The effect of defoliation on flower production in subterranean clover (T. subterraneum L.)

1972 ◽  
Vol 23 (3) ◽  
pp. 427 ◽  
Author(s):  
RC Rossiter
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Early Flowering ◽  
Flower Initiation ◽  
Flower Production ◽  
Mature Leaves ◽  
Opposing Effects ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Three experiments were done in an open-sided glasshouse during the normal winter growing season. In experiment 1, swards of the Dwalganup strain which were severely defoliated, either after flower initiation or at early flowering, had 17% more flowers per unit ground area than uncut controls. Swards which were defoliated at both stages had 28% more flowers than the controls. In experiment 2, with single plants of the Dwalganup strain, comparable defoliations greatly decreased flower numbers per plant. The opposing effects of defoliation on flower numbers of single plants and of swards are believed to reflect opposing effects of defoliation on the rate of leaf appearance and on branching. In experiment 3, with single plants of the Dwalganup and Yarloop strains, either the young or the mature leaves were repeatedly removed before flower initiation. This delayed the date of commencement of flowering by 15–19 days; but the node of first flowering was not affected by defoliation.

The effect of leaf removal on flowering time in subterranean clover

1970 ◽  
Vol 21 (6) ◽  
pp. 893 ◽  
Author(s):  
WJ Collins ◽  
Y Aitken
Keyword(s):  
Flowering Time ◽  
Subterranean Clover ◽  
Early Growth ◽  
Grazing Management ◽  
Flower Initiation ◽  
Leaf Removal ◽  
Main Shoot ◽  
Delayed Flowering ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

The removal of fully expanded leaves delayed flowering by up to 30 days in subterranean clover cv. Mt. Barker sown in winter at Melbourne (38�S.). This effect on flowering was attributable partly to a delay in flower initiation and partly to a slower rate of leaf appearance after flower initiation. Thus leaf removal may be added to the factors already known to influence flower initiation in subterranean clover. When plants were grown under a 24 hr photoperiod. leaf removal had no effect on flower initiation; the slight delay that leaf removal caused in flowering was therefore due entirely to its effect in reducing the rate of leaf appearance. In other experiments leaf removal delayed the time of flower initiation but had no effect on the rate of leaf appearance. The effect of leaf removal on the time of flowering on the main shoot in lateral-dominant plants (as occur in the field) was qualitatively the same as in plants from which the laterals had been removed. Grazing management of subterranean clover which results in severe defoliation during early growth may delay flowering to such an extent that seed production is reduced substantially, and persistence thereby prejudiced.

Pre-maturation cold acquisition in Trifolium subterraneum

1974 ◽  
Vol 25 (6) ◽  
pp. 875 ◽  
Author(s):  
WJ Collins ◽  
DF Smith
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Seed Maturation ◽  
Flower Initiation ◽  
Appearance Time ◽  
Rate Of Development ◽  
Wide Range ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Different Levels

The influence of different levels of temperature during seed maturation on the subsequent rate of development in plants grown from that seed was studied in a range of subterranean clover cultivars. In one study the cultivars Carnamah, Yarloop, Woogenellup and Mt. Barker were grown at 7, 11, 14 and 17°C, and the seed produced grown on at 17°. Observations were made on the rate of leaf appearance, time of flower initiation, and time and node of first flowering. The rate of development was closely related to the temperature under which the seed was produced—the lower the temperature the faster was the rate of development. This effect was greatest with the later-flowering cultivars. In a second experiment, seed of a number of cultivars harvested commercially from a wide range of sites in southern Australia was grown on at 17°C and the rate of development observed. Time of flowering varied markedly between samples of only three cultivars. Accordingly seed of these samples were grown on for a further generation in a controlled environment. Within two of the cultivars, Mt. Barker and Bacchus Marsh, the differences in flowering observed in the previous generation persisted, which suggests that such differences were not based on environmental factors. In the cultivar Woogenellup the differences in flowering disappeared, which suggests that the original differences arose through different environmental conditions occurring during seed maturation. Cold acquisition in the maturing embryo does not seem to be a matter of practical consequence at present in subterranean clover, but may become so with changes in the location of seed production.

