Parameters Leaf Area Research Articles

How to better estimate leaf area index and leaf angle distribution from digital hemispherical photography? Switching to a binary nonlinear regression paradigm

Abstract Probabilistic modelling of gaps for light–canopy interactions has long served as a theoretical basis to estimate vegetation structural parameters—leaf area index (LAI) and leaf angle distribution (LAD)—from optical measurements such as hemispherical photos. Direct inversion of such probabilistic models provides a reliable statistical algorithm for parameter estimation, but this inferential paradigm has been seldom explored. Even worse, many classical LAI algorithms implicitly assume “wrong” statistical models inconsistent with the underlying probabilistic gap models—a subtle issue not articulated before but known to cause practical issues. Here, we clarified how to improve LAI and LAD estimation by directly inverting binary gap/non‐gap data of hemispherical photos via binary nonlinear regression (BNR). We implemented the new BNR method and some classical algorithms in an R package “hemiphoto2LAI”, comprising a total of 135 models for LAI estimation. Compared to classical algorithms, BNR features many theoretical advantages and allows estimating LAI and LAD simultaneously. BNR can address questions difficult to answer by classical algorithms (e.g. how better is one LAD than another?). We demonstrated the utility of the BNR paradigm based on both synthetic and real data. Overall, BNR is statistically more justifiable but its potential has been under‐appreciated. We encourage the community to embrace this new paradigm for reliable analyses of hemispherical photos or other gap data for canopy research.

Soil Amendment with Raw Garlic Stalk: A Novel Strategy to Stimulate Growth and the Antioxidative Defense System in Monocropped Eggplant in the North of China

Garlic (Allium Sativum L.) is a vegetable with known medicinal value. It is not only rich in nutrients, but also has the ability to combat different microbial infections. This is, however, the first study to investigate the effect of soil incorporation of the raw garlic stalk (RGS) on the growth and antioxidative defense system of eggplant. The experiments were conducted in pots using soil amendments of RGS in different ratios (RGS1 1:100; RGS2 3:100; RGS3 5:100 and control (CK) 0:100 of RGS: Soil w/w) and repeated in two consecutive years (2016 and 2017). A dose-dependent response of RGS amendment was observed in the growth and physiology of the eggplant. RGS1 and RGS2 significantly enhanced the plant height, root/shoot weight, stem diameter, leaf area, root length, root activity, pigment contents (chlorophyll a, chlorophyll b, and total chlorophyll), and photosynthetic parameters, but reduced intracellular CO2 (Ci) and enhanced fruit yield as compared with the respective controls. Consistently, RGS also enhanced activities of antioxidative enzymes of eggplant reported as a defense against stress indicators. RGS in its higher ratios (RGS3), however, caused a reduction in all of the growth and physiological parameters and increased stress indicators such as hydrogen peroxide (H2O2) and malondialdehyde (MDA). Overall, RGS2 was found to be the most efficient for regulation of plant defense systems, reducing H2O2 and MDA and enhancing superoxide dismutase (SOD), peroxidase (POD), and phenylalanine ammonia–lyase (PAL) activity. It can be concluded that the appropriate ratio of RGS could efficiently promote plant growth and regulate the reactive oxygen-based plant defense system.

Salt acclimation in sorghum plants by exogenous proline: physiological and biochemical changes and regulation of proline metabolism.

Mitigation of deleterious effects of salinity promoted by exogenous proline can be partially explained by changes in proline enzymatic metabolism and expression of specific proline-related genes. Proline accumulation is a usual response to salinity. We studied the ability of exogenous proline to mitigate the salt harmful effects in sorghum (Sorghum bicolor) leaves. Ten-day-old plants were cultivated in Hoagland'snutrient solution in either the absence or presence of salinity (NaCl at 75mM) and sprayed with distilled water or 30mM proline solution. Salinity deleterious effects were alleviated by exogenous proline 14 days after treatment, with a return in growth and recovery of leaf area and photosynthetic parameters. Part of the salinity response reflected an improvement in ionic homeostasis, provided by reduction in Na+ and Cl- ions and increases in K+ and Ca2+ ions as well as increases of compatible solutes. In addition, the application of proline decreased membrane damage and did not increase relative water content. Proline-treated salt-stressed plants displayed increase in proline content, a response counterbalanced by punctual modulation in proline synthesis (down-regulation of Δ1-pyrroline-5-carboxylate synthetase activity) and degradation (up-regulation of proline dehydrogenase activity) enzymes. These responses were correlated with expression of specific proline-related genes (p5cs1 and prodh). Our findings clearly show that proline treatment results in favorable changes, reducing salt-induced damage and improving salt acclimation in sorghum plants.

