scholarly journals Canopy Structure and Photosynthetic Performance of Irrigated Cassava Genotypes Growing in Different Seasons in a Tropical Savanna Climate

Agronomy ◽  
2020 ◽  
Vol 10 (12) ◽  
pp. 2018
Author(s):  
Supranee Santanoo ◽  
Kochaphan Vongcharoen ◽  
Poramate Banterng ◽  
Nimitr Vorasoot ◽  
Sanun Jogloy ◽  
...  
Keyword(s):  
Canopy Structure ◽  
Net Photosynthesis ◽  
Photosynthetic Performance ◽  
Lower Percentage ◽  
Starch Accumulation ◽  
Storage Roots ◽  
Area Index ◽  
Different Seasons ◽  
Crop Growth Modeling ◽  
Selection Of

Growth and photosynthesis performance of cassava during early vegetative growth are important determinants of final biomass. The objective of this work was to investigate canopy structure and photosynthesis performance of four cassava genotypes (Rayong 9, Rayong 11, Kasetsart 50, and CMR38-125-77) growing under irrigation at 3 and 6 months after planting (3MAP and 6MAP). Data for the 3MAP plants were collected from cassava planted on 30 June (Rainy PD), 10 November (Cool PD1), and 15 December (Cool PD2) 2015; and for the 6MAP from those planted on 20 April 2015 (Hot PD), Rainy PD, and Cool PD1. The plants growing in the rainy season had significantly higher leaf area index (LAI) than those growing in the cool and hot seasons. Consequently, they had lower percentage light penetration at the bottom of canopy, and therefore more light interception through the canopy, and hence a higher mean net photosynthesis rate (Pn) across the six canopy levels. At the 3MAP, which is the stage of maximum rate of leaf and stem growth, the Rainy PD and Cool PD2 plants of CMR38-125-77 showed the highest LAI and highest mean Pn. Similarly, the Cool PD1 plants of Kasetsart 50 showed the highest LAI and highest mean Pn. In contrast, at 6MAP during the stage of active starch accumulation in storage roots, the genotypes with the highest mean Pn were the ones having an intermediate (CMR38-125-77 for the Hot PD) or low LAI (Rayong 9 for the Rainy PD, and CMR38-125-77 for the Cool PD1). Data on variations in canopy structure and photosynthesis potentials of different cassava genotypes in response to seasonal variations may be useful for crop growth modeling and may be employed as a criterion for the selection of suitable genotypes for each growing season.

Studies of grain production in Sorghum bicolor (L. Moench). VI.* Profiles of photosynthesis, illuminance and foliage arrangement. 4. Profiles of Photosynthesis, Illuminance and Foliage Arrangement

1976 ◽  
Vol 27 (1) ◽  
pp. 35 ◽  
Author(s):  
KS Fischer ◽  
GL Wilson
Keyword(s):  
Leaf Surface ◽  
Canopy Structure ◽  
Light Extinction ◽  
Grain Production ◽  
Area Index ◽  
14Co2 Uptake ◽  
Total Light ◽  
Intercepted Radiation ◽  
Density Population ◽  
Sorghum Bicolor L

Grain sorghum was grown at two population densities in the field, and photosynthetic rates compared at noon. Profiles of photosynthesis were established by combining measurements of 12CO2 exchange and 14CO2 uptake. Canopy structure and light penetration were measured. Factors responsible for the superiority of the higher density population were evaluated. Photosynthesis–radiation responses of leaves were similar between the populations and there was little difference in total light interception. The high density population had leaves which were more vertically displayed, more uniformly dispersed, smaller in both length and width, and distributed over a greater height of canopy. Light was therefore more uniformly distributed down the profile, and coefficients of light extinction were lower. Associated with this was a higher leaf area index. The overall consequence was the distribution of intercepted radiation over a larger leaf surface, at a lower illuminance and therefore a higher efficiency of photosynthetic conversion, resulting in greater total photosynthesis. ___________________ ** Part V, Aust. J. Agric. Res., 26: 31 (1975).

