Striped maple: shoot growth and bud formation related to light intensity

1977 ◽  
Vol 7 (1) ◽  
pp. 1-7 ◽  
Author(s):  
B. F. Wilson ◽  
B. C. Fischer

Terminal shoot growth and bud formation in striped maple (Acerpensylvanicum) were followed both in vigorous and suppressed forest trees and in suppressed trees grown in the greenhouse and garden under 10 light intensities from 6 to 82% of solar radiation in the open. All buds contained (1) a pair of preformed early leaves that grew rapidly and (2) a pair of rudimentary primordia that became either bud scales in suppressed trees, after abortion of the blade, or a second pair of leaves in vigorous or released trees. The fate of the rudimentary primordia could be regulated by light intensity. They formed bud scales at 6% light or leaves at about 18% light. Maximum height growth and leaf pair formation occurred at 30–60% solar radiation in the open, although the first internode was longest under the lowest light. When leaf production stopped, bud formation was similar in vigorous and suppressed trees. The inner and outer bud scales and the pair of preformed early leaves were produced at 2- to 4-week intervals. The rudimentary primordia were not formed until after an interval of 8–12 weeks, in late summer near the end of bud formation.

HortScience ◽  
1992 ◽  
Vol 27 (6) ◽  
pp. 569e-569
Author(s):  
Roger Kjelgren ◽  
Mike Foutch

Growth and water relations of seedlings grown in protective tree shelters were investigated during establishment in a field nursery. Shelters, 1.2 m high, were placed over 0.5 m Kentucky coffee tree seedlings following spring transplanting in a field experiment. Predawn leaf water potential (ψ) and stomatal conductance (gs) were monitored periodically through the season and growth was measured in late summer. In a second experiment diurnal microclimate, and seedling water relations and use, in the shelters were studied under controlled conditions. In the shelters, leaf and air temperature, humidity, and gs exceeded non-sheltered levels while solar radiation was 70% lower. Despite greater gs, normalized water use was 40% lower in the sheltered trees. While midday gs was similarly high in the field-grown trees, no differences in predawn ψ were detected through the season. Sheltered trees in the field had four times more shoot growth but 40% less caliper growth. Sheltered trees had leaf thickness lower than control trees, and together with the growth and radiation pattern, indicated that they were shade acclimated. Shelters can improve height growth and reduce water loss during establishment, but may not allow sufficient trunk development or taper for upright support


1971 ◽  
Vol 49 (10) ◽  
pp. 1821-1832 ◽  
Author(s):  
Edward Sucoff

During the 1969 and 1970 growing season buds were collected almost weekly from matched trees in northeastern Minnesota. Cataphyll primordia for the year n + 1 shoot began forming at the time that internodes in the year n shoot started elongating (late April) and continued forming until early September. Primordia for axillary buds started forming about 2 months later and stopped forming at the same time as cataphylls. The size and deposition activity of the apical dome simultaneously increased during the early growing season and decreased during the late season. The maximum rates in July were over nine cataphylls per day.Rate of cataphyll deposition paralleled elongation of the needles on subtending shoots. Forty to fifty percent of the cataphylls had been formed when shoot growth was 95% complete. Although the bulk of the depositions occurred earlier in 1970, when growing degree days were used as the clock, the 2 years were similar.The results provide quantitative data to complement the histologic emphasis of previous studies.


2013 ◽  
Vol 36 (1-2) ◽  
pp. 83-94 ◽  
Author(s):  
Franciszka Jaumień

The growth of trees sprayed in spring with chlormequat is weaker, and their elongation growth ends 2 - 3 weeks earlier than that of unsprayed trees. Trees with growth inhibited by chlormequat set flower buds on the spurs and in the subapical part of long shoots. The course of flower bud differentiation starts in the second half of July and is similar to that in the apple tree.


2015 ◽  
Vol 140 (1) ◽  
pp. 38-44 ◽  
Author(s):  
Alisson P. Kovaleski ◽  
Jeffrey G. Williamson ◽  
James W. Olmstead ◽  
Rebecca L. Darnell

Blueberry (Vaccinium spp.) production is increasing worldwide, particularly in subtropical growing regions, but information on timing and extent of inflorescence bud development during summer and fall and effects on bloom the next season are limited. The objectives of this study were to determine time of inflorescence bud initiation, describe internal inflorescence bud development, and determine the relationship between internal inflorescence bud development and bloom period the next spring in two southern highbush blueberry [SHB (Vaccinium corymbosum interspecific hybrids)] cultivars. ‘Emerald’ and ‘Jewel’ SHB buds were collected beginning in late summer until shoot growth cessation in late fall for dissection and identification of organ development. Inflorescence bud frequency and number, vegetative and inflorescence bud length and width throughout development, and bloom were also assessed. Inflorescence bud initiation occurred earlier in ‘Emerald’ compared with ‘Jewel’. Five stages of internal inflorescence bud development were defined throughout fall in both cultivars, ranging from a vegetative meristem to early expansion of the inflorescence bud in late fall. ‘Emerald’ inflorescence buds were larger and bloomed earlier, reflecting the earlier inflorescence bud initiation and development. Although inflorescence bud initiation occurred earlier in ‘Emerald’ compared with ‘Jewel’, the pattern of development was not different. Timing of inflorescence bud initiation influenced timing of bloom with earlier initiation resulting in earlier bloom.