Simulated projections of boreal forest peatland ecosystem productivity are sensitive to observed seasonality in leaf physiology†.

We quantified seasonal CO2 assimilation capacities for seven dominant vascular species in a wet boreal forest peatland then applied data to a land surface model parametrized to the site (ELM-SPRUCE) to test if seasonality in photosynthetic parameters results in differences in simulated plant responses to elevated CO2 and temperature. We collected seasonal leaf-level gas exchange, nutrient content and stand allometric data from the field-layer community (i.e., Maianthemum trifolium (L.) Sloboda), understory shrubs (Rhododendron groenlandicum (Oeder) Kron and Judd, Chamaedaphne calyculata (L.) Moench., Kalmia polifolia Wangenh. and Vaccinium angustifolium Alton.) and overstory trees (Picea mariana (Mill.) B.S.P. and Larix laricina (Du Roi) K. Koch). We found significant interspecific seasonal differences in specific leaf area, nitrogen content (by area; Na) and photosynthetic parameters (i.e., maximum rates of Rubisco carboxylation (Vcmax25°C), electron transport (Jmax25°C) and dark respiration (Rd25°C)), but minimal correlation between foliar Na and Vcmax25°C, Jmax25°C or Rd25°C, which illustrates that nitrogen alone is not a good correlate for physiological processes such as Rubisco activity that can change seasonally in this system. ELM-SPRUCE was sensitive to the introduction of observed interspecific seasonality in Vcmax25°C, Jmax25°C and Rd25°C, leading to simulated enhancement of net primary production (NPP) using seasonally dynamic parameters as compared with use of static parameters. This pattern was particularly pronounced under simulations with higher temperature and elevated CO2, suggesting a key hypothesis to address with future empirical or observational studies as climate changes. Inclusion of species-specific seasonal photosynthetic parameters should improve estimates of boreal ecosystem-level NPP, especially if impacts of seasonal physiological ontogeny can be separated from seasonal thermal acclimation.

Exogenous Melatonin Counteracts NaCl-Induced Damage by Regulating the Antioxidant System, Proline and Carbohydrates Metabolism in Tomato Seedlings.

Melatonin, a natural agent, has multiple functions in animals as well as in plants. However, its possible roles in plants under abiotic stress are not clear. Nowadays, soil salinity is a major threat to global agriculture because a high soil salt content causes multiple stresses (hyperosmotic, ionic, and oxidative). Therefore, the aim of the present study was to explore: (1) the involvement of melatonin in biosynthesis of photosynthetic pigments and in regulation of photosynthetic enzymes, such as carbonic anhydrase (CA) and ribulose-1,5-bisphosphate carboxylase/oxygenase (Rubisco); (2) the role of melatonin in osmoregulation by proline and carbohydrate metabolism; and (3) the function of melatonin in the antioxidant defense system under salinity. Outcomes of the study reveal that under non-saline conditions, application of melatonin (20 and 50 µM) improved plant growth, viz. shoot length, root length, shoot fresh weight (FW), root FW, shoot dry weight (DW), root DW and leaf area and physio-biochemical parameters [chlorophyll (Chl) a and b, proline (Pro) and total soluble carbohydrates (TSC) content, and increased the activity of CA and Rubisco]. However, tomato seedlings treated with NaCl exhibited enhanced Chl degradation, electrolyte leakage (EL), malondialdehyde (MDA) and reactive oxygen species (ROS; superoxide and hydrogen peroxide). ROS were detected in leaf and root. Interestingly, application of melatonin improved plant growth and reduced EL, MDA and ROS levels through upregulation of photosynthesis enzymes (CA, Rubisco), antioxidant enzymes (superoxide dismutase, catalase, glutathione reductase and ascorbate reductase) and levels of non-enzymatic antioxidants [ascorbate (ASC) and reduced glutathione (GSH)], as well as by affecting the ASC—GSH cycle. Additionally, exogenous melatonin also improved osmoregulation by increasing the content of TSC, Pro and Δ1-pyrroline-5-carboxylate synthetase activity. These results suggest that melatonin has beneficial effects on tomato seedlings growth under both stress and non-stress conditions. Melatonin’s role in tolerance to salt stress may be associated with the regulation of enzymes involved in photosynthesis, the antioxidant system, metabolism of proline and carbohydrate, and the ASC—GSH cycle. Also, melatonin could be responsible for maintaining the high ratios of GSH/GSSG and ASC/DHA.

