bluuebunny/crossref_metadata_2025 huggingface dataset:
Studies on the irrigation of sugar-cane
Authors: Yates RA
Published: November 2004

Eleven replicated irrigation trials on sugar-cane, together with some preliminary observation tests, were conducted in the Bundaberg region of southern Queensland during four seasons, 1961–62 to 1964–65. Irrigation control was through actual measurements of potential evapotranspiration of cane (Etc) or grass (Etg) with lysimeters. In conjunction with the lysimeter work, pan evaporation (Ep), mean air temperature (Ta), and sufficient data to calculate Penman's potential evaporation (E0) were recorded. Etc consistently exceeded Ep, and Etg slightly exceeded Ep in summer. Et was fairly well correlated with Ep and Ta, but less well correlated with E0. The inclusion of Ta in regressions of Et on Ep or E0 improved these regressions; Ta presumably reflects the additional external source of energy which was causing the high Et values. Yield responses to irrigation were very different on two soil types: on a deep red volcanic loam they were 10 times as great as those on a heavy alluvial clay. The reasons for the poor response on the alluvial clay appear to be threefold: (i) a permanently moist (but saline) subsoil maintained some growth in dry weather; (ii) growth in soils kept moist by irrigation virtually stopped when heavy rain fell; (iii) heavy rain falling on previously dry soil resulted in an abnormal increase in growth rate, an effect which was associated with a dramatic increase in soil mineral nitrogen. The most satisfactory indicator of water use by cane was Etg; growth rate data indicated that 100% Etc is required, but yield data suggested that 66% Etc is adequate. The latter value approximates to 100% Etg or 100% Ep in the summer months. Growth, and therefore growth response to irrigation, is very severely curtailed when mean temperatures fall below 70°F; soil temperature appears to be the critical factor. Growth rate was too susceptible to factors such as temperature to be of any value as an indicator of the need for irrigation.
Superphosphate on wheat: The cumulative effect of repeated applications on yield response
Authors: McClelland VF
Published: November 2004

The cumulative effects of repeated applications of superphosphate on wheat yield responses, over a period of 26 years (10 cycles of a rotation system), were examined. Since cumulative effects are the sum of current and residual effects and current effects diminish with repeated applications of superphosphate, this approach enabled residual effects to be inferred. Residual effects were apparent at all rates of application (30, 60, 90, and 120 lb/acre), being greater at the three higher levels. The influence of rainfall in the growing period (April to October) on cumulative effects was also examined. April rainfall increased yield at all levels of application, whereas September rainfall increased yield only at 90 and 120 lb/acre of superphosphate. The results indicate that, for this particular experimental site, residual phosphorus has become more important in determining yield responses than currently applied phosphorus.
Response to selection in Australian Merino sheep. I. Selection for high clean wool weight, with a ceiling on fibre diameter and degree of skin wrinkle. Response in wool and body characteristics
Authors: Turner HN , Dolling CHS , Kennedy JF
Published: November 2004

Direct and correlated responses are reported for two groups of sheep selected for high clean wool weight. The work covers two periods. In the first (1950–59), both groups had selection against high average fibre diameter and high degree of skin wrinkle, but in one group (S) the performance of the ram's half-sibs was considered as well as his own, while in the other (MS) mass selection was practiced for rams. For ewes, mass selection was practiced in both groups. In the second period (1961–64), mass selection was used for both sexes in both groups, with selection against high diameter and degree of wrinkle in one group (S), and against low crimp frequency and high degree of wrinkle in the other (MS). In both periods response to selection was assessed by comparison with a random control group. In the first period, response in clean wool weight was similar in S and MS, both for rams measured at 10–11 months, when a preliminary selection on them was carried out, and for ewes measured at 15–16 months, when final selection was made for both sexes. The annual rates of increase in clean wool weight for S and MS were 2.1 and 1.8% for rams and 2.4 and 2.7% for ewes, the lower rate in rams being due to the fact that response at 10–11 months is a correlated response to the final selection at 15–16 months. As the rates of increase in the two groups are similar, it can be concluded that examination of half-sibs is not worth while; this would in fact have been predicted from the high heritability estimates for clean wool weight. There were negligible trends in fibre diameter and wrinkle score, indicating that counter-selection has been effective in preventing an increase in these characteristics. Fibre number per unit skin area made the greatest contribution to the increases in clean wool weight, the annual rates of increase for S and MS being 2.0 and 2.2% for rams and 2.0 and I .8% for ewes. Greasy wool weight, percentage clean yield, body weight, and staple length also showed increases with increasing clean wool weight in both selected groups. In spite of the fact that fibre diameter did not increase, crimp number per unit of staple length decreased in both groups. This is a further confirmation of the strong negative genetic correlation between clean wool weight and crimp number, and of the lack of a strong association between crimp number and fibre diameter. In the second period, no further response was observed. It is impossible to say at this stage whether a selection plateau has been reached or whether drought conditions interfered with response.
Mating types, sex, dissemination, and possible sources of clones, of Hypomyces (Fusarium) solani, f. pisi in South Australia
Authors: Cook RJ , Ford EJ , Snyder WC
Published: November 2004

