scholarly journals The Effect of Plant Pruning on the Light Conditions and Vegetative Development of Eggplant (Solanum Melongena L.) in Greenhouse Cultivation

2008 ◽  
Vol 68 (1) ◽  
pp. 57-70 ◽  
Author(s):  
Anna Ambroszczyk ◽  
Stanisław Cebula ◽  
Agnieszka Sękara
Keyword(s):  
Leaf Area ◽  
Solanum Melongena ◽  
Early Spring ◽  
Light Conditions ◽  
Vegetative Development ◽  
Area Index ◽  
Mass Unit ◽  
Leaf Area And Thickness ◽  
Greenhouse Cultivation ◽  
Pruning Methods

The Effect of Plant Pruning on the Light Conditions and Vegetative Development of Eggplant (Solanum MelongenaL.) in Greenhouse CultivationThe aim of the present investigations was to find the relations between pruning methods and chosen parameters of vegetative eggplant development in greenhouse conditions. The plant shape modifies the photosynthetically active radiation (PAR) conditions in the plant profile. Independence between different pruning methods and vegetative plant development particularly leaves characteristics as well as pigments and photosynthesis products content in leaves was stated. The investigations were carried out in 1999-2001 in the experimental greenhouse of Agricultural University in Kraków, Poland. Eggplant of Tania F1hybrid was used in the early spring-summer production in a heated greenhouse. The following pruning systems were applied: pruning to one shoot with leaving on every node 2 fruit sets and 1, 2 or 3 leaves, and pruning to two shoots with leaving on every node 1 fruit set and 1, 2 or 3 leaves. With the introduction of a greater number of leaves and fruit sets on eggplant shoots irradiation in plant profile was reduced. The value of leaf area index (LAI) depended on the way of pruning. Chemical composition of leaves was slightly dependent on the method of pruning only in the case of assimilation products, i.e. reducing sugar and starch. Improvement of photosynthesis efficiency of intensively pruned eggplants was achieved by the increase of single leaf area and thickness of leaf mesophyll tissues without the increase of the level of assimilative pigments per plant mass unit.

scholarly journals Adjusting Ceptometer Data to Improve Leaf Area Index Measurements

Agronomy ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 866 ◽  
Author(s):  
Klára Pokovai ◽  
Nándor Fodor
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Measurement Techniques ◽  
Well Being ◽  
Average Error ◽  
Light Conditions ◽  
Simple Method ◽  
Area Index ◽  
Expert Opinions ◽  
Optimal Illumination

Leaf Area Index (LAI) is an important plant parameter for both farmers and plant scientists to monitor and/or model the growth and the well-being of plants. Since direct LAI measurement techniques are relatively laborious and time-consuming, various indirect methods have been developed and widely used since the early 1990s. The LP-80 ceptometer uses a linear array of PAR (photosynthetically active radiation) sensors for non-destructive LAI measurements that is backed by 15 years of research. Despite this, considerable discrepancy can be found between the expert opinions regarding the optimal illumination conditions recommended for the measurement. The sensitivity of ceptometer-based LAI values to PAR was investigated, and a simple method was devised to correct raw ceptometer data collected under non-ideal light conditions. Inadequate light conditions (PAR < 1700 µmol m−2 s−1) could cause an underestimation of LAI. Using the corrected LAI values, the ceptometer data showed a significantly better fit (higher R2, smaller mean average error and closer to zero mean signed error values) to the destructive LAI data for both wheat and maize. With the help of the correction equations, the use of the LP-80 ceptometer could be extended to days when light conditions are not ideal.

scholarly journals The effect of light availability on leaf area index, biomass production and plant species composition of park grasslands in Warsaw  

2013 ◽  
Vol 59 (No. 12) ◽  
pp. 543-548 ◽  
Author(s):  
P. Dąbrowski ◽  
B. Pawluśkiewicz ◽  
Kalaji HM ◽  
Baczewska AH
Keyword(s):  
Solar Radiation ◽  
Leaf Area Index ◽  
Leaf Area ◽  
Light Availability ◽  
Vegetation Coverage ◽  
Light Conditions ◽  
Area Index ◽  
Sward Height ◽  
Poa Trivialis ◽  
Leaf Density