Growth Response and Crop Production (Brassica Juncea L.) Against Watering Time Interval at Various Hydroponics Media

This study aims to determine the Response Growth and Production of Crops (Brassica juncea L.) Against Watering Time Interval In Various Hydroponics Media. The research was conducted at the experimental gardens of Faculty of Agriculture, Faculty of Agriculture, University of Medan Area, located on No. Pond Street. 1 Medan Estate. This research was conducted from October 2013 until December 2013. The design used was RAL Factorial, with 2 replications, 10 combinations. The first factor of the hydroponic planting medium is: M1: Frying Roots, M2: Coconut Coir Powder, M3: Fryer Seal, M4: Rokwool, and M5: Sawdust, the second factor is the time interval: I1: 3 hours a day I2: 5 hours a day, starting from 08:00 a.m to 06:00 p.m. The result of this research indicates that the treatment of watering liquid fertilizer with different time interval does not show a real effect on the growth of mustard plants, Media treatment used on hydroponic systems have an influence very evident on the parameters of plant height, leaf number, leaf area, production weight and significant effect on leaf level parameters, influential planting medium and have the best number is M3 (fuel husk). Interaction interval of watering time on various hydroponic media did not have a significant effect on observed parameters, namely: plant height, leaf number, wet weight, and weight of production, while the leaf color parameter had significant effect on leaf width.

Ameliorate the cadmium toxicity in Solanum tuberosum L. plants with selenium and silicon application

The present study aimed to prove the efficiency of Se or Si as relievers of the Cd toxicity in potato plants. Solanum tuberosum plants, Asterix genotype, from in vitro propagation were placed in pots with sand and irrigated with complete nutrient solution for 60 days under six treatments: T1: Control (nutrient solution); T2: 2.5 µM Se; T3: 2.5 mM Si; T4: 50 µM Cd; T5: 50 µM Cd + 2.5 µM Se; T6: 50µM Cd + 2.5 mM Si. The treatments were arranged in completely randomized design, with four replicates for each treatment and six plants per replicate. The plants were collected at 30 and 60 days after application of the treatments. Cadmium was highly toxic in all parameters (dry and fresh weight, plant height, leaf number, leaf area, root and photosynthetic parameters), in both assessments. However, Se and Si were effective in mitigating Cd toxicity in all parameters, although Si has been shown to be more efficient than Se in dry weight and plant height parameters. Thus, from data obtained in this study, it is clear that the beneficial elements tested have power to ameliorate Cd toxicity.

Development and improvement of the simulation of woody bioenergy crops in the Soil and Water Assessment Tool (SWAT)

Quantifying Populus growth and the impacts on hydrology and water quality are important should it be widely planted. Soil and Water Assessment Tool (SWAT) tree growth algorithms and parameters for hybrid poplar in Midwestern US and cottonwood in Southern US were improved. Tree growth representation led to SWAT2012 code changes including a new leaf area parameter (TREED), new leaf area index algorithm, and leaf biomass algorithm. Simulated hybrid poplar LAI and aboveground woody biomass (PBIAS: 34 - 5%, NSE: 0.51–0.99, and R2: 0.72–0.99), and cottonwood aboveground biomass, runoff, sediment, and nitrate-N (PBIAS: 39 - 11%, NSE: 0.86–0.99, and R2: 0.93–0.99) from the modified SWAT were satisfactory. Improved algorithms, and parameter values and potential ranges for Populus were reasonable. Thus, the modified SWAT can be used for Populus biofeedstock production modeling and hydrologic and water quality response to its growth.

An ecophysiologically based mapping model identifies a major pleiotropic QTL for leaf growth trajectories of Phaseolus vulgaris.

