Impact of broom, Cytisus scoparius (Fabaceae), in naturally treeless sub-alpine frost-hollow vegetation communities at the Barrington Tops, south-eastern Australia

The exotic shrub Cytisus scoparius (L.) Link (family Fabaceae), known as broom, is having a major impact on native vegetation in naturally treeless sub-alpine frost-hollow areas (c. 32o 01’ 37” S, 151o 26’ 12” E’, 1440 m elevation) at the Barrington Tops, New South Wales, in south-eastern Australia. This vegetation is of limited extent and has significant biogeographical and ecological importance. Nine paired 10 m line transects were compared, with one of the pair in areas of almost 100% Cytisus scoparius and the other in adjacent areas without Cytisus scoparius. Results were compared with species recorded from this area in the 1930s. There are obvious differences in native vegetation in areas with and without Cytisus scoparius. On average there were 5.1 (range 2–10) species per 10 m in areas of almost 100% Cytisus scoparius cover and 17.0 (12–25) species per 10 m in areas adjacent to infested areas but without Cytisus scoparius. Other than Cytisus scoparius, the area surveyed had little in the way of exotic species and these were only present at low densities. Native species present in 2008 are similar to those recorded in the 1930s; there were no records of Cytisus scoparius in the area in the 1930s. The study suggests that control of Cytisus scoparius in naturally treeless areas at the Barrington Tops should be a priority to prevent a decline in the distribution and abundance of many plant species, many of which only occur in treeless areas of the Barrington Tops

Endogenous and exogenous control of ovarian dynamics in wapiti

A series of studies were guided by the principal hypothesis that it was necessary to characterize ovarian function during the seasons of the annual reproductive cycle in wapiti and that from this knowledge novel methods of exogenous control of ovarian function would be possible. To augment existing knowledge about endogenous control of ovarian function in wapiti studies were conducted to characterize ovarian follicle dynamics during the estrous season and to characterize ovarian follicular dynamics during the periods of transition into and out of the breeding season. The third study was designed to characterize ovarian follicle development and ovulation synchrony subsequent to an estrous synchronization protocol used commercially. To evaluate novel methods of exogenous control of ovarian function studies were conducted to determine if follicular wave emergence could be electively induced using hormonal or surgical treatments to evaluate novel ovarian superstimulatory treatment protocols. It was concluded from the studies of ovarian function that follicle development during the breeding season was characterized by the regular and synchronous development of follicular waves and that 2, 3, or 4 waves occurred during each interovulatory interval. Transition into the breeding season was preceded by one short interovulatory interval (9 days) characterized by one wave of follicle development and a small, short-lived and hypo-functional corpus luteum. The last estrous cycle of the breeding season was similar to estrous cycles during the rut (21 days), but and transition to anestrus was marked by a failure of the dominant follicle to ovulate after luteal regression. The treatment protocol used commercially for estrous synchronization was effective, but unnecessarily long. It was concluded from the studies on exogenous control of ovarian function that follicular wave emergence could be electively induced using steroid hormones or follicle ablation and may be useful for estrus synchronization and superstimulatory protocols. The tested superstimulatory treatments were effective and had the advantage of reducing the treatment period by 6 days and the number of times the animals are handled by one third over a more conventional method. However, oocyte and embryo quality were not evaluated. As a result of the studies conducted and one previous study during the anouvlatory season follicle and luteal dynamics are now known in wapiti for all seasons of the year and this knowledge will provide a template upon which other species of deer can be compared. The final two studies support the principal hypothesis. The novel methods of exogenous ovarian control tested increase the potential for success when applying reproductive technologies and the successful application of these methods in wapiti should lead to their successful use in other species of deer

Rhizobial inoculation versus nitrogen fertiliser for mungbean, peanut and soybean in rainfed upland areas of Cambodia

The objective of this work was to determine if mung-bean, peanut and soybean respond to rhizobial inoculation under rainfed upland conditions in Cambodia and to compare the response to inoculation with application of a nitrogenous fertiliser. The effect of rhizobial inoculation and fertiliser nitrogen on nodulation and yield of mungbean, peanut and soybean under rainfed upland conditions was studied in a series of 28 experiments in 2004, 2005, and 2006 in the provinces of Kampong Cham and Battambang, Cambodia. Sites were selected on the two main soil groups used for upland crop production: Kompong Siem (vertosol) and Labansiek (ferrosol). Commercial inoculum containing 'Bradyrhizobium' strains specific to the three crops was obtained from Australia. The experiments were of factorial design with two levels of inoculum (nil, plus) and three levels of nitrogen as Urea (0. 40 and 80 kg N/ha) in a split-plot design with three replicates

Can diurnal variation in velocity of grazing pregnant Merino ewes be used to identify lambing?