How light conditions affect development of park grasslands is a question that has not been satisfactory addressed. The aim of this study was therefore determination of the level to which unfavorable light conditions influence grassy parks area and relationships between parameters which determine state of turf grasses. Researches were conducted in two parks in Warsaw, in various light conditions and included measurement of: leaf density, sward height, leaf area index (LAI), and botanical composition of the communities. The leaf density of shaded areas did not exceed 70%. LAI value varied from 0.5 to 0.9-fold lower than in the areas in half-shade and in sun. The participation of basic lawn species at Skaryszewski Park was higher under shade, while at Łazienki Kr&oacute;lewskie was higher in full-sunlight areas. The state of tested grassy areas in limited solar radiation does not satisfy the requirements of recreational and representational functions. The development processes of vegetation coverage were inhibited at the sites of lower solar radiation. LAI was influenced by both leaf coverage and sward height. Agrostis stolonifera and Poa trivialis may be recommended to create grass areas under limited solar radiation.

scholarly journals Components of the leaf area index of marandu palisadegrass swards subjected to strategies of intermittent stocking

2009 ◽  
Vol 66 (6) ◽  
pp. 721-732 ◽  
Author(s):  
Alessandra Aparecida Giacomini ◽  
Sila Carneiro da Silva ◽  
Daniel Oliveira de Lucena Sarmento ◽  
Cauê Varesqui Zeferino ◽  
Júlio Kuhn da Trindade ◽  
...  
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Specific Leaf Area ◽  
Management Practices ◽  
Block Design ◽  
Early Spring ◽  
Light Interception ◽  
Area Index ◽  
Early Return ◽  
Index Site

Leaf area index is the main sward characteristic related to the processes of light interception and competition in plant communities. The objective of this experiment was to quantify and evaluate the composition of the leaf area on tillers of marandu palisadegrass (Brachiaria brizantha cv. Marandu) subjected to strategies of intermittent stocking. The experiment was carried out in Piracicaba, state of São Paulo, Brazil, from October/2004 to December/2005. Swards were grazed at 95 and 100% canopy light interception (LI) to post-grazing heights of 10 and 15 cm, following a 2 ' 2 factorial arrangement with four replications in a randomised complete block design. Estimates were made of sward leaf area index, site filling, specific leaf area and the dimensionless ratio between tiller leaf area and volume (R), as well as the relative contribution of basal and aerial tillers to these variables. In early spring, values of leaf area index and specific leaf area were low when compared to the other seasons, and swards grazed at 95% LI presented higher site filling and specific leaf area than those grazed at 100% LI. This resulted in higher tillering activity and increase in leaf area index in late spring, indicating quick recovery and early return of swards grazed at 95% LI to growing conditions. Aerial tillers corresponded to an important morphological adaptation of marandu palisadegrass to increase its competitive ability. Treatment 100/10 resulted in the highest and 95/15 in the lowest R values throughout the experiment, suggesting an allometric pattern of growth of tillers during regrowth in order to compensate low tiller population and optimise the leaf area index. Grazing management practices can benefit from this knowledge by promoting ideal sward conditions to maximise and accelerate growth.

The physiology of forage rye (Secale cereale)

1983 ◽  
Vol 101 (1) ◽  
pp. 63-70 ◽  
Author(s):  
R. K. M. Hay ◽  
M. K. Abbas Al-Ani
Keyword(s):  
Leaf Area ◽  
Photosynthetic Apparatus ◽  
Early Spring ◽  
Net Assimilation Rate ◽  
Winter Rye ◽  
Assimilation Rate ◽  
Light Conditions ◽  
Net Assimilation ◽  
Leaf Appearance ◽  
Forage Yields

SUMMARYField and pot investigations of the vegetative and early reproductive growth of a winter wheat and a winter rye cultivar over three seasons (1978–9, 1980–2) have shown that higher and earlier forage yields of rye are due to a combination of factors, notably more rapid rates of germination, crop emergence, leaf appearance and leaf expansion coupled with higher leaf area ratios. There was no evidence, from studies of net assimilation rate, that the photosynthetic apparatus of rye plants is better adapted than wheat to the low temperature and light conditions of winter and early spring. However, the earlier initiation of rye stem extension was associated with significant increases in net assimilation rate, which compensated for reductions in the leaf area ratio. Practical aspects of these results are discussed briefly.

scholarly journals Effect of Growth Regulators and Organics on Growth and Yield of Spiny Brinjal Variety VRM (Br) -1

2021 ◽  
pp. 222-229
Author(s):  
S. Nanthakumar ◽  
C. Pravin Kumar ◽  
P. Thilagam
Keyword(s):  
Salicylic Acid ◽  
Leaf Area ◽  
Growth Regulators ◽  
Field Experiments ◽  
Solanum Melongena ◽  
Foliar Spray ◽  
Fruit Weight ◽  
Growth And Yield ◽  
Area Index ◽  
Maximum Value

