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Silva, Luciana Maria da, Lucas Robson Oliveira, Fabrício Rodrigues, Katiane Santiago Silva Benett, and Cleiton Gredson Sabin Benett. "RELATIVE CHLOROPHYLL INDEX OF MAIZE AND SOYBEAN ACCORDING TO WEATHER CONDITIONS AT DIFFERENT TIMES OF DAY." JOURNAL OF NEOTROPICAL AGRICULTURE 7, no. 2 (June 29, 2020): 66–71. http://dx.doi.org/10.32404/rean.v7i2.5058.
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The present study aimed to identify the best day time to evaluate the relative chlorophyll index in maize and soybean crops as a function of weather conditions. The experiments were conducted in the 2018/2019 harvest, in January and February, in the experimental area of the State University of Goiás, Ipameri University Unit, in Ipameri-GO. A completely randomized design with three replications and 40 plants per plot was used. The measurements of relative chlorophyll index at 7:00, 10:00, 13:00, 16:00, and 19:00, at the maize stage R1 (silking) and soy stage R2 (full bloom), were evaluated. The replications consisted of alternating days over seven days. The relative chlorophyll index, leaf temperature, air temperature, and relative humidity, and light incidence were evaluated. The data were organized, and regression analysis was performed for all variables. The statistical analysis was processed using the Sisvar statistical analysis software. The maize shows higher values of relative chlorophyll index at times with the highest temperatures. For soybean, the relative chlorophyll index must be measured at temperatures close to 30 ºC. Studies with more species of C3 metabolisms, such as soybeans, should be carried out to standardize an adequate time to read the relative chlorophyll index.
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Chen, Ji-Jhong, Shuyang Zhen, and Youping Sun. "Estimating Leaf Chlorophyll Content of Buffaloberry Using Normalized Difference Vegetation Index Sensors." HortTechnology 31, no. 3 (June 2021): 297–303. http://dx.doi.org/10.21273/horttech04808-21.
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Commercial optical chlorophyll meters estimate relative chlorophyll content using the ratio of transmitted red light and near-infrared (NIR) light emitted from a red light-emitting diode (LED) and an NIR LED. Normalized difference vegetation index (NDVI) sensors have red and NIR light detectors and may be used to estimate chlorophyll content by detecting the transmitted red and NIR light through leaves. In this study, leaf chlorophyll content of ‘Torrey’ buffaloberry (Shepherdia ×utahensis) plants treated with 0 mm [zero nitrogen (N)], 2 mm (medium N), or 4 mm (ample N) ammonium nitrate for 3 weeks were evaluated using two commercial chlorophyll meters and NDVI sensors. The absolute chlorophyll content was determined using chlorophyll extraction. Our results showed that plants receiving ample N and medium N had decreased transmitted red light (i.e., greater absorption in red light). Measurements of optical chlorophyll meters, NDVI sensors, and chlorophyll extraction similarly showed that plants receiving medium N and ample N had greater leaf chlorophyll content than those receiving zero N. Relative leaf chlorophyll content estimated using NDVI sensors correlated positively with those from the chlorophyll meters (P < 0.0001; r2 range, 0.56–0.82). Therefore, our results indicate that NDVI measurements are sensitive to leaf chlorophyll content. These NDVI sensors, or specialized sensors developed using similar principles, can be used to estimate the relative chlorophyll content of nursery crops and help growers adjust fertilization to improve plant growth and nutrient status.
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Mauricio, Gruska, Ohse Silvana, and Belmont Pereira Andre. "Chlorophyll relative index for diagnosing nitrogen status in corn hybrids." African Journal of Agricultural Research 12, no. 27 (July 6, 2017): 2273–82. http://dx.doi.org/10.5897/ajar2017.12216.
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Kaspary, Tiago Edu, Luan Cutti, Cristiano Bellé, Gabriele Casarotto, Mártin Zanchett Groth, Gerarda Beatriz Pinto Da Silva, and Adalin Cezar Moraes De Aguiar. "Non-destructive analysis of photosynthetic pigments in Avena strigosa and Avena sativa." 2019 13, (03) 2019 (May 20, 2019): 354–59. http://dx.doi.org/10.21475/ajcs.19.13.03.p1149.
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Chlorophylls and carotenoids are the main photosynthetic pigments in plants. The photosynthetic potential of crop plants is used to determine the correct rate of nitrogen fertilization. To date, no studies have been conducted to understand the relationship between different methods of measurement of photosynthetic pigments in oats. The objective of this study was to quantify and compare the levels of photosynthetic pigments in Avena strigosa and A. sativa using two different methods, the extraction method and portable chlorophyll meter, and to determine whether the results of these two methods showed a significant correlation. Photosynthetic pigments were measured using both methods in a greenhouse and the laboratory at four developmental stages: tillering [28 days after sowing (DAS)], vegetative stage I (55 DAS), vegetative stage II (75 DAS), and reproductive stage (120 DAS). The same leaves were used to measure the relative chlorophyll content using a portable chlorophyll meter and extractable chlorophyll using the laboratory extraction method. The readings of the chlorophyll index differed for each developmental stage of both A. sativa and A. strigosa. The contents of chlorophyll a, chlorophyll b, and carotenoids determined using the extraction method showed high coefficients of correlation with the total chlorophyll index determined using the portable chlorophyll meter. Thus, the measurement of chlorophyll using the portable chlorophyll meter can be used for the accurate evaluation of the photosynthetic potential of oats, thus saving time and reagents.
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POURMOHAMMAD, Azam, Mahmoud TOORCHI, Seyed S. ALAVIKIA, and Mohammad R. SHAKIBA. "Genetic Analysis of Yield and Physiological Traits in Sunflower (Helianthus annuus L.) under Irrigation and Drought Stress." Notulae Scientia Biologicae 6, no. 2 (June 10, 2014): 207–13. http://dx.doi.org/10.15835/nsb629173.
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Implementing appropriate breeding strategies for sunflower, alongside dependable information on heritability and gene effects upon yield and related traits under drought conditions, are all necessary. Thirty sunflower hybrids were produced by line × tester cross of six male-sterile and five restorer lines. Their hybrids were evaluated in three levels of irrigation, as follows: (1) non-stressed plots, irrigated at regular intervals (W1); (2) mild water stress (W2), irrigated from the beginning of the button stage (R4) to seed filling initiation (R6); (3) severe water stress (W3) started from the beginning of button stage (R4) to physiological maturity. Based on observations and specific methods for determination, canopy temperatures, chlorophyll index, relative water content and proline content, were studied by additive effects, under the different irrigation conditions. Canopy temperatures,chlorophyll index, relative water content, leaf water potential, proline content and yield were controlled by additive effects under mild stressed conditions. Under severe stress conditions however, canopy temperatures, leaf water potential and proline content were controlled by additive effects, while chlorophyll index and relative water content were controlled by both additive and dominant effects, as seed yield was mainly influenced by the dominant effects. The narrow sense heritability ranged from 47-97% for all traits, except for chlorophyll fluorescence. Yield correlated positively with chlorophyll index and relative water content, and negatively with canopy temperature and leaf water potential. Therefore, under drought stressed conditions in breeding programs, canopy temperatures, chlorophyll index and relative water content can be reliable criteria for the selection of tolerant genotypes with prospect to higher yields.
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Meskini-Vishkaee, Fatemeh, Mohammad Hosein Mohammadi, Mohammad Reza Neyshabouri, and Farid Shekari. "Evaluation of canola chlorophyll index and leaf nitrogen under wide range of soil moisture." International Agrophysics 29, no. 1 (January 1, 2015): 83–90. http://dx.doi.org/10.1515/intag-2015-0014.
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Abstract The paper presents a study on the effect of soil matric suction on the variation of leaf chlorophyll index and nitrogen concentration of canola. Results showed that chlorophyll index increases exponentially with soil matric suction, especially at the late season of canola growing time. At moderate matric suction (200 and 300 kPa soil suction heads), chlorophyll index remains nearly constant, but in drier soil (matric suction >300 kPa), chlorophyll index increases gradually with time. Despite the variation of the total leaf nitrogen with the soil matric suction, it is similar to the variation of the chlorophyll index, but the results showed that the chlorophyll index - nitrogen concentration curve has a demarcated bi-modal shape. We suggest that 2.7% of nitrogen and 69.8 of the chlorophyll index value represent the upper limit of the chlorophyll meter reliability for estimation of canola nitrogen under a wide range of soil moisture levels. These results confirm that the chlorophyll meter can be used as an effective tool for rapid and non-destructive estimation of the relative chlorophyll and nitrogen content in canola leaves at a wide range of soil moisture content, except for nearly wilting coefficient or extremely high drought stress
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Maria, Olívia Assis de Oliveira, Martins de Freitas Alves Sueli, de Fátima Miranda Freitas Elaine, Felipe Lopes de Faria Hiago, and Fernandes Lisboa Cristiane. "Relative chlorophyll index on doses of nitrogen fertilization for cherry tomato culture." African Journal of Agricultural Research 12, no. 39 (September 28, 2017): 2946–53. http://dx.doi.org/10.5897/ajar2016.12051.
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Vendruscolo, Eduardo Pradi, Aliny Heloísa Alcântara Rodrigues, Sávio Rosa Correa, Alexander Seleguini, and Sebastião Ferreira de Lima. "Different soaking times and niacin concentrations affect yield of upland rice under water deficit conditions." Agronomía Colombiana 37, no. 2 (May 1, 2019): 166–72. http://dx.doi.org/10.15446/agron.colomb.v37n2.72765.
