Plant Relative Growth Rate Research Articles

Drought and mycorrhizal inoculation affect growth and morphology of Australian stormwater biofilter plants

This study evaluated the effect of mycorrhizal inoculation on six common Australian biofilter plant species using a pot experiment. We divided 120 pots planted with six common biofilter species into four treatments: control water-deficit, inoculated water-deficit, control well-watered, and inoculated well-watered. Inoculated treatments were inoculated with a commercially available blend of arbuscular mycorrhizal fungi spores. While well-watered pots were watered to pot capacity daily, water-deficit pots were subjected to a simulated drought that lasted six weeks until harvesting. All plants inoculated with arbuscular mycorrhizal fungi developed greater total root surface area, plant biomass, and plant relative growth rate. Which are associated with better stormwater nutrient removal. Mycorrhizal inoculation also increased the average root diameter, total length, and surface area of thick roots (diameter > 1 mm) of six species, which are essential to maintain the infiltration rates and hydraulic functions of biofilter systems. Moreover, an increase in shoot biomass following inoculation was also observed across six species, potentially contributing to higher water loss and stormwater volume reduction. Although the water-deficit condition greatly limited the effects of mycorrhizal inoculation on other morphological traits, we still observed the benefits of inoculation on total root length and surface area in well-watered J. pallidus and C. appressa. As drought stress imposes limitations on the effects of inoculation, we recommend inoculation should be carried out in advantageous times, such as during wet periods before the drought season for the optimal colonization and plant biomass and morphological responses. Additionally, selecting mycorrhizae-responsive species like C. appressa, J. pallidus, and G. sieberiana can result in favorable outcomes.

Interactions between leaf traits and environmental factors help explain the growth of evergreen and deciduous species in a subtropical forest

It is well known that evergreen and deciduous species possess different functional traits and utilize different strategies in growth and adaptation to environments. However, little work has been done to elucidate whether leaf habits mediate the effect of trait-environment interactions on plant performance. In this study, our subjective was to illuminate whether relative growth rate of deciduous and evergreen species is influenced by multiple trait-environment interactions. We conducted measurements on eight leaf traits of 1230 individuals belonging to 25 species in a subtropical evergreen and deciduous broad-leaved mixed forest. Additionally, we collected data on topographic factors, edaphic variables and competition index. Subsequently, we employed generalized linear mixed model to analyze plant relative growth rate, considering high-order trait-environment interactions for both evergreen and deciduous species. We also visualized the effects of these interactions on growth patterns. Our results showed that leaf habits were divided by trait PC1 (41.8%) which was related to leaf lifespan and resource acquisition. Evergreen species tended to have greater interspecific variation compared to deciduous species. Notably, the inclusion of trait-environment interactions significantly improved growth predictions for both leaf habits, although explanatory power of deciduous models was always higher than that of evergreen species. Furthermore, we observed variability in the effects of trait-environment interactions on plant performance varied between leaf habits, leading to different optimal models for each leaf habit, even when they shared similar trait-environment context. These results indicated that difference of life history strategies between leaf habits could be reflected by trait-environment interactions. We emphasized the importance of leaf habits in explaining forest productivity and functions, and future research should focus on the effects of leaf habits on other demographic metrics to understand species coexistence in mixed forests.

Is soilless agriculture feasible for hybrid seed production in tomato (Solanum lycopersicum L.)?

Hydroponics and aeroponics are advanced techniques for cultivating plants under controlled conditions without soil in polyhouses to address soil-related problems. An experiment was designed to evaluate the potentiality of soilless methods over conventional soil-based methods for hybrid seed production of tomatoes. For initial standardization of nutrient solution and pH of the media, six different nutrient solutions viz., Hoagland’s, CPRI, Chikkaballapur, Ethiopia, USDA and Komosa nutrient solutions, were tested, and pH was standardized. The crop performance was superior in Hoagland’s nutrient solution with a pH range of 5.5–6.4. The experiment comprised three methods of production, two parental lines (TAG 1 F and TAG 2 F), and two seed treatments (S1: Control and S2: Thiram @ 2 g kg-1 + chlorpyrifos @3 g kg-1) for hybrid seed production of tomato. A hundred percent survival rate was recorded in a soilless medium, whereas seed treatment increased the percent survival rate by 9% under the conventional system. Soiless method performed better than the conventional method. Aeroponics recorded a higher plant relative growth rate (1.17), fruit weight (124.54 g), total biomass (106.44 g), and seed index (3.95 g). Hydroponics produced a higher number of seeds fruit 1 (98.42), SVI-II (294), and 6% higher protein than the conventional method. The soilless method may open up a new approach for high-quality and year-round healthy hybrid tomato seed production under protected cultivation.

