The Growth and Development of Caltha introloba F. Muell. I. The Pattern and Control of Flowering

1989 ◽  
Vol 37 (4) ◽  
pp. 275 ◽  
Author(s):  
IF Wardlow ◽  
MW Moncur ◽  
CJ Totterdell

The floral development of Caltha introloba F. Muell. was surveyed in the short alpine herbfield areas located in the vicinity of Charlottes Pass, in the Kosciusko National Park. This study included a detailed examination, by scanning electron microscopy, of changes occurring at the shoot apex. Floral initiation occurred in mid summer (January) and flowers were fully developed and in many instances ready to shed pollen, before the first snow fall in late autumn (May). The flowers generally remained closed until after the snow melted in spring (October), although some opening did occur under the snow if this remained until late in the year (mid November). Seed development was normally complete towards the end of summer (late January to February). Controlled environment studies demonstrated that floral initiation and development were favoured by long days and high irradiance. These factors may represent important controls in the field where floral initiation occurs as daylength and irradiance reach their maximum levels. Also it was shown experimentally that there is a cold requirement before the flowers, that are otherwise fully developed, will open. This requirement should ensure that premature opening will not occur in autumn.

1970 ◽  
Vol 21 (3) ◽  
pp. 395 ◽  
Author(s):  
FX Jozwik

Controlled environment experiments were carried out to determine the effect of temperature and photoperiod on Astrebla pectinata, A. lappacea, A. elymoides, and A. squarrosa. Photoperiod had little effect on growth and development of tillers and on floral initiation, but did affect numbers of emergent inflorescences. Usually, inflorescence production increased with decreasing photoperiod. Temperature had significant effects on all parameters measured (number of main tillers and emergent inflorescences, elongation of main tillers, and number of leaves and axillary tillers per main tiller). Growth per tiller and leaf production increased with temperature (up to 30/25�C) but for tiller numbers the optimum was about 28/23�, Geographically separated strains of A. pectinata generally exhibited similar responses to photoperiod and temperature while different species from the same location differed in their response.


1972 ◽  
Vol 8 (3) ◽  
pp. 213-218 ◽  
Author(s):  
P. C. Owen

SUMMARYUnder controlled environment conditions rice variety IR8 was subjected to night temperatures of 15, 20 and 25°C during each of the three periods (a) sowing to floral initiation, (b) initiation to panicle emergence, and (c) panicle emergence to maturity, with day temperatures of 30°C throughout. Night temperatures of 15°C prevented floral initiation throughout the experiment, an effect partly overcome by transfer to higher temperatures after 102 days but not without yield loss. The optimum night temperature was 20–25°C, with some evidence of change of temperature effects, as distinct from the effect of actual temperature levels. As IR8 was developed under relatively stress-free conditions, its sensitivity to temperatures below 15°C may be greater than in varieties developed elsewhere.


1973 ◽  
Vol 81 (2) ◽  
pp. 219-229 ◽  
Author(s):  
P. A. Chadhokar ◽  
L. R. Humphreys

SummaryPaspalum plicatulum was grown at Brisbane in boxes of sand receiving basal nutrients and frequent irrigation; weekly levels of ammonium nitrate application were varied according to growth and development stage.The rate of tiller appearance increased to a maximum 40–50 days after sowing and almost ceased thereafter. Tiller leaf number, survival, fertility, inflorescence branching, seeds per raceme and seed size were positively related to tiller age. Young tillers were more sensitive to variations in nitrogen supply than old tillers.Adequate nitrogen nutrition during the vegetative phase from sowing to floral initiation (93 days) increased tiller and hence inflorescence density; increased inflorescence branching was compensated by fewer seeds per raceme. Good nitrogen nutrition during the phase from floral initiation to inflorescence exsertion (142 days) increased survival of late-formed tillers and hence inflorescence density; inflorescence branching, seeds per raceme and seed size were also increased. Nitrogen stress during the final maturation phase did not affect seed yield.