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Rice is an important source of energy for a large part of the world’s population. The development and application of technologies that contribute to the improvement of production forthis grain have great importance. The objective of this study was to evaluate the influence of rice seed immersion in a niacin solution on plant development, physiology and production. Thetreatments were defined by a combination of two immersion times for the seeds (12 h and 24 h) in four niacin concentrations (0.00, 100, 200 and 300 mg L-1) distributed in five replicates. Characteristics relating to seedling emergence, plant vegetativedevelopment, relative indices of chlorophyll and grain yield were evaluated. We verified that the immersion of the seeds for 12 h gave higher relative indices of chlorophyll, whereas immersion for 24 h increased the speed of emergence and the number of tillers and panicles. The doses of niacin positively affected the relative chlorophyll indices and the production characteristics, up to a maximum concentration of 172.57 mg L-1. We concluded that the immersion of rice seeds for 24 h increased the speed of seedling emergence, leaf number, and panicles per area. However, the relative indices of chlorophyll in leaves decreased. The use of niacin promoted the numbers of spikelets per panicle, fertility of the spikelets and the weight of 1000 grains, besides increasing the relative index of chlorophyll in the leaves of rice plants.
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Zhang, Jing, Haiqing Tian, Di Wang, Haijun Li, and Abdul Mounem Mouazen. "A novel spectral index for estimation of relative chlorophyll content of sugar beet." Computers and Electronics in Agriculture 184 (May 2021): 106088. http://dx.doi.org/10.1016/j.compag.2021.106088.
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GHASSEMI-GOLEZANI, Kazem, Salar FARHANGI-ABRIZ, and Ali BANDEHAGH. "Salicylic acid and jasmonic acid alter physiological performance, assimilate mobilization and seed filling of soybean under salt stress." Acta agriculturae Slovenica 111, no. 3 (December 12, 2018): 597. http://dx.doi.org/10.14720/aas.2018.111.3.08.
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<p>This research was conducted to investigate the morpho-physiological effects of salicylic acid and jasmonic acid on soybean performance and productivity under salinity. Leaf chlorophyll content index, carotenoids and anthocyanins content, photosystem II efficiency, relative water content, leaf area, leaf mass, specific leaf area, water use efficiency, seed filling duration, assimilate mobilization efficiency and seed mass decreased, but leaf temperature, specific leaf mass and electrolytic leakage of leaves increased with enhancing salinity. Salicylic acid improved leaf chlorophyll content index, anthocyanins content, leaf area, specific leaf area, water use efficiency, seed filing duration, assimilate mobilization efficiency and seed mass under both saline and non-saline conditions. The superior effects of salicylic acid on some traits such as maximum quantum yield of PSII, relative water content and leaf electrolytic leakage only occurred under different salinity levels. Jasmonic acid improved leaf mass, specific leaf mass, carotenoids content, relative water content, seed filling rate and reduced chlorophyll content index, leaf temperature, leaf area, specific leaf area, seed filling duration, assimilates mobilization efficiency and relative electrolytic leakage of soybean, with no significant effects on photosystem II efficiency and seed mass. Application of salicylic acid was, therefore, the superior treatment for enhancing physiological performance and seed mass of soybean plants under different salinity levels.</p>
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Maia, Suelen Cristina Mendonça, Rogério Peres Soratto, Beatriz Nastaro, and Lucas Barbosa de Freitas. "The nitrogen sufficiency index underlying estimates of nitrogen fertilization requirements of common bean." Revista Brasileira de Ciência do Solo 36, no. 1 (February 2012): 183–92. http://dx.doi.org/10.1590/s0100-06832012000100019.
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Chlorophyll determination with a portable chlorophyll meter can indicate the period of highest N demand of plants and whether sidedressing is required or not. In this sense, defining the optimal timing of N application to common bean is fundamental to increase N use efficiency, increase yields and reduce the cost of fertilization. The objectives of this study were to evaluate the efficiency of N sufficiency index (NSI) calculated based on the relative chlorophyll index (RCI) in leaves, measured with a portable chlorophyll meter, as an indicator of time of N sidedressing fertilization and to verify which NSI (90 and 95 %) value is the most appropriate to indicate the moment of N fertilization of common bean cultivar Perola. The experiment was carried out in the rainy and dry growing seasons of the agricultural year 2009/10 on a dystroferric Red Nitosol, in Botucatu, São Paulo State, Brazil. The experiment was arranged in a randomized complete block design with five treatments, consisting of N managements (M1: 200 kg ha-1 N (40 kg at sowing + 80 kg 15 days after emergence (DAE) + 80 kg 30 DAE); M2: 100 kg ha-1 N (20 kg at sowing + 40 kg 15 DAE + 40 kg 30 DAE); M3: 20 kg ha-1 N at sowing + 30 kg ha-1 when chlorophyll meter readings indicated NSI < 95 %; M4: 20 kg ha-1 N at sowing + 30 kg ha-1 N when chlorophyll meter readings indicated NSI < 90 % and, M5: control (without N application)) and four replications. The variables RCI, aboveground dry matter, total leaf N concentration, production components, grain yield, relative yield, and N use efficiency were evaluated. The RCI correlated with leaf N concentrations. By monitoring the RCI with the chlorophyll meter, the period of N sidedressing of common bean could be defined, improving N use efficiency and avoiding unnecessary N supply to common bean. The NSI 90 % of the reference area was more efficient to define the moment of N sidedressing of common bean, to increase N use efficiency.
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Vincze, Éva, and Péter Pepó. "Study of plant physiological parameters in winter oilseed rape (Brassica napus var. napus f. biennis L.) production on chernozem soil." Acta Agraria Debreceniensis, no. 68 (February 18, 2016): 111–15. http://dx.doi.org/10.34101/actaagrar/68/1779.
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We made plant physiology examinations in Arkaso winter oilseed rape hybrid substance: relative chlorophyll content (SPAD) and leaf area index (LAI) measurements. The experiment was set in University of Debrecen Agricultural Sciences Center at Látóképi Experimental Station in four replications, in two different sowing times (I. sowing date on 08/22/2014 and II. sowing date on 09/09/2014 sowing againhappened because of the incomplete germination in the second subtance 01/10/2014) Three different plant density 200, 350 and 500 thousand ha-1, under the same nutrient supply, 45 cm row spacing. The experiment was green crop of winter wheat. The relative chlorophyll content (SPAD) and leaf area index (LAI) measurements were made in seven different times. We measured the maximum value of chlorophyll content in the first sowing time at 500, and the second sowing time at 350 thousand ha-1 plant density. The measurement results proved that there was a linear relationship between the number of plants and the LAI. The maximum leaf area index values we measured in both the sowing time at 500 thousand ha-1 reached.
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Attila Dobos, Róbert Víg, and János Nagy. "The impact of environmental factors on the measurement of the normalized difference vegetation index." Acta Agraria Debreceniensis, no. 49 (November 13, 2012): 141–47. http://dx.doi.org/10.34101/actaagrar/49/2512.
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The level of nitrogen supply of a plant population can be quickly measured with non-destructive optical measurement devices and the differentiated determination of nitrogen shortage and the replenishment of nitrogen can also be carried out. The level of nitrogen supply is based on the fact that the chlorophyll content of crops is in close correlation with nitrogen content and that the amount of chlorophyll can be easily measured on the basis of the light absorption of chlorophyll molecules. The successfulness of optical measurements can be influenced by the change of weather parameters; therefore, it is important to know the correlations between measurement results and weather parameters when it comes to practical use.The GreenSeeker Model 505 measurement device determines the relative chlorophyll content in the form of the Normalized DifferenceVegetation Index (NDVI) calculated on the basis of the intensity of the reflected red and infrared rays of light from the crop population. The measurements were performed in alfalfa population with 10 replications at five measurement heights and four measurement times. The weather parameters were measured by a weather station located in the middle of the alfalfa population and the correlations between the meteorological data and the NDVI values were examined. During the statistical evaluation of the results, it was established that the NDVI measurement is primarily influenced by the relative humidity of the air, secondly by air temperature and thirdly by wind speed. Relative humidity was in strong correlation with the NDVI values which were also influenced by the measurement height and time. Regression was not significant in the case of 20 cm measurement height, but the measurements above 40 cm height showed significant correlations. The correlation was shown to be strong at each measurement time, but the influence of humidity was the lowest at 11:00 and 14:00.
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Farshadfar, E., M. Farshadfar, and J. Sutka. "COMBINING ABILITY ANALYSIS OF DROUGHT TOLERANCE IN WHEAT OVER DIFFERENT WATER REGIMES." Acta Agronomica Hungarica 48, no. 4 (January 1, 2001): 353–61. http://dx.doi.org/10.1556/aagr.48.2000.4.5.
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To study the properties of some drought tolerance criteria and agronomic characters in wheat, an eight-parental diallel cross, excluding reciprocals, was grown in a randomized complete block design with three replications under two different water regimes (irrigated and rainfed) for two years in the College of Agriculture at Razi University, Kermanshah, Iran. High broad-sense heritability estimates were observed for harvest index, grain yield, and earliness. Additive gene action was found to be predominant for grain yield, harvest index, relative water content and chlorophyll fluorescence. The results of combining ability analysis revealed that Plainsman was the best general combiner and Plainsman × Kobomugi was the best specific combination for improving drought tolerance. The pooled analysis of variance for combining ability over rainfed conditions reflected that the GCA × environment interaction was not significant for harvest index and chlorophyll fluorescence, and the SCA × environment interaction was non-significant for relative water content and relative water loss, indicating that genes controlling osmoregulation and the other physiological traits mentioned are not affected in these varieties by different rainfed conditions and hence show static stability.