The development of remote monitoring of animal behaviour will have many implications. One major issue with these technologies is that they generate large datasets. Therefore, methods are required that can reduce these datasets to more manageable sizes and therefore help to improve decision making for livestock management and welfare. It is known that pregnant ewes change their behaviour around lambing, with one observed change being that the ewe drops behind the main flock as lambing approaches. A benefit from knowing when the ewe is about to lamb, or has lambed, could be a reduction in lamb mortality at this critical time. Dobos et al (2010) showed that Bayesian change point analysis could be used to identify the onset of lambing using mean daily speed as a metric. However, there may be other methods that could be used to identify lambing. To test if changes in diurnal variation with velocity as a metric can be used to identify lambing, data from an investigation on shelter use by pregnant grazing Merino ewes (Taylor et al. 2011) was summarised for this analysis. The mean hourly velocities (m/s) calculated from GPS locations taken at 10 minute intervals from five grazing pregnant Merino ewes seven days before lambing, at lambing, three and seven days after lambing (period) were analysed using a mixed model. Variation in hourly velocity between ewes in all periods was high. No significance difference (P>0.05) was found in diurnal variation between periods. Mean hourly velocity peaked at 5h and at 16h for ewes 7d before, 3d after and 7d after lambing. At lambing mean hourly velocity was reduced, with two short peaks at 5h and 9h and two higher peaks at 12h and 20h. Because of the large variation in individual ewe velocity in all periods, further research is required to determine if these changes in peak velocity times correlate with changes in behaviour at lambing

Oberflaechentechnik. Abscheidung von TIN unter Vermeidung von Hochvakuum, Fertigung der Versuchsproben und Pruefung der Schichtqualitaet iim praxisgerechten Test Abschlussbericht

SIGLEAvailable from TIB Hannover: F02B809+a / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Bildung und Forschung, Berlin (Germany)DEGerman

Yield, development and quality response of dual-toxin Bt-cotton to manual simulation of damage by 'Helicoverpa' spp. in Australia

Larvae of Helicoverpa spp. can occasionally be found in Bollgard II® cotton (Gossypium hirsutum L.), raising concerns about the validity of current thresholds for their control. Experiments were conducted in two seasons to test these thresholds using artificial damage to different fruiting structures (squares or bolls or both) at three stages of cotton growth. At early flowering, Bollgard II® cotton plants tolerated 100% square removal from all plants without significant yield loss, indicating substantial compensation primarily through increased survival of subsequently produced fruit. This delay in the fruiting cycle, however, resulted in maturity delays of up to 6-13 d. At peak flowering, only 100% square removal or the combination of 30% boll damage and 100% square removal caused significant yield loss. Compensation in other treatments was primarily through increased boll weight. Square removal or square removal plus boll damage significantly delayed cotton maturity by about 5 d, but boll damage alone did not. At late flowering, the heaviest damage treatments (30% bolls damaged across 50% or all plants) significantly reduced yield, and there was a trend toward lower yield as damage increased, suggesting limited compensation. Boll damage had no effect on cotton maturation at late flowering. Damage distribution (all or half of the plants damaged) affected yield proportional to the amount of damage inflicted. Across all times and treatments, fiber quality was never affected to a degree that incurred price penalties commercially. In commercial fields, we rarely encountered damage levels equivalent to the heavier damage treatments, suggesting that current thresholds are adequate

Preferences of field bollworm larvae for cotton plant structures: impact of Bt and history of survival on Bt crops

Cultivars of Bollgard II® cotton ['Gossypium hirsutum' L. (Malvaceae)] express the cry1Ac and cry2Ab genes from 'Bacillus thuringiensis' Berliner (Bt) and are valuable for managing 'Helicoverpa' spp. in Australia. However, substantial densities of 'Helicoverpa' larvae can survive and feed on flowering Bollgard II® plants. Monitoring demonstrates that this larval survival is not because of physiological resistance. One hypothesis for this occurrence is that larvae have adapted their behaviour to reduce exposure to toxic compounds. The survival and distribution among cotton structures of 'Helicoverpa armigera' (Hübner) (Lepidoptera: Noctuidae) larvae were examined using choice tests. Two hours after introduction to an arena, there were no differences between non-Bt cotton and Bollgard II® in the numbers of larvae on different plant structures. However, 24 and 48 h after their introduction, most larvae on Bollgard II® were on flowers (mean of 80.5%), whereas on non-Bt cotton, many larvae were also on flowers (58.5%), but there was also a considerable proportion (11%) on squares. In a subsequent experiment, we found similar numbers of larvae on the different structures of Bollgard II® plants regardless of whether their parents were collected as survivors on Bollgard II® cotton or non-Bt hosts. Cry1Ac and Cry2Ab expression varied among cotton structures, but there were no significant differences between the two popular Bollgard II® varieties used in this study. Bt toxin levels did not correlate well with the number of larvae among the structures from Bollgard II® plants. Thus, we conclude that although the distribution of Bt-susceptible larvae was somewhat different among plant structures on non-Bt and Bollgard II® cotton, history of survival on Bollgard II® cotton does not significantly impact on this behaviour

How do susceptible 'Helicoverpa' larvae behave on Bollgard II?

Shortly after the widespread adoption of Bollgard II cotton in Australia there were reports that Helicoverpa larvae were surv1vmg in these crops at levels that exceeded the recommended threshold levels for control. In response to these reports, Crop Consultants Australia members were surveyed for data from the 2005-06, 2006-07, and 2007-08 seasons (see the June 2009 issue of The Australian Cottongrower for a full report). This work showed that in any year an average of 15 per cent of the Bollgard U area planted carried larvae at above threshold levels, and that survivors were present in some fields in all cotton growing regions. Survival always occurred during flowering, and could follow low or high egg pressure but was always within the range of one to three larvae per metre. Within a region. survivors were localised to particular fields, and within a field the distribution of larvae could be uniform or patchy. But in general only between 20-60 per cent of plants in a field sustained damage from surviving larvae. Mediumsized larvae were most commonly found on bolls, but were also found in disproportionately large numbers on flowers of Bollgard U cotton. These have relatively low levels of Bt in their components