Crop modeling, a widely used tool to predict plant growth and development in heterogeneous environments, has been increasingly integrated with genetic information to improve its predictability. This integration can also shed light on the mechanistic path that connects the genotype to a particular phenotype under specific environments. We implemented a bivariate statistical procedure to map and identify quantitative trait loci (QTLs) that can predict the form of plant growth by estimating cultivar-specific growth parameters and incorporating these parameters into a mapping framework. The procedure enables the characterization of how QTLs act differently in response to developmental and environmental cues. We used this procedure to map growth parameters of leaf area and mass in a mapping population of the common bean (Phaseolus vulgaris L.). Different sets of QTLs are responsible for various aspects of growth, including the initiation time of growth, growth rate, inflection point and asymptotic growth. A major QTL of a large effect was identified to pleiotropically affect trait expression in distinct environments and different traits expressed on the same organism. The integration of crop models and QTL mapping through our statistical procedure provides a powerful means of building a more precise predictive model of genotype-phenotype relationships for crops.

Pertumbuhan dan produksi bayam merah (Amaranthus tricolor L.) dengan pemberian pupuk kandang dan giberelin

The research aimed to study the growth and yield of red spinach as affected by manures and giberelin. This research used monofactor experiment with Completely Randomized Design consist of 7 treatments and 3 replications. The treatments were T0 (control), T1 (GA3 100 ppm and cow manure 6,250 kg / ha), T2 (GA3 200 ppm and cow manure 12,500 kg / ha), T3 (GA3 300 ppm and cow manure 18,750 kg / ha), T4 (GA3 100 ppm and goat manure 3,750 kg / ha), T5 (GA3 200 ppm and goat manure 7,500 kg / ha), T6 (GA3 300 ppm and goat manure 11.250 kg / ha). Observed parameters were plant height, leaf number, leaf area, wet weight and dry weight. The data were processed by analysis of variance and further test with Duncan Multiple Range Test and Contrast Test. The best plant height growth was in the treatment of 18,750 kg / ha of cow manure and 300 ppm gibberellin resulted plant height of 21.11 cm. The highest number of leaves in the treatment of 11,250 kg / ha of goat manure and 300 ppm gibberellin resulted 21.44 leaves. Leaf area (528.79 cm2), fresh weight (68,50 g), and best dry weight (26.97 g) were achieved at 7,500 kg / ha goat manure treatment and 200 ppm giberelin. It was concluded that the application of manure and gibberellin increased plant growth (plant height, leaf number, leaf area), and crop production (fresh weight and dry weight) of red spinach. The combination of goat manure and giberelin was better than cow manure on all parameters. Goat manure of 7,500 kg / ha and 200 ppm gibberellin increased growth and production of red spinach on leaf area parameters, fresh weight, and dry weight. Keywords : red spinach, manure, gibberellin

Symbiotic Response of Drought Tolerant Soybean Varieties, DSR 2 and DSR 12 to Different Arbuscular Mycorrhizal Fungi

Arbuscular mycorrhizal fungi (AMF) are known for symbiotic association with crop plants. A glasshouse experiment was conducted to screen and select the efficient AMF for inoculating two drought tolerant soybean varieties DSR 2 and DSR 12. Screening was done with 10 different species of AMF and plant parameters like plant height, stem diameter, biovolume index, total leaf area, dry biomass, P concentration, and mycorrhizal parameters like root colonization, spore number in the root zone soil were recorded according to the standard procedures. Based on the improved plant parameters viz., plant dry biomass, pod and seed yield, total leaf area and P uptake, it was concluded that Rhizophagus fasciculatus is the best AMF for inoculating DSR 2 variety and Ambispora leptoticha is the best for inoculating DSR 12 variety.