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Ansorena, María Roberta, María Victoria Agüero, María Grabriela Goñi, Sara Roura, Alejandra Ponce, María del Rosario Moreira, and Karina Di Scala. "Assessment of lettuce quality during storage at low relative humidity using Global Stability Index methodology." Food Science and Technology 32, no. 2 (April 17, 2012): 366–73. http://dx.doi.org/10.1590/s0101-20612012005000043.
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During postharvest, lettuce is usually exposed to adverse conditions (e.g. low relative humidity) that reduce the vegetable quality. In order to evaluate its shelf life, a great number of quality attributes must be analyzed, which requires careful experimental design, and it is time consuming. In this study, the modified Global Stability Index method was applied to estimate the quality of butter lettuce at low relative humidity during storage discriminating three lettuce zones (internal, middle, and external). The results indicated that the most relevant attributes were: the external zone - relative water content, water content , ascorbic acid, and total mesophilic counts; middle zone - relative water content, water content, total chlorophyll, and ascorbic acid; internal zone - relative water content, bound water, water content, and total mesophilic counts. A mathematical model that takes into account the Global Stability Index and overall visual quality for each lettuce zone was proposed. Moreover, the Weibull distribution was applied to estimate the maximum vegetable storage time which was 5, 4, and 3 days for the internal, middle, and external zone, respectively. When analyzing the effect of storage time for each lettuce zone, all the indices evaluated in the external zone of lettuce presented significant differences (p < 0.05). For both, internal and middle zones, the attributes presented significant differences (p < 0.05), except for water content and total chlorophyll.
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Popescu, Elena Corina, and Claudia Lavinia Buruleanu. "Heat Degradation Kinetics of the Chlorophyll from Spinach and its Correlation with the Reflection Spectra." Revista de Chimie 68, no. 4 (May 15, 2017): 830–34. http://dx.doi.org/10.37358/rc.17.4.5561.
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Chlorophyll, the pigment responsible for the green color specific to the spinach leaves, is sensitive to temperature, pH, activity of enzymes. The heat degradation kinetics of the chlorophyll a and chlorophyll b from the spinach leaves was studied at different temperatures (60, 70, 80 and 900C) and different times (3, 9, 12, 15 min). The degradation of the chlorophyll a and chlorophyll b followed a first-order reaction, and the rate constant had values between 0.0199-0.0695 min-1 for chlorophyll a and 0042 -0.011 min-1 for chlorophyll b respectively. The dependence between the chlorophyll degradation and temperature was modeled using the Arrhenius�a equation. The activation energy was by 44.316 Kjmol-1 for chlorophyll a and 35.384 Kjmol-1 for chlorophyll b respectively. Using the rapid, non-invasive measuring method of the reflection spectra in red band and in NIR region and the calculation of the index Clred edge, the chlorophyll quantity from spinach leaves was measured with a relative error ErCle between 1.27 and 8.65%.
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Bhardwaj, Anuja, R. K. Aggarwal, and S. K. Bhardwaj. "Study on Spatial and Seasonal Variation in APTI of Tree Species along Roads of Shivalik Foothills in Himachal Pradesh." International Journal of Bio-resource and Stress Management 12, no. 3 (June 30, 2021): 247–54. http://dx.doi.org/10.23910/1.2021.2299.
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The present study was conducted during the year 2018-2019 to determine the impact of road on Air Pollution Tolerance Index (APTI) of plants growing along the road. A comparative study was done between three roads viz., National highway, State highway and Link Road. Among three roads, link road can be considered as control because vehicular emissions were minimal or non-existent. Three plants (Dalbergia sisso, Mangifera indica and Ficus palmata) were selected as per their uniform presence along all three roads. Four biochemical parameters viz., ascorbic acid, total chlorophyll, leaf extract pH and relative water content were used to calculate the air pollution tolerance index. Season wise maximum ascorbic acid, leaf extract pH and relative water content was observed during post monsoon season whereas total chlorophyll content was observed during pre monsoon season. The APTI of the selected plant species ranged from 8.23 to 10.76 during pre-monsoon and 9.03 to 11.09 during post-monsoon. Anticipated Performance Index (API) was in order of Mangifera indica with highest API grade (6) and it was excellent among plants followed by Dalbergia sisso (5) in very good and Ficus palmata (3) in moderate. Student t-test analysis of seasonal variation of biochemical parameters in leaf of selected tree species was carried out and it was observed that there was significant seasonal effect on mean values of ascorbic acid content and APTI whereas there was no impact of seasons on total chlorophyll content, leaf extract pH and relative water content.
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Ananthi, K., H. Vijayaragh, M. Karuppaiya, and T. Anand. "Drought-induced Changes in Chlorophyll Stability Index, Relative Water Content and Yield of Cotton Genotypes." Insight Botany 3, no. 1 (January 1, 2013): 1–5. http://dx.doi.org/10.5567/botany-ik.2013.1.5.
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Kasim, Nijat, Rukeya Sawut, Abdugheni Abliz, Shi Qingdong, Balati Maihmuti, Ahunaji Yalkun, and Yasenjiang Kahaer. "Estimation of the Relative Chlorophyll Content in Spring Wheat Based on an Optimized Spectral Index." Photogrammetric Engineering & Remote Sensing 84, no. 12 (December 1, 2018): 801–11. http://dx.doi.org/10.14358/pers.84.12.801.
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Guo, Shao Fen, Shou Fu Yu, and Xiao Hua Huang. "Effect of La (III) on some Physiological Index and Ultrastructure of Honeysuckle (Lonicera japonica Thunb.)." Advanced Materials Research 864-867 (December 2013): 295–98. http://dx.doi.org/10.4028/www.scientific.net/amr.864-867.295.
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In this paper, the effect of La (III) on some physiological index and ultrastructure of honeysuckle leaves were investigated. The experimental results indicated that the effect of La (III) on honeysuckle growth depended on La (III) concentration. When the concentration of La (III) was low, it can increase POD activity, increase the chlorophyll contents and the chlorophyll a/b value, decrease the contents of MDA and H2O2, so the photosynthetic capacity was strengthened and the membrane lipid peroxidation was decreased. When the concentration of La (III) was high, La (III) could inhibit POD activity, decrease the chlorophyll contents and the chlorophyll a/b value, increase the contents of MDA and H2O2, so the photosynthetic capacity was inhibited and the membrane lipid peroxidation was increased. Meanwhile, the low concentration of La (III) did not destroy the cell structure, however, the high concentration of La (III) acted as a heavy metal and destroyed the cell structure and membrane system, La (III) showed a hormesis effecton honeysuckle growth.Abbreviations. ROS: reactive oxygen species, POD: peroxidase, CAT: catalase, SOD: superoide dismutase, MDA: malondialdehyde, TCA: trichloroacetic acid, REL: relative electrolyte leakage,
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Pariz, C. M., M. Andreotti, A. F. Bergamaschine, S. Buzetti, N. R. Costa, M. C. Cavallini, N. A. Ulian, and F. G. Luiggi. "Yield, chemical composition and chlorophyll relative content of Tanzania and Mombaça grasses irrigated and fertilized with nitrogen after corn intercropping." Revista Brasileira de Zootecnia 40, no. 4 (April 2011): 728–38. http://dx.doi.org/10.1590/s1516-35982011000400005.
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It was evaluated the effect of the absence and of application of three nitrogen doses (50, 100 and 200 kg ha-1of N) and four harvest times in the winter/spring season (from July to October) on dry mass yield (DMY), on the relative chlorophyll contents (ICF _ leaf chlorophyll index) and on the contents of total digestible nutrients (TDN), crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF) and lignin, and their respective correlations on Tanzania and Mombaça grasses after intercrop with corn in distroferric red latosol (Oxisol) soil as well. It was used a random block design, in split-plot with four replicates. The greatest DMY occured with the increase of photoperiod (from August), neverthless responses to nitrogen fertilization over cuts difered among the grasses. In an irrigated crop-livestock integration system under cerrado conditions, it is technically feasible the establishment of Tanzania and Mombaça grass intercroped with corn at sowing or if cover nitrogen fertilization is performed because even in the abscence of nitrogen fertilization, great satisfactory quantity of forage was produced, with average DMY of 2,000 kg ha-1 per cut during the highest shortage of roughage for animals (winter/spring). Nitrogen fertilization after corn harvest increases DMY and improves bromatologic composition of the grasses, as contents of chlorophyll and CP in winter/spring is increased, besides the increase of contents of TDN and a reduction on the contents of NDF and ADF until September. Leaf chlorophyll index can be used to estimate the DMY and CP content and as a marker of the need of nitrogen fertilization of Tanzania and Mombaça grasses submitted to cutting.
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Alvarez, Rita de C. F., Jamile Benetão, Gustavo R. Barzotto, Maria G. de O. Andrade, and Sebastião F. de Lima. "Application methods of Azospirillum brasilense in first- and second-crop corn." Revista Brasileira de Engenharia Agrícola e Ambiental 23, no. 11 (November 2019): 840–46. http://dx.doi.org/10.1590/1807-1929/agriambi.v23n11p840-846.
