Longevity of zinc phosphide on wheat bait in tropical Australia

2001 ◽  
Vol 28 (3) ◽  
pp. 261
Author(s):  
Laurie E. Twigg ◽  
Gary R. Martin ◽  
Noel Wilson ◽  
Derek Goddard ◽  
Richard Watkins ◽  
...  
Keyword(s):  
Western Australia ◽  
Zinc Phosphide ◽  
Agricultural Crops ◽  
Wet Season ◽  
Total Rainfall ◽  
Rainfall Events ◽  
Tropical Environments ◽  
Whole Wheat ◽  
Tropical Australia ◽  
Bait Stations

The longevity of zinc phosphide (ZP) on whole wheat bait (2.5% A.I.) was determined at the end of the ‘dry’ and ‘wet’ seasons at Kununurra, Western Australia, the time when rats can damage agricultural crops. While the total rainfall during the two trials was 74 mm and 155 mm, substantial loss of ZP was recorded only after significant rainfall events. Irrespective of season, the loss of ZP from bait applied in bait stations was minimal. The maximum recorded loss was 17%, and this occurred after 21 days’ exposure during the wet season where the bait stations were placed in-crop. Bait stations on the adjacent ‘hilled’ fallow recorded only an 8% loss of A.I. during the same period. However, the loss of ZP from exposed, simulated broadcast bait was much greater: 43% and 91% of ZP was lost from the wheat bait within 21 days during the ‘dry’ and ‘wet’ seasons, respectively. Nevertheless, regardless of the application method, sufficient ZP always remained on the wheat bait for it to be theoretically lethal to rats for at least 8–14 days. The potential of ZP bait for controlling rodent pests in tropical environments, and possible associated ‘problems’ of such an approach, are discussed.

Feral pigs in north-western Australia: population recovery after 1080 baiting and further control

2006 ◽  
Vol 33 (5) ◽  
pp. 417 ◽  
Author(s):  
Laurie E. Twigg ◽  
Tim Lowe ◽  
Michael Everett ◽  
Gary Martin
Keyword(s):  
Western Australia ◽  
Population Recovery ◽  
Feral Pigs ◽  
Muddy Water ◽  
Good Body Condition ◽  
Bait Station ◽  
Before And After ◽  
Bait Stations ◽  
North Western ◽  
Fitzroy River

The recovery rate of a population of feral pigs (Sus scrofa) in the west Kimberley in north-western Australia was determined 12 months after a 1080 (sodium fluoroacetate)-baiting program. An estimated 56 pigs were present in the 15 000-ha study area in August 2005 compared with the prebaiting levels of 250–275 pigs in 2004 (11 pigs were known to be alive on site after the 2004 baiting). This represents a population recovery of 20–23% of the 2004 prebaiting levels. Although most pigs were in good body condition, environmental conditions were quite different between the two years. In 2005, some waterholes were dry or comprised mainly muddy water with little associated shelter for feral pigs. Consequently, and in contrast to 2004, no pigs were seen, and no bait take could be attributed to feral pigs, at the four resurveyed waterholes. Most pig sightings, and activity, were close to the Fitzroy River. Fermented wheat, with blood and bone, was used to determine areas of pig activity, and also used as prefeed before 1080-baiting commenced in 2005. Using the same bait stations as for 2004, plus additional stations established in new areas of pig activity, 1080-treated wheat and malted barley again proved highly effective in reducing pig numbers. The daily sighting index before and after 1080-baiting indicated that pig numbers had been reduced by ~90% within four days. Estimated pre- and postpoisoning density, with and without an edge effect, was 0.12–1.7 pigs km–2 and 0.05–0.67 pigs km–2. Pig tracks decreased to zero on the six track plots within two days of baiting, but the number of macropod tracks remained constant over the four-day baiting period. Thirty-eight poisoned pigs were found after 1080-baiting, and these were generally in clustered groups within 200 m of an active bait station. Poisoned juvenile pigs were again found closer to the active bait stations than were adult or subadult pigs (P < 0.05).

