Predetermination of lateral shoot characteristics in grand fir

1984 ◽  
Vol 62 (6) ◽  
pp. 1309-1315
Author(s):  
John Worrall
Keyword(s):  
Apical Meristem ◽  
Compensatory Growth ◽  
Growing Season ◽  
Light Interception ◽  
Internode Length ◽  
Vertical Position ◽  
Lateral Shoot ◽  
Terminal Bud ◽  
Number Of Leaves

The terminal bud and all but one subterminal bud were removed from the terminal leaders of shade-grown 15-year-old grand fir plants at monthly intervals during the season of their formation. The growth of shoots from the remaining subterminal bud was assessed in August of the following growing season and compared with control shoots. These latter displayed marked plagiotropy and distichy under the conditions of the experiment. In treated plants, compensatory growth occurred, with respect to both number of leaves and internode length. The shoots assumed a more vertical position, earlier treatment being more effective. The distichous positioning of leaves on these shoots, however, was not affected, causing leaves to be oriented in a manner inefficient for light interception. Plagiotropy seemed to have been imposed on the shoot gradually, during the season prior to its growth, whereas distichy was perhaps imposed close to the time of inception of the shoot's apical meristem. Possible reasons for this are discussed.

The effect of N-dimethyl amino succinamic acid (Alar) on six-year-old Gravenstein apples

1967 ◽  
Vol 7 (28) ◽  
pp. 476
Author(s):  
N Veinbrants
Keyword(s):  
Leaf Size ◽  
Growing Season ◽  
Internode Length ◽  
Extension Growth ◽  
Succinamic Acid ◽  
Number Of Leaves

Applications of N-dimethyl amino succinamic acid to the foliage on six-year-old Gravenstein apples restricted the extension growth. The reduced growth was characterized by shorter internode length giving the trees a more compact appearance. The number of leaves was also reduced although not to the same extent as extension growth. The leaf size was not affected. Two successive applications of 1,000 p.p.m. or a single spray of 2,000 p.p.m. applied early in the growing season resulted in highly significant increase of bloom in the following year. Yields were doubled by both treatments.

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.

scholarly journals The Effect of Irradiance, Defoliation, and Bulb Size on Flowering of Nerine bowdenii W. Watson (Amaryllidaceae)

1996 ◽  
Vol 121 (1) ◽  
pp. 115-122 ◽  
Author(s):  
K.I. Theron ◽  
G. Jacobs
Keyword(s):  
Developmental Stage ◽  
Dry Weight ◽  
Growing Season ◽  
Growth Unit ◽  
Growing Seasons ◽  
Number Of Leaves

Large Nerine bowdenii bulbs (>14 cm in circumference) were exposed to low ligbt intensities for different periods during two successive growing seasons. The flowering percentage and number of florets in the current season's inflorescence were recorded at anthesis. Small and large bulbs were subjected to continual defoliation starting at different times during the growing season. Bulbs were dissected at planting (26 Sept. 1992) and on 12 Jan. 1993 (nondefoliated control bulbs) to determine growth and developmental stage. At anthesis, inflorescences were harvested and the florets per inflorescence were counted. After anthesis in the fall, all bulbs were dissected and the following variables recorded: 1) percentage flowering, quiescence, or abortion of the current season's inflorescence; 2) developmental stage of quiescent inflorescences; 3) number of florets in the outermost inflorescence; 4) developmental stage of the innermost inflorescence; 5) number of leaves or leaf bases in each growth unit; 6) number of daughter bulbs; and 7) dry weight of new leaf bases. There were three reasons for nonflowering of the bulbs, viz., failure to initiate an inflorescence, inflorescences remaining quiescent, and inflorescence abortion. Individual florets that had not reached stage “Late G” (gynoecium elongated, carpels fused) at the start of rapid inflorescence elongation aborted. The more florets that aborted, the greater the probability that the entire inflorescence aborted. The inflorescence was more vulnerable to stress during the first half of the growing season due to its relatively weak position in the hierarchy of sinks within the bulb.