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ABSTRACT This study investigated whether inoculation of Azospirillum brasilense in the seeds or sowing furrow could reduce the need for nitrogen fertilizer application in the corn grown in the first and second crop harvest. The experiments were conducted, in the municipality of Chapadão do Sul, MS, Brazil, in the first crop harvest (2014/2015) and in the second crop harvest (2016). The early maturity hybrids CD 384 HX and P3132H were used in the first and in the second harvest corn, respectively. In both experiments, the experimental design was the randomized blocks with eight treatments and three repetitions. At the silking (R1 stage), the leaf N concentration, relative chlorophyll index and nitrate reductase activity were measured, at the physiological maturity (R6 stage), the plant height, first ear insertion height, one hundred grain mass, grain yield and grain N concentration were measured. In the first crop harvest, the application of Azospirillum brasilense at the sowing furrow resulted in higher N concentration and relative chlorophyll index in corn leaves, while the inoculation of A. brasilense in the seeds provided higher N concentration in the grains. The nitrate reductase activity in corn leaves was lower when inoculation was performed. In the second crop harvest, the inoculation did not affected the N concentration in the leaves and in the grains, the relative chlorophyll index and the growth of corn plants. Inoculation in the sowing furrow associated with the application of 20 kg N ha-1 at sowing and 120 kg N ha-1 at topdressing resulted in lower nitrate reductase activity.
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Gonçalves, José Francisco de Carvalho, Ulysses Moreira dos Santos Junior, and Emerson Alves da Silva. "Evaluation of a portable chlorophyll meter to estimate chlorophyll concentrations in leaves of tropical wood species from Amazonian forest." Hoehnea 35, no. 2 (June 2008): 185–88. http://dx.doi.org/10.1590/s2236-89062008000200002.
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A portable chlorophyll meter can be an important tool to estimating chlorophyll contents in leaves of tree species under field conditions. The method is quick and non-destructive compared to the classic chemical methods of pigment extraction. The aim of this work was to evaluate the performance of a portable chlorophyll meter (CCM-200, Opti-Science) to estimate the concentrations of chloroplastid pigments and the fraction of photosynthetically active irradiance absorbed by leaves (α) in four tropical wood species from Amazonian forest. The results shown positive correlation between the chlorophyll contente index (CCI) readings and concentrations of Chl a (P < 0.0001; r² = 0.904), Chl b (P< 0.0001; r² = 0.803), Chl tot (P< 0.0001; r² = 0.923) and α (P< 0.0001; r² = 0.886), suggesting that the portable chlorophyll meter can be an effective tool for the relative estimation of chlorophyll concentrations and the fraction of the photosynthetically active irradiance absorbed by the leaves of tropical tree species.
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Kaya, Gamze. "Gamze Kaya GERMINATION, STOMATAL AND PHYSIOLOGICAL RESPONSE OF ROCKET (Eruca sativa L.) TO SALINITY." Acta Scientiarum Polonorum Hortorum Cultus 20, no. 4 (August 31, 2021): 135–44. http://dx.doi.org/10.24326/asphc.2021.4.12.
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The response of rocket (Eruca sativa L.) to salinity stress was tested for several germination and physiological parameters during seedling development. Two rocket cultivars (Ilıca and Istanbul) and various salinity stresses of 0, 5, 10, 15 and 20 dS m–1 created by NaCl were used in the study. Germination percentage (GP), mean germination time (MGT), germination index (GI), germination stress tolerance index (GSTI), stomata morphology, chlorophyll content (SPAD value), leaf dry matter, relative water content (RWC), cellular injury (CI) and cell membrane stability (CMS) were evaluated. Results showed that high salinity stresses led to a decrease in GP, GI and GSTI index, while MGT increased. Salinity reduced stoma length and pore length. Under saline conditions, leaf dry matter, chlorophyll content and CMS increased, while RWC decreased. Also, CI was enhanced by salinities over 10 dS m–1. It was concluded that lower CMS, CI and RWC, and greater dry matter and chlorophyll were considered as salinity tolerance at the seedling stage of the rocket, and Istanbul was more tolerant to salinity than Ilıca.
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Tobiasz-Salach, Renata, and Anna Augustyńska-Prejsnar. "RESPONSE OF SPRING BARLEY TO FOLIAR FERTILIZATION WITH Cu AND Mn." Acta Scientiarum Polonorum Agricultura 19, no. 1 (March 17, 2020): 29. http://dx.doi.org/10.37660/aspagr.2020.19.1.4.
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Background. Spring barley grain yield and chemical composition depend on mineral fertilization as well as soil and climatic conditions during plant growth. It is especially important to provide fertilization with microelements that are connected with photosynthesis and respiration rate. The aim of this study was to evaluate the effect of foliar fertilization with manganese and copper on grain yield and its components, chlorophyll content in leaves, selected chlorophyll fluorescence indexes, leaf area index (LAI) and the chemical composition of grain in 3 spring barley fodder cultivars and 1 malting cultivar.Material and methods. The field experiment was carried out during 2014‒2016 at the Experimental Station for Variety Testing in Dukla (49o55’ N; 21o68’ E), in a split-plot design in 4 repetitions. The study factors were: 4 spring barley cultivars and foliar feeding (control, Cu and Mn).Results. The foliar fertilizers used in the experiment increased grain yield, ear density, number of grains per ear and 1000 grain weight. The content of chlorophyll in subflag leaves was usually higher in cultivars fertilized with copper compared to manganese, with only the cultivar Suweren having an inverse relationship. Copper application favorably increased the value of the PSII functioning index both compared to the control and to fertilization with manganese. The LAI index was dependent on the cultivar and the foliar feeding. A slight tendency to a higher content of total protein and raw ash on plants fertilized with foliar micronutrients was observed. A larger increase of these contents in comparison to the control was found after the application of copper than of manganese.Conclusion. Spring barley yield, yield structure components, the relative content of chlorophyll in the leaves, LAI index and chemical composition of grain depended on the weather conditions during the plant growing periods. Foliar feeding with manganese resulted in an increase in grain yield and 1000 grain mass when compared to foliar feeding with copper. Copper fertilization resulted in a greater increase in the relative content of chlorophyll in the leaves and a higher content of total protein and crude ash in the grain compared to manganese fertilization. A greater increase in the LAI index compared to the control was observed in plants fertilized with manganese rather than with copper.
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ARAÚJO, ALANA CRISTINA FERREIRA, JOÃO CARLOS MADALÃO, ADRIANO JAKELAITIS, ALAN CARLOS COSTA, and GABRIEL MARTINS ALMEIDA. "RESIDUES OF FORAGE SPECIES AFFECT PHOTOSYNTHETIC CHARACTERISTICS OF THE PEQUIZEIRO." Revista Caatinga 31, no. 1 (March 2018): 9–18. http://dx.doi.org/10.1590/1983-21252018v31n102rc.
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ABSTRACT Some forages release allelopathic substances into the environment, and may prevent consortium with arboreal species in pastures. The objective of this work was to evaluate photosynthetic characteristics of pequizeiro plants (hereafter pequi) influenced by concentrations of residues of the forage species Urocholoa decumbens, Melinis minutiflora and Paspalum notatum. The treatments consisted of pequi cultivation under aerial residues of the three forage species mixed to the substrate in four concentrations (1, 2, 3 and 4% mass/mass), plus an additional treatment (comparative control) with pequi cultivated on the substrate without waste. The following parameters were evaluated: photosynthetic rate, stomatal conductance, transpiration rate, relationship between internal and external CO2 concentration (Ci/Ca), maximum quantum yield, effective quantum yield of FS II, electron transport rate, nonchemical quenching and chlorophyll index, concerning the content of chlorophyll a, b and total in pequi plants at 50 and 100 days after transplanting (DAT), and the relative production of dry matter at 100 DAT. At 50 DAT, the following photosynthetic variables were affected in pequi plants: A, gs, chlorophyll a, chlorophyll b and total chlorophyll when cultivated in the presence of forage residues. At 100 DAT, the following photosynthetic variables were affected in pequi plants: A, Fv/Fm, ETR, NPQ, chlorophyll a, chlorophyll b and total chlorophyll, when cultivated in the presence of forage residues. Pequi plants had reduced relative dry matter yield when grown in the presence of U. decumbens. This variable was also affected when pequi was grown in increasing concentrations of residues of the species U. decumbens, M. minutiflora and P. notatum.
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Kumari, Priyanka, and H. K. Jaiswal. "Effect of cold stress on boro rice seedlings." Journal of Applied and Natural Science 9, no. 2 (June 1, 2017): 1036–41. http://dx.doi.org/10.31018/jans.v9i2.1318.
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Cold stress at seedling stage is a major constraint in boro rice production. Nine boro rice lines were crossed in diallel fashion excluding reciprocals to obtain 36 crosses. All the 36 crosses along with parents were grown in nursery in three seasons (boro-2014, kharif-2015 and boro-2015). Performance of seedlings for survival per cent, chlorophyll content, relative water content, membrane stability index was recorded just before transplanting in all the three seasons. Scoring for cold tolerance was done in both boro seasons. Gautam showed highest survival rate over three seasons. Among crosses, IR 64 x Krishna Hamsa showed highest survival (84%) in boro-2014, MTU 1010 x Jaya (86.33%) in boro-2015 and MTU 1010 x Krishna Hamsa (95.67%) in kharif-2015. Jaya x Krishna Hamsa was most cold tolerant cross over both boro seasons. Significant positive correlation was observed among survival per cent, chlorophyll content, relative water content and membrane stability index over seasons.