The effect of raised beds on soil structure, waterlogging, and productivity on duplex soils in Western Australia

Soil Research ◽  
2005 ◽  
Vol 43 (5) ◽  
pp. 575 ◽  
Author(s):  
D. M. Bakker ◽  
G. J. Hamilton ◽  
D. J. Houlbrooke ◽  
C. Spann
Keyword(s):  
Western Australia ◽  
Soil Structure ◽  
Root Zone ◽  
Infiltration Rate ◽  
Climatic Conditions ◽  
Agricultural Crops ◽  
Yield Increase ◽  
Major Constraint ◽  
No Till ◽  
Poor Soil

Waterlogging and poor soil structure in the root-zone of duplex soils in Western Australia has long been recognised as a major constraint to the production of agricultural crops and pastures. The effect of raised beds on waterlogging, soil structure, and productivity of duplex soils was investigated. Five experimental sites were established, monitored, and operated over 5 years as well as 3 larger scale demonstration sites which were operated over 4 or 3 years. Treatments consisted of raised beds and a normal no-till seed bed as the control. The beds were made with a bed former after the soil had been deep cultivated. Bulk density and steady-state infiltration rate observations indicated significant and lasting improvements in soil structure in the beds. The incidence of waterlogging in raised beds was reduced and this was accompanied by an increase in runoff from the raised beds. The average grain yield increase from the beds was 18% for a variety of crops across a range of climatic conditions and duplex soils. Seven years after the introduction of raised beds for broad-acre farming in Western Australia, more than an estimated 30 000 ha of crops is now grown on raised beds.

scholarly journals Individual Rainfall Change Based on Observed Hourly Precipitation Records on the Chinese Loess Plateau from 1983 to 2012

Water ◽  
2020 ◽  
Vol 12 (8) ◽  
pp. 2268
Author(s):  
Wenbin Ding ◽  
Fei Wang ◽  
Kai Jin ◽  
Jianqiao Han ◽  
Qiang Yu ◽  
...  
Keyword(s):  
Loess Plateau ◽  
Heavy Rainfall ◽  
Rainfall Intensity ◽  
Rainfall Amount ◽  
The Loess Plateau ◽  
Total Rainfall ◽  
Rainfall Events ◽  
Rainfall Duration ◽  
Rainfall Frequency ◽  
Annual Total

The magnitude and spatiotemporal distribution of precipitation are the main drivers of hydrologic and agricultural processes in soil moisture, runoff generation, soil erosion, vegetation growth and agriculture activities on the Loess Plateau (LP). This study detects the spatiotemporal variations of individual rainfall events during a rainy season (RS) from May to September based on the hourly precipitation data measured at 87 stations on the LP from 1983 to 2012. The incidence and contribution rates were calculated for all classes of rainfall duration and intensity to identify the dominant contribution to the rainfall amount and frequency variations. The trend rates of regional mean annual total rainfall amount (ATR) and annual mean rainfall intensity (ARI) were 0.43 mm/year and 0.002 mm/h/year in the RS for 1983–2012, respectively. However, the regional mean annual total rainfall frequency (ARF) and rainfall events (ATE) were −0.27 h/year and −0.11 times/year, respectively. In terms of spatial patterns, an increase in ATR appeared in most areas except for the southwest, while the ARI increased throughout the study region, with particularly higher values in the northwest and southeast. Areas of decreasing ARF occurred mainly in the northwest and central south of the LP, while ATE was found in most areas except for the northeast. Short-duration (≤6 h) and light rainfall events occurred mostly on the LP, accounting for 69.89% and 72.48% of total rainfall events, respectively. Long-duration (≥7 h) and moderate rainfall events contributed to the total rainfall amount by 70.64% and 66.73% of the total rainfall amount, respectively. Rainfall frequency contributed the most to the variations of rainfall amount for light and moderate rainfall events, while rainfall intensity played an important role in heavy rainfall and rainstorms. The variation in rainfall frequency for moderate rainfall, heavy rainfall, and rainstorms is mainly affected by rainfall duration, while rainfall event was identified as a critical factor for light rainfall. The characteristics in rainfall variations on the Loess Plateau revealed in this study can provide useful information for sustainable water resources management and plans.

Response of soybeans to sowing date during the wet season in the Ord Irrigation Area, Western Australia

1988 ◽  
Vol 28 (3) ◽  
pp. 357 ◽  
Author(s):  
DF Beech ◽  
AL Garside ◽  
IM Wood
Keyword(s):  
Western Australia ◽  
Cropping Systems ◽  
Plant Morphology ◽  
Sowing Date ◽  
Wet Season ◽  
Double Cropping ◽  
Affected Plant ◽  
Pod Development ◽  
Late Maturity ◽  
Seed Yields