Synergistic Combination of Plants and Microbial-Rich Substrates Improves Water Quality in an Integrated Plant-Substrate System

Nutrient enrichment is one of the main reasons causing water quality deterioration and eutrophication in aquaculture systems, such as tanks, ponds, and natural water bodies where cage aquaculture is located. The integration of aquatic plants and substrates synergistically utilises nutrients for the development of biofilm and plant growth, thus improving the water quality in tanks. The experiment was performed in three trials to assess the use of commercial plants integrated with substrates in enhancing nutrient removal in nutrient-enriched mesocosms. Among the plants, the combination of water spinach and lemon basil exhibited significantly higher (P < 0.05) nutrient removal without causing adverse effects on plant growth when compared to the other treatments. For the substrates, the lava rock and bamboo showed the highest (P < 0.05) periphyton development and productivity. The integration of water spinach and lava rock resulted in the highest (P < 0.05) nutrient removal and plant relative growth rates indicating the positive effects of synergistic interaction between plants and microbial-periphyton colonised substrates. A total of 27 bacterial phyla (mainly non-pathogenic) were identified in the integrated water spinach and lava rock substrate treatment. Microbial community structure analysis showed that Proteobacteria, Planctomycetota, Verrucomicrobiota and Bacteroidota were the main groups found in water, roots of water spinach, and substrates. The highest (P < 0.05) bacterial diversity was observed in the substrates, followed by plant roots and water. This study illustrated that the water quality could be significantly improved by integrating suitable plants and microbial-periphyton colonised substrates in tanks.

Effects of light regimes and benthic fish disturbance on the foraging behavior of Vallisneria natans in heterogeneous sediments.

In shallow eutrophic lakes, submersed macrophytes are significantly influenced by two main factors: light availability and benthic fish disturbance. Plant foraging is one of the most crucial aspects of plant behavior. The present study was carried out to effects of light regimes and fish disturbance on the foraging behavior of Vallisneria natans in heterogeneous sediments. V. natans was cultivated in heterogeneous sediments with four treatments: high-light regime (H), high-light regime with benthic fish (HF), low-light regime (L), and low-light regime with benthic fish (LF). We use plant trait network analysis to evaluate the relationships between traits in heterogeneous sediments. We found the plant foraging intensity was positively correlated with trait network modularity. The biomass of stem, maternal plant biomass ratio, and ramet number were the hub traits of plant growing in heterogeneous habitats. Although the plant relative growth rate (RGR) was positively correlated with foraging intensity, the hub traits had closer links with plant RGR than foraging intensity. Light regime and benthic fish indirectly affected the plant foraging intensity by changing the chlorophyll a content and pH of overlying water. Overall, our analysis provides valuable insights into plant foraging behavior in response to environmental changes.

Root vascular anatomy predicts maximum growth rates in savanna trees and grasses

AbstractRoot‐based functional traits are relatively overlooked as drivers of savanna plant community dynamics, an important gap in water‐limited ecosystems. Recent work has shed light on patterns of trait coordination in roots, but less is known about the relationship between root functional traits, water acquisition, and plant demographic rates. Here, we investigated how fine‐root vascular and morphological traits are related in two dominant PFTs (C3 trees and C4 grasses from the savanna biome), whether root traits can predict plant relative growth rate (RGR), and whether root trait multivariate relationships differ in trees and grasses. We used root data from 21 tree and 18 grass species grown under greenhouse conditions, and quantified a suite of vascular and morphological root traits. We used a principal components analysis (PCA) to identify common axes of trait variation, compared trait correlation matrices between the two PFTs, and investigated the relationship between PCA axes and individual traits and RGR. We found that there was no clear single axis integrating vascular and morphological traits, but found that vascular anatomy predicted RGR in both trees and grasses. Trait correlation matrices differed in trees and grasses, suggesting potentially divergent patterns of trait coordination between the two functional types. Our results suggested that, despite differences in trait relationships between trees and grasses, root conductivity may constrain maximum growth rate in both PFTs, highlighting the critical role that water relations play in savanna vegetation dynamics and suggesting that root water transport capacity is an important predictor of plant performance in the savanna biome.

