The effects of cutting frequency on yield of Hunter River lucerne grown at wide and close spacing in the Mediterranean climate of South Australia

1970 ◽  
Vol 10 (46) ◽  
pp. 582 ◽  
Author(s):  
GJ Leach
Keyword(s):  
South Australia ◽  
Late Summer ◽  
Ground Level ◽  
Early Summer ◽  
Late Spring ◽  
Sowing Time ◽  
Wide Spacing ◽  
Close Spacing ◽  
Number Of Stems ◽  
Autumn And Winter

Hunter River lucerne, sown in April, June, and August, was planted out at 60 cm X 60 cm or 20 cm X 20 cm spacings on a red brown earth soil. Plants were cut 2.5 cm above ground level every six to eight weeks (standard cutting), or twice as often (frequent cutting), for two years : the yield of dry matter and number of stems per plant were measured at each cut. Yields were smallest in late summer and autumn, and largest in late spring and early summer. Treatments generally had little effect on the seasonal growth rhythm. Frequent cutting nearly always decreased yields. The relative decrease was greatest when standard cut plants were growing most rapidly in late spring, and it was also greater with wide spacing than close spacing. Wide-spaced plants yielded more per plant, and less per unit area, than close-spaced plants, except in late summer. Sowing time influenced yield only until the middle of the first summer. Number of stems per plant, and the mean weight of each stem, were both smallest in autumn and winter, and largest in spring and early summer. Frequent cutting slightly, and increasingly, decreased stem numbers relative to the number present with standard cutting during the experiment. The number of stems per plant was largest, and generally increased throughout, at wide spacing, whereas at close spacing maximum stem numbers were attained in the establishment year. Weight per stem showed greater seasonal variation than numbers. Low winter yields and low yields with frequent cutting could both be largely attributed to the small stem weights. Some implications of these results for lucerne management, and breeding for yield improvement, are discussed.

scholarly journals Spatial and temporal distribution of phytoplankton in Lake Skadar

2012 ◽  
Vol 64 (2) ◽  
pp. 585-595 ◽  
Author(s):  
Jelena Rakocevic
Keyword(s):  
Spatial Heterogeneity ◽  
Phytoplankton Community ◽  
General Pattern ◽  
Seasonal Succession ◽  
Temporal Distribution ◽  
Late Summer ◽  
Early Summer ◽  
Quantitative Composition ◽  
Autumn And Winter ◽  
Lake Skadar

Phytoplankton seasonal succession and spatial heterogeneity were studied in Lake Skadar from February to December 2004. A total of 167 taxa from 6 algal divisions were observed, with Bacillariophyta being best represented (52.8%). The general pattern of phytoplankton seasonal succession in Lake Skadar was: Bacillariophyta in the spring, Chlorophyta in early summer, Cyanobacteria and Chlorophyta in late summer and Bacillariophyta and Chlorophyta in autumn and winter. Distinct spatial heterogeneity was observed. The central, open part of the lake (pelagic zone) was characterized by dominant euplanktonic species, mostly diatoms, whereas the western and northwestern parts (more isolated and shallower) had higher abundance of greens and blue-greens and a higher percentage of resuspended benthic-epiphytic forms in the phytoplankton community. Comparison with former phytoplankton data showed distinct differences in terms of the qualitative and quantitative composition of the phytoplankton community of Lake Skadar, which indicates lake deterioration.

Seasonal Changes in the Germination Responses of Buried Witchgrass (Panicum capillare) Seeds

Weed Science ◽  
1986 ◽  
Vol 34 (1) ◽  
pp. 22-24 ◽  
Author(s):  
Jerry M. Baskin ◽  
Carol C. Baskin
Keyword(s):  
Seasonal Changes ◽  
Late Summer ◽  
Late Spring ◽  
Seasonal Temperature ◽  
Temperature Changes ◽  
Late Autumn ◽  
Buried Seeds ◽  
Autumn And Winter