Isolates of Hypornyces (Fusarium) solani f. pisi collected in South Australia, when single-spored and cultured under the same conditions, were separable into three distinct clones. Pairings of the three clones (SA-1, 2, and 3), and of a fourth collected in New South Wales (NSW-I), with tester clones of known mating type and sex, showed that SA-1 and SA-2 were of one mating type (+), while SA-3 and NSW-1 were of another mating type (–). SA-1 and NSW-1 were hermaphrodites; SA-2 and SA-3 functioned only as males. When SA-1 and NSW-1 were paired in reciprocal crosses, fertile perithecia developed in both cases. Fertile perithecia also developed when SA-2 and SA-3 were used as males to fertilize NSW-1 and SA-1 respectively. A clone of H. solani f. pisi, identical with SA-1 in pathogenicity, cultural appearance, sex, and mating type, was recovered from wind-blown soil in a virgin area approximately 1 mile from a pea field but not from soil taken from districts some distance (30 miles in one case and 200 miles in another) from pea-growing districts. Other isolates identical with SA-1 in cultural appearance, mating type, sex, and pathogenicity were recovered from dust taken from a bag of non-treated, certified New Zealand pea seed imported into South Australia, from field soil collected in pea seed-producing areas of the Pacific North-west of the United States, and from England. The occurrence of compatible clones on different continents appears to be due to an international movement of the fungus on pea seed.
The survival and development of fertilized eggs transferred between Border Leicester and Merino ewes
Authors: Moore NW
Published: November 2004

Fertilized eggs were transferred reciprocally, at a rate of one or three per animal, between Merino and Border Leicester (B.L.) ewes. Recipients were either allowed to go to term or autopsied 14–15 days after transfer. The number of recipients becoming pregnant was not affected by breed of recipient, breed of egg, or number of eggs transferred. The survival rate of eggs transferred at a rate of three per recipient was less than that of those transferred at a rate of one per recipient (55% v. 75%, P < 0.01). Irrespective of breed of egg transferred, Border Leicesters had more triplet and less single pregnancies than Merinos. The vast majority of pre-natal loss occurred early in pregnancy and was evident at autopsy as missing eggs or abnormal embryos. In both single and multiple pregnancies, gestation length was markedly affected by breed of lamb carried (see PDF).In the larger breed (B.L.) gestation was extended when the smaller breed (Merino)
was carried, while gestation in the smaller breed was shortened when the larger breed
was carried.
Response to selection in Australian Merino sheep. II. Estimates of phenotypic and genetic parameters for some production traits in Merino ewes and an analysis of the possible effects of selection on them
Authors: Brown GH , Turner HN
Published: November 2004

Estimates of heritabilities and of phenotypic and genetic correlations are given, based on extensive measurements on medium Peppin Merino ewes at 15–16 months of age. In general these substantiate results obtained by other workers and, in particular, confirm the high heritabilities of the traits measured. An effort has been made to try to detect possible changes in additive genetic variance for the trait under selection (clean wool weight). Estimates are obtained for data from animals at different stages of selection: (A) either unselected, or with little selection history, and (B and C) with varying amounts of selection. For stage A data the average estimated additive genetic variance was 0.31. There are problems involved in estimating from stage (B+C) data but an upper limit average value of 0.22 was obtained. Thus, although a decrease in additive genetic variance has occurred, its statistical significance is unknown and conclusions about the decrease must necessarily be tentative. In practically all cases the estimates of phenotypic and genetic correlations are of the same order of magnitude, and for the genetic correlations may be summarized as: See PDFAll other combinations of traits have negligible genetic correlations (in the range –0.20 to + 0.2).
A congenital deformity in calves induced by the maternal consumption of lupin
Authors: Shupe JL , Binns W , James LF , Keeler RF
Published: November 2004

A congenital skeletal deformity called "crooked calf syndrome" occurs in many of the beef cattle-producing areas of the western United States. This deformity is characterized by arthrogryposis, torticollis, scoliosis, and cleft palate. The condition is non-hereditary, and is due to the consumption of lupin by the dam. The most severe and characteristic deformities are produced between the 40th and 70th days of gestation.
The in vitro digestibility of parents and hybrids of cocksfoot (Dactylis glomerata L.)
Authors: Knight R , Yates NG
Published: November 2004

The digestibility of a range of genotypes of cocksfoot (Dactylis glomerata L.) and their hybrids was estimated by an in vitro technique at eight harvests over a period of 14 months. The material for analysis was grown in a Mediterranean type environment with summer irrigation and obtained by recurrent defoliation of sward plots. Digestibility values tended to be lower in summer than in winter, although some material showed a fall in digestibility in the middle of winter. Within a harvest there were correlations between general combining ability and parental performance, but there was little uniformity in ranking of parents or their progenies from one harvest to the next, which would make selection for uniform high digestibility very difficult. Reasons for the fluctuations are not known, and were not obviously correlated with any aspect of the growth rhythm apart from a correlation with heading on one harvest occasion.
The growth of the lucerne plant after cutting: I. The effects of cutting at different stages of maturity and at different intensities
Authors: Leach GJ
Published: November 2004