scholarly journals Selection of sowing date and biofertilization as alternatives to improve the yield and profitability of the F68 rice variety

2020 ◽  
Vol 38 (1) ◽  
pp. 61-72
Author(s):  
Yeison Mauricio Quevedo-Amaya ◽  
José Isidro Beltrán-Medina ◽  
José Álvaro Hoyos-Cartagena ◽  
John Edinson Calderón-Carvajal ◽  
Eduardo Barragán-Quijano
Keyword(s):  
Leaf Area Index ◽  
Leaf Area ◽  
Carbon Balance ◽  
Sowing Date ◽  
Dry Matter Accumulation ◽  
Phosphate Solubilizing Bacteria ◽  
Area Index ◽  
Use Of Resources ◽  
High Efficient ◽  
Selection Of

Multiple factors influence rice yield. Developing management practices that increase crop yield and an efficient use of resources are challenging to modern agriculture. Consequently, the aim of this study was to evaluate biological nitrogen fixation and bacterial phosphorous solubilization (biofertilization) practices with the selection of the sowing date. Three sowing dates (May, July and August) were evaluated when interacting with two mineral nutrition treatments using a randomized complete block design in a split-plot arrangement. Leaf carbon balance, leaf area index, interception and radiation use efficiency, harvest index, dry matter accumulation, nutritional status, and yield were quantified. Results showed that the maximum yield was obtained in the sowing date of August. Additionally, yield increased by 18.92% with the biofertilization treatment, reaching 35.18% of profitability compared to the local production practice. High yields were related to a higher carbon balance during flowering, which was 11.56% and 54.04% higher in August than in July and May, respectively, due to a lower night temperature. In addition, a high efficient use of radiation, which in August was 17.56% and 41.23% higher than in July and May, respectively, contributed to obtain higher yields and this behavior is related to the selection of the sowing date. Likewise, a rapid development of the leaf area index and an optimum foliar nitrogen concentration (>3%) were observed. This allowed for greater efficient use of radiation and is attributed to the activity of nitrogen-fixing and phosphate solubilizing bacteria that also act as plant growth promoters.

scholarly journals EFEKTIFITAS JALUR HIJAU DALAM MENGURANGI POLUSI UDARA OLEH KENDARAAN BERMOTOR

NALARs ◽  
2017 ◽  
Vol 16 (1) ◽  
pp. 91
Author(s):  
Lukmanul Hakim ◽  
Priambudi Trie Putra ◽  
Azka Lathifa Zahratu
Keyword(s):  
Canopy Structure ◽  
Tree Canopy ◽  
Toxic Substances ◽  
Main Function ◽  
Cross Sectional ◽  
Green Belt ◽  
Healthy Environment ◽  
Lead Dust ◽  
The Many ◽  
Selection Of