Buried seeds of witchgrass (Panicum capillare L., # PANCA) exposed to natural seasonal temperature changes in Lexington, KY, for 0 to 35 months exhibited annual dormancy/nondormancy cycles. Seeds were dormant at maturity in early October. During burial in late autumn and winter, fresh seeds and those that had been buried for 1 and 2 years became nondormant. Nondormant seeds germinated from 76 to 100% in light at daily thermoperiods of 15/6, 20/10, 25/15, 30/15, and 35/20 C, while in darkness they germinated from 1 to 24%. In late spring, seeds lost the ability to germinate in darkness, and by late summer 63 to 100% of them had lost the ability to germinate in light. As seeds became nondormant, they germinated (in light) at high (35/20, 30/15 C) and then at lower (25/15, 20/10, and 15/6 C) temperatures. As seeds reentered dormancy, they lost the ability to germinate (in light) at 15/6 C and at higher thermoperiods 2 to 3 months later.

scholarly journals Fungal Decay of First-Crop and Main-Crop Figs

Plant Disease ◽  
2007 ◽  
Vol 91 (12) ◽  
pp. 1657-1662 ◽  
Author(s):  
Mark A. Doster ◽  
Themis J. Michailides
Keyword(s):  
Aspergillus Niger ◽  
Alternaria Alternata ◽  
Late Summer ◽  
Early Summer ◽  
Late Spring ◽  
Fungal Decay ◽  
Main Crop ◽  
Low Levels ◽  
Serious Disease

Fig cultivars grown in California typically have two crops, although the first crop may be unimportant commercially. The first crop, also known as the breba crop, ripens in late spring and early summer, whereas the main or second crop ripens in late summer. For both cultivars studied, Conadria and Calimyrna, the first-crop figs typically are left in the orchard unharvested. First-crop figs had relatively high levels of fungal decay and tended to have more fungal decay than main-crop figs, especially Alternaria rot (caused by Alternaria alternata and Ulocladium atrum). At least 16 different Aspergillus spp. were found decaying first-crop figs. Fig smut, a serious disease caused by Aspergillus niger and related fungi, usually was present at approximately the same level in first-crop and main-crop figs. Aspergillus spp. known to produce the mycotoxins aflatoxin or ochratoxin were found decaying first-crop figs. Aflatoxin was detected in first-crop figs at low levels similar to those detected in the main-crop figs. Because the abundant spores produced on the first-crop figs can infect main-crop figs, the fungal decay of first-crop figs might result in higher levels of decay for main-crop figs.

scholarly journals Flowering Response of Bougainvillea Cultivars to Dikegulac

HortScience ◽  
1994 ◽  
Vol 29 (4) ◽  
pp. 282-284 ◽  
Author(s):  
J.G. Norcini ◽  
J.H. Aldrich ◽  
J.M. McDowell
Keyword(s):  
Sodium Salt ◽  
Growth Habit ◽  
Foliar Spray ◽  
Late Summer ◽  
Early Summer ◽  
Late Spring ◽  
The Other ◽  
Spray Application ◽  
Flowering Response ◽  
Bougainvillea Glabra

Foliar spray application of dikegulac at 1600 mg·liter-1 during production of Bougainvillea glabra Choicy `Mauna Kea White', and Bougainvillea `Raspberry Ice', `Royal Purple', `Summer Snow', and `Temple Fire' in 4.5-liter hanging baskets (25.4 cm in diameter) was investigated in relation to flowering. The effect of foliar-applied dikegulac at 0, 400, 800, 1200, and 1600 mg·liter-1 on bracteole size of `Mauna Kea White' was also determined. Liners of `Temple Fire' pruned at transplanting (0 weeks) and sprayed with dikegulac at, 0 and 4 weeks had increased flowering and a slightly more compact, pendulous growth habit than plants that had only been pruned at 0 and 4 weeks. Dikegulac had little to no effect on flowering of the other cultivars. Under late-spring to early summer conditions (generally increasing temperatures), bracteole size of `Mauna Kea White' was reduced ≈25 % by 400 mg dikegulac/liter compared to nontreated plants; 800 to 1600 mg dikegulac/liter reduced bracteole size ≈37%. Under late-summer to mid-fall conditions when the weather was cooler and wetter, dikegulac had little to no effect on bracteole size; however, bracteoles of nontreated plants were ≈25% smaller than those of plants grown under the warmer and drier conditions of late spring to early summer. Chemical name used: sodium salt of 2,3:4,6-bis -O- (1-methylethylidene) -α-l-xylo- 2-hexulofuranosonic acid (dikegulac).