Linking trait network parameters with plant growth across light gradients and seasons

Abstract Reduced light availability induced by eutrophication has dramatically affected the growth of submerged macrophytes and caused their rapid decline globally in lakes. Functional traits have usually been used to predict ecological processes and explain plant adaptation. Trait networks, which are constructed from a series of nodes (traits) and edges (trait–trait correlations), can reveal complex relationships among traits. Plant traits belonging to different organs are considered relevant for overall plant performance. Therefore, variation in trait network topology at the whole plant level can better reflect plant adaptation and response to environments than traditional methods, but the mechanisms underlying the decline of plants from a trait network perspective are not well understood. In this study, based on a 1‐year manipulation experiment for Potamogeton maackianus cultured with four levels of light intensity, we constructed trait networks from 20 traits belonging to different organs. Our results showed that trait network connectivity decreases in harsh environments, probably due to increased trait modules responding independently to stress. Network connectivity was positively related to the plant relative growth rate (RGR), as high trait connectivity and coordination should be beneficial for plants to acquire and transport resources efficiently across the whole plant. Additionally, we found that specific stem length, leaf: root mass ratios and leaf total non‐structural carbohydrates were hub traits with high connectivity. Hub traits expressed high phenotypic plasticity, had close links with plant growth and consistently held their higher importance within the network across light gradients or seasons. We found that low phenotypic integration in stressful environments may constrain plant growth, which can provide important implications for understanding plant adaptation strategies to low‐light stress and even predicting community dynamics in the context of global environmental change. Read the free Plain Language Summary for this article on the Journal blog.

Effect of Biofertilizers and Organic Amendments on Germination and Seedling Growth of Common Dry Zone Forest Species in Sri Lanka: Sustainable Reforestation Practices in Sri Lanka

Most of the dry zone forests in Sri Lanka are arisen after unsustainable farming practices. Therefore, the natural regeneration of plant species in these forests reported to be very poor due to the reduced soil fertility. This study was conducted to find possible measures for the successful seed germination and seedling establishment of common dry zone forest tree species by sustainable soil fertility management. A pot trial was carried out in a greenhouse at the Faculty of Applied Sciences, Rajarata University, Mihintale, Sri Lanka. The experiment comprised of 128 pots and four replicates. Pots were assigned with different soil fertility managements: T0: control (Top soil only), T1: Arbuscular Mycorrhizal Fungi (AMF), T2: a traditional mixed microbial culture (Jeewamurthum), T3: Compost, T4: Biochar, T5: T1+T2, T6: T1+T3, T7: T1+T4; and different forest plant species: Manilkara hexandra, Feronia limonia, Pterospermum conscens and Bauhinia racemosa. Seed germination percentage was measured two weeks after sowing, and shoot biomass, relative plant growth rate, and AMF colonization percentage were measured after four months of germination. The results revealed that inoculation of AMF enhance the seed germination percentage of all the selected plant species. Both sole and combined application of AMF and compost gives more benefits to all the tested plant species by enhancing all the measured growth parameters. The findings of present study would be useful in reforestation programs of dry zone forests in Sri Lanka by practicing sustainable procedures.

Phytoremediation of mercury from water by monocultures and mixed cultures pleustophytes

Mercury pollution is a global environmental problem. An alternative to the chemical method of removing mercury from the aquatic environment is the phytoremediation process, based on phytofiltration, phytoextraction, and phytovolatilization techniques. The study showed the effectiveness of phytoremediation with plants Lemna minor and Salvinia natans carried out in monoculture systems and mixed cultures. We used Hoagland's mercury-contaminated liquid medium: 0.15 mgHg/dm3, 0.20 mgHg/dm3 and 0.30 mgHg/dm3. The relative growth rate of plants in the control samples was 0.04–0.07 g/gd. In the presence of mercury for monocultures, observed a toxic effect in the form of growth stimulation, and the relative growth rate reached 0.12 g/gd. The bioconcentration factor was the highest on the 7th day of mercury exposure and was 216–856. The efficiency of mercury removal from the substrate in the phytoremediation process was 96 %. The total protein was increased for Lemna minor by 34 %, Salvinia natans by 84 %, and in mixed culture by up to 99 %. Also, the total chlorophyll increased for Lemna minor by 14 % and for the mixed culture by up to 60 %. For Salvinia natans, the total chlorophyll decreased by 53 %. The biochemical changes may have been a toxic effect of mercury in the environment.

