scholarly journals Canopy Light Signals and Crop Yield in Sickness and in Health

ISRN Agronomy ◽  
2013 ◽  
Vol 2013 ◽  
pp. 1-16 ◽  
Author(s):  
Jorge J. Casal
Keyword(s):  
Crop Yield ◽  
Significant Influence ◽  
Photosynthetic Capacity ◽  
Plant Performance ◽  
Canopy Architecture ◽  
Plant Defences ◽  
Stem Height ◽  
Light Signals ◽  
Sensory Photoreceptors ◽  
Main Effects

Crop management decisions such as sowing density, row distance and orientation, choice of cultivar, and weed control define the architecture of the canopy, which in turn affects the light environment experienced by crop plants. Phytochromes, cryptochromes, phototropins, and the UV-B photoreceptor UVR8 are sensory photoreceptors able to perceive specific light signals that provide information about the dynamic status of canopy architecture. These signals include the low irradiance (indicating that not all the effects of irradiance occur via photosynthesis) and low red/far-red ratio typical of dense stands. The simulation of selected signals of canopy shade light and/or the analysis of photoreceptor mutants have revealed that canopy light signals exert significant influence on plant performance. The main effects of the photoreceptors include the control of (a) the number and position of the leaves and their consequent capacity to intercept light, via changes in stem height, leaf orientation, and branching; (b) the photosynthetic capacity of green tissues, via stomatic and nonstomatic actions; (c) the investment of captured resources into harvestable organs; and (d) the plant defences against herbivores and pathogens. Several of the effects of canopy shade-light signals appear to be negative for yield and pose the question of whether breeding and selection have optimised the magnitude of these responses in crops.

scholarly journals Yield and performance of sugarcane in on-farm interface with rubber in Brazil

2006 ◽  
Vol 41 (2) ◽  
pp. 251-255
Author(s):  
Luís Fernando Guedes Pinto ◽  
Marcos Silveira Bernardes ◽  
Antônio Roberto Pereira
Keyword(s):  
Crop Yield ◽  
Dry Matter ◽  
Field Experiments ◽  
Management Strategies ◽  
Saccharum Officinarum ◽  
Agroforestry Systems ◽  
Plant Performance ◽  
Matter Production ◽  
And Performance ◽  
On Farm

Agroforestry systems are indicated as an alternative for sugarcane (Saccharum officinarum) cultivation in Piracicaba, SP, Brazil, however there are not many field experiments on plant performance under these conditions in the world. The objective of this work was to assess crop yield and partitioning in a sugarcane-rubber (Hevea brasiliensis) interface in on-farm conditions. The availability of irradiance for the crop along the interface was simulated and its effe ct over sugarcane dry matter production was tested. Crop yield was negatively affected by distance of the trees, but development and sucrose were not affected. Above ground dry matter increased from 16.6 to 51.5 t ha-1 from trees. Partitioning did not have a defined standard, as harvest index increased from 0.85 to 0.93, but specific leaf area was not significant along the transect, ranging from 13.48 to 15.73 m² kg-1. Light is the main factor of competition between the trees and the crop, but the relative importance of below ground interactions increases closer to the trees. Feasibility of the system depends on maturity of the trees and management strategies.

scholarly journals Functional differences in seasonally absorbed nitrogen in a winter-green perennial herb

2020 ◽  
Vol 7 (1) ◽  
pp. 190034
Author(s):  
Satomi Nishitani ◽  
Atsushi Ishida ◽  
Toshie Nakamura ◽  
Naoki Kachi
Keyword(s):  
Environmental Changes ◽  
Photosynthetic Capacity ◽  
Leaf Growth ◽  
N Uptake ◽  
Plant Performance ◽  
N Availability ◽  
Storage Organs ◽  
Different Seasons ◽  
N Use ◽  
Leaf N

Nitrogen (N) uptake in response to its availability and effective N-use are important for determining plant fitness, as N is a major limiting resource and its availability changes both seasonally and annually. Storage organs such as bulbs are considered an adaptive trait with respect to plant N-use strategies. It is well known that N is remobilized from storage organs to satisfy the high demand for new growth that is not completely satisfied by external uptake alone. However, little is known about how this N absorbed during different seasons contributes to plant performance. By manipulating seasonal N availability in potted Lycoris radiata var. radiata (Amaryllidaceae), a winter-green perennial, we found that the N absorbed during different seasons had different effects on leaf growth and leaf N concentrations, effectively increasing the growth and survival of the plants. N absorbed during the summer (leafless period; N was thus stored in the bulb) enhanced plant growth by increasing leaf growth. Compared with the plants supplied with N during autumn (leaf flush period), the leafy plants also showed greater growth per unit leaf area despite the lower area-based photosynthetic capacity of the latter. By contrast, N absorbed during the autumn increased the leaf N concentration and thus the photosynthetic capacity, which was considered to enhance survival and growth of the plant during winter by reducing the potentially fatal risk caused by the absorption of photons under low temperature. Our findings have important implications for estimating plant responses to environmental changes. We predict that changes in seasonal N availability impact the performance of plants, even that of perennials that have large storage organs, via an altered relative investment of N into different functions.