Seasonal changes in prevalence and intensity of Cosmocercoides dukae (Nematoda: Cosmocercoidea) in Deroceras laeve (Mollusca)

1987 ◽  
Vol 65 (7) ◽  
pp. 1662-1665 ◽  
Author(s):  
Daryl J. Vanderburgh ◽  
R. C. Anderson
Keyword(s):  
Natural Population ◽  
Seasonal Changes ◽  
Late Summer ◽  
Early Summer ◽  
Late Spring ◽  
New Host ◽  
Histological Sections ◽  
Arion Fasciatus ◽  
New Host Records

A natural population of Deroceras laeve was examined regularly for the presence of Cosmocercoides dukae (Holl, 1928) Travassos, 1931. Transmission of C. dukae in D. laeve occurred in late spring and early summer before adult slugs from the previous year died in July. Transmission to juvenile slugs (hatched from eggs laid in spring) continued in late summer and fall. Histological sections of slugs exposed experimentally to larvae of C. dukae revealed that larvae penetrate slug tissues. Arion fasciatus, Arion hortensis, and Zonitoides nitidus represent new host records for C. dukae.

Nitrogen fertilization enhances cold tolerance of red spruce seedlings

1989 ◽  
Vol 19 (8) ◽  
pp. 1037-1043 ◽  
Author(s):  
D. H. DeHayes ◽  
M. A. Ingle ◽  
C. E. Waite
Keyword(s):  
Cold Tolerance ◽  
N Uptake ◽  
Late Summer ◽  
N Deposition ◽  
Early Summer ◽  
Red Spruce ◽  
Atmospheric N Deposition ◽  
N Application ◽  
Cold Tolerant ◽  
Autumn And Winter

Red spruce (Picearubens Sarg.) seedlings were treated with one of four concentrations of NH4NO3 (0, 300, 1500, and 3000 kg N•ha−1•year−1) applied to the soil, with and without triple superphosphate, during early, mid-, or late summer. Laboratory freezing assessments indicated that cold tolerance of treated seedlings generally increased with increasing nitrogen (N) uptake, with the exception of the highest N treatment. Seedlings receiving 1500 kg N•ha−1•year−1 were most cold tolerant on most sample dates. In general, these seedlings were hardier than those receiving 300 kg N•ha−1•year−1, which were hardier than unfertilized control seedlings. Seedlings receiving supplemental N also acclimated to cold more rapidly in autumn and deacclimated more slowly in spring than unfertilized controls. Supplemental phosphorus (P) had no influence on cold tolerance, and there was no evidence of a N × P interaction. Significant differences in cold tolerance associated with time of N application (early, mid-, and late summer) were detected in autumn and winter, but not in spring. In general, seedlings receiving N in mid- or late summer were as hardy or hardier than seedlings fertilized in early summer, regardless of the concentration of fertilizer. Significant interactions between N and timing of treatments occurred primarily because N applied in early summer resulted in only a slight increase in cold tolerance, whereas mid- and late summer N application resulted in a substantial increase in cold tolerance. Combined results suggest that it is highly unlikely that either the amount or timing of atmospheric N deposition is responsible for the winter injury frequently observed in red spruce.