Calibration of Inexact Computer Models with Heteroscedastic Errors

Computer models are commonly used to represent a wide range of real systems, but they often involve some unknown parameters. Estimating the parameters by collecting experimental data becomes essential in many scientific fields, ranging from engineering to biology. However, most of the existing methods are developed under the assumption that the experimental data contains homoscedastic measurement errors. Motivated by an experiment of plant relative growth rates where replicates are available, we propose a new calibration method for inexact computer models with heteroscedastic measurement errors. Asymptotic properties of the parameter estimators are derived which can be used to quantify the uncertainty of the estimates, and a goodness-of-fit test is developed to detect the presence of heteroscedasticity. Numerical examples and empirical studies demonstrate that the proposed method not only yields accurate parameter estimation, but also provides accurate predictions for physical data in the presence of both heteroscedasticity and model misspecification. An R package for the proposed methodology is provided in an open repository.

Testing the association of relative growth rate and adaptation to climate across natural ecotypes of Arabidopsis.

Ecophysiologists have reported a range of relationships, including intrinsic trade-offs across and within species between plant relative growth rate in high resource conditions (RGR) vs adaptation to tolerate cold or arid climates, arising from trait-based mechanisms. Few studies have considered ecotypes within a species, in which the lack of a trade-off would contribute to a wide species range and resilience to climate change. For 15 ecotypes of Arabidopsis thaliana in a common garden we tested for associations between RGR vs adaptation to cold or dry native climates and assessed hypotheses for its mediation by 15 functional traits. Ecotypes native to warmer, drier climates had higher leaf density, leaf mass per area, root mass fraction, nitrogen per leaf area and carbon isotope ratio, and lower osmotic potential at full turgor. Relative growth rate was statistically independent of the climate of the ecotype native range and of individual functional traits. The decoupling of RGR and cold or drought adaptation in Arabidopsis is consistent with multiple stress resistance and avoidance mechanisms for ecotypic climate adaptation and would contribute to the species' wide geographic range and resilience as the climate changes.

The negative effects of soil microorganisms on plant growth only extend to the first weeks

Abstract Soil biotic communities can strongly impact plant performance. In this paper, we ask the question: how long-lasting the effect of the soil microbial community on plant growth is. We examined the plant growth rates at three stages: early, mid and late growth. We performed two growth experiments with Jacobaea vulgaris, which lasted 49 and 63 days in sterilized soil or live soil. In a third experiment, we examined the effect of the timing of soil inoculation prior to planting on the relative growth rate of J. vulgaris with four different timing treatments. In all experiments, differences in biomass of plants grown in sterilized soil and live soil increased throughout the experiment. Also, the relative growth rate of plants in the sterilized soil was only significantly higher than that of plants in the live soil in the first two to three weeks. In the third experiment, plant biomass decreased with increasing time between inoculation and planting. Overall, our results showed that plants of J. vulgaris grew less well in live soil than in sterilized soil. The negative effects of soil inoculation on plant mass appeared to extend over the whole growth period but arise from the negative effects on relative growth rates that occurred in the first weeks.

RESPON PEMBERIAN KOMPOS DAUN KELAPA SAWIT DAN NPK 16.16.16 TERHADAP PERTUMBUHAN SERTA PRODUKSI BAWANG MERAH (Allium ascalonicum L.)