ABSTRAK. Ameliorasi iklim adalah salah satu manfaat yang diberikan alam khususnya tumbuhan terhadap lingkungan hidup, dengan cara meningkatkan kualitas lingkungan untuk menjamin tersedianya lingkungan yang sehat. Salah satunya adalah dengan menyediakan oksigen (O2) untuk kebutuhan pernafasan dan meminimalisir gas buang kendaraan bermotor yang beracun seperti gas carbon monooksida (CO) dan debu timbal (Pb). Kedua zat beracun ini sangat berbahaya bagi kesehatan manusia, khususnya yng berada disekitar jalan raya dan sekitar kawasan industri.Green belt adalah salah satu desain penghijauan yang fungsi utamanya adalah untuk mengurangi debu pencemaran ini. Yang diuji dalam penelitian ini adalah efektifitas desain green belt di sisi jalan raya dalam menangkap atau menjerap partikel (debu) polusi yang ditimbulkan oleh kendaraan bermotor. Fakta dalam percobaan yang dilkukan menunjukkan, bahwa bentuk struktur tajuk dan luas penampang daun sangat menentukan efektifitas dari penyerapan debu polusi. Daun yang mempunyai permukaan yang lebih luas dan mempunyai permukaan yang kasar, mempunyai nilai efektifitas yang tinggi. Begitu juga dengan pohon yang bertajuk rapat dan lebat akan sangat efektif dalam menjerap debu polusi atau polutan. Dalam hal ini, untuk desain green belt, diperlukan beberapa pertimbangan untuk efektifitas dalam mengurangi polusi udara. Yaitu pemilihan jenis vegetasi yang mempunyai daun yang lebar dan kasar serta pemilihan jenis struktur tajuk pohon yang disesuaikan dengan lokasi green belt tetapi dipilih yang rimbun dan lebat.Kata kunci: Ameliorasi iklim, vegetasi, penyerapan dan polusiABSTRACT. Climate amelioration is one of the many benefit from that nature, particularly plant that, provides to the environment, by enhancing quality of environment and guaranting the provision of healthy environment. For example is by providing oxygen (O2) for respiration and minimalizing toxic gas such as carbon monoxide (CO) and lead dust (Pb) emitted by vehicle. Both mentioned are toxic substances which highly dangerous for human health, especially for those residing around streets and industrial areas.Green belt is a greening design having main function to reduce pollution dust. This research tested the effectiveness of green belt on side roads in catching or absorbing pollution dust or particles emitted by vehicles. Facts from this research showed that the shape of canopy structure and leaves’ cross sectional area highly determine the effectiveness of pollution dust absorpsion. Leaves with wider surface area and rough texture have high effectiveness. Trees having dense canopy and bushy are very effective in absorpsion of pollution dust. In this case, to design a green belt will required a few considerations that are affecting effectiveness in reducing air polution. Namely, selection of vegetation that has wide and rough leaves and type selection of tree canopy structure that is dense and bushy and suitable to green belt location.Keywords : climate amelioration, vegetation, absorpsion and pollution

scholarly journals Asparagine accumulation in chicory storage roots is controlled by translocation and feedback regulation of asparagine biosynthesis in leaves

2020 ◽  
Author(s):  
Emanoella Soares ◽  
Leonard Shumbe ◽  
Nicholas Dauchot ◽  
Christine Notté ◽  
Claire Prouin ◽  
...  
Keyword(s):  
Public Health ◽  
High Temperature ◽  
Feedback Loop ◽  
Reducing Sugars ◽  
Feedback Regulation ◽  
Negative Feedback Loop ◽  
List Type ◽  
Storage Roots ◽  
Crop Species ◽  
Selection Of

SummaryThe presence of acrylamide (AA), a potentially carcinogenic and neurotoxic compound, in food has become a major concern for public health. AA in plant-derived food mainly arises from the reaction of the amino acid asparagine (Asn) and reducing sugars during processing of foodstuffs at high temperature.Using a selection of genotypes from the chicory germplasm we performed Asn measurements in storage roots and leaves to identify genotypes contrasting for Asn accumulation. We combined molecular analysis and grafting experiments to show that leaf to root translocation controls asparagine biosynthesis and accumulation in chicory storage roots.We could demonstrate that Asn accumulation in storage roots depends on Asn biosynthesis and transport from the leaf, and that a negative feedback loop by Asn on CiASN1 expression impacts Asn biosynthesis in leaves.Our results provide a new model for asparagine biosynthesis in root crop species and highlight the importance of characterizing and manipulating asparagine transport to reduce AA content in processed plant-based foodstuffs.

scholarly journals Participatory ranking of fodders in the western hills of Nepal

2020 ◽  
Vol 3 (1) ◽  
pp. 20-28
Author(s):  
Bir Bahadur Tamang ◽  
Manoj Kumar Shah ◽  
Bishnu Dhakal ◽  
Pashupati Chaudhary ◽  
Netra Chhetri
Keyword(s):  
Milk Fat ◽  
Farming System ◽  
Preference Ranking ◽  
Feeding Time ◽  
Scoring Methods ◽  
Tree Fodder ◽  
Different Seasons ◽  
Fodder Yield ◽  
Fat Yield ◽  
Selection Of