2020 ◽  
Vol 2 (1) ◽  
pp. 50-60
Author(s):  
Pramila Koirala ◽  
Bijaya Neupane ◽  
Thakur Silwal ◽  
Bijaya Dhami ◽  
Siddhartha Regmi ◽  
...  

Blue bull is Asia’s largest antelope, a species of least concern in IUCN Red data list of 2020. In Nepal, it is vulnerable and is often considered as a problem animal for its crop raiding habit. Although, its population is restricted in India and Nepal, there are insufficient studies conducted on the distribution and threats of the species at local level. This study aimed to assess the distribution of blue bull and its conservation threats in Bardia National Park and its buffer zone. Field survey was carried out to identify the potential area with the information provided by park staff and buffer zone people and by the transect method in the selected habitat to determine the distribution of blue bull population. Additionally, six focus group discussions (1 in each of thefive sites and 1 with park staff) and a half-day workshop (involving 25 participants representing each site and park office) were organized to assess the existing threats to the species. Data were analyzed descriptively using MS Excel, while the distribution map was prepared using Arc GIS. Also, 8 major identified threats were ranked using relative threat ranking procedure and classified into four severity classes. We found that the population of blue bull was dispersed from core area of Bardia National Park towards the buffer zone area. Open grazing, invasive species, predation by tiger and flash flood were the major threats to the blue bull as perceived by the local people. Habitat management activities including control of grazing, removal of invasive plant species, plantation of palatable grass species, increase in other prey species of tiger and control of flood in blue bull’s habitats are recommended to protect the species and thus sustain their threatened population.


2019 ◽  
pp. 183-194
Author(s):  
Serhii Vdovenko

In order to study the effect of the time of sowing seeds on the passage of morphogenesis and productivity of rapeseed, the scheme included experiments where the seeds were sown in I, II, III in April, I and II in May. The experiment used varieties of Golden Ball, Purpurleopop, Purpurov and Geisha, and control was the variant in which the seeds of the Golden Ball varieties were sown in the second decade of April with a row spacing of 45 cm. laboratory - to determine the total yield; statistical - to establish the reliability of the investigated factors. Seed germination analysis used in the experiment ranged from 78.9% to 81.1% on average. The highest indicator of seed germination was characterized by the Purpulepop variety, where the studied value was 83.2%, which was dominated by the seed germination of the control variant by 2.1%. In the early stages of sowing seeds, the period of seedling formation was shorter. Seeding of seeds in the first two decades of April on the surface of the soil was observed for 8 days. The short sprouting period was characterized by all varieties of turnips. As a result of sowing turnip seeds at a later date, namely in the third decade of April - the first and second decade of May and the setting of a higher soil temperature, the period of germination was extended and ranged from 8 to 10 days. By using the term of sowing seeds I-II decade of April, the short interphase period was characterized by Purpleupop and Purpurova varieties, where the specified period was only 22 days. The sowing of turnip seeds at a later date ensured the formation of an interphase period of "seedlings - leaf rosette" in 23-25 days except Purpulopop variety. The interphase period "leaf rosette - the beginning of rooting" and "the beginning of rooting - technical maturity" determined the benefits of early seeding, namely in the first decade of April on varieties Purpulopop and Purpurov.The short vegetation period was characterized by the Golden Ball plants for sowing seeds in the first and third decades of April and the first of May. During the specified seeding period the duration of the growing season was only 40 days. A longer vegetation period was characterized by plants of the Geisha variety for sowing seeds in the first two decades of April. As a result of the use of the researched elements of technology to grow turnips in open soil, the total yield varied from 11.0 t / ha to 24.0 t / ha. The most productive is the first sowing of rapeseed, where its value ranged from 20.6 t / ha to 22.7 t / ha. At the same time, when sowing seeds in the first decade of April, the yield of turnip varieties Purpulepop was the highest and was 22.7 t / ha, or the increase was 2.4 t / ha.