English

English

Динаміка формування площі листя рослин ячменю ярого залежно від впливу норми висіву та позакореневих підживлень

У статті представлені результати досліджень, проведених протягом 2015, 2016 рр. на дослідному полі ХНАУ ім. В. В. Докучаєва щодо впливу норм висіву і позакореневих підживлень на варіабельність показників площі листя і зміну лінійних розмірів другого листка рослин ячменю ярого. Встановлено, що досліджувані варіанти норми висіву та позакореневих підживлень полімерним добривом «Вуксал» істотно впливали на площу листової поверхні рослин і лінійні розміри другого листка рослин ячменю ярого. Максимальні показники площі листя рослин у досліджувані фази розвитку забезпечувала норма висіву 5,0 і 5,5 млн нас./га. Кращим варіантом позакореневого підживлення посівів ячменю ярого, який забезпечував формування найбільшої площі листя та максимальні лінійні розміри другого листка був варіант дворазового внесення препарату «Вуксал» – у фазу трубкування і колосіння в нормах 1,0 л/га.
 The article presents the results of studies conducted during 2015, 2016. On the experimental field of KHNAU named after V. V. Dokuchaiev concerning the influence of seeding rates and foliar fertilization on the variability of leaf area parameters and changes in the linear dimensions of second leaves of spring barley plants. It was found that the investigated variants of the seeding rate and foliar fertilizing with polymeric fertilizer «Vuksal» significantly influenced the area of the plant leaves and the linear dimensions of the second leaf of the spring barley plants. The maximal parameters of the leaf area of plants in the research phases of development provided a seeding rate of 5,0 and 5,5 million/ha. The best option for foliar top dressing of barley spring crops, which provided the formation of the largest leaf area, and the maximum linear dimensions of the second leaf was a variant of double application of the «Vuksal» – during the time of exit into the tube and earing in doses – 1,0 l/ha.

Growth and yield prediction of Indian mustard using InfoCrop model at Hisar, Haryana

The InfoCrop v.2.0, model was calibrated and validated with the field experimental data having four dates of sowing (Oct 15th& 25th and Nov 5th& 15th) and five nitrogen levels (0, 40, 60, 80 and 100 kg N ha-1) conducted during 2013-15 at Hisar (29°10È N and 75°46È E). The model performance was evaluated using RMSE, MAE and MBE and it was observed that InfoCrop model could predict the growth parameters leaf area index, nitrogen uptake, biomass and seed yield with reasonably good accuracy.

Traffic effects on soil compaction and sugar beet (Beta vulgaris L.) taproot quality parameters

Soil compaction is a critical issue in agriculture having a significant influence on crop growth. Sugar beet (Beta vulgaris L.) is accounted as a crop susceptible to compaction. Reduction of leaf area, final yield, and root quality parameters are reported in compacted soils. The most obvious visual indicator of topsoil compaction is root depth affected by agricultural tractor and machinery traffic up on the soil. Such indicators are mainly correlated to initial soil condition, tyre features, and number of passages. Monitoring and controlling frequency and position of machine traffic across the field, in such a way that passages are completed on specific, well-defined tracks, can assist with minimization of compaction effects on soil. The objective of the present work was to analyze the subsoil compaction during the growing period of sugar beet with different farming approaches including controlled traffic passages and random traffic. To this end, tests were carried out following each agro technical operation using penetrometer readings in order to monitor the state of cone-index after each step. In addition, at the harvesting time, root quality parameters were analyzed with particular attention to length and regularity of the taproot, total length, circumference, mass, and above-ground biomass. Such parameters were usefully implemented in order to evaluate the effects of controlled traffic passages compared to the random traffic in a cultivation of sugar beet. Results highlight how an increase in crop yield, derived from samples monitored, higher than 10% can be expected with implementation of a careful traffic management.

Penggunaan Limbah Baglog Tiram dan Jenis Nutrisi Terhadap Pakcoy Pada Hidroponik Substrat

<p>The increase of oyster mushroom farmers in wonogiri will be impact immediately on increasing waste baglog. One of the utilization is to be medium on hydroponic substrate for growing mustard greens and it will combined with charcoal and various types of nutrients. The research was conducted from October to December 2015 at the Greenhouse C and Laboratory EMPT UNS.the research employed completely random design (CRD) with two factor that is ratio of medium and various types of nutrients. The result of research showed that interaction between ratio of medium and various types affected significantly the parameters of leaf area, leaf fresh weight and leaf biomass. Root fresh weight, root volume, root length and root biomass is only influenced by the type of nutrition with the ab mix is the most good in improving and supplying nutrients</p>

English

English

Effect of the Hydric Factor and Arbuscular Mycorrhizal Fungi (AMF) on the Severity of <i>Phytophthora colocasiae</i>

