scholarly journals Effect of the Matric Potential on Growth and Water, Nitrate and Potassium Absorption of Vegetables under Soilless Culture

2021 ◽  
Author(s):  
Diego Alves Peçanha ◽  
Tatiana Pagan Loeiro da Cunha-Chiamolera ◽  
Yasmina Chourak ◽  
Evelynn Yoselinn Martínez-Rivera ◽  
Miguel Urrestarazu
Keyword(s):  
Plant Growth ◽  
Growth Stages ◽  
Full Potential ◽  
Coconut Fiber ◽  
Matric Potential ◽  
Available Water ◽  
Level Of Use ◽  
Research Goal ◽  
Potassium Absorption ◽  
The University

Abstract  To exploit the full potential of plants, it is essential to provide an adequate water balance during critical growth stages. With knowledge of the substrate’s matric potential, it is possible to realistically measure the amount of water available to the plant. The objective of this research is to study the effect of the matric potential of the substrate on the growth of beans, lettuce, sweet peppers, watermelon, and cauliflower plants. The research goal was to evaluate the effect of the matric potential on the main fertigation parameters of horticultural plants. The plants were cultivated at the University of Almería (Spain) in a controlled chamber in a pot with 250 mL of coconut fiber substrate from block propagation. For treatments T15, T30, T45, and T60, new irrigation was applied when easily available water (EAW) depletion levels of 15, 30, 45, and 60% were reached, respectively. The efficiency of the use of water (WUE), nitrate (NUE), and potassium (KUE) was measured. From T15 to T60, a significant effect was found for the absorption of water, nitrate and potassium, WUE, NUE, and KUE. T60 reduced the plant growth by half. The largest growth was between 15 and 30% of the level of use of EAW. Two different models were constructed according to each plant. It is possible to have a small depletion in the available water and still have plant growth, if there is a balance between the air and water needs of the substrate.

scholarly journals Vegetation Response to Goats Grazing Intensity in Semiarid Hilly Grassland of the Loess Plateau, Lanzhou, China

2021 ◽  
Vol 13 (6) ◽  
pp. 3569
Author(s):  
Hua Cheng ◽  
Baocheng Jin ◽  
Kai Luo ◽  
Jiuying Pei ◽  
Xueli Zhang ◽  
...  
Keyword(s):  
Growth Rate ◽  
Community Structure ◽  
Plant Growth ◽  
Loess Plateau ◽  
Grazing Intensity ◽  
Gps Tracking ◽  
Growth Stages ◽  
The Loess Plateau ◽  
Vegetation Community ◽  
Natural Grasslands

Quantitatively estimating the grazing intensity (GI) effects on vegetation in semiarid hilly grassland of the Loess Plateau can help to develop safe utilization levels for natural grasslands, which is a necessity of maintaining livestock production and sustainable development of grasslands. Normalized difference vegetation index (NDVI), field vegetation data, and 181 days (one goat per day) of GPS tracking were combined to quantify the spatial pattern of GI, and its effects on the vegetation community structure. The spatial distribution of GI was uneven, with a mean value of 0.50 goats/ha, and 95% of the study area had less than 1.30 goats/ha. The areas with utilization rates of rangeland (July) lower than 45% and 20% made up about 95% and 60% of the study area, respectively. Grazing significantly reduced monthly aboveground biomass, but the grazing effects on plant growth rate were complex across the different plant growth stages. Grazing impaired plant growth in general, but the intermediate GI appeared to facilitate plant growth rate at the end of the growing seasons. Grazing had minimal relationship with vegetation community structure characteristics, though Importance Value of forbs increased with increasing GI. Flexibility in the number of goats and conservatively defining utilization rate, according to the inter-annual variation of utilization biomass, would be beneficial to achieve ecologically healthy and economically sustainable GI.

Echinoderm skeletal crystallography and paleobiological applications

1997 ◽  
Vol 3 ◽  
pp. 191-204 ◽  
Author(s):  
B. E. Bodenbender
Keyword(s):  
Skeletal Structure ◽  
Growth Stages ◽  
Full Potential ◽  
Initial Growth ◽  
Developmental Sequence ◽  
Coarse Scale ◽  
Common Pattern ◽  
Plate Morphology ◽  
Oriented Parallel ◽  
High Level

