Effect of nutrients and salinity pulses on biomass and growth of 
            Vallisneria americana
            in lower St Johns River, FL, USA

We determined the interactive effects of nutrient loading and salinity pulsing on Vallisneria americana Michx., the dominant submerged aquatic vegetation species in the lower St Johns River (LSJR), FL, USA, and its associated algal community. Five hundred and ninety 6-inch diameter intact plant plugs of Vallisneria were collected from the LSJR in March 2003 and transported to US Geological Survey mesocosm facilities in Lafayette, LA, USA. A 3×3 experimental design consisting of three nutrient levels (control, 1/3 control and 3× control) and three salinity pulsing regimes (no pulse, 1-pulse at 18 ppt and 2-pulse at 12 and 18 ppt) was implemented with three replicates per treatment for a total of 27 experimental tanks. Salinity pulsing significantly reduced all measured Vallisneria growth parameters including above- and below-ground biomass, areal productivity and leaf area index. Nutrient levels had little effect on plants subjected to salinity pulses, but in non-salinity pulse treatments we observed higher mean macrophyte biomass in the low-nutrient loading treatments. Macroalgal components (epiphytes and surface algal mats) were not significantly different ( p =0.2998 and p =0.2444, respectively), but water column chlorophyll a (phytoplankton) was significantly higher ( p <0.0001) in all salinity pulse treatments except for the 1-pulse, low-nutrient treatment. A single salinity pulse at 18 ppt resulted in 22% pot mortality and two consecutive pulses of 18 and 12 ppt resulted in an additional 14% mortality. Individual leaves and ramets lost 59.7% and 67.8%, respectively, in the combined salinity pulse treatments. Nutrient loading tends to have a long-term effect on Vallisneria through complex community interactions while salinity pulsing frequency and intensity has an immediate and direct influence on growth and distribution.

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Alternative stable states in the aquatic vegetation of shallow urban lakes. I. Effects of plant harvesting and low-level nutrient enrichment

Marine and Freshwater Research ◽

10.1071/mf02002 ◽

2003 ◽

Vol 54 (3) ◽

pp. 185 ◽

Cited By ~ 17

Author(s):

Kay Morris ◽

Paul I. Boon ◽

Paul C. Bailey ◽

Leesa Hughes

Keyword(s):

Nutrient Enrichment ◽

Phytoplankton Biomass ◽

Aquatic Vegetation ◽

Alternative Stable States ◽

Vallisneria Americana ◽

Stable States ◽

Area Index ◽

Urban Lakes ◽

Low Level ◽

Plant Harvesting

Shallow urban lakes are often subject to chronic nutrient enrichment and their submerged plants are sometimes harvested to facilitate recreational use. The theory of alternative stable states predicts that: (i) low levels of nutrient enrichment should have little effect on the existing communities of submerged macrophytes in such lakes; but (ii) harvesting the plants should facilitate a shift to phytoplankton dominance. These two predictions were tested with large (3000 L), replicated mesocosms in a shallow urban lake densely colonized by the submerged angiosperm, Vallisneria americana Michaux. Harvesting V. americana substantially increased light penetration through the water column, but did not significantly increase phytoplankton biomass. Vallisneria americana regrew rapidly after harvesting and Chara species, which were previously absent, appeared in the harvested mesocosms. Chronic low-level nutrient enrichment significantly increased phytoplankton biomass (>100 μg chlorophyll a L–1) but not epiphyte biomass on the leaves of V. americana or on plastic leaf surrogates. The aboveground biomass and leaf area index of V. americana were not affected significantly by nutrient enrichment. The theory of alternative stable states successfully predicted the resilience of the submerged angiosperm community to low-level nutrient enrichment, but did not accurately predict the response to plant harvesting. The response of the lake vegetation to higher levels of nutrient enrichment is reported.