Author(s):  
S L Myer ◽  
E P De Crom

Farms in South Africa have to compete in a very hostile agricultural economic environment and it has become imperative for farmers to find new ways of generating additional income. Research undertaken in the Mopani District Municipality (MDM) in the Limpopo Province of South Africa identified agritourism as a potential means to this end. The main aim of this primarily qualitative study was to gain a better understanding of the perceptions and opportunities for agritourism in the study area. Data were mainly collected through interviews and questionnaires. Participants consisted of farmers and tourists, as well as owners of existing agritourism farms within the MDM. Five current active agritourism establishments were identified. Key fidnings revealed that agritourism is not being utilised to its full potential. Although perceptions of respondents towards agritourism are positive, marketing around it is insufficient and not all farmers are willing to host agritourism activities on their farms for various reasons. However, the MDM is a tourist hub with many visitors passing through various reasons. However, the MDM is a tourist hub with many visitors passing through the area en route to the Kruger National Park. Therefore, the potential already exists to host agritourism activities that will benefit farmers in various ways. By developing farm trails, scheduling daily farm activities, using information brochures, forming networks with existing tourist establishments, encouraging the use of local and fresh produce and providing good roadside signage, farmers can gain increased exposure and recognition for what they do and opportunities for growth and development may be realised. Keywords: Agritourism, farm tourism, alternative tourism, farm activities, tourism


2020 ◽  
Vol 9 (1) ◽  
pp. 59-70
Author(s):  
A.A. Thasun Amarasinghe ◽  
◽  
Awal Riyanto ◽  
Mumpuni Mumpuni ◽  
Lee L. Grismer

A new bent-toed gecko species of the genus Cyrtodactylus is described herein from West Bali National Park on the island of Bali, Indonesia. The Cyrtodactylus from Bali have been recognized as C. fumosus for nearly a century. However, recent detailed examination of the type material of C. fumosus has revealed that Balinese Cyrtodactylus represent at least one different species. A morphological examination of the new species and samples from different biogeographic regions revealed that the new species is similar to C. seribuatensis from Pulau Seribuat in West Malaysia. Morphologically, the new species can be distinguished from its congener by having 40–43 femoro-precloacal pores (vs 10–12 precloacal pores, 14–16 femoral pores), 40–48 ventral scales between ventrolateral folds (vs 28–39), 24–29 rows of dorsal tubercles (vs 27–35), and presence of tubercles on lateral skinfold (vs absent).


1969 ◽  
Vol 20 (3) ◽  
pp. 417 ◽  
Author(s):  
JH Silsbury

Lolium rigidum Gaud. and a summer-dormant and a non-dormant form of Lolium perenne L. were grown as seedling plants for 32 days in controlled environment cabinets at constant temperatures of either 10, 20, or 30°C and in all cases with a 16-hr photoperiod at a light intensity of 3600 lm ft-2. Sampling at 4-day intervals permitted the detailed examination of dry matter growth curves. Differences in total dry matter production were related to initial differences in seedling dry weight, and the general responses to temperature were similar for each ryegrass. Total dry matter production was greatest at 20°C and lowest at 10°. A temperature of 30° did not induce dormancy in the summer-dormant ryegrass but did depress growth. Relative growth rate fell with time at each temperature.


1994 ◽  
Vol 34 (8) ◽  
pp. 1209 ◽  
Author(s):  
LJ Rohl ◽  
AM Fuss ◽  
JA Dhaliwal ◽  
MG Webb ◽  
BB Lamont

Floral initiation and development in relation to time of flowering were investigated in Banksia baxteri and B. hookeriana with the aid of scanning electron microscopy. Floral initiation occurred in spring in B. baxteri and in early summer in B. hookeriana. Floral development was rapid in B. baxteri (3 months to reach anthesis in summer). In B. hookeriana, development took 5 months, with anthesis occurring in winter. Most B. hookeriana blooms were produced on 2-year-old shoots, while B. baxteri produced about half of its blooms on 2-year-old shoots and almost as many on 3-year-old shoots. In both species, shoots that flowered within 2 years were longer and thicker in their first year than other shoots. A critical minimum stem length was determined for the first year's growth, to be used as a criterion for determining which shoots to remove during pruning. Details are provided for the timing of pruning to achieve maximum bloom production in B. baxteri and B. hookeriana.


Sign in / Sign up

Export Citation Format

Share Document