Fodder is an important source of feed of the ruminants in Nepal. In the mid hills of Nepal, farmers generally practice integrated farming system that combines crop cultivation with livestock husbandry and agroforestry. Tree fodders are good sources of protein during the forage and green grass scarcity periods especially in dry season. Local communities possess indigenous knowledge for the selection of grasses and tree fodders at different seasons in mid hills of western Nepal. A study was conducted on the perception of farmers with respect to selection of fodder species in eight clusters in Kaski and Lumjung districts that range 900-2000 meter above sea level and receive average precipitation of 2000- 4500mm per annum. During the fodder preference ranking, farmers prepared the inventory of fodders found around the villages and nearby forests and selected top ten most important fodders in terms of their availability, palatability, fodder yield, milk yield and milk fat yield. In total, 23 top ranking fodders species were selected from the eight clusters. These fodder species were also ranked using pairwise ranking and weighted scoring methods and ranking was done on the basis of merit numbers obtained from weighted scores. The analysis revealed Artocarpus lakoocha as best tree fodder followed by Ficus semicordata, Thysanolena maxima and Ficus calvata. Similarly, the calendar of fodders trees for lopping season and the best feeding time was prepared on the basis of farmers’ local knowledge. This study suggests strategies for promotion of locally preferred tree fodder species and supplementing tree fodder with feed in different seasons depending on their availability and local preferences.

scholarly journals Evaluation of the Effect of Irrigation on Biometric Growth, Physiological Response, and Essential Oil of Mentha spicata (L.)

Water ◽  
2019 ◽  
Vol 11 (11) ◽  
pp. 2264 ◽  
Author(s):  
Marino ◽  
Ahmad ◽  
Ferreira ◽  
Alvino
Keyword(s):  
Water Stress ◽  
Essential Oil ◽  
Water Status ◽  
Stomatal Closure ◽  
Critical Role ◽  
Net Photosynthesis ◽  
Leaf Biomass ◽  
Water Losses ◽  
Mentha Spicata ◽  
Area Index

A field experiment was performed on spearmint (Mentha spicata L.) under different irrigation regimes in a hilly area of Southern Italy. Objectives of the study include evaluating the physiological and biometrical response of mint from plant establishment up to its complete maturation, as well as the yield composition in essential oil at two different dates. Increasing levels of water stress affected later developing leaves and plant’s water status and net photosynthesis (from the beginning of stress (DAT 63), while affecting negatively the biometric response very soon and significantly from 35 DAT. Photosynthesis limitation played a critical role from DAT 53 on, namely later, in the harvest period (DAT 35–70). Under severe water stress, crop restricted water losses by modulating stomatal closure and, at harvest, showing lowered mesophyll conductance. Irrigation treatments did not affect the concentration of organic compounds, while the yield of essential oils was negatively affected by water stress due to reduced crop growth, in terms of total and leaf biomass, leaf area index (LAI) and crop height.

Influence of Herbaceous Interference on Growth and Biomass Partitioning in Planted Loblolly Pine (Pinus taeda)

Weed Science ◽  
1990 ◽  
Vol 38 (6) ◽  
pp. 497-503 ◽  
Author(s):  
John R. Britt ◽  
Bruce R. Zutter ◽  
Robert J. Mitchell ◽  
Dean H. Gjerstad ◽  
John F. Dickson
Keyword(s):  
Leaf Area ◽  
Pinus Taeda ◽  
Loblolly Pine ◽  
Growth Efficiency ◽  
Biomass Partitioning ◽  
Lower Percentage ◽  
Total Biomass ◽  
Growth Responses ◽  
Area Index ◽  
Weed Interference