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Competitive attributes ofA. sativa, T. aestivum, andH. vulgareare conserved in no-till cropping systems

Weed Science ◽

10.1017/s0043174500091384 ◽

1999 ◽

Vol 47 (6) ◽

pp. 712-719 ◽

Cited By ~ 3

Author(s):

Anne Légère ◽

Yuguang Bai

Keyword(s):

Hordeum Vulgare ◽

Avena Sativa ◽

Growth Parameters ◽

Cropping Systems ◽

Seedling Emergence ◽

Biomass Accumulation ◽

Tillage Systems ◽

Area Index ◽

No Till ◽

Lower Test

The robustness of competitive attributes of cereals such as rapid and uniform seedling emergence, tillering, early biomass accumulation and canopy closure, and height advantage over weeds have not yet been tested under environmental conditions typical of no-till (NT) cropping systems. Our objective was to evaluate the effects or NT practices on growth and productivity ofAvena sativa, Triticum aestivum, Hordeum vulgare, and associated weeds. The experiment was conducted on a Kamouraska clay at La Pocatière, QC, in 1994, 1995, and 1996.Avena sativa, T. aestivum, andH. vulgarewere grown under tilled and NT practices. Cereal growth parameters were measured six (1994) or seven (1995) times between planting and the 11th week after planting but only once in 1996. Grain yields and yield components were determined at crop maturity.Avena sativaandH. vulgarepopulations were little affected by tillage, whereasT. aestivumpopulations were reduced by 16 to 20% in NT systems. Growth in height in NT systems was either similar or greater than in tilled systems in all three cereals. Cereal leaf area index (LAI) and biomass accumulation was also comparable between tillage systems, except forT. aestivumLAI in 1994, which was greater in tilled plots on two sampling dates. Response of annual dicots to tillage was inconsistent in all crops. Annual monocots dominated in some but not all NT systems. Perennial dicots dominated in NT systems, whereas perennial monocots were more abundant in tilled systems in all three cereals.Avena sativaandT. aestivumyields in NT plots were comparable or greater than in tilled plots, in spite of having either lower test weights (A. sativa) or lower 1,000-grain weights (T. aestivum). NTT. aestivumproductivity was maintained in spite of reduced plant establishment.Hordeum vulgareyields were also similar across tillage systems, except in 1995, when yields in tilled plots were greater than in NT plots. The height advantage observed for NTH. vulgaredid not result in improved yields. All three cereals, and particularlyA. sativa, appeared well suited to NT systems, despite the pressure provided by different weed groups, compared to tilled systems. However, results suggest that NT production of cereals could benefit from improved attention to perennial dicot control and crop seedling establishment, particularly forT. aestivum.

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Feed Composition Differences Resulting from Organic and Conventional Farming Practices Affect Physiological Parameters in Wistar Rats—Results from a Factorial, Two-Generation Dietary Intervention Trial

Nutrients ◽

10.3390/nu13020377 ◽

2021 ◽

Vol 13 (2) ◽

pp. 377

Author(s):

Marcin Barański ◽

Dominika Średnicka-Tober ◽

Leonidas Rempelos ◽

Gultakin Hasanaliyeva ◽

Joanna Gromadzka-Ostrowska ◽

...

Keyword(s):

Crop Production ◽

Wistar Rats ◽

Dietary Intervention ◽

Growth Parameters ◽

Crop Protection ◽

The Body ◽

Interactive Effects ◽

Supporting Evidence ◽

Feed Composition ◽

Npk Fertilizer

Recent human cohort studies reported positive associations between organic food consumption and a lower incidence of obesity, cancer, and several other diseases. However, there are very few animal and human dietary intervention studies that provide supporting evidence or a mechanistic understanding of these associations. Here we report results from a two-generation, dietary intervention study with male Wistar rats to identify the effects of feeds made from organic and conventional crops on growth, hormonal, and immune system parameters that are known to affect the risk of a number of chronic, non-communicable diseases in animals and humans. A 2 × 2 factorial design was used to separate the effects of contrasting crop protection methods (use or non-use of synthetic chemical pesticides) and fertilizers (mineral nitrogen, phosphorus and potassium (NPK) fertilizers vs. manure use) applied in conventional and organic crop production. Conventional, pesticide-based crop protection resulted in significantly lower fiber, polyphenol, flavonoid, and lutein, but higher lipid, aldicarb, and diquat concentrations in animal feeds. Conventional, mineral NPK-based fertilization resulted in significantly lower polyphenol, but higher cadmium and protein concentrations in feeds. Feed composition differences resulting from the use of pesticides and/or mineral NPK-fertilizer had a significant effect on feed intake, weight gain, plasma hormone, and immunoglobulin concentrations, and lymphocyte proliferation in both generations of rats and in the second generation also on the body weight at weaning. Results suggest that relatively small changes in dietary intakes of (a) protein, lipids, and fiber, (b) toxic and/or endocrine-disrupting pesticides and metals, and (c) polyphenols and other antioxidants (resulting from pesticide and/or mineral NPK-fertilizer use) had complex and often interactive effects on endocrine, immune systems and growth parameters in rats. However, the physiological responses to contrasting feed composition/intake profiles differed substantially between the first and second generations of rats. This may indicate epigenetic programming and/or the generation of “adaptive” phenotypes and should be investigated further.

