Effects of Low Levels of Lead on Growth and Reproduction of the Asian Earthworm Perionyx excavatus (Oligochaeta)

1999 ◽  
Vol 44 (3) ◽  
pp. 236-240 ◽  
Author(s):  
M.S. Maboeta ◽  
A.J. Reinecke ◽  
S.A. Reinecke
Keyword(s):  
Perionyx Excavatus ◽  
Low Levels ◽  
Growth And Reproduction

Seasonal variations in growth and reproduction of the earthworm Perionyx excavatus (Oligochaeta: Megascolecidae)

1999 ◽  
Vol 28 (4) ◽  
pp. 389-392 ◽  
Author(s):  
V. A. Biradar ◽  
S. D. Amoji ◽  
U. M. Shagoti ◽  
P. M. Biradar
Keyword(s):  
Seasonal Variations ◽  
Perionyx Excavatus ◽  
Growth And Reproduction

Effects of protein meal supplements on the growth and reproduction of Hereford heifers and cows grazing a native grass pasture in the subtropics

1988 ◽  
Vol 28 (4) ◽  
pp. 439 ◽  
Author(s):  
DW Hennessy ◽  
PJ Williamson
Keyword(s):  
New South ◽  
Organic Matter Content ◽  
Matter Content ◽  
Protein Meal ◽  
South Wales ◽  
Digestible Organic Matter ◽  
Low Levels ◽  
Calving Rate ◽  
Growth And Reproduction

In the coastal subtropics of New South Wales, pasture growth occurs mainly in summer, when 500-600 mm of rain is expected. During winter, pasture quality declines, with digestible organic matter content as low as 374 g/kg DM in August and nitrogen down to 6.5 g/kg DM. Growth and reproduction of British breed cattle is also low so that, in an attempt to increase these attributes, protein meal supplements were offered to Hereford heifers and cows over 5 years. Heifers without supplements lost liveweight during their first winter and none calved after being mated at 15 months of age to Hereford bulls during a 9-week joining period. During their second winter, 58% of the heifers calved and, over 5 mating seasons, their mean annual calving rate was 48%. Supplemented heifers gained liveweight during their first winter and 95% of them calved, after first-joining at 15 months of age. Over 5 years their mean calving rate was 85%. Delaying first-joining to 27 months of age, as determined by a second group also supplemented with protein meal, did not increase production or mean calving rate (81%) over 5 years. The 230-day adjusted liveweight of calves weaned from non-supplemented heifers was 138 kg, significantly (P< 0.01) less than the 179 �10 kg (mean � s.e.d.) for calves weaned from the supplemented early-calving group, or 198 kg for the supplemented late-calving group. The results highlight the limitation to cattle production imposed by the low levels of nitrogen and poorly digestible pasture, and emphasise the important role of protein meal supplements with added minerals in increasing production of breeding herds grazing unimproved pastures in the subtropics.

Factors affecting growth and reproduction of Noogoora burr (Xanthium occidentale Bertol.)

1984 ◽  
Vol 35 (2) ◽  
pp. 271 ◽  
Author(s):  
RJ Martin ◽  
JA Carnahan
Keyword(s):  
Plant Density ◽  
Unit Area ◽  
Dry Weight ◽  
Low Light ◽  
Factors Affecting ◽  
Shoot Dry Weight ◽  
High Plant Density ◽  
Low Levels ◽  
Net Assimilation ◽  
Growth And Reproduction

Plant density and availability of light and water significantly affected growth and reproduction of Noogoora burr plants grown in a glasshouse. Burr yield was reduced most by low levels of available water. Low light intensity, low water availability and high plant density reduced net assimilation rates and, in combination, caused the greatest reduction in burr production. Under field conditions the ratio of burr dry weight to total shoot dry weight decreased with increasing plant density. In terms of production per unit area, dry weight of main stems and main stem leaves increased with increasing plant density at the expense of burr dry weight. We conclude that the success of Noogoora burr as a fleece contaminant could be attributed, in part, to: the insensitivity of burr production to variation in soil fertility and length of growing season; the ability to regulate plant density under conditions of limiting light or water; and the ability to regulate plant components so that the efficiency of burr production increases with a decrease in plant density.

Postfire Demography of the Wet-Mallee Eucalyptus luehmanniana F Muell (Myrtaceae)

1991 ◽  
Vol 39 (5) ◽  
pp. 459 ◽  
Author(s):  
SJ Davies ◽  
PJ Myerscough
Keyword(s):  
Water Availability ◽  
Seedling Recruitment ◽  
Seedling Emergence ◽  
Seed Viability ◽  
Experimental Methods ◽  
Low Levels ◽  
Seed Fall ◽  
Experimental Plots ◽  
Mature Population ◽  
Growth And Reproduction

The post-fire demography of Eucalyptus luehmanniana, a wet-mallee eucalypt restricted to the Sydney region, was studied by descriptive and experimental methods. Patterns of growth and reproduction were related to time since the last fire for 15 populations burned from 2 to 24 years previously. After fire, mature individuals (clumps) resprout from subterranean lignotuberous buds producing numerous narrow stems. Resprouted clumps flower within 2-4 years and fruit within 5-6 years of the last fire. Fruits accumulate in the canopy with increasing time, up to at least 24 years since fire. Measurements from one reproductively mature population showed that there is a low level of seed-fall below the canopy (0.98 seeds m-2 day-1) in the absence of fire. Recruitment without fire appears unlikely due to a combination of factors: low seed viability (34.9%, s.e. = 5.3), low levels of field emergence, no soil-stored seed, and a high proportion (86.9%, s.e. = 3.4) of seed failing enclosed in capsules. Canopy-stored seed is released en masse following fire. Three factors potentially influencing the recruitment of E. luehmanniana seedlings, fire-related effects, water availability and protection of developing seedlings from animals, were investigated experimentally in the field. Seedling emergence was uniformly low (2.2-2.6%), and not significantly increased on burned plots, caged plots, or water-added plots alone. In one experiment, plots both burned and caged had significantly higher emergence. Mortality in all experimental plots was 100% within 6 months. Seedling recruitment of E. luehmanniana will not occur following all fires, and will depend on the coincidence of fire with suitable post-fire conditions.

Growth and reproduction of the vermicomposting earthworm Perionyx excavatus as influenced by food materials

1996 ◽  
Vol 24 (1) ◽  
pp. 129-132 ◽  
Author(s):  
M. C. Manna ◽  
M. Singh ◽  
S. Kundu ◽  
A. K. Tripathi ◽  
P. N. Takkar
Keyword(s):  
Perionyx Excavatus ◽  
Growth And Reproduction
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