Predictions of likely theft by ants of oversown seed for the Northern Tablelands of New South Wales

1976 ◽  
Vol 16 (79) ◽  
pp. 257 ◽  
Author(s):  
GG Johns ◽  
LR Greenup

At Armidale, New South Wales, ant theft rates of pasture seeds at sites that had been topdressed with 10 kg ha-1 seed immediately before a four day observation period averaged 27 per cent less than on areas where no such application was made. Strong regression relationships were established between theft rates of the various seed types and both air and soil temperatures, but no relationship was found between either relative humidity or soil water availability and theft rate. High theft rates recorded in the first 24 hours after seed placement were not sustained over longer periods of time. A relationship between the decline in theft rate and the quantity of seed available was established. A series of predictions have been made of the proportion of seed likely to remain during fine weather following oversowing in the Armidale environment. These predictions incorporate seed type, time since sowing and prevailing air temperatures. It is predicted that during winter 70 to 80 per cent of bare seed and 90 to 97 per cent of coated seed could remain 30 days after oversowing. During summer the comparable figures are 7 to 30 per cent and 22 to 36 per cent respectively.

1967 ◽  
Vol 7 (27) ◽  
pp. 372 ◽  
Author(s):  
H Philpotts

In two pot experiments at Narrabri, New South Wales, Poona cowpeas (Vigna sinensis) were sown in a black chernozemic soil at 1, 2, and 4 inches, and at 1 1/2 and 4 inches with and without a straw mulch, to give a range of soil temperatures at the depth of sowing. It was found that the higher the soil temperature at sowing depth the lower was the percentage of plants with nodules and the number of nodules per plant.


1969 ◽  
Vol 17 (4) ◽  
pp. 655 ◽  
Author(s):  
EM Russell

Types of habitat in which euros were seen during the day in summer in the far west of New South Wales are described. At air temperatures between 32.5 and 42.5�C, more animals were seen in shelters among a rocky outcrop providing almost complete protection from solar radiation than among dense tree-shrub shelters which did not afford the same degree of protection. At lower air temperatures, more animals were seen in tree-shrub shelters. The most noticeable features of the behaviour of the animals in these shelters were the relatively high proportion of time spent standing crouched and the time spent licking forelimbs and abdomen in relation to any other grooming activity. Time spent licking tends to increase at higher temperatures, and there is also a slight positive correlation between time spent standing and temperature.


1985 ◽  
Vol 12 (3) ◽  
pp. 387 ◽  
Author(s):  
I Parer ◽  
JA Libke

Rabbit warrens in a semiarid environment of New South Wales were concentrated in those areas where impact penetrometer readings indicated friable soil to a depth of at least 75 cm. Isolated warrens in areas with few warrens were found in restricted patches of favourable soil. The absence of warrens from areas with shallow soil was considered to be due to high soil temperatures. The distribution of the rabbit in Australia was examined in relation to deep soil temperatures. It was suggested that the application of bituminous coating on ripped warrens may be a useful technique for the control of rabbits in the arid zone.


1976 ◽  
Vol 1 (1) ◽  
pp. 7 ◽  
Author(s):  
AD Wilson ◽  
WE Mulham ◽  
JH Leigh

In a Belah - Rosewood woodland in western New South Wales, stocking with feral goats over a four year period effected changes in the composition of the tree and shrub component. The most readily browsed tree was Rosewood and mature trees of this species were stripped of foliage to a height of 2 m. At an early stage Desert broombush (Templetonia egena) and young Warrior bush (Apophyllum anomalum) were severely damaged and young Yarran (Acacia homalophylla) and Belah defoliated. Most defoliated Yarran died within the observation period. Two shrubs regarded as weed species, Punty bush (Cassia eremophila var. platypoda) and Desert cassia (C. eremophila var. coriacea) were heavily browsed in the third year and subsequently eliminated. The weed shrub Turpentine (Eremophila sturtizl was not browsed at any time.