ABSTRACT Response to Composting Palm Leaves and NPK 16.16.16 in Improving Growth and Production of Shallots (Allium ascalonicum L.). The purpose of this study was to determine the interaction effect and the main growth and production of shallots given oil palm leaf compost and NPK 16.16.16. This research was carried out at the Experimental Garden of the Faculty of Agriculture, Pasir Pengaraian University, Rokan Hulu Regency. This research will be carried out for three months starting from October 2021 to December 2022. This study used a factorial completely randomized design (CRD) consisting of two factors. The first factor was the provision of Palm Leaves Compost (K) consisting of 4 levels and the second factor was NPK 16.16.16 (G) fertilizer which consisted of 4 levels so that 16 treatment combinations were obtained with 3 replications, so there were 48 experimental units. Each unit consisted of 6 plants per plot and all plants were observed as samples so that the total plants were 288 plants. The parameters observed were the relative growth rate of plants, plant height, harvest age, number of tubers per clump, wet weight per clump, dry weight per clump, and tuber weight loss. The data were statistically analyzed and presented with the Honest Significant Difference Test (BNJ) at the 5% level. The results of the study can be concluded as follows: The interaction of oil palm leaf compost and NPK 16.16.16 fertilizer had a significant effect on: plant height, harvest age, number of tubers per clump, wet weight of tubers per clump, dry weight of tubers per clump and tuber weight loss. The best treatment was a combination of oil palm leaf compost treatment of 45 grams/polybag (K3) and NPK fertilizer 16.16.16 1.55 grams/polybag (G2). The main effect of oil palm leaf compost was significant on all observation parameters. The best treatment is a dose of 45 grams/polybag (K3). The main effect of the dose of NPK fertilizer 16.16.16 was significant on all observation parameters. The best treatment is a dose of 1.55 grams/polybag (G2).

Disentangling the roles of plant functional diversity and plaint traits in regulating plant nitrogen accumulation and denitrification in freshwaters

Abstract There is a growing recognition that functional measures of diversity, based on quantification of functionally important species traits, are useful for explaining variation in ecosystem processes. However, the mechanisms linking functional diversity to different processes remain poorly understood, hindering development of a predictive framework for ecosystem functioning based on species traits. The current understanding of how the functional traits of aquatic plants (macrophytes) affect nitrogen (N) cycling by regulating microbial communities and their activity in freshwater habitats is particularly limited. Denitrifying bacteria are typically associated with the roots of both aquatic and terrestrial plants and denitrification is the main cause of loss of N from ecosystems. Disentangling the interplay between plants and microbial denitrifiers is key to understanding variation in rates of denitrification from local to landscape scales. In a mesocosm experiment, we varied the species richness (monocultures or two‐species mixtures) and composition of macrophytes. We quantified effects of both macrophyte functional diversity, quantified as functional trait dissimilarity, and functional trait composition, quantified as community weighted mean trait values, on N removal in wetlands. We used structural equation modelling to disentangle the direct and indirect influences of traits on N accumulation in plant biomass, denitrification activity and abundance of key bacterial denitrification genes (nirS and nirK). Both functional diversity and functional trait composition regulated N removal, explaining 70%–94% variation in the underlying ecosystem processes. Increased macrophyte functional diversity increased plant N accumulation, and indirectly enhanced denitrification by increasing denitrification gene abundance. Among traits, greater plant relative growth rates, specific leaf area and above‐ground biomass increased plant N accumulation. Denitrification activity increased with increasing below‐ground biomass but decreased with increasing root diameter. These findings improve our understanding of N removal in freshwater wetlands dominated by macrophytes, and have broad ecological implications for wetland management targeting enhanced ecosystem services. Our results highlight the potential for optimizing denitrification and plant N accumulation in wetlands and thereby improving water purification by increasing macrophyte functional diversity and ensuring the presence of key traits in macrophyte assemblages. A free Plain Language Summary can be found within the Supporting Information of this article.

The growth rate of hydroponic lettuce at various nutrient compositions from liquid synthetic, solid synthetic, and liquid organic fertilizers

The hydroponic system of lettuce cultivation has become popular in the new normal era after the Covid 19 pandemic. So that the efficiency of input and the ease of supplying nutrients in hydroponic farming deserves to be a concern. Hydroponics commonly uses synthetic fertilizers that are completely available and sold commercially. Efforts are needed to make media choices by utilizing easier and cheaper resources, among others by making various alternative nutrient source compositions from widely available, cheap, and commonly used synthetic fertilizers such as NPK and Gandasil. Another option that also needs to be tested for the efficiency of its utilization is the use of liquid organic fertilizers from chicken feather waste. Calculation of the growth rate of lettuce grown on various nutrient compositions of liquid organic and synthetic fertilizers was carried out. The types of fertilizer composition tested were P1= AB-mix (control) 50 ml in 10 liters of water, P2= NPK 10 g + Gandasil 5 g in 10 liters of water, P3= AB-mix 25 ml + 5 g NPK + 2.5 g Gandasil in 10 liters of water, P4= AB-mix 25 ml + 400 ml chicken feather LOF in 10 liters of water, and P5= 5 g NPK + 2.5 g Gandasil + 400 ml chicken feather LOF in 10 liters of water. The results showed that the highest growth rate of lettuce was obtained in the P4 composition, with the best results for Net assimilation rate (NAR), total wet biomass production per plant, ratio of wet weight of shoot: wet weight roots, relative plant height growth rate, relative leaf number growth rate, and relative plant growth rate.