Dwarfism does not modify mean area per leaf and light interception in indeterminate autumn-sown white lupin

1996 ◽  
Vol 127 (3) ◽  
pp. 337-345 ◽  
Author(s):  
N. Harzic ◽  
C. Huyghe
Keyword(s):  
Lupinus Albus ◽  
Leaf Size ◽  
Branch Length ◽  
Light Interception ◽  
White Lupin ◽  
Low Light ◽  
First Order ◽  
Logistic Equations ◽  
Wide Range ◽  
Number Of Leaves

SUMMARYThe effect of dwarfism on leaf number and size was investigated on six pairs of tall and dwarf nearisogenic lines of indeterminate autumn-sown white lupins (Lupinus albus L.). Dwarfism reduced mainstem height by 41% and first-order branch length by 22%. It also slightly decreased the number of leaves on the mainstem and first-order branches without affecting the time of flowering. Leaf size was not reduced. Logistic equations were used to analyse differences in the patterns of light interception by leaf canopies relative to thermal time from sowing during the growth of seven dwarf lines and three tall cultivars sown on different dates. The genotypes studied had long periods of low light interception during their early growth. No differences were found between most of the equation parameters for dwarf and tall genotypes. Only the proportion of light intercepted at flowering differed and this was explained by differences in flowering time. The dwarf character did not limit the ability of the crop canopies to intercept light. It is concluded that the character can be introduced into a wide range of genetic backgrounds without deleterious effects.

scholarly journals Pasture characteristics of Italian ryegrass and milk production under different management strategies

2012 ◽  
Vol 47 (6) ◽  
pp. 863-868 ◽  
Author(s):  
Marcolino Frederico Miguel ◽  
Henrique Mendonça Nunes Ribeiro Filho ◽  
Steben Crestani ◽  
Fabiana da Rocha Ramos ◽  
Tereza Cristina Moraes Genro
Keyword(s):  
Dry Matter ◽  
Nutritional Value ◽  
Lolium Multiflorum ◽  
Management Strategies ◽  
Growing Season ◽  
Light Interception ◽  
Italian Ryegrass ◽  
Neutral Detergent Fiber ◽  
Low Light ◽  
Canopy Light Interception

The objective of this work was to assess the effects of the sward structure of Italian ryegrass (Lolium multiflorum), during the first grazing cycle, on its morphological and bromatological characteristics throughout the growing season, and on the performance of dairy cows. The treatments consisted of two structures obtained as a function of canopy-light interception: high-light interception (HLI) and low-light interception (LLI), with different pre-grazing heights in the first grazing cycle. Pasture was managed under rotational grazing with a herbage allowance not below 30 kg dry matter (DM) per cow per day. Three grazing cycles, with a grazing interval of 30 days, were evaluated. Pre-grazing herbage mass was greater (2,240 vs. 1,656 kg ha-1 DM), but the proportion of leaf blades was smaller (0.35 vs. 0.43) for HLI swards. Neutral detergent fiber (NDF) content and organic matter digestibility (OMD) were similar between treatments in the first grazing cycle, but in the second and third ones NDF was greater, and OMD lower, for the HLI swards. Milk yields were greater for cows grazing LLI swards (19.4 vs. 21.1 kg per day). Initial grazing with 90% of light interception promotes greater nutritional value in the subsequent cycles.

POTENTIAL VEGETATIVE PRODUCTIVITY IN CANADA

1983 ◽  
Vol 63 (1) ◽  
pp. 1-10 ◽  
Author(s):  
M. TOLLENAAR
Keyword(s):  
Photosynthetic Efficiency ◽  
Theoretical Estimate ◽  
Growing Season ◽  
Crop Growth ◽  
Light Interception ◽  
Crop Species ◽  
Potential Productivity ◽  
Crop Growth Rate ◽  
Water Nutrients ◽  
Productivity Estimate