Two field experiments were carried out at Horticultural College, Kalavai to study the effect of growth regulators and organics on growth and yield of spiny brinjal (Solanum melongena) var.VRM-1. Growth regulators viz., Salicylic acid @ 200 ppm, Brassinosteriods  @ 0.1 ppm, Triacontanol @ 5 ppm and NAA @ 40 ppm and organics viz., Seaweed extract @ 1.0%, Humic acid @ 1.0%, Panchagavya @ 5.0% and Vermiwash @ 5.0% were tested and applied as foliar spray in spiny brinjal var VRM-1. Among the treatments tested, Panchagavya treatment recorded maximum value with regard to plant height (85.45 cm), leaf area (131.59 cm),  leaf area index (3.66), branches per plant (21.3 Nos) , flowers per plant (55.5 Nos), fruits per plant (20.9 Nos), fruit length (5.8 cm), fruit circumference (14.7 cm)  and individual fruit weight (82.1 g). Brassinosteroids treatment found to be effective in increasing root length (22.75 cm).

Transplanting Shock and Water Relations in Urban Tree Species

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 540b-540
Author(s):  
Amy J. Barton ◽  
Christopher S. Walsh
Keyword(s):  
Leaf Area ◽  
Early Spring ◽  
Area Index ◽  
Notable Effect ◽  
Water Potentials ◽  
Open Canopy ◽  
Transplanting Shock ◽  
Pressure Bomb ◽  
Water Potential Measurements ◽  
Acer Ginnala

Large-caliper trees transplanted into urban settings show low survivability. A 1-year transplanting experiment was conducted using Acer ginnala and Acer truncatum. Trees were blocked by species and size, with three blocks of four trees per species. Three trees of each species were left in their original location for purpose of comparison. A 2 × 2 factorial was used to assign treatments (water, water and top prune, top prune, and transplanted control). Using a Schollander Pressure Bomb, predawn and midday water potential measurements were recorded biweekly from early May through September. The first 8 weeks following transplant, all transplanted trees of both species had significantly (P ≥ 0.05) more negative midday water potentials than those not transplanted. During periods of stress, predawn water potentials of transplanted trees did not recover overnight. By September, irrigated trees had water potentials not significantly different from those of trees not transplanted. Canopy closure was measured on the same schedule using a Li-Cor Canopy Analyzer. Leaf area index of transplanted trees was nearly half that of non-transplanted trees. Trees treated with water did have slight, but significantly greater leaf area indexes than those of other treatments. It appears that the most notable effect of transplanting is the inhibition of leaf expansion resulting from early spring water stress. This leads to an open canopy for the whole season following transplant.

EFFECT OF ALTERING PLANT DENSITY ON GROWTH CHARACTERISTICS OF SUMMER RAPE

1990 ◽  
Vol 70 (1) ◽  
pp. 139-149 ◽  
Author(s):  
M. J. MORRISON ◽  
P. B. E. McVETTY ◽  
R. SCARTH
Keyword(s):  
Brassica Napus ◽  
Leaf Area ◽  
Growth Analysis ◽  
Plant Density ◽  
Dry Weight ◽  
Growth Characteristics ◽  
Row Spacing ◽  
Vegetative Development ◽  
Brassica Napus L ◽  
Area Index

The effect of 15- and 30-cm row spacings and 1.5, 3.0, 6.0 and 12.0 kg ha−1 seeding rates on growth characteristics, as measured by growth analysis, of summer rape (Brassica napus L.) was studied under southern Manitoba growing conditions. Growing degree days (GDD) was used in the growth analysis formulae as a measurement of time. Over all seeding rates, summer rape grown in rows spaced 15 cm apart produced more dry weight (W), a greater leaf area index (LAI) and a greater leaf area duration (LAD) than when grown in rows spaced 30 cm apart. The 15-cm row spacing treatments had a higher crop growth rate (CGR) and a greater net assimilation rate (NAR) than the 30-cm row spacing treatments. Summer rape grown at seeding rates of 6.0 and 12.0 kg ha−1 had a greater W, LAI and LAD during vegetative development than summer rape grown at seeding rates of 1.5 and 3.0 kg ha−1. This was primarily due to increased plant density. After flowering there were no differences for W, LAI and LAD attributable to differences in seeding rates. Summer rape grown at seeding rates of 6.0 and 12.0 kg ha−1 had a lower CGR and NAR during flowering than that grown at 1.5 and 3.0 kg ha−1 seeding rates indicating that plants produced from lower seeding rates were more photosynthetically efficient than plants produced from higher seeding rates.Key words: Brassica napus, growth analysis, row spacing, seeding rates, rape (summer)

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