Some characteristics of "Carnamah", a very early-flowering strain of Trifolium subterraneum L., when grown as single plants

1961 ◽  
Vol 12 (1) ◽  
pp. 27 ◽  
Author(s):  
RC Rossiter ◽  
AJ Millington
Keyword(s):  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Early Flowering ◽  
Winter Period ◽  
Flower Initiation ◽  
Total Production ◽  
Initiation Rate ◽  
The Difference ◽  
Early Flower ◽  
Early Strain

A very early-flowering strain of subterranean clover was discovered in 1957 at Carnamah, W.A. From extensive studies at several field centres, it was demonstrated that the new strain – now called Carnamah – commenced flowering from 30 to 10 days before Dwalganup (the standard commercial "early" strain) when sown in the autumn-early winter period. With very early planting – late March – the difference in flowering time was even greater (about 45–50 days). The very early-flowering nature of the Carnamah strain is associated with early flower initiation. Rate of flower development (from flower initiation to flower appearance) in relation to temperature was similar for Carnamah and Dwalganup. Under spaced-plant conditions the total production of Carnamah was much less than that of Dwalganup, a finding which conforms to the results of previous single-plant studies. The new strain was not readily distinguished from Dwalganup, but several minor differences in morphology are mentioned. The chromosome number was normal for the species (2n = 16). The relevance of these data to sward conditions is discussed briefly, and it is suggested that the Carnamah strain may be more effective than Dwalganup in extending the "clover belt" inland in southern Australia.

Seed production and persistence of Carnamah and other early strains of Trifolium subterraneum in the wheatbelt of Western Australia

1967 ◽  
Vol 7 (24) ◽  
pp. 25 ◽  
Author(s):  
GB Taylor ◽  
RC Rossiter
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Western Australia ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Growing Season ◽  
Early Flowering ◽  
The Other ◽  
Factors Affecting ◽  
Seed Yields

Seed production and persistence of the Carnamah, Northam A, Dwalganup, and Geraldton strains of subterranean clover (Trifolium subterraneum L.) were examined in undefoliated swards in the wheatbelt of Western Australia. The early flowering characteristic of Carnamah was not always associated with higher seed yields. Only when there was a well-defined, early finish to the growing season, or when flowering was very much earlier in Carnamah (viz., following an early 'break' to the season), did this strain clearly outyield both Northam A and Geraldton. The seed yield of Dwalganup was generally inferior to that of the other strains. Factors affecting regeneration are discussed. Under low rainfall conditions, poorer germination-regulation of Carnamah, compared with Geraldton and Northam A, would be expected to result in poorer persistence unless offset by higher seed yields in the Carnamah strain.

The effect of defoliation on flowering and seed yield in subterranean clover

1973 ◽  
Vol 24 (2) ◽  
pp. 211 ◽  
Author(s):  
MW Hagon
Keyword(s):  
Seed Production ◽  
Seed Yield ◽  
Subterranean Clover ◽  
Early Flowering ◽  
Floral Initiation ◽  
Leaf Appearance

The effect of defoliation on flowering and seed production in Woogenellup subterranean clover was studied under sward conditions. Defoliation prior to floral initiation (FI) delayed this event but did not alter the time from sowing to flowering compared with the undefoliated control. However, defoliation between FI and flowering reduced the time from sowing to flowering by 10 days. These findings are discussed in relation to the changes in rates of leaf appearance which resulted from defoliation. Defoliation of the plots either before FI, after FI, or at early flowering did not alter seed yield or any of its components.

Photoperiod and temperature effects on the rate of leaf appearance in quinoa (Chenopodium quinoa)

2000 ◽  
Vol 27 (4) ◽  
pp. 349 ◽  
Author(s):  
H. Daniel Bertero ◽  
Roderick W. King ◽  
Antonio J. Hall
Keyword(s):  
Chenopodium Quinoa ◽  
Photoperiod Sensitivity ◽  
Early Flowering ◽  
Base Temperature ◽  
Dry Climates ◽  
Leaf Appearance ◽  
The Tropics ◽  
Rate Of Leaf Appearance ◽  
Photoperiod Control ◽  
Short Days