Improving crop yield and resilience through photosynthesis optimisation: panacea or pipe dream?

2021 ◽  
Author(s):  
José L Araus ◽  
Ruth Sanchez-Bragado ◽  
Rubén Vicente
Keyword(s):  
Crop Yield ◽  
Green Revolution ◽  
Crop Productivity ◽  
Canopy Architecture ◽  
Canopy Photosynthesis ◽  
Stay Green ◽  
Whole Plant ◽  
Reference Target ◽  
Pipe Dream ◽  
Uptake Of Nutrients

Abstract Increasing the speed of breeding to enhance crop productivity and adaptation to abiotic stresses is urgently needed. The perception that a second Green Revolution should be implemented is widely established within the scientific community and among stakeholders. In recent decades, different alternatives have been proposed for elevating crop yield through manipulation of leaf photosynthetic efficiency. However, none of these have delivered practical or relevant outputs. Indeed, the actual increases in photosynthetic rates are not expected to translate into yield increases beyond 10-15%. Furthermore, instantaneous rates of leaf photosynthesis are not necessarily the reference target for research. Yield is the result of canopy photosynthesis, understood as the contribution of laminar and non-laminar organs over time, within which concepts such as canopy architecture, stay-green or non-laminar photosynthesis need to be taken into account. Moreover, retrospective studies show that photosynthetic improvements have been more common at the canopy level. Nevertheless, it is crucial to place canopy photosynthesis in the context of whole-plant functioning, which includes sink/source balance and transport of photoassimilates, and the availability and uptake of nutrients, such as nitrogen in particular. Overcoming this challenge will only be feasible if a multiscale crop focus combined with a multidisciplinary scientific approach is adopted.

scholarly journals Reciprocal Garden Study Reveals Acute Spatial-Edaphic Adaptation for Cycas micronesica

Diversity ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 237
Author(s):  
Thomas E. Marler
Keyword(s):  
Local Adaptation ◽  
Plant Size ◽  
Plant Performance ◽  
Stem Height ◽  
The South ◽  
The North ◽  
Survival And Growth ◽  
Local Genotypes ◽  
North And South

A long-term reciprocal garden study was used to determine adaptive variation between Cycas micronesica K.D. Hill plants from north versus south Guam. Half-siblings from each location were planted as one-leaf seedlings in north and south gardens and monitored for 15 years. Stem height and diameter, and leaf number and maximum length were measured yearly. Survival and plant size traits were evaluated using a two-way factorial. In both locations, the local genotypes out-performed the foreign genotypes in terms of survival and growth. Survival of the foreign genotypes began to decline by year 4 and was less than 10% by year 15. Survival of the local genotypes was 70% for the north garden and 100% for the south garden. The north site was more hostile to plant performance because overall survival and plant growth were less than for the south site. The most likely environmental factor provoking local adaptation was highly contrasting soil characteristics between north and south Guam. The results indicates that long-term conservation success for C. micronesica and other cycad species must include the concept of local adaptation into decisions for transplantation and restoration projects.

scholarly journals Canopy Photosynthetic Capacity and Light Response Parameters of Rubber Hevea brasiliensis with Reference to Exploitation

2013 ◽  
Vol 1 (1) ◽  
pp. 01-12 ◽  
Author(s):  
H Gunasekera ◽  
W De Costa ◽  
A Nugawela
Keyword(s):  
Leaf Area ◽  
Photosynthetic Rate ◽  
Photosynthetic Capacity ◽  
Light Response ◽  
Co2 Assimilation ◽  
Canopy Architecture ◽  
Canopy Photosynthesis ◽  
Canopy Layer ◽  
Area Index ◽  
Consistent Variation