Variation in shoot number, shoot size, and yield of dry matter occurring in the regrowth from lucerne plants cut at different stages of maturity and at different intensities is reported. The main effects of the treatments arose through variation in shoot number and changes in the time at which each shoot commenced extension growth; a linear regression utilizing this information about the population of shoots accounted for nearly all the variation in yield. Less severe, or later, cutting resulted in greater yields of dry matter in a 4 week period of regrowth. Changes in shoot number and shoot size both contributed to the variation in the yield of regrowth. Shoot size was mainly determined by the time at which the shoot resumed extension growth, and once such growth was resumed the shoot growth rate was apparently independent of the cutting treatment applied. The results are discussed in relation to currently held concepts on the role of "reserves" and of residual leaf area in promoting the regrowth of pasture plants. The development of lucerne adapted to grazing management is also considered.
Developmental growth and body weight loss of cattle. III. Dissected components of the commercially dressed carcass, following anatomical boundaries
Authors: Seebeck RM , Tulloh NM
Published: November 2004

This paper describes part of an investigation of the effects of developmental growth and body weight loss on the carcass composition of Angus steers. A method of anatomical dissection was used on one half (the right side) of each carcass to find the weights of each carcass component. The results are compared with those obtained from a method of dissecting butcher's joints used on the other (left) half of each carcass. Two groups of steers were used in this experiment: group A, which grew continuously, and group B, which grew like group A and were then subjected to a period of weight loss before slaughter. Corresponding animals in both groups were killed at the same body weights. Statistical analysis was by analyses of covariance of weights of components converted to logarithms. As carcass weight increased, the proportions of muscle, bone, and fascia and tendons decreased, while the proportions of the fat components increased. This result was similar to that obtained. previously by joint dissection, but the changes differed in degree. Distribution of muscle and bone changed significantly as the total weights of these components increased. Distribution of the other components was known only in so far as they came from either the hindquarter or the forequarter; no changes were found in their distribution as their total weights increased. Comparison of group A and group B animals at the same carcass weight showed that body weight loss led to a significant increase in the proportion of bone in the carcass but only a slight decrease in the proportion of muscle. Body weight loss had a differential effect on the proportion of kidney and channel fat in the carcass, the result depending on the weight at which animals were killed. The weight of subcutaneous and intermuscular fat in the group B carcasses did not vary significantly from that of group A carcasses of the same weight. These results were similar to those found by joint dissection but there were differences in magnitude. In particular, the differences in muscle weight between group A and group B carcasses was more pronounced in the joint dissection, where it was statistically significant. Also bone weight from the joint dissection was affected differentially by the weight loss treatment at the different killing weights; however, there was no evidence of a differential effect on bone weight in the anatomical dissection. These differences were ascribed to more accurate separation of tissues in the joint dissection. Distributions of muscle, bone, and fascia and tendon were affected by loss of body weight. Unlike joint dissection, anatomical dissection did not show significant effects on the distribution of subcutaneous fat and intermuscular fat due to the weight loss treatment; these differences between results are ascribed to differences between the units used for assessing these distributions.
Photosynthesis of wheat under field conditions. I. The interaction of photosynthetic organs
Authors: Puckridge DW
Published: November 2004

Four wheat varieties were examined to determine differences of grain production in response to ear shading and defoliation treatments under field conditions. Responses to both ear shading and defoliation were affected by the level of competition and by the number of tillers on the plants. There was a movement of assimilates between shoots. Compensation, in production of assimilate by other organs, was very pronounced when parts of the plant were shaded or leaves removed. "Sink" size appears to be an important factor in the supply of carbohydrate to the grain. The nitrogen content of the grain was not affected by ear shading.
The role of temperature in the development of blue mould (Peronospora tabacina Adam) Disease in tobacco seedlings. III. The effect of pre-inoculation temperature and of shade on plant growth and disease development
Authors: Hill AV , Green S
Published: November 2004

The spread and effect on plant growth of blue mould disease of tobacco was measured on cv. Virginia Gold and SO1 under controlled conditions. The factors considered were the effect of three pre-inoculation temperatures on response to post-inoculation temperature and the direct effects of shade under three temperature regimes. Different pre-inoculation temperatures did not modify significantly the response to inoculation at three post-inoculation temperatures. As post-inoculation temperature increased, the amount of stem mould decreased and the sizes of both healthy and inoculated plants increased. The effects of pre-inoculation temperature on plant growth persisted to the end of the experiments. Only for the stem length of healthy plants was there a significant interaction with post-inoculation temperature, and even then the stem length increased for all post-inoculation temperatures. Under the two higher temperature regimes shaded plants were smaller than unshaded. Shaded and unshaded plants held at the same temperature were equally susceptible to blue mould.
The metabolic rate of Merino rams bred for high or low wool production
Authors: McCGraham N
Published: November 2004

