COMPLETION OF THE JUVENILE STAGE IN ORCHARDGRASS

1972 ◽  
Vol 52 (2) ◽  
pp. 203-207 ◽  
Author(s):  
V. KOZUMPLIK ◽  
B. R. CHRISTIE
Keyword(s):  
Juvenile Stage ◽  
Point Of View ◽  
Induction Treatment ◽  
Leaf Stage ◽  
Different Temperatures ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
Different Origins ◽  
Main Tiller ◽  
Rate Of Leaf Appearance

Three orchardgrass strains of different origins were used to determine the stage at which seedlings become capable of responding to induction treatment. The seedlings were grown under long photoperiods and warm temperatures after emergence until the sixth to ninth leaf appeared on the main tiller (shoot), and were then exposed to the induction conditions (10 hr photoperiod at 10 C) for 6 weeks. The juvenile stage in all three strains was completed at the eighth to ninth leaf stage. From the practical point of view, the eighth leaf stage can be used as an indicator of the completion, since about 90% of the seedlings induced at this stage subsequently developed heads, compared with 100% at the ninth leaf stage and 30–60% at the seventh leaf stage. Different photoperiods (14, 17, 24 hr) and different temperatures (15.5, 21 C), prior to the induction treatment, influenced the rate of leaf appearance, but did not affect subsequent heading. The maximum rate of leaf appearance occurred under long photoperiods (17 and 24 hr) and a warm temperature (21 C). Under these conditions, seedlings reached the eight-leaf stage in 3–4 weeks after emergence. The number of tillers was not as good a criterion of the completion of the juvenile stage as was the number of leaves on the main tiller.

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.

Short Day Induction of Flowering in Pearl Millet (Pennisetum typhoides) and its Effect on Plant Morphology

1979 ◽  
Vol 15 (4) ◽  
pp. 401-410 ◽  
Author(s):  
C. K. Ong ◽  
A. Everard
Keyword(s):  
Pearl Millet ◽  
Subsequent Development ◽  
Plant Morphology ◽  
Short Day ◽  
Head Development ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
The Tropics ◽  
Rate Of Leaf Appearance ◽  
Short Days

SUMMARYFour hybrids of pearl millet (Pennisetutn typhoides) were screened for photoperiod sensitivity in a heated temperate glasshouse and the effects of 12 h short day induction on the reproductive development and plant morphology were examined. All the hybrids (BK 560, MBH 104, MBH 110 and ICH 105) responded to 14 short days by a considerable reduction in the time to anthesis, plant height and the final number of leaves produced, without any adverse effect on head development. In another experiment BK 560 required at least four short days for floral initiation and another four for subsequent development. Short day induction had no apparent effect on the rate of leaf appearance. The results were compared to those reported for millets in general and to millets grown in the tropics.

Rate of leaf appearance in sugarcane, including a comparison of a range of varieties

1998 ◽  
Vol 25 (7) ◽  
pp. 829 ◽  
Author(s):  
G. D. Bonnett
Keyword(s):  
Power Law ◽  
Large Change ◽  
Thermal Time ◽  
Linear Polynomial ◽  
Appearance Rate ◽  
Biological Explanation ◽  
Leaf Appearance Rate ◽  
Number Of Leaves ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Leaf appearance rate is a major determinant of canopy establishment, radiation interception and therefore yield. The effect of genotype on leaf appearance rate in sugarcane is largely unknown. Leaf appearance rate was recorded for the mainstems of pot grown sugarcane plants of nine commercial varieties, over 10 months in Townsville, Australia. Bi-phasic linear, polynomial and power-law models were fitted to data describing leaf appearance with thermal time. The bi-phasic model (previously used for sugarcane) had a single large change in phyllochron for which no biological explanation is apparent. Polynomials were less likely to predict leaf appearance accurately outside the range of fitted data. The power-law model gave a continuously increasing thermal time between the appearance of successive leaves (phyllochron) and was used to compare the varieties. An increasing phyllochron for the first 15 leaves could be explained, in part, by the increasing length of lamina each successive leaf had to grow through. However, an explanation for an increasing phyllochron throughout ontogeny has yet to be found. The rate of leaf appearance was significantly different between the varieties. After 5000˚Cd the number of leaves predicted to have appeared ranged from 35 to 46. These variety specific parameters make an important contribution to describing how different varieties produce leaf area.