Duration of the growing season appears to be the single most important factor limiting vegetative productivity in Canada. A theoretical estimate of annual vegetative productivity in the absence of limitations due to water, nutrients or soil structure, shows that potential productivity in the 5-mo growing season of Southern Canada is in the range of 25–55 tonne/ha. Maximum productivity, however, lies considerably below the potential productivity estimate due to lower-than-expected photosynthetic efficiency during periods of high solar irradiance. Crop growth rates appear to be rather independent of variation in radiant flux density during the growing season. Consequently, a realistic estimate of maximum vegetative productivity can be obtained by multiplying number of days of full light interception by a crop canopy, by a crop growth rate of 230 kg∙h−1∙day−1 and adding the weight of the crop at the onset of full light interception by the canopy. Maximum vegetative productivity could likely be improved by extending the period of full light interception by crop canopies through the cultivation of perennial species or double-crop sequences. Alternatively, vegetative productivity could likely be improved through increased photosynthetic efficiency. Very high photosynthetic efficiencies of crops grown under field conditions have been reported occasionally in the literature, but factors underlying this high photosynthetic efficiency have not yet been identified.Key words: Vegetative production, photosynthetic efficiency, potential productivity, duration of growing season, crop species

Some observations on the shoot growth of pine seedlings

1976 ◽  
Vol 6 (3) ◽  
pp. 341-347 ◽  
Author(s):  
S. Thompson
Keyword(s):  
Scots Pine ◽  
Shoot Apex ◽  
Shoot Growth ◽  
Lodgepole Pine ◽  
Growing Season ◽  
Pine Seedlings ◽  
Terminal Bud

Sequential observations in lodgepole pine (Pinuscontorta Dougl.) and Scots pine (P. sylvestris L.) showed that the second season's shoot was not produced solely from stem units in the terminal resting bud as previously assumed. The stem units held in the rosette of primary needles surrounding the terminal bud elongated to form most of the second season's shoot. The terminal bud only contributed 29 to 54% of the stem units. There was a marked difference between an inland and a coastal provenance of lodgepole pine in the appearance of the shoot apex at the end of the first growing season.

Influence of row spacing on water use and yield of rain-fed wheat (Triticum aestivum L.) in a no-till system with stubble retention

2010 ◽  
Vol 61 (11) ◽  
pp. 892 ◽  
Author(s):  
S. G. L. Kleemann ◽  
G. S. Gill
Keyword(s):  
Grain Yield ◽  
Water Use Efficiency ◽  
Water Use ◽  
Vegetative Growth ◽  
Growing Season ◽  
Light Interception ◽  
Row Spacing ◽  
Spike Density ◽  
Stubble Retention ◽  
Use Efficiency

A 3-year field study was undertaken to investigate the effect of row spacing on vegetative growth, grain yield and water-use efficiency of wheat. All 3 years of the study experienced 21–51% below-average rainfall for the growing season. Widening row spacing led to reduced biomass and tillers on per plant basis which could be related to the reduction in light interception by the wheat canopy in the wide rows which in turn could have reduced assimilate production. Reduction in vegetative growth in 54-cm rows translated into a significant reduction in grain yield which was strongly associated (r2 = 0.71) with the loss of spike density. The pattern of crop water use (evapotranspiration, ET) during the growing season was very similar for the three row-spacing treatments. However, there was some evidence for slightly lower ET (~5%) in 54-cm rows in two growing seasons. More importantly, there was no evidence for increased ET during the post-anthesis phase in wide rows as has been speculated by some researchers. Over the 3 years of the study, grain yield declined by 5–8% as row spacing increased from 18 to 36 cm and by a further 12–20% as row spacing increased from 36 to 54 cm. There was a consistent decline in water-use efficiency for grain (WUEG) with increasing row spacing over the 3 years. WUEG declined by 6–11% as crop spacing increased from 18 to 36 cm and declined further by 12–15% as row spacing increased to 54 cm. Lower light interception at wider row spacing could have reduced assimilate production by wheat as well as increased soil evaporation due to lower shading of the soil surface in more open canopies. Growers adopting wider row spacing on these relatively heavy textured soils are likely to experience some reduction in grain yield and WUEG. However, some growers may be prepared to accept a small yield penalty from intermediate row spacing as a trade-off for increased stubble retention and soil health.