Colocasia esculenta (L.) Schott is an important food for millions of people in countries of Africa, Asia and Central America. The cultivation of taro suffers from an epidemic disease, the taro mildew, caused by P. colocasiae, which is a disease that manifests itself as oily and circular spots on tubers, stems, petioles and on taro leaves causing losses of more than 50% in less than ten days. This study was carried out to evaluate the impact of this pathogen on the leaf area parameter in two varieties of taro (Ibo coco and Atangana) at different water levels, then evaluate the incidence of the disease severity on the leaves at different water levels and study the behavior of this pathogen on plants previously inoculated with arbuscular mycorrhizal fungi (AMF) of the genus Gigaspora magarrita and Acaullospora tuberculata. The plants were separated into three batches (control batch not infected, batch infected with pathogen and batch not only infected but also inoculated with AMF at different water contents (500 ml, 370 ml, 250 ml and 125 ml), the batch infected with the pathogen alone showed a reduction in the growth parameters compared to the control, and the inoculated and infected batch also showed a reduction in growth parameters but closer to the control. In addition, the speed of propagation of the lesion in the inoculated batch is reduced compared to that of the uninoculated batch, and this speed also decreases with the water content, as a result of which the mildew of taro develops easily. Moreover, the addition of AMF makes it possible to minimize its propagation.

A biophysical representation of seagrass growth for application in a complex shallow-water biogeochemical model

Seagrasses are a critical component of the healthy functioning of many coastal marine ecosystems. Capturing the dynamics of seagrass communities requires both a detailed representation of processes such as seagrass nutrient uptake and photosynthesis, as well as models of light penetration, water column and sediment biogeochemical processes and other ecosystem characteristics that determine the environmental state. Here we develop a new two-state, 13-parameter seagrass model with the aim of providing sufficient detail to represent light and nutrient limitation, but simple enough to be coupled into a 60 state variable biogeochemical model. The novel formulation is built around a nitrogen-specific leaf area parameter, Ω, that is well-constrained and is used in calculating both the rate of photosynthesis and the fraction of the seafloor covered by seagrass, Aeff, where Aeff=1−exp(−ΩSGA) and SGA is the aboveground areal seagrass biomass. The model also contains terms for the uptake of nutrients from multiple layers of varying-porosity sediments, translocation of organic matter between leaves and roots, respiration and simple mortality terms. The model is applied to Gladstone Harbour, a macro-tidal sub-tropical estuary in northeast Australia, and is able to simulate realistic spatial seagrass distributions. A simplified form of the model is derived, which can be used to predict seagrass light-limited growth based on five measurable species-specific parameters (maximum growth rate, mortality rate, compensation irradiance, leaf blade angle and nitrogen-specific leaf area). The steady-state percent coverage of seagrass achieved at varying light levels and mortality intensity is calculated as a means of understanding the dynamics of the new seagrass model.

Crescimento de crambe na presença ou ausência de competição interespecífica

RESUMOCrambe (Crambe abyssinica) has a cropping cycle of around 90 days, being suitable as an alternative to the second grain crop planted after soybean is harvested in the Center West region of Brazil. It is necessary to understand the growth and development dynamics of crambe plants in order to allow correct management of the production factors. This study aimed to describe the growth and development parameters of crambe plants under presence or absence of interspecific competition. The experiment was installed in the fall-winter 2011 in an Oxisoil, in completely randomized blocks design with three replications. Treatments comprised crambe plants growing either in presence or absence of interspecific simulated competition, throughout the cropping cycle. Plants were collected for the growth analysis every 15 days from harvest until 75 days after emergence. Growth parameters leaf area (AF), dry mass of stems/culms (MSC), leaves (MSF) and total (MST) dry mass, leaf area index (IAF), absolute (TCA) and relative (TCR) growth rates, net assimilation rate (TAL), specific leaf area (AFE), leaf area duration (DAF), leaf area ratio (RAF) and leaf mass ratio (RMF) were determined for the crop plants, subjected or not to competition, as well as for the simulated competitor. Crambe is a low competitive crop, being the competition more severe until 60-70 days after emergence. Besides, crop performance under field conditions was properly described by the net assimilation rate (TAL), which is also affected by the leaf area duration (DAF) and leaf mass ratio (RMF).