The responses of 3 soybean cultivars to sowing date during the wet season in the Ord Imgation Area (OIA) in northern Western Australia are described. The cultivars, Buchanan, Ross and Durack, are classified as early, medium and late maturity respectively, when grown during the wet season in the OIA. The cultivars were grown 10 times between 22 December and 18 April during 2 wet seasons and we investigated the patterns of phenology, growth and seed production. Sowing date had no significant effect (P> 0.05) on the time to flowering (26-36 days) with cv. Buchanan, but the duration of flowering was curtaiied so that the period from sowing to maturity declined from 120 to 95 days as sowing was delayed from December to April. In contrast the time to flowering of cv. Durack declined in response to photoperiod from about 70 to 40 days and the time from sowing to maturity declined from about 160 to 100 days. The responses of cv. Ross were intermediate between those of Buchanan and Durack. The phenological responses to sowing date were consistent with responses to photoperiod rather than to temperature. Sowing date also affected plant morphology and yields and quality of seed. Delay in sowing after December led to declines in above-ground dry matter yields at flowering, in number of nodes on the main stem at flowering, crop height at maturity and seed yields. Mean individual seed weights increased with delay in sowing. Oil concentrations in the seed declined (from 23 to 17%) and protein concentrations increased (from 32 to 45%) as the period of pod development occurred later in the season. Phenology is a major determinant of the suitability of a cultivar for specific cropping systems. The early maturing cultivar, Buchanan, most closely meets the requirements for a system of double cropping in which the wet season soybean crop is followed by a May sown dry season crop. The late maturing cultivar, Durack, is suitable for a system involving a single wet-season crop.

Scats can reveal the presence and habitat use of cryptic rock-dwelling macropods

2006 ◽  
Vol 54 (5) ◽  
pp. 325 ◽  
Author(s):  
Wendy R. Telfer ◽  
Anthony D. Griffiths ◽  
David M. J. S. Bowman
Keyword(s):  
Habitat Use ◽  
Radio Telemetry ◽  
Classification Tree ◽  
Habitat Preferences ◽  
Wet Season ◽  
Survey Tool ◽  
Faecal Pellets ◽  
Tropical Environments ◽  
The Tropics ◽  
Larger Sample

The rock-dwelling macropod species of the tropics of the Northern Territory, Australia, are behaviourally elusive and difficult to observe in their rugged habitats. Hence, little is understood about their ecology. We evaluated the potential of using scats (faecal pellets) as a survey tool for this faunal assemblage by: (1) developing a key to the scats of the species; (2) examining the rates of loss and decomposition of short-eared rock-wallaby (Petrogale brachyotis) scats in these tropical environments; and (3) comparing the distribution of scats of P. brachyotis with the species’ use of space and habitats as determined with radio-telemetry. Classification tree modelling discriminated the scats of the seven macropod species, primarily on the basis of width. The reliability of identification was greatly improved with larger sample sizes and inclusion of a habitat parameter. Rates of scat loss and decay were variable and the greatest losses occurred in the wet season, particularly on sandy soils. Scat censuses underestimated the total area used by P. brachyotis but the distribution of scats showed the same broad pattern of habitat use found by radio-telemetry. We conclude that scats can accurately indicate the presence and habitat preferences of rock-dwelling macropod species.

scholarly journals The 2018 Long Rainy Season in Kenya: Hydrological Changes and Correlated Land Subsidence

2020 ◽  
Vol 12 (9) ◽  
pp. 1390 ◽  
Author(s):  
Ashraf Rateb ◽  
ElSayed Hermas
Keyword(s):  
Land Subsidence ◽  
Rainy Season ◽  
Active Faults ◽  
Wet Season ◽  
Rainfall Events ◽  
Environmental Disasters ◽  
Hydrological Changes ◽  
The Stability ◽  
Sbas Insar ◽  
Scientific Attention

The wettest 2018 long rainy season (March to May (MAM)) resulted in daily intensive rainfall events in East Africa that have seriously affected the environment and economy in many countries. Land subsidence is one of the environmental disasters that has occurred due to the long rainy season in Kenya for many years. However, it has received limited scientific attention. In this paper, we incorporate hydrological (soil moisture active–passive (SMAP) and loading models) and geodetic data (global positioning system (GPS) and interferometric synthetic aperture radar (InSAR)) to study hydrological changes and their associated subsidence potential in Kenya. Results show that widespread subsidence of more than 20 mm was associated with the MAM season in Kenya during 2018, based on SBAS InSAR measurements. The high values of land subsidence were well correlated with the areas of intense flooding during the MAM season. The widespread subsidence during the wet season has implications for the stability of the earth’s surface during the season rather than creating the possibility of potential stresses along active faults. These stresses may trigger seismicity that is expected to pose risks to urban features. The results of the current study can help governmental authorities to adopt proper urban planning that avoids or minimizes the risks of land subsidence in the areas of sinkholes.