Foraging behaviour of beef cattle in the hilly terrain of a Mediterranean grassland

2012 ◽  
Vol 34 (2) ◽  
pp. 163 ◽  
Author(s):  
Z. Henkin ◽  
E. D. Ungar ◽  
A. Dolev
Keyword(s):  
Foraging Behaviour ◽  
Nutritive Value ◽  
Late Summer ◽  
Beef Cows ◽  
Early Morning ◽  
Grazing Pressure ◽  
Early Spring ◽  
Early Summer ◽  
Late Spring ◽  
Full Potential

The objective of this study was to determine the role of terrain in the foraging behaviour of beef cows grazing hilly Mediterranean grasslands. The study was conducted in eastern Galilee, Israel, during 2002 and 2003 on two similar 28-ha paddocks encompassing distinct terrain types in terms of slope and rock cover. The paddocks were continuously grazed by cows from mid winter (January–February) to autumn (September) at two different stocking rates (1.1 and 0.56 cows per ha). From early June to the end of September the cows were offered poultry litter ad libitum as a supplementary feed. The location and activity of cows were monitored with GPS collars during four periods in each year: early spring (February–March), late spring (April), early summer (June) and late summer (August). Herbage mass was measured at the beginning of each of these periods. During early and late spring, when the herbage mass and nutritive value of herbage were high, the cows spent 40–50% of the day grazing, with peaks in the morning and afternoon. In the dry, late summer period (August), grazing of the herbage was 20–22% of the day, occurring only in the early morning and late afternoon with sporadic bouts of grazing until midnight. In all periods the cows tended to prefer the flattest terrain sites. As the herbage mass declined to 1000–1500 kg ha–1, the exploitation of the pasture during grazing became increasingly similar among the different terrains. Even on relatively small paddocks, where grazing pressure was close to the full potential of the site, free-ranging cows tended to prefer less sloping and rocky sites. It is concluded that the grazing strategy of beef cows is determined by the interaction between terrain, the distribution of the herbage mass and the nutritive value of the herbage. As herbage mass declines during the growing season, the distribution of grazing becomes uniform and all terrain types are exploited.

scholarly journals EFFECT OF HEDGING ON FROST TOLERANCE OF `DELITE' RABBITEYE BLUEBERRIES

HortScience ◽  
1990 ◽  
Vol 25 (9) ◽  
pp. 1162d-1162
Author(s):  
E. W. Neuendorff ◽  
K. D. Patten
Keyword(s):  
Late Summer ◽  
Ground Level ◽  
Frost Damage ◽  
Frost Tolerance ◽  
Late Spring ◽  
Spring Frost ◽  
Stage Of Development ◽  
Late Spring Frost ◽  
Flower Stage ◽  
Fall Growth

A late spring frost, -2°C on 10 Mar 1989, destroyed all blossoms on `Delite' rabbiteye blueberries. To determine the effect of hedging as a rejuvenation method, six-year-old `Delite' plants were pruned on 26 April 1989. All branches were removed at 46 cm from ground level. Unpruned control plants were approximately 184 cm tall. On 21 Mar 1990 a frost of -2°C occurred. Two days later bud damage was assessed on three wood types: spring-old (SO), spring growth on old, weak wood; spring-new (SN), spring growth on vigorous 1-year-old shoots; and fall (F), postharvest late summer/fall growth. Buds were identified as to their stage of development. Buds formed on both types of spring wood were further developed than those on fall wood. As flower stage advanced frost damage increased. Blossoms on fall growth were most frost tolerant and SN was more hardy than SO. Subsequent yields will be determined and reported.

scholarly journals Distribution, abundance and biology of ringed seals (Phoca hispida): an overview

1998 ◽  
Vol 1 ◽  
pp. 9 ◽  
Author(s):  
Randall R Reeves
Keyword(s):  
Polar Bear ◽  
Late Summer ◽  
Early Summer ◽  
Ringed Seal ◽  
Late Spring ◽  
Late Winter ◽  
Polar Cod ◽  
World Population ◽  
Phoca Hispida ◽  
Ringed Seals