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Effects of Crop Planting Structure Adjustment on Water Use Efficiency in the Irrigation Area of Hei River Basin

Water ◽

10.3390/w10101305 ◽

2018 ◽

Vol 10 (10) ◽

pp. 1305 ◽

Cited By ~ 5

Author(s):

Xin Han ◽

Zheng Wei ◽

Baozhong Zhang ◽

Congying Han ◽

Jianzheng Song

Keyword(s):

Assessment Tool ◽

Growth Parameters ◽

Water Productivity ◽

Swat Model ◽

Irrigation Efficiency ◽

Irrigation District ◽

Observation Data ◽

Net Income ◽

Area Index ◽

Crop Planting

The adjustment of crop planting structure can change the process of water and material circulation, and thus affect the total amount of water and evapotranspiration in the irrigation district. To guide the allocation of water resources in the region, it is beneficial to ascertain the effects of changing the crop planting structure on water saving and farmland water productivity in the irrigation district. This paper takes Yingke Irrigation District as the background. According to the continuous observation data from 2012 to 2013, Based on the modified Soil and Water Assessment Tool (SWAT) model and taking advantage of monthly scale remote sensing EvapoTranspiration (ET) and crop growth parameters (leaf area index and shoot dry matter), we tested the simulation accuracy of the model, proposed irrigation efficiency calculation methods considering water drainage, and established the scenario analysis method for the spatial distribution of crop planting structure. Finally, we evaluated the changes in water savings in irrigation district projects and resources, the irrigation water productivity and the net income water productivity under different planting structure scenarios. The results indicate that the efficiency of irrigation has increased by 15~20%, while considering drainage, as compared with conventional irrigation efficiency. Additionally, the adjustment of crop planting structure can reduce regional evapotranspiration by 14.9%, reduce the regional irrigation volume by 30%, and increase the net income of each regional water area by 16%.

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Effect of Foliar Application of Growth Regulators on Vegetative and Physiological Growth Parameters in Ajowan (Trachyspermum ammi L. Sprague)

Current Journal of Applied Science and Technology ◽

10.9734/cjast/2020/v39i2930962 ◽

2020 ◽

pp. 100-109

Author(s):

Y. Rajasekhara Reddy ◽

G. Ramanandam ◽

P. Subbaramamma ◽

A. V. D. Dorajeerao

Keyword(s):

Leaf Area ◽

Foliar Application ◽

Growth Parameters ◽

Block Design ◽

Foliar Spray ◽

Dry Weight ◽

Area Index ◽

Chlorophyll Contents ◽

Trachyspermum Ammi ◽

Number Of Leaves

A field experiment was carried out during rabi season of 2018-2019, at college farm, College of Horticulture, Dr. Y.S.R. Horticultural University, Venkataramannagudem, West Godavari District, Andhra Pradesh. The experiment was laidout in a Randomised Block Design with eleven treatments (viz., T1- NAA @ 50 ppm, T2-NAA @ 100 ppm, T3-GA3 @ 50 ppm, T4-GA3 @ 100 ppm, T5-Thiourea @ 250 ppm, T6-Thiourea @ 500 ppm, T7-28-Homobrassinolide @ 0.1 ppm, T8-28-Homobrassinolide @ 0.2 ppm, T9-Triacontinol @ 2.5 ppm, T10-Triacontinol @ 5 ppm, T11-(Control) Water spray) and three replications. The treatments were imposed at 30 and 45 DAT in the form of foliar spray. Foliar application of GA3@ 100 ppm (T4) had recorded the maximum plant height (108.20 cm), leaf area (9.53 cm2) and leaf area index (0.74). Foliar application of thiourea @ 250 ppm (T5) had recorded the maximum values with respect to number of primary branches (15.03 plant-1), number of secondary branches (83.40 plant-1), plant spread (1793 cm2 plant-1), fresh weight (376.29 g plant-1), dry weight (103.54 g plant-1) and number of leaves plant-1((298.8). The same treatment (T5) had recorded the highest values with respect to crop growth rate (1.44 gm-2d-1), chlorophyll-a (1.40 mg g-1), chlorophyll-b (0.076 mg g-1) and total chlorophyll contents (1.48 mg g-1) in the leaves.