Knowledge of factors controlling leaf appearance is important for understanding climatic adaptation of a plant species. For quinoa (Chenopodium quinoa Willd.) we show that both temperature and photoperiod control the rate of leaf appearance. Minimum phyllochron (thermal time between the appearance of two successive leaves as observed under short days) and photoperiod sensitivity of the phyllochron decreased as latitude of origin of a cultivar increased from 1˚13¢ N to 38˚46¢ S. Minimum phyllochron ranged from 21.8 ˚Cd in the Colombian cv. Nariño, to 15.9 ˚Cd in the Chilean cv. Baer (estimated for a common base temperature of 2˚C). Photoperiod sensitivity ranged from 1.2 ˚Cd h –1 in Nariño to insensitivity (0 ˚Cd h –1 ) in the Bolivian and Peruvian altiplano cvv. Kanckolla, Blanca de Juli and Sajama. The phyllochron sensitivities to photoperiod and temperature were linearly and positively associated with photoperiod and temperature sensitivities of time to visible flower buds (R 2 = 0.70 and 0.55, respectively, P < 0.05), so that shorter phyllochrons were associated with early flowering cultivars. Temperature sensitivity was highest in cvv. originating in cold or dry climates, and lowest for cvv. from more humid and warm climates. We suggest, therefore, that in its domestication as a crop plant, photoperiod sensitivity of quinoa has been selected for as a homeostatic mechanism to counteract the potentially reduced leaf area associated with early flowering under short days and high temperatures in the tropics.

Evolution of subterranean clover in South Australia. I. The strains and their distribution

1979 ◽  
Vol 30 (6) ◽  
pp. 1035 ◽  
Author(s):  
PS Cocks ◽  
JR Phillips
Keyword(s):  
Flowering Time ◽  
South Australia ◽  
Subterranean Clover ◽  
Growing Season ◽  
Genetic Change ◽  
Early Flowering ◽  
Alkaline Soils ◽  
Seed Certification ◽  
Yorke Peninsula ◽  
Viable Seeds

The distributions of the strains of subterranean clover were determined from the presence of burrs in wool collected at the Adelaide Wool Sales. Of 7600 samples examined, nearly 1300 contained viable seeds. This seed was grown, the strains were identified, and their distributions in South Australia were mapped. Subterranean clover was found in wool from most areas with more than 400 mm of rain. However, it was absent from the climatically favourable Yorke Peninsula, and it seems clear that distribution of subterranean clover in South Australia is limited by the presence of alkaline soils. Divergent strains are widespread in South Australia. In all, 435 divergent strains were discovered from 325 farms. The presence of these strains leads us to believe that genetic change in subterranean clover, previously thought to be genetically stable, has been brought about by infrequent outcrossings, mainly in mixtures of cultivars. We discuss evidence for this proposal, and the consequences that it has for seed certification schemes. The distribution of flowering time amongst the divergent strains differed from the cultivars. Many of them flowered about half way between the mid-season cultivar Mount Barker and the early-flowering cultivar Dwalganup. There was no strain later than Tallarook, the latest-flowering cultivar, and very few earlier than Dwalganup. Flowering time of the divergent strains was weakly related to the length of growing season of the farms which produced the wool. Strains were also discovered which were morphologically identical with a cultivar but which flowered either earlier or later. The first-released cultivars, Mount Barker and Dwalganup, were the most widely distributed of all strains. Indeed success, in terms of the number of seeds of a cultivar found in the wool, could be broadly related to the number of years since release. The data illustrate the significance of the early-flowering cultivars on the distribution of subterranean clover, but indicate that, apart from T. brachycalycinum, there is little need in South Australia for yet earlier cultivars.

The effects of grazing on the phosphorus requirement of an annual pasture

1971 ◽  
Vol 22 (1) ◽  
pp. 81 ◽  
Author(s):  
PG Ozanne ◽  
KMW Howes
Keyword(s):  
Subterranean Clover ◽  
Growing Season ◽  
Maximum Growth ◽  
Grazing Pressure ◽  
Light Interception ◽  
Botanical Composition ◽  
Stocking Rate ◽  
Phosphorus Requirement ◽  
Root Size

The applied phosphorus requirement of a pasture sown to subterranean clover was measured with and without grazing. Under moderate grazing pressure, in the year of establishment, the pasture required about 50 % more phosphorus than when ungrazed. In the following season, at a higher stocking rate, the grazed areas needed twice as much phosphorus as the ungrazed to make 90% of their maximum growth. In both years this difference in requirement between stocked and unstocked treatments was present throughout the growing season. Increased phosphorus requirement under grazing is associated with the need for greater uptake of phosphorus under conditions where redistribution of absorbed phosphorus within the plant is prevented by defoliation. It does not appear to be due to effects of defoliation on root size. Nor does it depend on differential light interception or on changes in botanical composition.