Five rams from a flock bred for high wool production at pasture and six rams from another flock bred for low production were studied. The two groups had also grown differing amounts of wool when rationed to 800 g food per day in pens. The high producers were somewhat larger and heavier than the low producers and had greater fat-free body weights. Both groups had higher metabolic rates (fasting heat production) than ewes and wethers of the same weight, in whatever units metabolism was expressed. The high producers were judged to have higher metabolic rates than the low producers; some of this difference may have been due to the larger skeletal size of the high producers.
Vital statistics for an experimental flock of Merino sheep. V. The effects pf age of ram, maternal handicap, and year of measurement on 10 wool and body characteristics for unselected rams
Authors: Brown GH , Turner HN , Dollling CHS
Published: November 2004

Estimates were made of the effects of the following factors on 10 fleece and body characteristics measured on rams aged 1½ to 5½ years in a randomly bred control flock, for rams born 1953 to 1957 inclusive: age of ram, single or twin birth, age of dam, and the year in which measurements were made. Changes with age were present in all characteristics and the ranges of the age deviations from the overall mean were larger in magnitude than the corresponding figures for ewes. Greasy and clean wool weights showed a similar pattern of change with age as ewes. For greasy wool weight the age deviation increased from –2.4 lb at 1½ years to 1.1 lb at 3½ years and then declined to 0.5 lb at 5½ years of age. The corresponding figures for clean wool weight were –0.7 to 0.5 lb. falling to –0.2 lb at 5½ years of age. Other characteristics showed different patterns of change with age from the corresponding figures for ewes. Staple length, crimps per inch, yield, and fibre population density decreased with age over the range available, whilst face cover, body weight, fibre diameter, and wrinkle score increased. The fitted mean difference in clean wool weight between rams and ewes was 33%, largely attributed to differences in body area (25%) with a smaller contribution from staple length (7%). Twin-born rams cut 0.28 lb of clean wool weight per year less than single-born rams over the five shearings, whilst the progeny of 2-year-old dams did not differ significantly from the progeny of adults. Large between-year differences occurred for most characteristics. For clean wool weight the range was from –1.52 to 1.44 lb, fibre volunme being the most important component, while for body weight the range was –18.6 to 19.7 lb.
Studies on the number of ewes joined per ram for flock matings under paddock conditions. I. Mating behaviour and fertility
Authors: Lightfoot RJ , Smith JAC
Published: November 2004

In a series of six experiments rams were joined either singularly or in groups to varying numbers of ewes so that the number of ewes joined per ram varied between 25 and 100. Under the conditions of these experiments, decreasing the number of ewes joined per ram was associated with more rams serving each oestrous ewe, a greater proportion of ewes served during the first 2 weeks of joining, less ewes remaining unserved at the end of a 6 week joining period, and higher fertility (the proportions of ewes lambing and ewes twinning to ewes joined). A highly significant interaction (P < 0.001) between number of ewes joined per ram and ram age was found. Joining 25 ewes per ram gave higher fertility than 50 ewes per ram when 1½ -year-old rams were used, but similar fertility with 3½–5½-year-old rams. Older rams were more fertile than 1½-year-olds when joined at 50 ewes per ram, but not at 25 ewes per ram. These findings are discussed in relation to other factors that may influence the effect on flock fertility of varying the number of ewes joined per ram.
Studies with antitranspirants on grapevines (Vitis vinifera Var. Sultana)
Authors: Possingham JV , Kerridge GH , Bottrill DE
Published: November 2004

A range of antitranspirants has been tested under glasshouse conditions for their effectiveness In reducing the water consumption of grapevines (Vitis vinifera cv. Sultana). The substances tested included three that form plastic films, Polycote J (Tag), Polycote S720, and Acropol (S789, a silicone type compound), and the inhibitor phenyl mercurrc acetate which 1s known to be effective at suppressing transpiration In cotton. The only substance found to be an effective transpiration suppressant was Acropol, which reduced water consumption by an average of 50% when applied as a leaf spray. Repeated applications at 12-day intervals were necessary and the substance had a morphogenetic effect, bringing about a significant increase In the leaf area but a decrease in dry matter production, especially evident In the lower root weight of treated plants. (Similar morphogenetic effects were shown with Polycote S720, where the increased leaf area was shown to be a result of increased leaf number despite a slightly lower mean leaf area ) In short-term experiments both Acropol and Polycote S720 reduced carbon dioxide uptake in the light and carbon dioxide output in the dark. When Acropol was applied to plants in the field it did not affect the rate of sugar accumulation In grapes.
Response to partial selection on clean fleece weight in South Australian strong-wool Merino sheep
Authors: Mayo O , Potter JC , Brady RE , Hooper CW
Published: November 2004