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Integration ofAndrographis paniculataas Potential Medicinal Plant in Chir Pine (Pinus roxburghiiSarg.) Plantation of North-Western Himalaya

Scientifica ◽

10.1155/2016/2049532 ◽

2016 ◽

Vol 2016 ◽

pp. 1-7 ◽

Cited By ~ 1

Author(s):

Chandra Shekher Sanwal ◽

Raj Kumar ◽

S. D. Bhardwaj

Keyword(s):

Plant Height ◽

Growth Parameters ◽

Andrographis Paniculata ◽

Growth And Yield ◽

Economic Viability ◽

Pinus Roxburghii ◽

Area Index ◽

Net Returns ◽

Chir Pine ◽

North Western

The integration ofAndrographis paniculataunderPinus roxburghii(Chir pine) plantation has been studied to evaluate the growth and yield for its economic viability and conservation. It was grown on three topographical aspects, namely, northern, north-western, and western, at a spacing of 30 cm × 30 cm, followed by three tillage depths, namely, minimum (0 cm), medium (up to 10 cm), and deep (up to 15 cm) tillage. The growth parameters, namely, plant height and number of branches per plant, were recorded as significantly higher on western aspect and lowest on northern aspect except for leaf area index which was found nonsignificant. However under all tillage practices all the growth parameters in both understorey and open conditions were found to be nonsignificant except for plant height which was found to be significantly highest under deep tillage and lowest under minimum tillage. The study of net returns forAndrographis paniculatarevealed that it had positive average annual returns even in understorey conditions which indicate its possible economic viability under integration of Chir pine plantations. Hence net returns can be enhanced by integratingAndrographis paniculataand this silvimedicinal system can be suggested which will help utilizing an unutilized part of land and increase total productivity from such lands besides conservation of theA. paniculata in situ.

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GROWTH AND YIELD RESPONSES OF OPEN POLLINATED MAIZE (Zea mays) TO TYPES AND RATES OF ORGANIC FERTILISERS IN RAINFOREST TRANSITORY AGROECOLOGY OF NIGERIA

Journal of Agricultural Science and Environment ◽

10.51406/jagse.v15i2.1979 ◽

2020 ◽

Vol 15 (2) ◽

pp. 85-94

Author(s):

S. G. ADERIBIGBE ◽

O. S. SAKARIYAWO ◽

A. A. SORETIRE ◽

A. A. OYEKANMI ◽

P. A.S. SOREMI

Keyword(s):

Zea Mays ◽

Leaf Area ◽

Growth Parameters ◽

Field Trials ◽

Growth And Yield ◽

Area Index ◽

Organic Fertiliser ◽

Application Rates ◽

Organic Fertilisers ◽

Yield Responses

Sustainable maize (Zea mays) production in resource challenged regions of the world is achievable among others through optimal utilisation of organic fertilisers at varying rates. Field trials were conducted in Abeokuta (Latitude 7010' N and Longitude 3015' E) in the late cropping season of 2010 and 2011. Three commercially available organic fertilisers [(Gateway 1 (GF1), Gateway 2 (GF2) and Sunshine (SF)], at three rates (0, 10 and 20 t ha-1) and three replicates were used on improved open-pollinated maize variety (Swam 1 yellow). The experiment was laid out in a randomised completely blocked design. GF1 had significantly (P < 0.05) the highest effect on growth parameters (Plant height, stem girth, leaf area and leaf area Index), with SF the least. A significant depression was observed in most growth parameters at increasing application rates of organic fertiliser, a converse pattern was observed on 1000 grain weight (GW), harvest index and cob length. A significantly higher (P < 0.05) vegetative growth, cob weight and grain yield was observed in 2010 than 2011, while 2011 had longer cobs and more 1000 GW than 2010. GF1 was recommended in Rainforest transitory zone of Nigeria at higher application rates though mediated by environmental factors. Keywords: , , ,

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Approach to Petiole Sap Nutritional Diagnosis Method by Empirical Model Based on Climatic and Growth Parameters

Agronomy ◽

10.3390/agronomy10020188 ◽

2020 ◽

Vol 10 (2) ◽

pp. 188

Author(s):

Alfonso Llanderal ◽

Pedro García-Caparrós ◽

José Pérez-Alonso ◽

Juana Isabel Contreras ◽

María Luz Segura ◽

...