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Gökmen, Emine, and Ercan Ceyhan. "Effects of drought stress on growth parameters, enzyme activities and proline content in chickpea genotypes." Bangladesh Journal of Botany 44, no. 2 (October 13, 2018): 177–83. http://dx.doi.org/10.3329/bjb.v44i2.38505.
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Drought stress decreased leaf water absorption capacity and real water content and increase relative water content in genotypes of chickpea. It decreased chlorophyll a and b content. Drought increased peroxidase superoxide dismutase, glutathione reductase, ascorbate peroxidase and catalase in stress groups. Proline content increased drastically index stress condition.
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Parveen, Rabiya, Satish Kumar Singh, Mithilesh Kumar Singh, and Mainak Barman. "Character association studies in Bread wheat genotypes for early heat tolerance and grain micronutrient content." Environment Conservation Journal 22, no. 1&2 (June 4, 2021): 111–25. http://dx.doi.org/10.36953/ecj.2021.221216.
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Thirty bread wheat genotypes were tested by adopting Randomized Block Design with three replications during 2019-20, under two different environments, i.e. early and timely sown conditions. The ultimate goal was to determine the relationship between yield and yield contributing traits and classify traits that have the highest direct and indirect effects on grain yield under both environmental circumstances. Grain yield was positively and significantly correlated with no. of tiller/plant, no. of grains/spike, relative water content, spike fertility, harvest index, grain zinc content and chlorophyll content at the level of both genotype and phenotype; conversely, found significantly negative with canopy temperature and non-significant with days to 50 % flowering and seedling length. Under stress condition, the correlation for grain yield/plant was found significant, and it was correlated positively with no. of tiller/plant, spike fertility, relative water content, harvest index and grain zinc content and non-significantly with seedling length, no. of grain/spike, chlorophyll content, flag leaf area and thousand-grain weight. At the level of both genotype and phenotype, grain yield per plant had a high direct effect in the positive direction by harvest index followed by no. of tiller/plant, no. of grain/spike, relative water content. Thus, more weightage should be given towards these traits as selecting these traits can be rewarding to achieve high yielding wheat genotypes.
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Yang, Hong, and Gui Xiang Dai. "Effects of Thermal Discharge from the Coastal Power Plant on the Phytoplankton in Mesocosm Experiments." Advanced Materials Research 610-613 (December 2012): 3428–31. http://dx.doi.org/10.4028/www.scientific.net/amr.610-613.3428.
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In order to study the effects of power plant thermal discharge on phytoplankton in different temperature rise. Mesocosm experiment has been done in Guohua plant near the Xiangshan Bay in July 2011. The variances of the water-quality index such as Chlorophyll a, DO, COD and nutrients were analyzed. The results shown that relative to the control area M3,the Chlorophyll a in M1 ( increased 0.8°C) decreased by 45%, while the M2 (increased 0.4°C) increased by 26%, thus, this paper comes to the conclusion that exotherm exceed 0.8°C cause harm on phytoplankton growth, and exotherm that is lower than 0.4°C cause little effect. The experiment found that the COD, DO and Chlorophyll a were positive correlation; nutrients and chlorophyll-a were negative correlation, these indicators can be used as auxiliary indicators in the damage assessment of the thermal discharge for phytoplankton.
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Ferrarezi, Rhuanito Soranz, Ondino Cleante Bataglia, Pedro Roberto Furlani, and Eliana Aparecida Schammass. "Iron sources for citrus rootstock development grown on pine bark/vermiculite mixed substrate." Scientia Agricola 64, no. 5 (October 2007): 520–31. http://dx.doi.org/10.1590/s0103-90162007000500010.
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For high technology seedling production systems, nutrition plays an important role, mainly the fertigation with iron chelates to prevent its deficiency. This study had the goal of searching for alternative iron sources with the same nutrient efficiency but lower cost in relation to nutrient solution total cost. An experiment was carried out in 56 cm³-conic-containers tilled with a pine bark/ vermiculite mixed substrate using Fe-DTPA, Fe-EDDHA, Fe-EDDHMA, Fe-EDTA, Fe-HEDTA, FeCl3, FeSO4, FeSO4+citric acid plus a control, and the rootstocks Swingle, Rangpur, Trifoliata and Cleopatra, in a randomized complete block design, with four replicates. Seedlings were evaluated for height, relative chlorophyll index, total and soluble iron leaf concentrations. Cleopatra was the only rootstock observed without visual iron chlorosis symptoms. There was a low relative chlorophyll index for Rangpur, Swingle and Trifoliata rootstocks in the control plots, in agreement with the observed symptoms. High total iron concentrations were found in the control and Fe-EDTA plots, whereas soluble iron represented only a low percent of the total iron. The economical analysis showed the following cost values of iron sources in relation to the nutrient solution total costs: Fe-HEDTA (37.25%) > FeCl3 (4.61%) > Fe-EDDHMA (4.53%) > Fe-EDDHA (3.35%) > Fe-DTPA (2.91%) > Fe-EDTA (1.08%) > FeSO4+citric acid (0.78%) > FeSO4 (0.25%). However, only plants from Fe-EDDHA and Fe-EDDHMA treatments did not present any deficiency visual symptoms. The relative cost of Fe-EDDHA application is low, its efficiency in maintaining iron available in solution resulted in high plant heights, making it recommendable for citric rootstock production in nurseries.
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Živčák, M., M. Brestič, K. Olšovská, and P. Slamka. "Performance index as a sensitive indicator of water stress in Triticum aestivum L." Plant, Soil and Environment 54, No. 4 (April 11, 2008): 133–39. http://dx.doi.org/10.17221/392-pse.
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Polyphasic chlorophyll α fluorescence represents a promising tool for detection of plant tolerance to various environmental stresses. In pot vegetation experiments, plants of seven winter wheat varieties were screened for their drought tolerance. The drought stress was initiated in plants by withholding water at the beginning of anthesis. While water content was measured continuously as relative water content (RWC), fast chlorophyll α fluorescence kinetics was measured and analysed on dehydrating intact leaves by the JIP-test (analysis of O-J-I-P fluorescence transient). Maximum quantum efficiency of PS II photochemistry (<I>F</I><sub>V</sub><I>/F</I><sub>M</sub>) parameter was almost unaffected by dehydration until the severe water stress occurred. In contrast to this a continuous decrease of performance index (PI<sub>abs</sub>) parameter (Strasser et al. 1995) was observed from the very beginning of dehydration following the decrease of RWC. Statistically significant differences were also found in the PI<sub>abs</sub> parameter among all tested varieties. The results show that PI<sub>abs</sub> may serve as an index of plant/variety vitality and/or sensitivity to water stress reflecting their different drought tolerance.
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Sadar, Nadja, and Angelo Zanella. "A Study on the Potential of IAD as a Surrogate Index of Quality and Storability in cv. ‘Gala’ Apple Fruit." Agronomy 9, no. 10 (October 16, 2019): 642. http://dx.doi.org/10.3390/agronomy9100642.
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The decline of relative chlorophyll contents during fruit ripening is considered to be an important indicator of fruit physiological condition. The recent availability of low-cost portable visible spectrum (VIS) spectrometers has spurred research interest towards optical sensing of chlorophyll changes in intact fruit, with many scientists attempting to link the shifts in optical signals, attributed to chlorophyll changes, to different maturity and quality parameters. One of the widely available portable devices for non-destructive estimation of relative chlorophyll contents is the DA meter, which provides a maturity index that is calculated as a difference between absorption at 670 nm (near the chlorophyll-a absorption peak) and 720 nm (background of the spectrum), abbreviated as IAD. In the present study, the evolution of IAD and its relation to starch pattern index (SPI) and fruit flesh firmness (FFF) was monitored in fruit of two cv. ‘Gala’ clones during maturation and storage, aiming to identify a potential existence of a usable IAD range for the assessment and prediction of the optimal harvest window and storage potential. In both clones, canopy positions, fruit sides, and seasons IAD, SPI, and FFF generally changed in a linear fashion over time, but with partially very different slopes, i.e., they were changing at different rates. What all of these parameters had in common was the presence of a very high biological variability, which is typical of apple fruit. Significantly powerful estimations of SPI (r2 > 0.7, p < 0.005) and pre- and post-storage FFF (r2 > 0.6, p < 0.005) were achieved. However, the very large biological variability could not be neutralized, which means that the predictions always included large confidence intervals of up to 0.46–0.59 units for SPI and 0.82–1.1 kgF FFF, which ultimately makes them unusable for practical applications. Experiments done under real-life conditions in a commercial fruit storage facility on several different fruit batches confirmed that IAD measured at harvest cannot be used indiscriminately for predicting post-storage FFF of cv. ‘Gala’ originating from different orchards. Nevertheless, mean IAD values that were obtained at optimal maturity from samples of the same orchards remained stable over seasons (0.8–1.2), which strongly suggests that, provided that the calibrations and validations are not only cultivar, but also orchard-specific, IAD has a potential for estimating maturity and storability of apple fruit. In this case, IAD could replace standard maturity indices, otherwise it would be suited for use as a supplementary index for determining fruits physiological maturity status.
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Sandmann, Michael, Andreas Garz, and Ralf Menzel. "Physiological response of two different Chlamydomonas reinhardtii strains to light–dark rhythms." Botany 94, no. 1 (January 2016): 53–64. http://dx.doi.org/10.1139/cjb-2015-0144.