This paper reports the results of an experiment carried out at Roseworthy Agricultural College from 1953 to 1966 comparing two bases of selection of rams: (1) visual appraisal (the "visual" method); (2) visual culling of 70% of rams followed by selection of breeding animals from the remaining 30% on the basis of clean fleece weight (the "index" method). No selection for fleece weight was practiced on ewes. Seven rams were used in each of the two flocks, and six of the seven were replaced each year by 16-month-old animals from the succeeding drop, the seventh being a year older. Rams used for breeding in the Index flock were significantly higher in clean fleece weight than those of the Visual flock, and were higher, though not always significantly so, in greasy fleece weight. This led to a divergence between the flocks for clean fleece weight (P < 0.05), with an increase of c. 0.05 lb per year per head for the Index animals over the Visual animals. The Index rams were more wrinkly and lighter, on the whole, than the Visual rams, and the wrinkly effect carried over into their offspring with a slight divergence apparent, the Index animals becoming more wrinkled than the Visual (P < 0.05). In fibre diameter there were no differences between selected animals or between flocks. Visual rams tended to have more crimps per inch in their wool, and this was observed in the flocks also, but the divergence was not significant (P > 0.05). Index rams had longer wool than Visual rams, with the difference generally significant within years, and this tendency carried over in a lesser manner to the flocks. Fleece density was generally greater in the Index group, though not usually significantly so. This experiment did not include a randomly bred control flock, but was rather designed to compare two practical methods of selecting rams. Merits of this scheme are discussed in the light of both groups' failure to show increases in fleece weight over the course of the experiment
Corrigendum - Response to partial selection on clean fleece weight in South Australian strong-wool Merino sheep
Authors: Mayo O , Potter JC , Brady RE , Hooper CW
Published: November 2004

This paper reports the results of an experiment carried out at Roseworthy Agricultural College from 1953 to 1966 comparing two bases of selection of rams: (1) visual appraisal (the "visual" method); (2) visual culling of 70% of rams followed by selection of breeding animals from the remaining 30% on the basis of clean fleece weight (the "index" method). No selection for fleece weight was practiced on ewes. Seven rams were used in each of the two flocks, and six of the seven were replaced each year by 16-month-old animals from the succeeding drop, the seventh being a year older. Rams used for breeding in the Index flock were significantly higher in clean fleece weight than those of the Visual flock, and were higher, though not always significantly so, in greasy fleece weight. This led to a divergence between the flocks for clean fleece weight (P < 0.05), with an increase of c. 0.05 lb per year per head for the Index animals over the Visual animals. The Index rams were more wrinkly and lighter, on the whole, than the Visual rams, and the wrinkly effect carried over into their offspring with a slight divergence apparent, the Index animals becoming more wrinkled than the Visual (P < 0.05). In fibre diameter there were no differences between selected animals or between flocks. Visual rams tended to have more crimps per inch in their wool, and this was observed in the flocks also, but the divergence was not significant (P > 0.05). Index rams had longer wool than Visual rams, with the difference generally significant within years, and this tendency carried over in a lesser manner to the flocks. Fleece density was generally greater in the Index group, though not usually significantly so. This experiment did not include a randomly bred control flock, but was rather designed to compare two practical methods of selecting rams. Merits of this scheme are discussed in the light of both groups' failure to show increases in fleece weight over the course of the experiment
Developmental growth and body weight loss of cattle. IV. Chemical components of the commercially dressed and jointed carcass
Authors: Seebeck RM , Tulloh NM
Published: November 2004

This paper describes a study of chemical components of the carcasses from Angus steers. The left side of each carcass was jointed commercially and each joint was analysed for protein (N x 6.25), water, ash, and fat (ether extract). Two groups of steers were used, viz. group A which grew continuously and group B which grew like group A and were then subjected to a period of weight loss before slaughter. Corresponding animals in both groups were killed at the same body weight. Statistical analysis was by analyses of covariance of the weights of components converted to logarithms. As carcass weight increased, the proportions in the carcass of protein, water, and ash decreased while the proportion of chemical fat increased. When carcass composition was calculated on a fat-free basis, there were significant changes in the proportions of protein, water, and ash as the weight of the fat-free carcass increased during the age range of 12 to 24 months. These are contrary indications to the theory of chemical maturity put forward by Moulton (1923). As carcass weight increased, the weight of each chemical component increased but changes occurred in the distribution throughout the carcass of protein, ash, and chemical fat. The effect of the weight loss treatment on the proportion of each chemical component was independent of carcass weight. When group A and group B animals were compared at the same carcass weight, weight loss led to a significant increase in the proportion of ash and a significant decrease in that of protein. The weight of ash in group B carcasses was estimated to be slightly less than that expected in these animals at their peak of body weight, i.e. before weight loss commenced. There were significant differences between groups A and B in the distribution of the chemical components (particularly protein and fat); these treatment differences in distribution indicate a limitation to the use of chemical analyses of a single joint for predicting whole carcass composition. When relationships between chemical and dissected components were studied, each single chemical component was well related to its corresponding dissected component. For each dissected component except muscle, however, there were significant differences between groups A and B in the equation of best fit, either in slope or in the intercept (difference between adjusted means). Differences of this type limit the use of chemical analysis for estimating dissected components where differences between groups are being studied.
The influence of annual and perennial irrigated pastures on soil fertility as shown by the yield and quality of a subsequent wheat crop
Authors: Rixon AJ
Published: November 2004