The main objective of this study wasto investigate the relationship between canopy photosynthetic capacityand light response parametersof tapped and untapped trees of twoHeveabrasiliensis genotypes, i.e. RRISL 211 and RRIC 121. Moreover, attempts have been made to develop correlations between canopy photosynthesis and light response parameters Heveawith reference to exploitation. The canopy photosynthetic rates measured under optimal environmental conditions clearly showed clonal differences in CO2 assimilation rates. The photosynthetic capacities of leaves from all strata of RRISL 211 were greater than the corresponding strata values in RRIC 121. A greater canopy photosynthetic rate was observed in clone RRISL 211 despite its leaf area index being 2% lower than in RRIC 121. This could be because of the greater photosynthetic capacity of RRISL 211, as indicated by the greater Amax values.In each clone, Amax of the tapped trees was greater than the Amax of untapped trees, and this difference was greater in RRISL 211 than RRIC 121. Another reason for the greater canopy photosynthesis of clone RRISL 211 was the presence of a higher percentage of leaf area in the top canopy layer as compared to clone RRIC 121. Even though, the light saturation point, LSP (i.e. the light intensity at which photosynthetic rate reaches maximum), did not differ significantly between different canopy layers within a clone for both clones, RRIC 121 had greater LSP for corresponding layers than RRISL 211. Moreover, it was evident that, due to the more open canopy architecture of clone RRIC 121, LSP of its middle canopy layer was very close to LSP of the upper canopy layer.In both clones QE of all canopy layers did not show a consistent variation between tapped and untapped treatments The Rd rates of corresponding canopy layers were always slightly greater in RRISL 211 than in RRIC 121. In both clones there was a gradual reduction in Rd rates when moving from upper through middle to bottom layers of the canopy. However, detailed analysis of Rd rates in the different canopy layers between tapped and untapped treatments showed clonal differences. Nevertheless, in both clones Rd of all canopy layers did not show a consistent variation pattern between tapped and untapped treatments. The overall results of both clones clearly showed that tapped trees have a greater photosynthetic capacity as compared to untapped trees because tapping exerts a stimulatory effect on photosynthesis. This trend was more evident in clone RRISL 211.

scholarly journals Effect of Magnetopriming on Photosynthetic Performance of Plants

2021 ◽  
Vol 22 (17) ◽  
pp. 9353
Author(s):  
Mohammad Sarraf ◽  
Kricelle Mosquera Deamici ◽  
Houda Taimourya ◽  
Monirul Islam ◽  
Sunita Kataria ◽  
...  
Keyword(s):  
Crop Yield ◽  
Growth Parameters ◽  
Biomass Accumulation ◽  
Seed Priming ◽  
Fluorescence Yield ◽  
Photosynthetic Performance ◽  
Seed Vigor ◽  
Plant Performance ◽  
Ojip Transient ◽  
Pep Carboxylase

Magnetopriming has emerged as a promising seed-priming method, improving seed vigor, plant performance and productivity under both normal and stressed conditions. Various recent reports have demonstrated that improved photosynthesis can lead to higher biomass accumulation and overall crop yield. The major focus of the present review is magnetopriming-based, improved growth parameters, which ultimately favor increased photosynthetic performance. The plants originating from magnetoprimed seeds showed increased plant height, leaf area, fresh weight, thick midrib and minor veins. Similarly, chlorophyll and carotenoid contents, efficiency of PSII, quantum yield of electron transport, stomatal conductance, and activities of carbonic anhydrase (CA), Rubisco and PEP-carboxylase enzymes are enhanced with magnetopriming of the seeds. In addition, a higher fluorescence yield at the J-I-P phase in polyphasic chlorophyll a fluorescence (OJIP) transient curves was observed in plants originating from magnetoprimed seeds. Here, we have presented an overview of available studies supporting the magnetopriming-based improvement of various parameters determining the photosynthetic performance of crop plants, which consequently increases crop yield. Additionally, we suggest the need for more in-depth molecular analysis in the future to shed light upon hidden regulatory mechanisms involved in magnetopriming-based, improved photosynthetic performance.

How Neighbor Canopy Architecture Affects Target Plant Performance

Ecology ◽  
1993 ◽  
Vol 74 (7) ◽  
pp. 2114-2124 ◽  
Author(s):  
D. C. Tremmel ◽  
F. A. Bazzaz
Keyword(s):  
Plant Performance ◽  
Canopy Architecture ◽  
Target Plant

scholarly journals The behaviour of reinforced concrete beams under cyclic loading

1979 ◽  
Vol 12 (2) ◽  
pp. 158-167
Author(s):  
R. C. Fenwick ◽  
A. Fong
Keyword(s):  
Shear Stress ◽  
Cyclic Loading ◽  
Significant Influence ◽  
Concrete Beams ◽  
Reinforced Concrete Beams ◽  
Low Load ◽  
Low Shear Stress ◽  
Shear Stress Level ◽  
Main Effects ◽  
Low Shear