The crystallographic orientations of echinoderm skeletal elements can supplement standard morphological comparisons in the exploration of echinoderm evolution. At a coarse scale, many echinoderms share a crystallographic pattern in whichcaxes radiate away from the axis of pentaradial symmetry. Within this common pattern, however,caxes of different taxa can differ dramatically in their degree of variability, angles of inclination, and relationships to the external morphology of skeletal elements. Crystallographic data reflect a variety of taxon-specific influences and therefore reveal different information in different taxa. In echinoids, orientations ofcaxes in coronal plates correlate well with high-level taxonomic groupings, whilecaxes of apical plates record modes of larval development. In blastoids,caxes of radial plates have a structural interpretation, with thecaxis oriented parallel to the orientation of the surface of the radial plate during its initial growth stages. In crinoids,caxes do not correlate with taxonomic group, plate morphology, or developmental sequence, but instead correlate with relative positions of skeletal elements on the calyx. Although their full potential has yet to be explored, the varied crystallographic patterns in echinoderms have been used to clarify skeletal structure, characterize developmental anomalies, and infer homologies of skeletal plates both within specimens and between groups. A axes are less constrained in their orientations thancaxes and offer less promise of revealing novel paleobiological information.

Developmental stability, canalization and phenotypic plasticity in annual herbaceous species under different biotic and abiotic conditions

2021 ◽  
Author(s):  
Shu Wang ◽  
Dao-Wei Zhou
Keyword(s):  
Phenotypic Plasticity ◽  
Plant Growth ◽  
Mean Value ◽  
Developmental Stability ◽  
Soil Conditions ◽  
Growth Stages ◽  
Herbaceous Species ◽  
Fertile Soil ◽  
Plant Growth Stages ◽  
Positive Correlations

Abstract The relationships among developmental stability, canalization and phenotypic plasticity have not been well understood. Inconsistent conclusions from different studies suggested the complexity of their associations, probably depending on specific traits, environmental contexts and plant growth stages. To address this issue, we conducted three experiments (EXP I ~ III) with several annual herbaceous species, to investigate the relationships among leaf (or cotyledon) developmental stability, canalization and plasticity and their variations with different biotic and abiotic environmental conditions and plant growth stages, with comparisons among different species at their early growth stage. We analyzed variations in mean trait value, lamina fluctuating asymmetry (FA), coefficient of variation (CV) and plasticity (RDPIs) and their correlations for lamina size (LS) of individual plants, for LS, petiole length (PL) and petiole angle (PA) of different plant layers in Abutilon theophrasti at three densities in infertile and fertile (or only fertile) soil conditions at three (or two) stages, and for cotyledon size (CS) of five species in contrasting light conditions and seeding depths. High vs. low density decreased LS (with negative RDPIs), FA indexes and CVs, either for individual plants or different layers, especially in fertile soil. Shading was more likely to increase CS (except for A. therophrasti) and FA and decrease CV; deep seeding increased CS of some species in full light, but decreased CS and FA of other species in shading (except for A. therophrasti). FA indexes more likely had positive correlations with mean value, CV and RDPIs of traits; correlations between CV and RDPIs can be positive, negative or insignificant. Correlations among the three variables were more likely positive or insignificant for traits of LS, CS and PL, but more likely negative or insignificant for PA. High density and infertile soil may favor more positive over negative correlations among variables. Results suggested higher levels of lamina FA more likely indicate higher growth rates of plants or modules. Developmental stability was more likely to have positive correlations with canalization, and negative correlations with plasticity, indicating certain common mechanisms associated with them. Environmental stresses can lead to greater phenotypic variations at different levels, facilitating cooperation between the three processes in dealing with environmental challenges.

scholarly journals Hormesis with glyphosate depends on coffee growth stage

2013 ◽  
Vol 85 (2) ◽  
pp. 813-822 ◽  
Author(s):  
LEONARDO B. DE CARVALHO ◽  
PEDRO L.C.A. ALVES ◽  
STEPHEN O. DUKE
Keyword(s):  
Plant Growth ◽  
Weed Management ◽  
Growth Stage ◽  
Growth Stages ◽  
Coffee Plant ◽  
Herbicide Application ◽  
Coffee Plantations ◽  
Plant Growth Stages ◽  
Coffee Plants ◽  
Almost All

Weed management systems in almost all Brazilian coffee plantations allow herbicide spray to drift on crop plants. In order to evaluate if there is any effect of the most commonly used herbicide in coffee production, glyphosate, on coffee plants, a range of glyphosate doses were applied directly on coffee plants at two distinct plant growth stages. Although growth of both young and old plants was reduced at higher glyphosate doses, low doses caused no effects on growth characteristics of young plants and stimulated growth of older plants. Therefore, hormesis with glyphosate is dependent on coffee plant growth stage at the time of herbicide application.

scholarly journals Scale-Dependent Effects of Growth Stage and Elevational Gradient on Rice Phyllosphere Bacterial and Fungal Microbial Patterns in the Terrace Field