Three annual and three perennial pastures produced on a red-brown earth and consisting respectively of a legume, a grass, and the same grass supplied with fertilizer nitrogen were ploughed up and sown to wheat. The physical properties of the various pasture soils after cultivation were similar. After perennial pastures the yields of wheat were greater than after annual pastures. Nitrogen applied to the wheat crop at the rate of 112 kg/ha cancelled the differences in grain yields, which indicated that differential mineralization of nitrogen following annual and perennial pastures caused the yield differences. The observed differences in yield were unrelated or poorly related to simple chemical estimates of available nitrogen. The amounts of nitrate present after 2 weeks' incubation of the soils collected at sowing were greater after perennial pastures, and were related to the vegetative yields, the number of fertile tillers, grain yields, and the nitrogen uptake of the wheat crop. At all levels of available nitrogen, there was a 2 : 1 ratio between nitrogen in the grain and in straw plus chaff. Grain protein and gluten protein contents increased with nitrogen uptake and were inversely related to the extent of mottling.
The relationship between strains of Fusarium graminearum schwabe causing crown rot of various gramineous hosts and stalk rot of maize in Queensland
Authors: Purss GS
Published: November 2004

The fungus Fusarium graminearum is shown to have a wide host range on gramineous plants in Queensland. Isolates from hosts other than maize when inoculated onto wheat seed were capable of causing the disease known as crown rot in resulting plants. The same disease was reproduced by wheat isolates in other gramineous hosts including canary grass (Phalaris canariensis), barley, and rye but oats was only slightly susceptible. No symptoms typical of field infection could be reproduced in maize. Root rot occurred in linseed. The perfect state of the organism as it occurs in Queensland is described and identified as Gibberella zeae. This was reproduced experimentally, easily in the case of maize isolates but only with some difficulty with isolates from other hosts. The occurrence in Queensland of pathogenic races of Gibberella zeae is postulated.
Traps, male lures, and a warning system for Queensland fruit fly, Dacus tryoni (Frogg.) (Diptera, Trypetidae)
Authors: Monro J , Richardson NL
Published: November 2004

The attractiveness of eight prospective lures for male Queensland fruit fly was tested in a simple olfactometer. Six of these compounds were found to be attractive and these were ranked in field trials in which traps were baited with a mixture of each lure and malathion.Trap catches varied with lure, trapping site, weather (including wind speed), and season. Cue lure, 4-(p-acetoxyphenyl)butan-2-one, was the most attractive compound. Baits made by mixing cue lure and malathion were of unchanged attractiveness after more than 6 months but mixtures of cue lure and DDVP declined in attractiveness within 6–12 days. Funnel traps baited with cue lure and malathion and spaced 0.4 km apart in a square grid pattern caught 4.1% of newly emergent flies and 9% of mature flies (2–3 weeks old) released in the centre of the grid. The use of such a grid in early warning systems is discussed.
Seedling growth of summer-dormant and non-dormant ryegrasses in relation to temperature
Authors: Silsbury JH
Published: November 2004

Lolium rigidum Gaud. and a summer-dormant and a non-dormant form of Lolium perenne L. were grown as seedling plants for 32 days in controlled environment cabinets at constant temperatures of either 10, 20, or 30°C and in all cases with a 16-hr photoperiod at a light intensity of 3600 lm ft-2. Sampling at 4-day intervals permitted the detailed examination of dry matter growth curves. Differences in total dry matter production were related to initial differences in seedling dry weight, and the general responses to temperature were similar for each ryegrass. Total dry matter production was greatest at 20°C and lowest at 10°. A temperature of 30° did not induce dormancy in the summer-dormant ryegrass but did depress growth. Relative growth rate fell with time at each temperature.
The effects of some variables on the components of reproduction rate in the Merino
Authors: De Haas HJ , Dunlop AA
Published: November 2004

Reproductive records covering 4855 ewe-years coming from five strains of Merino ewe run at three locations over 5 years were classified into those which resulted in (a) failure to lamb, (b) a single birth, or (c) a multiple birth. Age of ewe was included as a further classification, while pre-mating body weight was considered as a covariate. The data were analysed by least squares procedures. In all analyses in which components of variance were estimated, error variance constituted more than 90% of the total. Of the main effects, those due to age were generally largest, particularly where they related to the proportion of dry ewes and multiple births, though year effects on the proportion of dry ewes ranged up to 0.10. The effects of pre-mating body weight on lambing performance were small though real, the largest being an increase of 0.37% of multiple births per pound increase in body weight. First order interactions were generally small, the most prominent being location x strain, location x age, and location x year. The third of these had the largest effects and accounted for more of the variance. This was particularly so in the proportions of dry ewes and single births. Location x age interactions, on the other hand, were more prominent in affecting the proportion of multiple births, where the increase with age was much less marked at one location than at the other two. Strain x location interactions were not large enough to suggest any marked adaptation of strains to particular locations in these mutually dependent traits.
The comparative applied phosphate requirements of eight annual pasture species
Authors: Ozanne PG , Keay J , Biddiscombe EF
Published: November 2004