Camaenid Land Sanil Reproductive Cycle and Growth Patterns in Semiarid Areas of North Western Australia

1984 ◽  
Vol 32 (4) ◽  
pp. 471 ◽  
Author(s):  
A Solem ◽  
CC Christensen
Keyword(s):  
Western Australia ◽  
General Pattern ◽  
Growth Patterns ◽  
Land Snails ◽  
Food Storage ◽  
Growth Time ◽  
Wet Season ◽  
Shell Size ◽  
Moisture Conditions ◽  
North Western

Dissections of camaenid land snails collected in the Kimberley Region of north-western Australia between 1975 and 1980 reveal a general pattern of sexual maturation. Snails reach half adult shell size in the wet season of their birth, reach adult shell size and become mature males at the end of their second wet season, and function as males at the beginning of their third wet season; the female genitalia mature near the end of this season; and snails function as both males and females in their fourth and subsequent wet seasons. A life span of >8 years is demonstrated. Seasonal genital variation in adults involves: (1) gross size reduction of the apical genitalia during the mid-wet season, which provides maximum space for food storage, thereby allowing survival during aestivation over the long dry season; (2) becoming male active at or shortly before the normal start ofthe wet season at that particular locality; (3) activation of the female system after the first rains of the wet season. Adult shell size is hypothesized to depend upon moisture conditions near the end ofthe snail's second wet season: any early interruption of moisture supply causes growth to stop at a lower whorl count and produces smaller adults; favourable moisture conditions allow extended growth time, with cessation occurring at a higher whorl count, and producing a larger sized adult.

scholarly journals Quantifying Land Surface Temperature Variability for Two Sahelian Mesoscale Regions during the Wet Season

2013 ◽  
Vol 14 (5) ◽  
pp. 1605-1619 ◽  
Author(s):  
Martin G. De Kauwe ◽  
Christopher M. Taylor ◽  
Philip P. Harris ◽  
Graham P. Weedon ◽  
Richard. J. Ellis
Keyword(s):  
Spectral Analysis ◽  
Surface Temperature ◽  
Land Surface Temperature ◽  
Land Surface ◽  
Land Surface Model ◽  
Surface Model ◽  
Wet Season ◽  
Rainfall Events ◽  
Spectral Variance ◽  
High Level

Abstract Land–atmosphere feedbacks play an important role in the weather and climate of many semiarid regions. These feedbacks are strongly controlled by how the surface responds to precipitation events, which regulate the return of heat and moisture to the atmosphere. Characteristics of the surface can result in both differing amplitudes and rates of warming following rain. Spectral analysis is used to quantify these surface responses to rainfall events using land surface temperature (LST) derived from Earth observations (EOs). The authors analyzed two mesoscale regions in the Sahel and identified distinct differences in the strength of the short-term (&lt;5 days) spectral variance, notably, a shift toward lower-frequency variability in forest pixels relative to nonforest areas and an increase in amplitude with decreasing vegetation cover. Consistent with these spectral signatures, areas of forest and, to a lesser extent, grassland regions were found to warm up more slowly than sparsely vegetated or barren pixels. The authors applied the same spectral analysis method to simulated LST data from the Joint UK Land Environment Simulator (JULES) land surface model. A reasonable level of agreement was found with the EO spectral analysis for two contrasting land surface regions. However, JULES shows a significant underestimate in the magnitude of the observed response to rain compared to EOs. A sensitivity analysis of the JULES model highlights an unrealistically high level of soil water availability as a key deficiency, which dampens the models response to rainfall events.

Efficacy of zinc phosphide, strychnine and chlorpyrifos as rodenticides for the control of house mice in South Australian cereal crops

2004 ◽  
Vol 31 (3) ◽  
pp. 249 ◽  
Author(s):  
Greg Mutze ◽  
Ron Sinclair
Keyword(s):  
Treatment Time ◽  
South Australia ◽  
Growing Season ◽  
Field Trials ◽  
Zinc Phosphide ◽  
Cereal Crops ◽  
House Mice ◽  
Wheat Grain ◽  
Potential Yield ◽  
Whole Wheat

Replicated field trials were conducted to compare the efficacy of zinc phosphide, strychnine and chlorpyrifos for the control of house mice (Mus domesticus) infesting recently sown wheat crops in South Australia. Bait was prepared using whole-wheat grain or grain-based pellets and broadcast into the crops at 1 kg ha–1. Treatment with zinc phosphide reduced mouse numbers by 98%. Two treatments with strychnine baits, applied 11 days apart, also reduced mouse numbers by 98% with no evidence of bait aversion in mice that survived the initial treatment. On the basis of these and other published results, zinc phosphide is considered an effective alternative to strychnine for control of house mice in cereal crops. Chlorpyrifos baits reduced mouse numbers by less than 10%. The trial began too late in the growing season to prevent substantial mouse damage to seed grain and seedlings. The number of seedlings established at treatment time one month after sowing explained 84% of variation in crop yield. Mouse damage is estimated to have reduced yield by more than 0.5 t ha–1 or 15% of potential yield and cost the grower more than $30 000 in lost production from the 300-ha study area.

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