1978 ◽  
Vol 26 (1) ◽  
pp. 119-127
Author(s):  
D.P. de Vries ◽  
L. Smeets

As a basis for breeding cvs adapted to flowering in winter light conditions, the growth of hybrid tea rose seedlings under controlled conditions was studied. Irradiance varied from 4-24 W/m2, day length was 8 h, temperature 21 deg C. Like cvs, the seedlings sometimes aborted the flower bud at low light intensity. With increasing irradiances, the following phenomena were observed: the juvenile period of the seedlings shortened; plants were longer at bud formation, at first flowering and at flower bud abortion; leaf area and the number of petals increased. Leaf number was constant at all irradiances. Flowering seedlings were smaller at bud formation, but taller at actual flowering than blind ones. Blind seedlings had fewer leaves with a smaller area. (Abstract retrieved from CAB Abstracts by CABI’s permission)


1995 ◽  
Vol 73 (2) ◽  
pp. 149-157 ◽  
Author(s):  
Takayoshi Koike

The foliar phenology of potted 1-year-old seedlings of alder (Alnus hirsuta Turcz.), maple (Acer mono Maxim.), and birch (Betula platyphylla Sukatch. var. japonica Hara) was observed from May to September in eight growth environments: factorial combinations of temperatures (light:dark, 30:20 °C and 26:16 °C), CO2 level (70 and 36 Pa), and nutrient regime (high versus low levels of fertilization). Seedlings grown at high fertility always had more leaves, and under high CO2, shed leaves slightly later than seedlings grown at low fertility. Except for maple, production of newly formed shoots and leaves was accelerated by high CO2. In maple, high CO2 only increased the number of flushes of the leader shoot. Alder and birch accelerated sylleptic shoot and leaf production at high CO2 in fertile conditions. The production of new leaves by alder grown at high CO2 and low fertility was almost the same as that grown under normal CO2, at high fertility. At high CO2, the timing of winter bud formation of monopodial alder and maple was delayed, while that of sympodial birch was almost the same as at ambient CO2. Key words: foliar phenology, elevated atmospheric CO2 and temperature, monopodial versus sympodial growth, nutrient levels, winter bud formation, global change.


1984 ◽  
Vol 32 (4) ◽  
pp. 387 ◽  
Author(s):  
EW Pook

The canopy dynamics of a regenerated 16-year-old stand of pole and sapling E. maculata were studied for 2½ years by repetitive non-destructive measurements in tree crowns accessed from a 20 m high scaffold tower. Average canopy leaf area density over a sample plot of 36 m2 was 0.23 m2 m-3 at a leaf area index of 4.3. Some 75% of leaf area was held in the canopies of overstorey eucalypts above 10 m in height. Average size of leaves increased gradually from top to bottom of tree canopies. Foliage production was usually concentrated in the upper crowns of trees where there was a higher proportion of active shoots, more frequent growth flushes and more rapid turnover of leaves than in lower canopy layers. Leaf area in the upper canopy fluctuated widely but increased in the long term, in mid canopy was more or less maintained and in lowest canopy declined. Crops of developing flower buds present on uppermost branches delayed and/or reduced shoot growth. Foliage production occurred in all months of the year. There was a unimodal annual rhythm of growth rate reaching a maximum in summer and a minimum in winter. Variable water supply, however, influenced production to peak in spring, summer or autumn. No shoot growth occurs in E. maculata at Kioloa when daily mean temperature (averaged for weekly intervals) falls below c. 10½C in winter. An upper temperature limit for growth could not be defined. The species apparently lacks dormancy mechanisms. Shoot growth is 'opportunistic' and occurs whenever environmental conditions are favourable. Patterns of leaf production and leaf fall were variable but peaks showed a general synchrony. Leaf fall, however, tended to lag behind leaf production. Leaves of all ages were shed but main losses were from older cohorts. Some 49% (s.d.±18%) of new leaves were lost while still small or immature, mainly during periods of vigorous shoot growth or low water supply. Browse of immature foliage was light. Normal senescence and leaf fall accounted for almost the entire loss of mature foliage.


1969 ◽  
Vol 49 (6) ◽  
pp. 685-699 ◽  
Author(s):  
C. A. Campbell ◽  
W. L. Pelton ◽  
K. F. Nielsen

The influence of solar radiation on the growth and yield of Chinook wheat was determined in a 5-year field shading study, and a 1-year, 3 × 3 shading × soil moisture lysimeter experiment.In the field, shading with saran mesh reduced solar radiation and wind but had little effect on air or soil temperature. In moist years shade maintained soil moisture at a higher level than no shade. Generally, mean leaf area ratio decreased and mean net assimilation rate and relative growth rate increased linearly with increases in the log of light intensity. There were interactions between shading × years (weather) relative to dry matter yield. The efficiency with which solar energy was used for grain production increased with shading. The effect of shading on crude protein and soluble sugars in grain was variable.In the lysimeter shading study, regression equations were used to relate several plant characters to shading and soil moisture (in the available range). Plant height, stem diameter, days to head, number of tillers, weights of grain and of straw, and percent cellulose were negatively related to soil moisture stress; crude protein was positively related. Days to head and crude protein were negatively related to light intensity, but all the other characters were positively related. The partial regression coefficients indicated that the influence of soil moisture stress was much more important than solar radiation on the crude protein content of the grain.


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