The ringed seal (Phoca hispida) has a circumpolar Arctic distribution. Because of its great importance to northern communities and its role as the primary food of polar bears (Ursus maritimus) the ringed seal has been studied extensively in Canada, Alaska, Russia, Svalbard and Greenland as well as in the Baltic Sea and Karelian lakes. No clear-cut boundaries are known to separate ringed seal stocks in marine waters. Adult seals are thought to be relatively sedentary, but sub-adults sometimes disperse over long distances. Stable ice with good snow cover is considered the most productive habitat although production in pack ice has been little studied. Populations appear to be structured so that immature animals and young adults are consigned to sub-optimal habitat during the spring pupping and breeding season. Annual production in ringed seal populations, defined as thepup percentage in the total population after the late winter pupping season, is probably in the order of 18-24%. Most estimates of maximum sustainable yield are in the order of 7%.The world population of ringed seals is at least a few million. Methods of abundance estimation have included aerial surveys, dog searches and remote sensing of lairs and breathing holes, acoustic monitoring, correlation analysis by reference to sizes of polar bear populations, and inference from estimated energy requirements of bear populations. Aerial strip survey has been the method of choice for estimating seal densities over large areas. Adjustment factors to account for seals not hauled out at the time of the survey, for seals that dove ahead of the aircraft, and for seals on the ice within the surveyed strip but not detected by the observers, are required for estimates of absolute abundance.Male and female ringed seals are sexually mature by 5-7 years of age (earlier at Svalbard). Pupping usually occurs in March or early April and is followed by 5-7 weeks of lactation. Breeding takes place in mid to late May, and implantation is delayed for about 3 months. In at least some parts of their range, ringed seals feed mainly on schooling gadids from late autumn through early spring andon benthic crustaceans and polar cod (Boreogadus saida) from late spring through summer. Little feeding is done during the moult, which takes place in late spring and early summer. Pelagic crustaceans offshore and mysids inshore become important prey in late summer and early autumn in some areas. Ringed seals have several natural predators, the most important of which is the polar bear in most arctic regions. Arctic foxes (Alopex lagopus) kill a large percentage of pups in someareas.From a conservation perspective, the ringed seal appears to be secure. Levels of exploitation of arctic populations have usually been considered sustainable, except in the Okhotsk Sea. Large fluctuations in production of ringed seals in the Beaufort Sea and Amundsen Gulf are thought to be driven by natural variability in environmental conditions. While concern has been expressed about thepotential impacts of industrial activity and pollution on ringed seals, such impacts have been documented only in limited areas. Because of their ubiquitous occurrence and availability for sampling, ringed seals are good subjects for monitoring contaminant trends in Arctic marine food chains. 

Growth and carcass characteristics of crossbred and straightbred Hereford steers. I. Post-weaning growth

1981 ◽  
Vol 32 (1) ◽  
pp. 161 ◽  
Author(s):  
JM Thompson ◽  
R Barlow ◽  
B Johnston ◽  
PJ Nicholls
Keyword(s):  
Growth Rate ◽  
Slow Growth ◽  
Carcass Characteristics ◽  
Late Summer ◽  
Coastal Environment ◽  
Early Summer ◽  
Significant Difference ◽  
The Mean ◽  
The Difference ◽  
Autumn And Winter

Post-weaning growth characteristics were examined in 28 Hereford, 27 Brahman x Hereford, 23 Simmental x Hereford and 26 Friesian x Hereford steers which were grazed on pasture in a central coastal environment at Paterson, N.S.W. Sixty-seven steers from a 1973 calving were allocated to three groups to be slaughtered when the mean liveweights of the Herefords were approximately 270, 370 and 470 kg. Thirty-seven steers from a 1974 calving were allocated to two groups to be slaughtered when the average liveweights of the Herefords were 470 and 570 kg. Average daily liveweight gains of the crossbred steers were greater (average 19%) than the Hereford steers from weaning to the four slaughter weights (P < 0.05). Of the crossbreds, the Brahman cross steers grew faster than the Simmental cross steers (P < O.05), although the difference was not significant at the highest slaughter weight. The growth advantage of the crossbreds was mainly realized in the periods of slow growth (mean growth rate of 320 g/day) during the late summer, autumn and winter months. During these periods the Brahman cross steers grew faster than the Herefords by an average of 89% (P < 0.05) and the Simmental and Friesian cross steers grew 39% faster than the Herefords (P < 0.05). In the periods of fast growth (mean growth rate of 667 g/day), during the spring and early summer months, there was no significant difference between the sire breeds in growth rate (P > 0.05).

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