The growth and development of cowpeas (Vigna unguiculata) under tropical field conditions: 1. Leaf area

1979 ◽  
Vol 93 (2) ◽  
pp. 291-307 ◽  
Author(s):  
E. J. Littleton ◽  
M. D. Dennett ◽  
J. Elston ◽  
J. L. Monteith
Keyword(s):  
Leaf Area ◽  
Leaf Growth ◽  
Leaf Size ◽  
Constant Number ◽  
Area Index ◽  
Number Of Leaves ◽  
The Mean ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance ◽  
Ibadan Nigeria

SUMMARYThe pattern of leaf growth and death was followed in stands of cowpea grown in the field at Ibadan, Nigeria. Temperature affected this pattern. Leaf area index increased quicker and leaf death started sooner during warm seasons. Individual leaves died while pods at the same node were filling. The rate of leaf appearance increased with temperature and the duration of expansion of individual leaves decreased so that a constant number of leaves were expanding at one time. The mean rate of expansion of individual leaves increased with temperature proportionately more than the duration decreased, hence final leaf size increased with temperature. Base temperatures for leaf appearance and leaf expansion were 16 and 20 °C respectively.

scholarly journals Influence of Height of Cane and Leaf Stage at Time of Sampling on Leaf-Nutrient Content of Sugarcane

1969 ◽  
Vol 44 (1) ◽  
pp. 11-15
Author(s):  
G. Samuels ◽  
S. Alers-Alers ◽  
P. Landrau, Jr.
Keyword(s):  
Nutrient Content ◽  
Leaf Nitrogen ◽  
Sampling Time ◽  
Nitrogen And Phosphorus ◽  
Leaf Sample ◽  
Leaf Stage ◽  
Fertilizer Experiment ◽  
Significant Difference ◽  
Leaf Sampling ◽  
Number Of Leaves

Leaf samples of sugarcane were taken from a fertilizer experiment at Río Piedras with varieties B. 41227 and M. 336 to determine whether the height of cane or the number of leaves present at leaf-sampling time influenced the nutrient content of the leaf sample. It was found that: 1. There was no significant difference in leaf nitrogen or potassium from cane tillers aged 3 months with heights of 12, 24, and 36 inches. 2. Variations in cane height at time of sampling did influence leaf-phosphorus values; there were increases in cane height. 3. The number of leaves present at time of sampling (7-13 weeks) did not influence leaf-nutrient values in general, except for nitrogen and phosphorus at 9 weeks of age. Here the trends of this influence with the two varieties studied were contrary.

Temperature and leaf area expansion of sugarcane: integration of controlled-environment, field and model studies

1998 ◽  
Vol 25 (7) ◽  
pp. 819 ◽  
Author(s):  
Michael J. Robertson ◽  
Graham D. Bonnett ◽  
R. Michael Hughes ◽  
Russell C. Muchow ◽  
James A. Campbell
Keyword(s):  
Leaf Area ◽  
Leaf Senescence ◽  
Leaf Size ◽  
Field Studies ◽  
Growth Conditions ◽  
Thermal Time ◽  
Leaf Position ◽  
Potential Growth ◽  
Leaf Stage ◽  
Leaf Appearance