The effects of a wide range of applied phosphate levels were compared on eight annual pasture species. Marked differences were found between species in response by tops, roots, or whole plant, and in top/root ratio. Different forms of yield response curve were given by the non-legumes, the clovers, and the lupin. At an early growth stage cape-weed, the three clovers, and erodium were highest in phosphorus requirement for near-maximum yield. At the full flowering stage, species ranked in the following decreasing order of requirement: cupped clover > rose clover > subterranean clover > lupin > erodium = cape-weed > Wimmera ryegrass = silver grass. Yields and phosphorus concentrations are compared in relation to applied phosphorus levels. In the early vegetative stage, all species needed at least 0.7% phosphorus in the tops for maximum yield, but by flowering this requirement had fallen to very much lower levels. It is suggested that differences between the species in response to applied phosphate are large enough to influence strongly the botanical composition of pasture and its fertilizer requirements.
A comparison of growth rates and phosphorus distribution in a range of pasture species
Authors: Biddiscombe EF , Ozanne PG , Barrow NJ , Keay J
Published: November 2004

Relative growth rates (RGR) of nine annual pasture species and lucerne were compared in two experiments. During the first 4 weeks of growth the RGR of the clovers tended to be slower than that of the herbs and grasses, especially at low levels of applied phosphate. This situation was reversed towards maturity. Slow RGR of the tops of the clovers at low phosphorus levels was associated with the development of large root systems relative to tops; but at least in subterranean clover, the RGR of the roots was also slow. Other associated characteristics of the clovers, a month from emergence and at low phosphorus levels, were low phosphorus concentrations in the tops relative to non-legumes, and a low proportion of their total phosphorus in the tops. The phosphorus content per unit weight of clover roots was low under these conditions. Differences between species in early growth rate were maintained on different sods, even though the soil solution contained widely different concentrations of phosphate. Establishment of species In the field, particularly during the seedling stage, is discussed in relation to growth rates at low and optimal levels of phosphorus.
The establishment and survival of Oesophagostomum columbianum in male and female sheep given high and low protein diets
Authors: Bawden RJ
Published: November 2004

Young sheep fed on a low protein (6%) diet were more susceptible to infection with O. columbianum than those on a high protein (18%) diet. Both the number of adult nematodes recovered 56 days after infection, and the fecundity of the female worms prior to autopsy, were greater in the former group. Examinations at the 10th and 56th days after infection revealed a marked reduction with time in the numbers and extent of distribution of macroscopic nodules, associated with the parasite, throughout the intestines; no differences associated with the diet were recorded. Differences in the susceptibility of the host were also associated with the host's sex. Thus the male sheep generally harboured more adult nematodes than the female sheep at autopsy. This effect was most pronounced with the sheep on the low protein diet. The female nematodes which parasitized the female sheep were more fecund than those in the male sheep.
Multivariate analysis approach to selection of parents for hybridization aiming at yield improvement in self-pollinated crops
Authors: Bhatt GM
Published: November 2004

A method of choosing parents for hybridization (aiming at yield improvement) by quantitatively measuring the genetic divergence is described, with the use of data on several characters measured on 40 genotypes of wheat (Triticum aestivum) which had their origin in different ecogeographic regions of Australia. The genotypes were grouped into 12 gene constellations by this method. The method of formulating a crossing programme based on the information on statistical distance between different gene constellations is discussed briefly.
Factors affecting the urinary excretion of urea nitrogen in cattle. I. Sodium chloride and water loads
Authors: Thornton RF
Published: November 2004

Urea metabolism in cattle was studied under conditions of different nitrogen, sodium chloride, and water intakes. Urea supplementation increased the concentrations of ammonia and trichloroacetic acid-insoluble nitrogen in ventral rumen fluid, raised the plasma urea concentration, and increased the excretion of faecal nitrogen and urinary urea and non-urea nitrogen. Sodium chloride loading increased the free water intake and urine flow rate, and the added sodium was quantitatively recovered in the urine. Plasma urea concentration was linearly related to urinary urea excretion but the slope of this relationship was influenced by the urine flow rate. Urea clearance and the fraction of filtered urea excreted were both related to the urine flow rate and to the urine-concentrating ability of the kidney, but not to the urinary urea output. During low nitrogen intakes, urinary urea excretion was influenced more by urine flow than by solute load.
Studies on the productivity of tropical pasture plants. II. Growth analysis, photosynthesis, and respiration of 20 species of grasses and legumes in a controlled environment
Authors: Ludlow MM , Wilson GL
Published: November 2004