Plant nitrogen status at flowering and kernel set efficiency in early- and late-sown maize crops

• We studied plant N status and kernel set efficiency (KSE) in contrasting sowing dates. • Plant N status at R1 was determined using SPAD readings in ear leaf-blade. • A boundary function analysis was performed to quantify the direct effects of plant N status on KSE. • Plant N status effect on KSE was recorded in late-sown crops at low plant growth rate (PGR). • Plant N status effect on KNP was regulated by prolificacy expression at high PGR in early-sown crops. In maize ( Zea mays , L.) genotypic variability in the relationship between total kernel number per plant (KNP) and plant growth rate (PGR) during the period bracketing silking (R1 ± 15 d), and in kernel set efficiency (KNP PGR −1 , KSE) have been widely documented. Nitrogen supply (N s ) affects PGR and hence KNP (i.e. indirect effect on KNP), but reports on a direct N effect on KNP PGR −1 are still contradictories. Moreover, recent studies have documented that prolificacy (the number of ears per plant) was cancelled out in N-limited plants despite of their high PGR. Additionally, PGR can be differentially affected by environmental conditions (e.g. sowing dates) through indirect effects on plant size or directly, which could determine changes on KSE. Field experiments were carried-out in Paraná (31° 48' S, 60° 32' W), Argentina, during two growing seasons (2014−15 and 2015−16). Two single cross hybrids were sown in two sowing dates (early: September and late: December), with three N fertilizer rates (0, 90, and 270 kg N ha −1 ) at three plant densities (5, 7 and 9 pl m −2 ). The effects of plant N status and plant size on KNP, KSE and prolificacy were study for a wide range of PGR and relative PGR (rPGR). Plant N status was estimated by using SPAD measurements on the ear-leaf blade at R1. Ranges of lower, mid and higher PGR (absolute and relative values) and SPAD units were established using 33rd and 66th percentiles. Curvilinear functions were fitted to kernel number at the apical ear (KN E1 ) vs. PGR and KNP vs. PGR and boundary functions were also fitted to calculate the unexplained variance (i.e. residuals) of these functions, indicative of direct plant N status effects on KSE. Residuals of KN E1 vs. PGR relationship decreased with increases in plant N status up to a threshold value of 46.8 SPAD units (R 2 = 0.75, P < 0.001). Prolificacy was expressed for plants with SPAD units greater than 50 and residuals of KNP vs. PGR relationship decreased with increases in SPAD units only in prolific plants of early-sown crops (R 2 = 0.55, P < 0.10). The analysis of KNP vs. PGR and KNP vs. rPGR allowed us to elucidate the direct effect of plant N status on KSE under a wide range of environmental conditions, especially those promoting by sowing date x plant density x N rate.

A Sustainable Solution to Obtain P-K-Mn Glass Fertilizers from Cheap and Readily Available Wastes.

The sustainable economy framework imposes the adoption of new ways for waste reuse and recycling. In this context, this paper proposes a new alternative to obtain glass fertilizers (agriglasses) by reusing two cheap and easily available wastes, wood ash and manganese rich sludge resulting from drinking water treatment processes for groundwater sources. Glasses were obtained using different amounts of wastes together with (NH4)2HPO4 and K2CO3 as raw materials. The P-K-Mn nutrient solubilization from the obtained glasses was investigated using a citric acid solution. The kinetics of the leaching process was studied after 1, 7, 14, 21 and 28 days, respectively. The intraparticle diffusion model was used to interpret kinetic data. Two distinct stages of the ion leaching process were recorded for all of the studied compositions: first through intraparticle diffusion (the rate-controlling stage) and second through diffusion through the particle–medium interface. The fertilization effect of the obtained agriglasses was studied on a barley crop. The specific plant growth parameters of germination percentage, average plant height, biomass and relative growth rate were determinate. The positive impact of the agriglasses upon the plants biomass and relative growth rate was highlighted. The effects of agriglasses can be tuned through glass compositions that affect the solubility of the nutrients.