Canopy development is an important determinant of crop radiation interception, and in the absence of stress is mainly driven by temperature. The responses to temperature of the component processes of canopy dynamics in sugarcane: leaf appearance, leaf size, tillering, and leaf senescence, were analysed for the commercial Australian cultivar, Q117. Data were derived under optimal growth conditions from controlled environments, and from irrigated field studies in subtropical and tropical locations. Regression of number of fully-expanded leaves in field-grown plants against cumulative thermal time revealed that the thermal time between the appearance of successive leaves increased as a function of leaf number, such that leaf 1 required 86˚Cd and leaf 40 required 160˚Cd. At any moment, on average there were 3.7 leaves still expanding on the stalks. Functions describing leaf appearance gave acceptable prediction of the time course of leaf appearance taken from independent datasets of field-grown plant and ratoon crops. Leaf size increased with leaf position, with the largest leaves observed at approximately leaf 17 and above. Combining functions describing leaf appearance and leaf size as a function of leaf position allowed estimation of leaf area index (LAI) of main stems in plant and ratoon crops in subtropical and tropical environments. Tiller LAI, derived by difference, accounted for 60–90% of total LAI at the 5- leaf stage, declining to 20–50% at the 15-leaf stage. Plant and ratoon crops were similar in terms of the amount and proportion of tiller LAI. Combining data from all field studies indicated under potential growth conditions, leaf senescence was closely related to leaf production. The functions derived in this study give a basis for simulating canopy dynamics under potential growth conditions in sugarcane, though the extent of genotypic variation for the key parameters and their modification by stress remains to be assessed.

Effect of Corn-Induced Shading and Temperature on Rate of Leaf Appearance in Redroot Pigweed (Amaranthus retroflexus L.)

Weed Science ◽  
1993 ◽  
Vol 41 (4) ◽  
pp. 590-593 ◽  
Author(s):  
Stephane M. Mclachlan ◽  
Clarence J. Swanton ◽  
Stephan F. Weise ◽  
Matthijs Tollenaar
Keyword(s):  
Field Experiments ◽  
Linear Increase ◽  
Amaranthus Retroflexus ◽  
Planting Date ◽  
Weed Interference ◽  
Redroot Pigweed ◽  
Field Temperature ◽  
Effects Of Temperature ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

Leaf development and expansion are important factors in determining the outcome of crop-weed interference. The comparative effects of temperature and corn canopy-induced shading on the rate of leaf appearance (RLA) of redroot pigweed were quantified in this study. Growth cabinet results indicated a linear increase in RLA with increased temperature. Weed RLA was predicted utilizing both this function and field temperature data. The ratio of observed to predicted RLA of redroot pigweed grown in field experiments decreased in 1990 and 1991 as shading increased with increased corn density and delayed weed planting date. Results indicated that RLA is substantially affected by canopy-induced shading in addition to temperature.

scholarly journals Developmental genetics of leaf formation in Lolium: 1. Basic Patterns of Leaf Development in L. Multiflorum and L. Perenne

1967 ◽  
Vol 9 (2) ◽  
pp. 233-245 ◽  
Author(s):  
K. J. R. Edwards
Keyword(s):  
Lolium Multiflorum ◽  
Leaf Size ◽  
Repeated Measurements ◽  
Developmental Genetics ◽  
Initial Growth ◽  
Leaf Elongation ◽  
Leaf Formation ◽  
Selection For ◽  
Leaf Appearance ◽  
Rate Of Leaf Appearance

1. Repeated measurements on the growth of individual leaves in seedlings and young plants of ryegrass combined with dissections of the apex of the shoot and of very young leaves have shown that the basic pattern of leaf formation is very similar in Lolium multiflorum and L. perenne.2. The initial growth rate of a leaf primordium is low but increases suddenly at a point when the primordium is somewhat longer than the apex and about 1 mm. in length. After this transition, which I have called the unfolding of the leaf, the rate of elongation is faster and more or less linear until the leaf is nearly mature.3. The time of unfolding of a leaf is very closely associated with the time of maturity of the next older leaf on the same side of the apex. Thus a leaf ceases growth when the next younger leaf immediately above it starts elongating rapidly, though which is cause and which is effect is it not possible to say.4. This close relationship between duration of leaf elongation and rate of unfolding of successive leaves holds for both species in two seasons. It leads one to predict that selection for increased leaf size, in so far as it is a result of greater duration of leaf elongation, is likely to be accompanied by a slower rate of leaf appearance, and conversely that selection for rate of leaf appearance is likely to result in smaller leaves.

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.

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