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Cells of a cell-wall deficient line (cw15-type) of Chlamydomonas reinhardtii and of the corresponding wild type were grown during repetitive light–dark cycles. In a direct comparison, both lines showed approximately the same relative biomass increase during light phase but the cw-line produced significantly more, and smaller, daughter cells. Throughout the light period the average cellular starch content, the cellular chlorophyll content, the cellular rate of dark respiration, and the cellular rate of photosynthesis of the cw-line was lower. Despite this, several non-cell volume related parameters like the development of starch content per cell volume were clearly different over time between the strains. Additionally, the chlorophyll-based photosynthesis rates were 2-fold higher in the mutant than in the wild-type cells, and the ratio of chlorophyll a to chlorophyll b as well as the light-saturation index were also consistently higher in the mutant cells. Differences in the starch content were also confirmed by single cell analyses using a sensitive SHG-based microscopy approach. In summary, the cw15-type mutant deviates from its genetic background in the entire cell physiology. Both lines should be used in further studies in comparative systems biology with focus on the detailed relation between cell volume increase, photosynthesis, starch metabolism, and daughter cell productivity.
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Ourcival, J. M., M. Méthy, and R. Burgess. "Mise en évidence, par la fluorescence de la chlorophylle, de la variabilité génotypique de la réponse à une contrainte hydrique chez le trèfle blanc (Trifolium repens) et l'ivraie vivace (Lolium perenne)." Canadian Journal of Botany 70, no. 8 (August 1, 1992): 1556–62. http://dx.doi.org/10.1139/b92-196.
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The genotypic variability of six interspecific neighbouring pairs of white clover (Trifolium repens L.) and perennial rye grass (Lolium perenne L.) has been examined in relation to chlorophyll fluorescence and leaf water content. Fluorescence was measured using wavelengths of 690 and 730 nm. The following indices of fluorescence were used: the fluorescence-decrease ratio at the two wavelengths (vitality index), their combination (adaptation index), and the ratio of the fluorescence intensities at 690 and 730 nm. The effect of the type of drought stress applied on leaf cutting and pot planted material was examined. The results show that the first two indices of fluorescence are precocious indicators of drought stress and that they allow to distinguish genetically close individuals. Fluorescence thus provides a mean of ranking genotypes of two species. Key words: fluorescence, vitality index, adaptation index, fluorescence ratio, relative water content.
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Cogato, Alessia, Vinay Pagay, Francesco Marinello, Franco Meggio, Peter Grace, and Massimiliano De Antoni Migliorati. "Assessing the Feasibility of Using Sentinel-2 Imagery to Quantify the Impact of Heatwaves on Irrigated Vineyards." Remote Sensing 11, no. 23 (December 2, 2019): 2869. http://dx.doi.org/10.3390/rs11232869.
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Heatwaves are common in many viticultural regions of Australia. We evaluated the potential of satellite-based remote sensing to detect the effects of high temperatures on grapevines in a South Australian vineyard over the 2016–2017 and 2017–2018 seasons. The study involved: (i) comparing the normalized difference vegetation index (NDVI) from medium- and high-resolution satellite images; (ii) determining correlations between environmental conditions and vegetation indices (Vis); and (iii) identifying VIs that best indicate heatwave effects. Pearson’s correlation and Bland–Altman testing showed a significant agreement between the NDVI of high- and medium-resolution imagery (R = 0.74, estimated difference −0.093). The band and the VI most sensitive to changes in environmental conditions were 705 nm and enhanced vegetation index (EVI), both of which correlated with relative humidity (R = 0.65 and R = 0.62, respectively). Conversely, SWIR (short wave infrared, 1610 nm) exhibited a negative correlation with growing degree days (R = −0.64). The analysis of heat stress showed that green and red edge bands—the chlorophyll absorption ratio index (CARI) and transformed chlorophyll absorption ratio index (TCARI)—were negatively correlated with thermal environmental parameters such as air and soil temperature and growing degree days (GDDs). The red and red edge bands—the soil-adjusted vegetation index (SAVI) and CARI2—were correlated with relative humidity. To the best of our knowledge, this is the first study demonstrating the effectiveness of using medium-resolution imagery for the detection of heat stress on grapevines in irrigated vineyards.
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Szalacsi, Árpád, Gergely Király, and Szilvia Veres. "Seasonal changes of photosynthetical parameters as a results of forest gap model." Acta Agraria Debreceniensis, no. 63 (February 17, 2015): 133–36. http://dx.doi.org/10.34101/actaagrar/63/1848.
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Photosynthetic parameters of English oak (Quercus robur L.) as a member of Querco robori-Carpinetum were investigated in two different habitat in terms of gap forest management: in the gap and in the host forest. The artifical opening process of the forest resulted in more light for growing saplings and need for acclimatization. Photosynthesis is one of the most important way for plant life and plant production. In the centre of photosynthetic efficiency the quality and quantity traits of photosynthetic pigments are standing. During our work some photosynthetic parameters of plants (in the gap and in the forest as well) were measured: relative chlorophyll content as SPAD index, chlorophyll a and b content, total chlorophyll content and ratio of chlorophyll a and b. Based on our results no significant differences among our data in early spring. Although, during the summer significant differences occurred between the measured values in the gap and in the forest area. Lower total chlorophyll content was experienced in the gap, than in the forest area due to the lower chlorophyll-b content. Because of the high light intensity higher chla/chlb ratio was measured in the gap. The lower chlorophyll contents of gap habitat may have a part of the acclimatization process of photosynthetic apparatus against high light stress, which can determinate the survival chance of individual.
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Niu, Zimian, Dapeng Zhang, Jicheng Zhan, and Curt Rom. "(320) Influence of Light Microclimate on the Growth, Yield, and Fruit Quality of Apple." HortScience 40, no. 4 (July 2005): 1037D—1038. http://dx.doi.org/10.21273/hortsci.40.4.1037d.
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Influence of photosynthetically active radiation (PAR) microclimate in the canopy of four training systems [open-center with high trunk (OH); open-center with middle trunk (OM); open-center with low trunk (OL); and a traditional round canopy (RC)] on the growth, yield and fruit quality of apple were studied in the Beijing area. The results showed that: 1) the growth and yield potential were affected by canopy light microclimate. The average leaf chlorophyll content from OH, OM and OL systems was 12.3% to 18.1% greater than that from the RC system. Trees from OH, OM, and OL systems produced 84.2% to 89.7% of shoot forming flower clusters compared to only 47.3% to 50.9% of the RC shoots. Training system did not affect total yield of 8-year-old trees, but in 10-year-old trees the RC system had lower yields compared with open-center systems. 2) Fruit quality was also affected by canopy light microclimate. The average anthocyanin content in the skin of fruit from OH, OM, and OL systems was 35.9% to 46.1% higher than that from the RC system, but chlorophyll content from the OL system was higher than in the open-center systems. Meanwhile, the contents of TSS and esters in apple flesh from the open-center systems were significantly higher than that from the RC system. 3) When the relative value of PAR in canopy exceeded 33.8%, the growth index of trees (chlorophyll: return-bloom ratio) exceeded 66.6% and the fruit quality index (TSS × anthocyanin) exceeded 94.7%. When PAR was less than 20.6%, the growth index was under 37.2% and the fruit quality index was under 67.5%. PAR value was significantly correlated with the growth and fruit quality index in the four training systems, and the total canopy volume of higher PAR(exceeding 33.8%, relative value) from OH, OM, and OL systems was 37.1% to 45.0% greater than that from the RC system.
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Leite, Bruna N., Karla Gabrielle D. Pinto, Victor Alexandre H. F. dos Santos, Marciel J. Ferreira, and Sônia Maria F. Albertino. "Photosynthetic Performance of Guaranazeiro Plants as Affected by Glyphosate Application." Journal of Agricultural Science 12, no. 10 (September 15, 2020): 287. http://dx.doi.org/10.5539/jas.v12n10p287.
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The unsuitable use of herbicides damages many cultures. In cases of high infestations and presence of aggressive weed species in guarana (Paullinia cupana) culture, glyphosate application is advisable, but its impact on guarana physiology is unknown. Therefore, leaf photosynthetic characteristics were measured with the aim of identifying if the photosynthetic performance of guaranazeiro plants is affected in response to glyphosate application. Three glyphosate doses (0 (control); 324 and 432 g a.i. ha-1) were applied to two guaranazeiro cultivars (BRS-Andirá and BRS-Maués) selected on the basis of productive performance. An analysis was made of the effects of these doses on characteristics that represent the photosynthetic process: gas exchange, maximum quantum efficiency of PSII, performance index and chlorophyll content. The application of glyphosate did not affect the short-term responses relative chlorophyll content (SPAD index) and light use (chlorophyll a fluorescence). After 168 h, there were changes only in gas exchange variables. The effects of glyphosate doses on gas exchange was different between guaranazeiro cultivars. The photosynthetic performance of the guaranazeiro seems to be tolerant to the effects of short-term of glyphosate application.
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Argenta, Gilber, Paulo Regis Ferreira da Silva, and Luis Sangoi. "Leaf relative chlorophyll content as an indicator parameter to predict nitrogen fertilization in maize." Ciência Rural 34, no. 5 (October 2004): 1379–87. http://dx.doi.org/10.1590/s0103-84782004000500009.