2022 ◽  
Vol 12 ◽  
Author(s):  
Pei Wang ◽  
Jianping Dai ◽  
Luyun Luo ◽  
Yong Liu ◽  
Decai Jin ◽  
...  
Keyword(s):  
Plant Growth ◽  
Growth Stage ◽  
Elevational Gradient ◽  
Fungal Communities ◽  
Growth Stages ◽  
Strong Positive Correlation ◽  
Elevation Gradients ◽  
Positive Correlation ◽  
Α Diversity ◽  
Phyllosphere Bacteria

The variation of phyllosphere bacterial and fungal communities along elevation gradients may provide a potential link with temperature, which corresponds to an elevation over short geographic distances. At the same time, the plant growth stage is also an important factor affecting phyllosphere microorganisms. Understanding microbiological diversity over changes in elevation and among plant growth stages is important for developing crop growth ecological theories. Thus, we investigated variations in the composition of the rice phyllosphere bacterial and fungal communities at five sites along an elevation gradient from 580 to 980 m above sea level (asl) in the Ziquejie Mountain at the seedling, heading, and mature stages, using high-throughput Illumina sequencing methods. The results revealed that the dominant bacterial phyla were Proteobacteria, Actinobacteria, and Bacteroidetes, and the dominant fungal phyla were Ascomycota and Basidiomycota, which varied significantly at different elevation sites and growth stages. Elevation had a greater effect on the α diversity of phyllosphere bacteria than on that phyllosphere fungi. Meanwhile, the growth stage had a great effect on the α diversity of both phyllosphere bacteria and fungi. Our results also showed that the composition of bacterial and fungal communities varied significantly along elevation within the different growth stages, in terms of both changes in the relative abundance of species, and that the variations in bacterial and fungal composition were well correlated with variations in the average elevation. A total of 18 bacterial and 24 fungal genera were significantly correlated with elevational gradient, displaying large differences at the various growth stages. Soluble protein (SP) shared a strong positive correlation with bacterial and fungal communities (p < 0.05) and had a strong significant negative correlation with Serratia, Passalora, unclassified_Trichosphaeriales, and antioxidant enzymes (R > 0.5, p < 0.05), and significant positive correlation with the fungal genera Xylaria, Gibberella, and Penicillium (R > 0.5, p < 0.05). Therefore, it suggests that elevation and growth stage might alter both the diversity and abundance of phyllosphere bacterial and fungal populations.

scholarly journals The Applications of Nanotechnology in Crop Production

Molecules ◽  
2021 ◽  
Vol 26 (23) ◽  
pp. 7070
Author(s):  
Chenxu Liu ◽  
Hui Zhou ◽  
Jie Zhou
Keyword(s):  
Plant Growth ◽  
Specific Surface ◽  
Crop Production ◽  
Molecular Level ◽  
High Specific Surface Area ◽  
Growth Stages ◽  
Crop Tolerance ◽  
Plant Growth Stages ◽  
Global Agriculture ◽  
Promote Plant Growth

With the frequent occurrence of extreme climate, global agriculture is confronted with unprecedented challenges, including increased food demand and a decline in crop production. Nanotechnology is a promising way to boost crop production, enhance crop tolerance and decrease the environmental pollution. In this review, we summarize the recent findings regarding innovative nanotechnology in crop production, which could help us respond to agricultural challenges. Nanotechnology, which involves the use of nanomaterials as carriers, has a number of diverse applications in plant growth and crop production, including in nanofertilizers, nanopesticides, nanosensors and nanobiotechnology. The unique structures of nanomaterials such as high specific surface area, centralized distribution size and excellent biocompatibility facilitate the efficacy and stability of agro-chemicals. Besides, using appropriate nanomaterials in plant growth stages or stress conditions effectively promote plant growth and increase tolerance to stresses. Moreover, emerging nanotools and nanobiotechnology provide a new platform to monitor and modify crops at the molecular level.

scholarly journals Enhancing Teaching and Learning at the University of Venda Utilising Digital Mobile Devices

2017 ◽  
Vol 3 (4) ◽  
pp. 11
Author(s):  
Ratchel Chikurunhe ◽  
Armstrong Kadyamatimba
Keyword(s):  
Mobile Devices ◽  
Teaching And Learning ◽  
Positive Impact ◽  
Academic Experience ◽  
Learning And Teaching ◽  
Tablet Pcs ◽  
Level Of Use ◽  
The University ◽  
Quality Learning ◽  
Rural Student