scholarly journals Growth and Flowering of Crapemyrtle in Response to Tree Shelters

2006 ◽  
Vol 24 (3) ◽  
pp. 155-159
Author(s):  
K.M. Brooks ◽  
G.J. Keever ◽  
J.E. Altland ◽  
J.L. Sibley
Keyword(s):  
Growing Season ◽  
Height Growth ◽  
Shoot Development ◽  
Lateral Shoot ◽  
Tree Form ◽  
Tree Shelters

Abstract Tree shelters were evaluated as a means of accelerating height growth of tree-form crapemyrtles. In two experiments, Dynamite™ grown in shelters were 124 and 48% taller at the end of the growing season, while shelter-grown ‘Potomac’ were 61 and 50% taller. Height of ‘Tuscarora’ was not affected by tree shelters. In the first experiment calipers of sheltered and non-sheltered ‘Tuscarora’ and Dynamite™ were similar at the end of the season, while caliper of ‘Potomac’ was 35% less when grown in shelters. In the second experiment there were no caliper differences between sheltered and unsheltered Dynamite™ or ‘Potomac’ at the end of the growing season. All plants grown in tree shelters flowered later than unsheltered plants and had visibly straighter, more upright trunks with minimal lateral shoot development.

scholarly journals Comparative Evaluation of the Influence of Organic and Inorganic Fertilizers on Growth Performance of Tetrapleura tetraptera

2020 ◽  
pp. 1-9
Author(s):  
U. L. Edem ◽  
E. E. Ekerette
Keyword(s):  
Leaf Area ◽  
Seedling Growth ◽  
Seedling Emergence ◽  
Leaf Length ◽  
Internode Length ◽  
Stem Diameter ◽  
Cross River ◽  
Tetrapleura Tetraptera ◽  
Chicken Litter ◽  
Number Of Leaves

The continuous destruction of our rainforest has threatened the existence of many useful and multipurpose plant species such as Tetrapleura tetraptera. To revert this situation, efforts must be made towards its sustainable use by encouraging reforestation which entails raising of seedlings for mass propagation of this crop. This study was aimed at comparing the effects of organic (chicken litter) and inorganic (NPK 15:15:15) fertilizers on seedling growth in four accessions of Tetrapleura tetraptera and hence determining fertilizer preference for this forest species. The Complete Randomized Design (CRD) was used in a factorial arrangement with four accessions and three fertilizer types in eight replicates. One month after transplanting, the fertilizers (organic and inorganic) were uniformly applied at the rate of 45 kg/hectare according to the experimental design. Data were collected monthly for a period of three months on plant height, stem diameter, leaf area, leaf length, member of branches, number of leaves, primary and secondary internode length per plant. Data on seedling emergence were also taken. Data collected were subjected to a two-way analysis of variance. Least significant difference (LSD) was used to separate significant means at p = 0.05. Result obtained revealed that the soil was rich in calcium, phosphorus and organic matter but low in nitrogen and potassium which were adequately complemented in mean days to seedling emergence in four accessions studied. Our findings also revealed that the organic (chicken litter) fertilizer did better (P<0.05) in all accessions than inorganic (NPK 15:15:15) fertilizer for all morphological traits studied. The performance of Cross River accession was outstanding as illustrated by the significant interaction obtained in most parameters. With chicken, litter fertilizer, Cross River accession produced the tallest plant (27.38 cm), largest leaf area (1.99 cm2), highest number of branches (20.13), highest number of leaves (66.75), longest stem diameter (0.93 cm), longest leaf length (1.94 cm), lowest primary (0.80) and lowest secondary (0.83) internode length. The use of organic fertilizers is therefore recommended for improved seedling growth of Tetrapleura tetraptera.

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