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The development of a portable chlorophyll meter (SPAD 502), that takes instantaneous measurements of greenness without leaf destruction, has emerged as a new tool to assess plant N status. This trial was carried out to determine the adequate SPAD readings to predict maize nitrogen needs in four growth stages. The experiment was conducted in the state of Rio Grande do Sul, southern Brazil, during the 1998/99 growing season. Treatments were two maize hybrids (Pioneer 32R21 and Cargill 901) and nine side-dressed nitrogen levels (0, 50, 100, 150, 200, 300, 400, 500 and 600kg ha-1). Nitrogen was side-dressed at the soil surface in four equal doses, according to the levels established on each treatment. The first, second, third and fourth applications were made in the stages of three to four, six to seven, 10 to 11 and 14 to 15 fully expanded leaves, respectively. Urea was used as the N source. Since there was no difference in the SPAD readings among maize hybrids, average values at each stage were used. Readings were carried out in the stages of three to four, six to seven, 10 to 11 fully expanded leaves and at silking. Chlorophyll evaluation samples were taken at two-thirds of the distance from the leaf tip towards the stem. The two upper leaves were sampled on each growth stage before maize flowering. The index leaf (first leaf below the ear) was evaluated during silking. Chlorophyll meter readings above 45.4, 52.1, 55.3, and 58.0 represented the adequate values for the stages of three to four, six to seven, 10 to 11 expanded leaves and at silking, respectively, to achieve high grain yield. The variation in SPAD readings were highest in the early stages of plant growth.
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Osório, Júlio, Maria Leonor Osório, and Anabela Romano. "Reflectance indices as nondestructive indicators of the physiological status of Ceratonia siliqua seedlings under varying moisture and temperature regimes." Functional Plant Biology 39, no. 7 (2012): 588. http://dx.doi.org/10.1071/fp11284.
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We investigated the use of spectral reflectance techniques to monitor the physiological responses of Ceratonia siliqua L. seedlings exposed to different levels of water availability under normal (25 : 18°C, day : night) and elevated (32 : 21°C, day : night) temperatures. Three spectral reflectance indices (photochemical reflectance index, PRI; water index, WI; red edge position, REP) were measured along with water status, chlorophyll fluorescence and chlorophyll concentration variables in the leaves of well watered, moderately stressed, severely stressed and rehydrated plants under each temperature regime. The PSII effective photochemical efficiency (φ2) and the intrinsic efficiency of open PSII centres (F′v/F′m) correlated significantly with PRI, and these three variables loaded heavily onto the same principal component of a three-factor principal component analysis solution. Water concentration (WC) and the succulence index (SI) were more strongly correlated with WI than either water potential (ΨPD) or relative water content (RWC). Accordingly, WI, WC and SI were combined in the second principal component, and ΨPD and RWC in the third. Our results provide clear evidence for interaction between water availability and temperature in the WI and the PRI response segments of the reflectance curves. Elevated temperature inhibited the recovery of WI spectral segments more than that of the PRI segments in SS plants. REP showed a strongly positive linear relationship with leaf total chlorophyll concentration across all water and temperature treatment combinations. PRI, WI and REP are therefore reliable markers that can be used to monitor φ2, WC and total chlorophyll concentration, respectively, in C. siliqua seedlings under drought and temperature stress.
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Zhang, Ying, Xiao Hu Zhao, and Cai Juan Li. "Soft Sensing for Algae Blooms Based on Physical-Chemical Factors of Marine Environment." Applied Mechanics and Materials 58-60 (June 2011): 630–35. http://dx.doi.org/10.4028/www.scientific.net/amm.58-60.630.
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Soft sensing can solve the problem of on-line measuring for some variables which are difficult to measure with common instruments commendably. Chlorophyll-a is an important index of water quality for seawater, which can indicate the state of algae reproduction, further more it can predict the disaster of red tide by prediction model. The content of chlorophyll-a of seawater is affected by many physical-chemical factors, this complex relationship among them is difficult to be described by ordinary mechanism expression. In this paper, we use Fuzzy BP model to describe this complex nonlinear system, and detect the content of chlorophyll-a by the method of soft sensing. The PCA(Principal Component Analysis) method had been used to reduce the dimension of the sample data, simplify the complexity of the model system, this method can make the model has a faster convergence rate and a relative low dimension. The experiment illustrates that the result of soft sensing for algae blooms can match the real changes of the content of chlorophyll-a in seawater basically.
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Quadros, Bárbara Rodrigues de, Edvar De Sousa da Silva, Luciana Da Silva Borges, Claudia De Araújo Moreira, Adriana Lima Moro, and Roberto Lyra Villas Bôas. "DOSES DE NITROGÊNIO NA PRODUÇÃO DE RABANETE FERTIRRIGADO E DETERMINAÇÃO DE CLOROFILA POR MEDIDOR PORTÁTIL NAS FOLHAS." IRRIGA 15, no. 4 (December 20, 2010): 353–60. http://dx.doi.org/10.15809/irriga.2010v15n4p353.
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A determinação do teor relativo de clorofila por meio do clorofilômetro é utilizada para predizer a necessidade de adubação nitrogenada visando incrementar a produção em várias culturas. Este trabalho objetivou avaliar a resposta de doses de nitrogênio adicionadas ao solo via fertirrigação na produção de rabanete e a relação de clorofila com o teor de nitrogênio foliar da cultivar Redondo Vermelho. O delineamento experimental foram blocos casualizados, com cinco tratamentos (0; 30; 60; 120; 240 kg N ha-1) , cinco repetições, com dois vasos por parcela contendo quatro plantas em cada vaso, sendo duas úteis. Foram avaliados o diâmetro transversal da raiz, área foliar, índice de cor verde, teor de N foliar, a produção da parte aérea; número de raízes comerciais e não comerciais; massa de raízes total e comercial. As doses de N não interferiram na produção do rabanete e as leituras efetuadas com medidor portátil de clorofila não são muito precisas na verificação do nível de N no desenvolvimento da planta de rabanete. UNITERMOS: Raphanus sativus, adubação nitrogenada, clorofilômetro. QUADROS, B.R.; SILVA, E.S.; BORGES, L.S.; MOREIRA, C.A.; MORO, A.L.; VILLAS BÔAS, R.L. NITROGEN LEVELS ON FERTIGATED RADISH PRODUCTION AND CHLOROPHYLL DETERMINATION BY LEAVES PORTABLE METER 2 ABSTRACT The relative chlorophyll determination is used to predict the need for nitrogen fertilization aiming to increase production in various cultures. The objective of this study was to evaluate the soil nitrogen dose response added to the soil via fertigation in radish production and the relation between chlorophyll and cultivar Redondo Vermelho leaf nitrogen content. Transverse diameter of root, leaf area, green index, leaf N contents, shoots (stem) production, number of commercial and noncommercial roots, and the total commercial mass roots were evaluated. The N doses didn’t interfere in the radish production and the readings taken with portable chlorophyll meter are not very accurate in ascertaining the level of N on radish plant growth. Keywords: Raphanus sativus, nitrogen fertilization, chlorophyll.
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Gao, Yu-Fu, Li-Ping Rong, Dong-Hui Zhao, Jia-Qi Zhang, and Jia-Shuo Chen. "Effects of simulated acid rain on the photosynthetic physiology of Acer ginnala seedlings." Canadian Journal of Forest Research 51, no. 1 (January 2021): 18–24. http://dx.doi.org/10.1139/cjfr-2020-0091.
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Extensive areas in China have been receiving high levels of acid rain. Acid rain affects plant growth by reducing the chlorophyll content, destroying leaf structure, and hindering photosynthesis. Acer ginnala Maxim. has a high economic, ornamental, and medicinal value. To clarify the acid rain resistance mechanism of maple trees, the chlorophyll content, gas exchange parameters, and chlorophyll fluorescence parameters were measured in the leaves of 2-year-old Acer ginnala seedlings 0, 15, and 30 days after simulated acid rain at pH 5.6, 5.0, 4.5, 4.0, 3.5, and 2.5. The results showed that the relative content of chlorophyll gradually decreased with the increasing acidity. The net photosynthetic rate (Pn) decreased with the increasing acidity, and the difference among the treatments was significant except for between pH 5.0 and the control. The stomatal conductance at pH < 5.0 was significantly lower than that of the control, and the intercellular carbon dioxide (CO2) concentration of the leaves with the pH < 4.5 treatments was significantly lower than that of the control. As the acidity increased, both Fv/Fm and Fv/F0 (Fv, variable fluorescence; Fm, maximum fluorescence; F0, initial fluorescence) decreased. The difference in the photosynthetic performance index based on the absorbed light energy (PIabs) between the pH 5.0 treatment and the control was not significant during the three periods after the simulated acid rain stress, whereas in the other treatments, this index was significantly lower than that of the control. Our results indicated that under mild acid rain (pH > 4.0) stress, the chlorophyll content, gas exchange parameters, and chlorophyll fluorescence parameters of Acer ginnala changed little, whereas in the other treatments, especially the severe acid rain (pH < 3.0) treatment, these indices showed significant changes that had a severe impact on plant growth and development.
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Dranski, João Alexandre Lopes, Ubirajara Contro Malavasi, and Marlene De Matos Malavasi. "Estimating chlorophyll content from Eucalyptus dunnii leaves by reflectance values." Semina: Ciências Agrárias 37, no. 3 (June 22, 2016): 1277. http://dx.doi.org/10.5433/1679-0359.2016v37n3p1277.