The University of Venda(Univen) distributed tablets to students for facilitating and enhancing their studies. However, the provision of tablet PCs to students may not be a panacea for quality learning, especially to technological disadvantaged rural student  population. The aim of study was to investigate the use of digital mobile devices for enhancing teaching and learning at the Univen. The research questions focused on determining the current level of use of mobile devices, how they can be used effectively for teaching and learning. Mixed methods approach was applied with data being solicited from a convenient sample of students, lecturers and an IT technician. The results of the study indicated that many students and lecturers are active and have higher perceptions of mobile devices usage. The results of the study are to be used to explicate and advance the integration of the mobile devices for promoting learning and teaching accomplishments. The findings clearly showed that mobile devices have a positive impact on the academic experience. The results also indicate that there is a gradual acceptance of the Learners Management Systems (Blackboard) by both academics and students. The digital mobile devices are eventually enhancing teaching and learning at Univen.

scholarly journals Changes in availability and uptake of soil phosphorus influenced by management practices and crop growth stages under peanut cultivation in medium black clay soil of Saurashtra region, Gujarat

2020 ◽  
Vol 41 (6) ◽  
pp. 1781-1787
Author(s):  
R.S. Yadav ◽  
◽  
H.N. Meena ◽  
N.K. Jain ◽  
D. Bhaduri ◽  
...  
Keyword(s):  
Plant Growth ◽  
Management Practices ◽  
Nutrient Management ◽  
Soil Phosphorus ◽  
Phosphorus Uptake ◽  
Clay Soils ◽  
Growth Stages ◽  
Olsen P ◽  
Black Clay ◽  
Raised Bed

Aim: To investigate efficient utilization of soil phosphorus for peanut nutrition through integration of management practices in medium black clay soils of Saurashtra region in Gujarat. Methodology: Soil phosphorus availability and uptake by peanut plants were assessed at five plant growth stages under six different management practices in Kharif season. The availability of soil P was estimated by Olsen P and Resin P extraction methods. The biomass production and phosphorus uptake at each growth stages were observed in order to draw the relationship between these parameters.? Results: The management practices like raised bed with polythene mulch, integrated and organic nutrient management was consistently found promising for enhanced availability and uptake of soil phosphorus under peanut cultivation. The Olsen P decreased with plant growth under all the management options, except organic and integrated nutrient management practices.? In contrary, the resin P generally increased with plant growth, especially under inorganic and organic nutrient management and raised bed with polythene mulch practices. Irrespective of growth stages, the phosphorus uptake by peanut plants was significantly and strongly correlated with biomass production (r=0.85, p<0.01) and Olsen P (r=0.41, P<0.05).? Interpretation: The results indicate that phosphorus requirement of peanut plants can be efficiently met by integrating land and nutrient management practices in these medium black clay soils.

scholarly journals Keanekaragaman Serangga Sebagai Pakan Alami Katak Tegalan (Fejervarya Limnocharis, Gravenhorst) pada Ekosistem Sawah di Desa Panggungharjo, Kecamatan Sewon, Kabupaten Bantul

2016 ◽  
Vol 1 (1) ◽  
pp. 1
Author(s):  
Farid Kuswantoro ◽  
R.C. Hidayat Soesilohadi
Keyword(s):  
Plant Growth ◽  
Paddy Field ◽  
Survey Method ◽  
Growth Stages ◽  
Insect Diversity ◽  
Insect Prey ◽  
Natural Prey ◽  
Plant Growth Stages ◽  
Generative Phase ◽  
Fejervarya Limnocharis

Paddy field was a dynamic and biodiversity rich ecosystems. Insect diversity in paddy field ecosystem was infected by paddy plant growth stages. Grass frog (Fejervarya limnocharis) ate insects as their natural prey. Insect population dynamics during vegetative, generative and reproductive stage of paddy plants infected F. limnocharis natural prey. This research aims were to study insect diversity and F. limnocharis insect prey diversity of vegetative, reproductive and generative paddy plant growth stages at Panggungharjo village, Sewon, Bantul. Insect sampling was conducted by direct survey method while F. limnocharis collection conducted by Visual Encounter Survey (VES) method. Ninety eight insect species from 51 different families and nine orders of insect were found. The orders were Coleoptera, Diptera, Hymenoptera, Odonata, Orthoptera, Dictyoptera, Dermaptera, Hemiptera and Lepidoptera. Stomachs analysis indicated F. limnocharis ate nine insect orders. The orders were Coleoptera, Diptera, Hymenoptera, Orthoptera, Dictyoptera, Dermaptera, Hemiptera, Lepidoptera and Isoptera. Most commonly insect prey in vegetative, reproductive and generative phase paddy growth stage were the members of the Order Coleoptera, Family Acrididae (Orthoptera) and Family Formicidae (Hymenoptera) respectively. This study concluded F. limnocharis main natural prey was the easily found and easily perceived insects.

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