The Effect of Additional Effective Microorganisms in Vegetative Growth of Aerobic Paddy

The influence of effective microorganisms (EM), microbial inoculant containing yeasts, fungi, bacteria and actinomycetes was evaluated in field trials of Aerob 1 paddy cultivation in Jasin, Melaka. Aerobic paddy is a new way of rice cultivation in areas where water resources have been scare and affected by the climate change. As water shortage and climate change is becoming severe, the technology of growing rice with aerobic rice systems need to be further refined or developed to ensure the quality of rice production in water-short areas. The objective of this study was to determine the effect of additional EM on the growth pattern, and to evaluate the efficiency of EM uptake on the aerobic plant. This experiment was carried out by using random controlled Randomized Controlled Block Design (RCBD) consisted of three treatments with two replications in four blocks. Aerobic seed cv. Aeron1 was used as planting materials and has been applied by three different treatments of EM during vegetative growth. The treatment for this study was T1 = 1.8 g NPK with urea (control) while T2 was 1.8 g NPK and T3, with 0.9 g NP with 100 mL of EM respectively during 15 (early vegetative stage) and 45 DAS (late vegetative stage). The RCBD experimental design was used with two replications in each treatment in four blocks. There are three series of harvesting (35, 50 and 60 DAS) was conducted throughout this study. The growth parameter studied was shoot and root dry biomass, number of tillers, RGR at each of harvesting. Our finding revealed that the application of EM did not improve plant growth parameter but the growth pattern of T2 and T3 showed steady improvement, although not significant compared to T1. The application of EM at different growth stages did not enhance the relative plant growth rate of Aeron 1 under aerobic condition, but in comparison to T1 and T2, T3 treatment with 50% reduction of NPK and EM could significantly reduce the cost of land management and fertilizer.

Plant growth rate after, and not during, waterlogging better correlates to yield responses in wheat and barley

AbstractWaterlogging is a stress that affects wheat (Triticum aestivum L.) and barley (Hordeum vulgare L. ssp. distichum) yield. This work aimed at analysing the impact of a waterlogging event during pre‐anthesis (critical period) on yield, its numerical components and their relationships with plant growth rate in wheat and barley. Two pot experiments were carried out under contrasting environmental conditions (early and late sowing date), in which six wheat and six barley cultivars were exposed to control and waterlogging conditions imposed c. 18 days prior to anthesis. Measurements included total above‐ground biomass at the beginning and at the end of the waterlogging treatment and at maturity, when grain yield and its numerical components were also measured. Wheat showed higher yield losses (−76%) due to waterlogging than barley (−49%). Grain yield was explained by both numerical components (the number of grains per plant and grain weight), which better correlated with the relative growth rate of plants during the post‐stress recovery than during the waterlogging period. Plant growth during the recovery period should be targeted as a key factor to estimate yield losses from waterlogging in these cereals.

Estimating optimal daily nitrate, potassium, and water requirements of Cannabis sativa ‘cherry wine’ during the vegetative phase

Mineral nutrient requirements of Cannabis sativa ‘cherry wine’ (hemp) were studied under steady-state nutrition where nutrients and water (H2O) removed via transpiration uptake were replenished daily. Nitrate (NO3 −), potassium (K+), and H2O uptake for hemp are presented for 24 h periods over the course of vegetative growth. This can estimate the changes in potential NO3 − and K+ uptake rate in accordance with demand. Daily nutrient uptake and transpiration rates are discussed relative to the plant's H2O uptake and relative growth rate. Non-limiting conditions were achieved at base nutrient recipe NO3 − and K+ concentrations of 201 and 290 ppm. Biomass accumulation and stem caliper increment increase over the vegetative growth cycle were found to have a positive linear correlation with NO3 −, K+, and H2O uptake. Consequently, NO3 − and K+ concentrations in the irrigation solution can be steadily increased throughout the hemp vegetative cycle in relation to the driving relative variables growth and transpiration rate. In so doing, a time dimension is introduced concerning the nutrient amount supplied relative to plant biomass accumulation and nutrient uptake via the transpiration stream. Overall, lower amounts of NO3 − and K+ were needed to optimize plant growth than previously thought by industry professionals.