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This study aimed to estimate photosynthetic pigments contents from leaves of Eucalyptus dunni Maiden based on values of reflectance spectra of red, green and blue colors obtained with a digital color analyzer. We collected fifty leaves from the lower third of the crown of twenty trees including young as well as mature leaves. From each leaf an area of 14 cm2 of the leaf blade was cut in which we measured reflectance values on the red, green and blue spectra with a portable digital colorimeter, obtained relative index of chlorophyll with a SPAD – 502 and determined the content of the chlorophyll a, b, and a + b by classic method of solvent extraction. We submitted the data to multiple linear regression and nonlinear analysis at 5% of error probability. It was evaluated the occurrence of multicollinearity. The negative exponential model resulted in good fit when data from red spectrum was used for chlorophyll a, green spectrum for chlorophyll b and a + b, making possible correlation coefficients between the estimated values and the extracted above 0.85. Except for the chlorophyll a content, the accuracy in estimates of photosynthetic pigments were higher than estimated by the chlorophyll meter, even with linearity between methods. Therefore, it is possible to estimate photosynthetic pigments on E. dunni leaves through values of red and green wavelengths from a digital color analyser.
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Lima, Geovani S. de, Jailson B. da Silva, Leandro de P. Souza, Reginaldo G. Nobre, Lauriane A. dos A. Soares, and Hans R. Gheyi. "Tolerance of precocious dwarf cashew clones to salt stress during rootstock formation stage." Revista Brasileira de Engenharia Agrícola e Ambiental 24, no. 7 (July 2020): 474–81. http://dx.doi.org/10.1590/1807-1929/agriambi.v24n7p474-481.
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ABSTRACT This study was conducted to evaluate the tolerance of precocious dwarf cashew clones to irrigation with waters of different salinity levels during rootstock formation. The experimental design consisted of randomized blocks, arranged in a 5 x 3 factorial scheme, corresponding to five levels of electrical conductivity of irrigation water (0.4; 1.2; 2.0; 2.8 and 3.6 dS m-1) and three clones of precocious dwarf cashew (Faga 11, Embrapa 51, CCP 76), with three replicates. Water salinity above 0.4 dS m-1 inhibited chlorophyll synthesis and growth, but led to cashew seedlings with the Dickson Quality Index (DQI) higher than the acceptable limit. Based on the relative yield of the total dry mass, the clones Faga 11, Embrapa 51 and CCP 76, at the highest salinity level studied, were classified as moderately sensitive, sensitive and moderately tolerant, respectively. There was interaction between water salinity and precocious dwarf cashew clones for chlorophyll a content, chlorophyll b content and DQI at 75 days after sowing.
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Khadka, Kamal, Andrew J. Burt, Hugh J. Earl, Manish N. Raizada, and Alireza Navabi. "Does Leaf Waxiness Confound the Use of NDVI in the Assessment of Chlorophyll When Evaluating Genetic Diversity Panels of Wheat?" Agronomy 11, no. 3 (March 5, 2021): 486. http://dx.doi.org/10.3390/agronomy11030486.
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Ground and aerial-based high throughput phenotyping platforms (HTPPs) to evaluate chlorophyll-related traits have been utilized to predict grain yield in crops including wheat (Triticum aestivum L.). This study evaluated chlorophyll-related and other physiological and yield traits in a panel of 318 Nepali spring wheat genotypes, termed the Nepali Wheat Diversity Panel (NWDP). Field experiments were conducted using an alpha-lattice design in Nepal and Canada. Chlorophyll-related traits were evaluated with a Soil Plant Analysis Development (SPAD) meter and the normalized difference vegetation index (NDVI) using a handheld GreenSeeker and an Unmanned Aerial Vehicle (UAV). Relative leaf epicuticular waxiness was recorded using visual assessments. There was a significant positive association (p < 0.001) between waxiness and SPAD-based chlorophyll estimates, and both of these traits displayed a significant positive relationship with grain yield. However, unexpectedly, NDVI derived from both GreenSeeker and UAV was negatively associated with waxiness and grain yield. The results obtained after segregating the trait means into groups based on waxiness scores and breeding history of genotypes indicated that waxiness along with precipitation could be affecting the multispectral reflectance. These results suggest that caution should be taken when evaluating a large and diverse wheat population for leaf chlorophyll using high-throughput NDVI methods.
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Lima, Gilmar Cotrin de, Mariangela Hungria, Marco Antonio Nogueira, Marcelo Carvalho Minhoto Teixeira Filho, Adônis Moreira, Reges Heinrichs, and Cecilio Viega Soares Filho. "Yield, yield components and nutrients uptake in Zuri Guinea grass inoculated with plant growth-promoting bacteria." International Journal for Innovation Education and Research 8, no. 4 (April 1, 2020): 103–24. http://dx.doi.org/10.31686/ijier.vol8.iss4.2268.
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The objective of this study was to evaluate the effects of strains of Azospirillum brasilense, Pseudomonas fluorescens and Rhizobium tropici on biomass yield and nutrients uptake of shoots and roots of Megathyrsus (syn. Panicum) maximus cultivar BRS Zuri (Zuri Guinea grass) inoculated with plant growth-promoting bacteria (PGPB). Treatments consisted of inoculation and re-inoculation with A. brasilense strains Ab-V5 and Ab-V6, P. fluorescens strain CCTB 03 and of co-inoculation with R. tropici strain CIAT 899 + A. brasilense Ab-V6, with or without N-fertilizer (100 mg dm-3). Evaluations were performed on three cuts for the determination of root and shoot dry weight yield, morphological compositions, tiller mass, number of tillers, and nutrient uptake. Inoculation with bacteria in association with N-fertilizer increased N, NH4+, Ca, Fe, Mn and Zn accumulation in shoots and P and K uptake in roots. P. fluorescens and co-inoculation with R. tropici CIAT 899 + A. brasilense Ab-V6 increased the relative chlorophyll index in relation to the non-inoculated control. As expected, PGPB were not able to fully replace N-fertilization. However, when combined with N-fertilizer, the PGPB increased yield, the relative chlorophyll index, and the uptake of N, NH4+, Ca, Zn, Mn and Fe of Zuri Guinea grass. The results indicate that PGPB can represent a sustainable alternative for reducing the use of N-fertilizers. There were no effects of re-inoculation with PGPB on the nutrition or yield of Zuri Guinea grass, demonstrating that the determination of the method of application and periodicity of inoculation still require investigation.
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Silva, Marcelo de A., John L. Jifon, Jorge A. G. da Silva, and Vivek Sharma. "Use of physiological parameters as fast tools to screen for drought tolerance in sugarcane." Brazilian Journal of Plant Physiology 19, no. 3 (September 2007): 193–201. http://dx.doi.org/10.1590/s1677-04202007000300003.
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Drought is one of the major limitations to plant productivity worldwide. Identifying suitable screening tools and quantifiable traits would facilitate the crop improvement process for drought tolerance. In the present study, we evaluated the ability of four relatively physiological parameters (variable-to-maximum chlorophyll a fluorescence ratio, F v/F m; estimated leaf chlorophyll content via SPAD index; leaf temperature, LT; and, leaf relative water content, RWC) to distinguish between drought tolerant and susceptible sugarcane genotypes subjected to a 90-d drought cycle. Eight field-grown genotypes were studied. By 45 d after the onset of treatments, the F v/F m, SPAD index and RWC of drought-stressed plants had declined significantly in all genotypes compared to values at the onset of well-watered treatments. However, the reductions were more severe in leaves of susceptible genotypes. Under drought stress, the tolerant genotypes as a group, maintained higher F v/F m (8%), SPAD index (15%), and RWC (16%) than susceptible genotypes. In general, LT of drought-stressed plants was higher (~4ºC) than that of well-watered plants but the relative increase was greater among drought susceptible genotypes. Under drought stress, LT of tolerant genotypes was on average 2.2ºC lower than that of susceptible genotypes. The results are consistent with the tolerant-susceptible classification of these genotypes and indicate that these tools can be reliable in screening for drought tolerance, with F v/F m, SPAD index and LT having the added advantage of being nondestructive and easily and quickly assessed.
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Salmi, Manel, Amar Benmahammed, Laid Benderradji, Zine El Abidine Fellahi, Hamenna Bouzerzour, Abdelmalek Oulmi, and Abdelkader Benbelkacem. "Generation means analysis of physiological and agronomical targeted traits in durum wheat (Triticum durum Desf.) cross." Revista Facultad Nacional de Agronomía Medellín 72, no. 3 (September 1, 2019): 8971–81. http://dx.doi.org/10.15446/rfnam.v72n3.77410.
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Genetic parameters such as leaf relative water content, leaf chlorophyll content, plant height, above-ground biomass, harvest index, grain yield, and grain yield components of Bousselam/Mrb5 durum wheat (Triticum durum Desf.) cross were estimated based on generation means analysis. A, B, C, and D scaling and Chi-square (χ2) tests revealed the inadequacy of the simple additive-dominance model. This result suggests the presence of digenic epistasis for most studied traits; the duplicate epistasis was present for relative water content, above-ground biomass, and grain yield; and complementary epistasis was observed for chlorophyll content. Significant genotypic correlation coefficients appeared among grain yield, relative water content, and above-ground biomass. This suggests useful indirect selection criteria to improve simultaneously these traits, which showed significant heritability. It can be concluded that the traits investigated show a complex genetic behavior, which implies that early selection would be less efficient; therefore, it is recommended delaying the selection to advanced generations to benefit from the reduction of non-fixable genetic variation and exploit transgressive segregators due to the significant interaction additivity×additivity (i) of the gene and duplicated epistasis.