Three herbaceous regimes were established, using herbicides, to examine the effects of interference on growth and biomass partitioning in loblolly pine (Pinus taedaL.). Trees were sampled near Auburn and Tallassee, AL. Trees at the Auburn site grown with low weed interference (LWI) had 4, 10, 10, 8, and 4 times greater total aboveground biomass than did trees with high weed interference (HWI) for ages one through five, respectively. Medium weed interference (MWI, Auburn site only) resulted in three times greater biomass the first 4 yr and two times greater total biomass by the fifth year compared to trees grown with HWI. Trees growing with LWI were 5, 8, 10, and 6 times larger than those with HWI for ages one through four, respectively, at the Tallassee site. At all levels of interference, the percentage of total biomass in foliage decreased, and stem and branch components increased, with increasing tree size at both sites. Trees growing with HWI had a lower percentage of total biomass in foliage and a greater percentage of total biomass in stem than those growing with LWI when compared over a common size. Growth efficiency per tree, expressed as annual increase in stem biomass per unit leaf area (g m−2), was slightly greater for trees growing with LWI compared to HWI when leaf area index (LAI3, total surface) was less than 0.2. For LAI values greater than 0.2 the relationship was reversed. The latter contradicts the idea that growth efficiency can be used as a measure of vigor for young loblolly pine. Changes in carbon partitioning to the development of leaf area are suggested to be driving the accelerated growth responses associated with a reduction of weed interference.

scholarly journals Herbage accumulation dynamics in digit grass subjected to defoliation frequencies

2019 ◽  
Vol 40 (2) ◽  
pp. 731
Author(s):  
Natan Teles Cruz ◽  
Braulio Maia de Lana Sousa ◽  
Jailson Lara Fagundes ◽  
Alfredo Acosta Backes ◽  
José Dantas Gusmão Filho ◽  
...  
Keyword(s):  
Accumulation Rate ◽  
Structural Characteristics ◽  
Block Design ◽  
Volume Density ◽  
Lower Percentage ◽  
Stem Volume ◽  
Accumulation Rates ◽  
Area Index ◽  
Randomized Block Design ◽  
Defoliation Frequency

This study was undertaken to examine the herbage accumulation dynamics and structural characteristics of digit grass subjected to different defoliation frequencies in the period of January 2015 to February 2016. Four defoliation frequencies [very high (25 cm), high (35 cm), medium (45 cm), and low (55 cm)] were evaluated in two periods of the year [greater insolation (September to March) and lesser insolation (April to August)]. The experiment was set up as a randomized-block design with four replicates. Overall, the decreasing defoliation frequencies increased the cutting interval; leaf area index; total-herbage, stem, and dead-herbage accumulation rates; and percentages of stems and dead herbage. This reduction in defoliation frequency also resulted in a lower leaf accumulation rate and percentage of leaves. In overall terms, digit grass showed higher total-herbage, leaf, and stem accumulation rates; percentages of stems and dead herbage; stem volume density; and tiller density in the period of greater insolation. In the period of lesser insolation, however, digit grass exhibited a lower dead-herbage accumulation rate and a lower percentage of dead herbage. Less frequent defoliations increase the herbage accumulation rates of digit grass, but result in a less desirable morphological composition.

scholarly journals Multi-Component Antioxidative System and Robust Carbohydrate Status, the Essence of Plant Arsenic Tolerance

Antioxidants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 283 ◽  
Author(s):  
Monika Kofroňová ◽  
Aneta Hrdinová ◽  
Petra Mašková ◽  
Jana Tremlová ◽  
Petr Soudek ◽  
...  
Keyword(s):  
Net Photosynthesis ◽  
Nicotiana Sylvestris ◽  
Arsenic Tolerance ◽  
Total Antioxidant ◽  
As Stress ◽  
First Time ◽  
Carbohydrate Status ◽  
New Evidence ◽  
Tolerant Genotype ◽  
Selection Of

