.19 � 0.11% respectively were established. Alternatively, a prognostic critical potassium:magnesium ratio of 14.8 � 0.8% was determined. The choice of the mathematical model used influenced the critical values obtained.
Potassium nutrition of irrigated potatoes in South Australia. 3. Effect on specific gravity, size and internal bruising of tubers
Authors: Maier NA , Dahlenburg AP , Frensham AB
Published: March 2005

The effects were studied of potassium sulfate and potassium chloride applied at rates up to 640 kg/ha K on tuber specific gravity, size and susceptibility to internal bruising. The field experiments from which these data were obtained were conducted during the 1982-83 and 1983-84 seasons throughout the main potato-growing areas of South Australia. For the deficient and marginal site groupings, there was a consistent positive trend in specific gravity as potassium sulfate rates increased up to 640 kg/ha K. There was a slight negative trend when potassium chloride was used. Potassium fertiliser had no consistent effect on specific gravity at sites in the non-responsive grouping. Petiole or tuber potassium concentrations were poorly correlated with specific gravity. In the deficient and marginal groups increasing rates of potassium increased the yield of 80-350, 350-450, 450-680 and greater than 680-g tubers. The percentage increase in yield was greatest for the larger size grades (350-450 g or larger). At sites in the non-responsive group potassium had no effect on tuber size. At 2 out of 9 sites the effect of potassium chloride on tuber size was significantly different from that of potassium sulfate. Potassium chloride at rates of 160 and 320 kg/ha K reduced the susceptibility of tubers to internal bruising at 3 out of 4 sites. Potassium sulfate was effective at 3 out of 6 sites but only at the highest rate tested (640 kg/ ha K). Susceptibility to internal bruising was significantly (P < 0.01) negatively correlated with both petiole and tuber potassium concentrations. Prognostic critical potassium concentrations above which internal bruising was minimised were 8.30% in petioles or 1.84% in tubers. These values were calculated using the Cate-Nelson separation.
Effects of irrigation regimes on powdery scab disease and yield of potatoes
Authors: Taylor PA , Flett SP , Boer RFde , Marshall D
Published: March 2005

The period of susceptibility of potato tubers to powdery scab (Spongospora subterranea) was studied by inoculating potato plants with spores, or by watering plants in infested soil, at different stages of plant development in greenhouse conditions. Maximum susceptibility began about 1 week before the stage when 50% of stolons had swollen to at least 5-mm diameter (tuber set), and ended 3-4 weeks later. With holding irrigation water during this period reduced the severity of powdery scab by 65-75% in field experiments in 1981-82 and 1982-83, but had no apparent effect on disease severity in 3 out of 6 large-scale field trials during 1984-85.