Keyword(s):

Soil Solution ◽

Nutrient Concentration ◽

Prediction Models ◽

Growth Parameters ◽

Sampling Period ◽

Tomato Crop ◽

Area Index ◽

Empirical Prediction ◽

Diagnosis Method ◽

Petiole Sap

The aim of this work is to evaluate the relationship between the nutrient concentration in petiole sap and different agronomic and climatic variables for a tomato crop grown in a greenhouse in Mediterranean conditions. In addition, the persistence of the nutrient concentration in petiole sap was investigated with the aim of determining the sampling period that implies the best trade-off nutritional information. The experiment consisted of the selection of 20 sampling points inside the greenhouse. The samples of petiole, fully expanded leaf, and soil solution samples were collected weekly from 86 to 163 days after transplanting. Chloride, NO3−-N, H2PO4−-P, Na+, K+, Ca2+, and Mg2+ concentrations were determined in petiole sap and soil solution obtained by suction cups. Nitrogen, P, K, Cl, and Na concentrations were also determined in leaf. Finally, the petiole sap nutritional diagnosis method is the highest sensitive nutritional diagnosis method which compares soil solution and nutrient leaf content related to yield, and the statistical analysis performed in this research demonstrates that crop evapotranspiration (ETc), vapor pressure deficit (DPV), and leaf area index (LAI) are considered the most significant variables that allow the development of these empirical prediction models regarding nutrient concentration in petiole sap.

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Test Analysis of MSD Crack Propagation Structure in 2524-T3 Aluminium Alloy

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.574.386 ◽

2014 ◽

Vol 574 ◽

pp. 386-390

Author(s):

Jian Ping Zhang ◽

Xiao Ling Zheng

Keyword(s):

Numerical Simulation ◽

Crack Propagation ◽

Aluminium Alloy ◽

Crack Growth ◽

Growth Parameters ◽

Interactive Effects ◽

Aviation Industry ◽

Test Analysis ◽

Finite Element Software ◽

Fast Prediction

The MSD phenomenon is an active research topic of the academic and the aviation industry. This paper puts emphasis on the multi-crack propagation with interactive effects of MSD structure in 2524-T3 aluminium alloy. Material tests were accomplished for the crack growth parameters. The multi-crack propagation tests were conducted on specimens containing 5-similar-details, and the corresponding fatigue crack growth analysis with a fast prediction of crack growth life method were accomplished with finite element software. The comparison of crack tip position vs. load cycling from the test and the numerical simulation shows that the numerical simulation can give a good agreement to the experiment result.

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The Response of Maize Lines to Foliar Fertilizing

Agriculture ◽

10.3390/agriculture10090365 ◽

2020 ◽

Vol 10 (9) ◽

pp. 365

Author(s):

Milan Brankov ◽

Milena Simić ◽

Željko Dolijanović ◽

Miloš Rajković ◽

Violeta Mandić ◽

...

Keyword(s):

Amino Acids ◽

Grain Yield ◽

Leaf Area ◽

Harvest Index ◽

Growth Parameters ◽

Growth Stages ◽

Fresh Matter ◽

Area Index ◽

Positive Effects ◽

The Impact

The objective of this study was to evaluate the impact of two foliar fertilizers applied on five maize (Zea mays L.) lines. Fertilizers were applied at different growth stages of maize, during three consecutive years (2010–2012) at the experimental field of the Maize Research Institute “Zemun Polje”, Serbia. Maize growth parameters such as fresh matter, height, leaf area and grain yield were recorded. Foliar fertilizer with amino acids (FAA) was more advantageous to maize plants compared to fertilizer containing phosphorus (FP) as a main component. Applied FAA has shown positive effects by increasing fresh matter, leaf area index, and plant height in all three years. In 2012, due to unfavorable meteorological conditions, grain yield and harvest index were very low, compared to the previous two years, although, positive effects on morphological traits were observed 21 days after treatments (DAT), as well as in the anthesis stage. The best results of 30% of grain yield and harvest index increase were recorded in line L1 in 2010 and 2011. The same line had an increase of more than 40% of fresh matter and leaf area on average for all three years. The positive effects that have been noticed in this research could recommend foliar fertilizing with fertilizer containing N in a form of an amino acids complex.

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