Effect of Plant Growth Regulators on Growth and Quality Flower Production of Chrysanthemum (Chrysanthemum Indicum L.)

2022 ◽  
Vol 2 (1) ◽  
pp. 10-18
Author(s):  
Md Ehsanullah ◽  
Ahasan Ullah Khan ◽  
Md Kamruzzam ◽  
Sarah Tasnim
Keyword(s):  
Plant Growth ◽  
Plant Growth Regulators ◽  
Growth Regulators ◽  
Block Design ◽  
Research Centre ◽  
Vase Life ◽  
Flower Initiation ◽  
Growth Promoter ◽  
Flower Production ◽  
Minimum Number

A field study was conceded to assess the effect of plant growth regulators on growth and quality flower production of chrysanthemum at Horticulture Research Centre (HRC), Gazipur, Bangladesh. The experiment was laid out in Randomized Complete Block Design (RCBD) with ten (10) treatments and three replications. The treatments of plant growth regulators concentration were T1-50 ppm GA3, T2-100 ppm GA3, T3-150 ppm GA3, T4-400 ppm CCC, T5-600 ppm CCC, T6-800 ppm CCC, T7-250 ppm MH, T8-500 ppm MH, T9-750 ppm MH and, T10-Control. The maximum spreading of plant (27.0 cm) was observed when plants were treated with GA3 @ 150 ppm where the minimum plant spread (16.8 cm) was recorded in plants treated with CCC @ 800 ppm. The higher number of suckers (33) per pot was produced when pots were treated with GA3 @ 150 ppm whereas, application of CCC at three different concentrations produced lower number of suckers.  The highest number of flower (40) was recorded with 150 ppm GA3, where minimum number of flowers (25) per pot in 800 ppm CCC. The plants sprayed with 50 ppm GA3 took 48 days to flower initiation, whereas, it took 70 days with 750 ppm MH. the highest plants recorded (7.40 cm) with 800 ppm CCC, whereas, lowest size (6.50 cm) was obtained with the application of 500 ppm MH. The maximum vase life of flowers was recorded for the treatment 800 ppm CCC (15 days), which was at par with 13 days vase life obtained by spraying 600 ppm CCC. Therefore, it is concluded that the GA3 acted as growth promoter and the CCC acted as growth retardants on yield and quality of chrysanthemum.

scholarly journals Effects of nitrogen on development and growth of the leaves of vegetables. 3. Appearance and expansion growth of leaves of spinach

1995 ◽  
Vol 43 (2) ◽  
pp. 247-260
Author(s):  
H. Biemond
Keyword(s):  
Leaf Area ◽  
Leaf Size ◽  
Field Trials ◽  
Leaf Expansion ◽  
Mature Leaf ◽  
Leaf Emergence ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Main Factor

In a series of greenhouse and field trials, spinach cv. Trias plants were supplied with different amounts of N fertilizer in various split applications. Rates of leaf emergence and expansion were recorded, as well as final leaf size. The rate of leaf appearance varied between 0.16 and 0.57/day across experiments, but was hardly affected by N treatment. The rate of leaf expansion and mature leaf area increased with leaf number, reaching maximum values at leaf pair 3+4 or 5+6 and decreasing subsequently. Both characteristics were positively correlated with N supply. The duration of expansion was not influenced by N treatments and varied between 15 and 30 days in most experiments. The rate of leaf expansion was the main factor determining mature leaf size. Specific leaf area over all green leaves slowly decreased with time in most experiments and was around 300 cmsuperscript 2/g. As the differences in the number of leaves were small, the differences in total green leaf area per plant resulted from differences in the areas of individual mature leaves.

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