Arsenic (As) contaminates the food chain and decreases agricultural production through impairing plants, particularly due to oxidative stress. To better understand the As tolerance mechanisms, two contrasting tobacco genotypes: As-sensitive Nicotiana sylvestris and As-tolerant N.tabacum, cv. ‘Wisconsin’ were analyzed. The most meaningful differences were found in the carbohydrate status, neglected so far in the As context. In the tolerant genotype, contrary to the sensitive one, net photosynthesis rates and saccharide levels were unaffected by As exposure. Importantly, the total antioxidant capacity was far stronger in the As-tolerant genotype, based on higher antioxidants levels (e.g., phenolics, ascorbate, glutathione) and activities and/or appropriate localizations of antioxidative enzymes, manifested as reverse root/shoot activities in the selected genotypes. Accordingly, malondialdehyde levels, a lipid peroxidation marker, increased only in sensitive tobacco, indicating efficient membrane protection in As-tolerant species. We bring new evidence of the orchestrated action of a broad spectrum of both antioxidant enzymes and molecules essential for As stress coping. For the first time, we propose robust carbohydrate metabolism based on undisturbed photosynthesis to be crucial not only for subsidizing C and energy for defense but also for participating in direct reactive oxygen species (ROS) quenching. The collected data and suggestions can serve as a basis for the selection of plant As phytoremediators or for targeted breeding of tolerant crops.

scholarly journals The Impacts of Growth and Environmental Parameters on Solar-Induced Chlorophyll Fluorescence at Seasonal and Diurnal Scales

2019 ◽  
Vol 11 (17) ◽  
pp. 2002
Author(s):  
Leizhen Liu ◽  
Wenhui Zhao ◽  
Jianjun Wu ◽  
Shasha Liu ◽  
Yanguo Teng ◽  
...  
Keyword(s):  
Chlorophyll Fluorescence ◽  
Water Stress ◽  
Growth Parameters ◽  
Pearson Correlation ◽  
Canopy Structure ◽  
Principal Component ◽  
Environmental Parameters ◽  
Area Index ◽  
Relationship Of ◽  
The Impact

Solar-induced chlorophyll fluorescence (SIF) is considered to be a potential indicator of photosynthesis. However, the impact of growth and environmental parameters on SIF at different time-scales remains unclear, which has greatly restricted the application of SIF in detecting photosynthesis variations. Thus, in this study, the impact of growth and environmental parameters on SIF was thoroughly clarified. Here, continuous time series of canopy SIF (760 nm, F760) over wheat and maize was measured based on an automated spectroscopy system. Meanwhile, field measurements of growth and environmental parameters were also collected using commercial-grade devices. Relationships of these parameters with F760, apparent SIF (F760/solar radiance, AF760), and SIF yield (F760/canopy radiance of 685 nm, Fy760) were analyzed using principal component analysis (PCA) and Pearson correlation to reveal their impacts on SIF. Results showed that F760 at seasonal and diurnal scales were mainly driven by solar radiation (SWR), leaf area index (LAI), chlorophyll content (Chl), mean leaf inclination angle (MTA), and relative water content (RWC). Other environmental parameters, including air temperature (Ta), relative humidity (Rh), vapor pressure deficit (VPD), and soil moisture (SM), contribute less to the variation of seasonal or diurnal F760. AF760 and Fy760 are likely to be less dependent on Ta, Rh, and VPD due to the removal of the impact from SWR, but an enhanced relationship of AF760 (and Fy760) with SM was observed, particularly under water stress. Compared with F760, wheat AF760 was better correlated to LAI and RWC as expected, while maize AF760 did not show an enhanced relationship with all growth parameters, probably due to its complicated canopy structure. The relationship of wheat Fy760 with canopy structure parameters was further reduced, except for maize measurements. Furthermore, SM-induced water stress and phenological stages should be taken into consideration when we interpret the seasonal and diurnal patterns of SIF since they were closely related to photosynthesis and plant growth (e.g., LAI in our study). To our knowledge, this is the first exploration of the impacts of growth and environmental parameters on SIF based on continuous ground measurements, not only at a seasonal scale but also at a diurnal scale. Our results could provide deep insight into the variation of SIF signals and also promote the further application of SIF in the health assessments of terrestrial ecosystems.

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