1976 ◽  
Vol 16 (79) ◽  
pp. 249 ◽  
Author(s):  
GG Johns ◽  
LR Greenup

To obtain probability information for the theft of oversown seed by ants in northern New South Wales, the seasonal pattern of theft of both bare and coated seed of Trifolium repens, Medicago sativa, Festuca arundinacea and Phalaris tuberosa was monitored at both Armidale and Tamworth. Average values for seed removed within 24 hours of placement ranged from < 1 per cent at Armidale and c. 25 per cent at Tamworth during winter to summer values of c. 40 per cent and c. 90 per cent for the two locations respectively. It was concluded that the theft of oversown seed by ants could be a problem in any month at Tamworth and in all but the winter months at Armidale. At both locations more phalaris seed was taken than seed of other species. Using coated seed significantly reduced theft at both locations. However, it was considered that the coating effect may often be of little practical value. At Armidale, theft rates from sites on a lateritic podsol were on average 47 per cent greater than the rates observed at sites on a black earth soil type. Theft rate was related to mean air temperature at both Armidale and Tamworth. For both bare and coated seed the theft rate for a particular temperature was generally much greater at Tamworth than at Armidale. Because of the spatial variability of theft encountered at both locations it was concluded that a simple exponential type extrapolation from the 24 hour theft data for longer periods of time would be unwise.


1994 ◽  
Vol 34 (8) ◽  
pp. 1197 ◽  
Author(s):  
GG Johns

Legume groundcovers have been promoted for controlling soil erosion in hillside banana plantations in northern New South Wales. An experiment was conducted at Alstonville to determine the effect of an Arachis pintoi (Pinto peanut) groundcover on banana productivity. The Arachis groundcover was slow to establish in the first year, but thereafter grew vigorously. While standing dry matter of groundcover was reduced at closer banana plant spacings, it was always more than adequate to control erosion. After 5.5 years many soil chemical parameters had been significantly affected by the presence of groundcover. Organic carbon concentrations to 30 cm depth were 5.6% greater on the groundcover plots (3.94 v. 3.71%), and total nitrogen was 8.5% greater (0.42 v. 0.39%). Other increases were exchangeable potassium 52%, calcium 26%, magnesium 43%, sodium 23%, electrical conductivity 24%, and pH 0.13 units. Banana leaf nutrient concentrations were not affected. Banana plants with groundcover produced 9% fewer bunches than their bare soil counterparts, with 4% fewer fingers per bunch. By the end of the experiment, fingers on the groundcover treatment were 9% lighter; consequently, the weight of marketable fruit (i.e. >120 g/finger) per bunch was reduced by 31% in the final year. The presence of groundcover reduced total fruit production over the whole trial by 16% and marketable fruit by 19%. In the last year of the experiment, total fruit production was reduced by 25%, and marketable fruit production by 40%. Over the whole trial, banana plants with groundcover produced 22% fewer suckers than the bare soil controls, with most of the effect occurring in the first 2 years. Soil temperatures at 20 cm under groundcover were as much as 0.7�C cooler than the controls in October-January, but similar for the rest of the year. This effect possibly contributed to decreased yields. Although the experiment was irrigated, the irrigation was possibly inadequate for the groundcover treatment, and competition for water between the Arachis and banana plants may also have been responsible for part of the yield depression. Rats fed on the buried Arachis seed each winter.


1975 ◽  
Vol 15 (77) ◽  
pp. 818 ◽  
Author(s):  
H Marcellos ◽  
WV Single

Plant and air temperatures were measured during radiation frost within a crop of wheat (Triticum aestivum cv. Timgalen) grown in 1974 on the Liverpool Plains Field Station, Breeza, New South Wales. Observations were made at different heights within the canopy at several stages of crop development, and these were related to screen and grass minimum temperatures recorded in a meteorological enclosure adjacent to the crop. Coldest conditions were found near the surface of the crop where temperatures were as much as 2�C lower than those in middle regions of the canopy. The temperature just below the soil surface was between 4� and 6�C warmer than that of plant or air at 5 cm to 10 cm above its surface. Grass minimum temperature was linearly related to screen minimum and found to be 3�C lower. Either measurement was useful in estimating the lowest temperature within that canopy.


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