A previous study of one grass and one legume at early vegetative stages has been extended to include a further nine species of each. It confirms the superior relative growth rates (RW) of grasses, arising from very high net assimilation rates (EA), in turn dependent on high photosynthetic rates (P). Leaf area ratios (FA) varied over a similar range in both groups. RW values of grasses in the second week after sowing varied from 0.41 to 0.55 gg-1 day-1; for legumes, they were 0.31-0.36. Corresponding EA values were 1.5-1.9 g dm-2 wk-1 in grasses, and 1.1-1.8 in legumes. Within both grasses and legumes, comparisons between species can be made with less certainty. In grasses, variation in FA combined with generally uniform EA values resulted in variable RW values. Both FA and EA varied in the legumes but were usually compensatory, leading to uniformity in RW. Watson and Hayashi's method of separating EA into photosynthetic and respiratory components was used. Differences both between and within grasses and legumes were shown, but there are probably important errors in this technique, particularly where there are discrepancies between light and dark respiration.
Control of oestrus and ovulation by progesterone and cronolone administered either intramuscularly or intravaginally and subsequent fertility
Authors: Holst PJ , Moore NW
Published: November 2004

A factorial test involving 960 cyclic Merino ewes was carried out to compare the effectiveness of two progestagens (progesterone and 17~-acetoxy-901-fluoro-11Phydroxypregn- 4-ene-3,20-dione: Cronolone) administered either by daily intramuscular injection (i/m) or by intravaginal sponge (i/vag) for the control of oestrus and ovulation. Other factors included in the test were dose of progestagen (three doses for each progestagen and method of administration), day of oestrous cycle on which treatment commenced (day 2, 6, 10, or I4), and method of mating (natural service or artificial insemination). An additional 160 untreated ewes were included as controls. Of the 960 ewes which were treated, 677 were detected in oestrus within 5 days after treatment and the onset of oestrus was earlier and more precise after intravaginal than after intramuscular treatment. There were significant effects of method of administration and of dose of progestagen on the number of ewes in which oestrus was controlled, but there were no effects of day of commencing treatment. Overall, treatment depressed fertility to both artificial insemination and natural service. Of the 677 ewes in which oestrus was controlled, 362 (54%) lambed compared with 110 of 160 control ewes (69%). However, two particular treatments, 12 mg/day progesterone by injection and 24 mg Cronolone by sponge, gave lambing performances comparable with that of control ewes. In addition both treatments gave excellent control of oestrus and ovulation.
Nodulation and growth of Medicago truncatula on acid soils. II. Colonization of acid soils by Rhizobium meliloti
Authors: Robson AD , Loneragan JF
Published: November 2004

Six strains of Rhizobium meliloti varied greatly in their ability to colonize two moderately acid sandy soils (pH 5.0-5.1 in 115 suspension of soil in 0.01M calcium chloride) in the year of sowing inoculated lime-coated seeds of Medicago truncatula. The strains also varied in their ability to nodulate M. truncatula in the year after sowing. With all rhizobial strains and on both soils, calcium carbonate applied in the year of sowing strongly promoted colonization in the year of sowing. It also greatly increased nodulation and growth of M. truncatula in the year after sowing. Apparently calcium carbonate increased second year nodulation by promoting the colonization of the acid soils by R. meliloti in the year of sowing. Differences among strains in second year nodulation appeared to be related to differences in the ability of the strains to colonize the soils in the year of sowing. Strains isolated from moderately acid sandy soils were markedly superior in both properties, and on both soils, to strain SU47 from commercial inoculum, but were generally no better than strain U45 from commercial inoculum. Even the most acid-tolerant strains colonized the acid soils relatively slowly. It is suggested that R. meliloti strains in general have a poor ability to colonize acid soils and that this property is a major factor limiting the growth and persistence of annual Medicago species on acid soils in the field.
Epidemiology of lettuce necrotic yellow virus in South Australia. I. Relationship between disease incidence and activity of Hyperomyzus lactucae L
Authors: Randles JW , Crowley NC
Published: November 2004

The seasonal incidence of lettuce necrotic yellows virus (LNYV) was investigated over a period of 19 months in lettuce crops at a site near Adelaide. Incidence was high in November and December 1965 and in May 1966 but was negligible in crops grown at other times. A constant association was observed between high disease incidence and increased migratory activity of Hyperomyzus lactucae. Peaks in the incidence of LNYV were observed 4-5 weeks after peak numbers of alate H. lactucae were trapped. Of the aphid species trapped at this site, it appears that H. Iactucae was the sole important vector of LNYV. Comparatively large numbers of alate H. lactucae were trapped only when mean weekly temperatures were in the range 60-72�F. It is suggested that meteorological data could be used in conjunction with observations of aphid populations to determine periods when spread of LNYV is likely.