The behaviour of beams in which plastic hinges are formed under cyclic loading is examined. The results are reported of five beam tests, in which the shear stress level was varied. It is shown that even relatively low shear stress levels have a significant influence on beam behaviour. Two main effects of shear are to reduce the ability of the hinge to dissipate energy and to reduce the stiffness of the beams at low load levels.. The degradation in shear under cyclic loading is accompanied by an appreciable growth in length of the beam.

scholarly journals Salinity impairs photosynthetic capacity and enhances carotenoid-related gene expression and biosynthesis in tomato (Solanum lycopersicum L. cv. Micro-Tom)

PeerJ ◽  
2020 ◽  
Vol 8 ◽  
pp. e9742 ◽  
Author(s):  
Andrés Leiva-Ampuero ◽  
Mario Agurto ◽  
José Tomás Matus ◽  
Gustavo Hoppe ◽  
Camila Huidobro ◽  
...  
Keyword(s):  
Gene Expression ◽  
Solanum Lycopersicum ◽  
Photosynthetic Capacity ◽  
Net Photosynthesis ◽  
Carotenoid Biosynthesis ◽  
Soluble Solids ◽  
Plant Performance ◽  
Photochemical Quenching ◽  
Related Gene ◽  
Essential Components

Carotenoids are essential components of the photosynthetic antenna and reaction center complexes, being also responsible for antioxidant defense, coloration, and many other functions in multiple plant tissues. In tomato, salinity negatively affects the development of vegetative organs and productivity, but according to previous studies it might also increase fruit color and taste, improving its quality, which is a current agricultural challenge. The fruit quality parameters that are increased by salinity are cultivar-specific and include carotenoid, sugar, and organic acid contents. However, the relationship between vegetative and reproductive organs and response to salinity is still poorly understood. Considering this, Solanum lycopersicum cv. Micro-Tom plants were grown in the absence of salt supplementation as well as with increasing concentrations of NaCl for 14 weeks, evaluating plant performance from vegetative to reproductive stages. In response to salinity, plants showed a significant reduction in net photosynthesis, stomatal conductance, PSII quantum yield, and electron transport rate, in addition to an increase in non-photochemical quenching. In line with these responses the number of tomato clusters decreased, and smaller fruits with higher soluble solids content were obtained. Mature-green fruits also displayed a salt-dependent higher induction in the expression of PSY1, PDS, ZDS, and LYCB, key genes of the carotenoid biosynthesis pathway, in correlation with increased lycopene, lutein, β-carotene, and violaxanthin levels. These results suggest a key relationship between photosynthetic plant response and yield, involving impaired photosynthetic capacity, increased carotenoid-related gene expression, and carotenoid biosynthesis.

scholarly journals Development and Validation of Methodology for Estimating Potato Canopy Structure for Field Crop Phenotyping and Improved Breeding

2021 ◽  
Vol 12 ◽  
Author(s):  
Filipe de Jesus Colwell ◽  
Jock Souter ◽  
Glenn J. Bryan ◽  
Lindsey J. Compton ◽  
Neil Boonham ◽  
...  
Keyword(s):  
Large Scale ◽  
Association Studies ◽  
Low Cost ◽  
Methodological Approach ◽  
Plant Performance ◽  
Initial Growth ◽  
Canopy Architecture ◽  
Canopy Development ◽  
Cloud Data ◽  
Canopy Volume

Traditional phenotyping techniques have long been a bottleneck in breeding programs and genotype- phenotype association studies in potato, as these methods are labor-intensive and time consuming. In addition, depending on the trait measured and metric adopted, they suffer from varying degrees of user bias and inaccuracy, and hence these challenges have effectively prevented the execution of large-scale population-based field studies. This is true not only for commercial traits (e.g., yield, tuber size, and shape), but also for traits strongly associated with plant performance (e.g., canopy development, canopy architecture, and growth rates). This study demonstrates how the use of point cloud data obtained from low-cost UAV imaging can be used to create 3D surface models of the plant canopy, from which detailed and accurate data on plant height and its distribution, canopy ground cover and canopy volume can be obtained over the growing season. Comparison of the canopy datasets at different temporal points enabled the identification of distinct patterns of canopy development, including different patterns of growth, plant lodging, maturity and senescence. Three varieties are presented as exemplars. Variety Nadine presented the growth pattern of an early maturing variety, showing rapid initial growth followed by rapid onset of senescence and plant death. Varieties Bonnie and Bounty presented the pattern of intermediate to late maturing varieties, with Bonnie also showing early canopy lodging. The methodological approach used in this study may alleviate one of the current bottlenecks in the study of plant development, paving the way for an expansion in the scale of future genotype-phenotype association studies.

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