Plant Growth Measurements Research Articles

Posidonia Natural Residues as Growing Substrate Component: An Ecofriendly Method to Improve Nutritional Profile of Brassica Microgreens.

The aim of this study was to test Posidonia oceanica (L.) Delile seagrass residues (leaves and fibers) as growing media component to improve the nutritional quality of two different brassica microgreens (Mizuna and Rapini). We hypothesized that addition of posidonia residues in the substrate would result in higher concentration of certain mineral nutrients in the edible parts of plants. Substrates were obtained by mixing leaves and fibers, each material at the rate of 25, 50 and 75% (v/v), with a peat based commercial substrate, that was also used at 100% rate as a control treatment. Two experiments were carried out (Experiment 1: Mizuna microgreens production in growth chamber conditions; Experiment 2: Mizuna and Rapini microgreens production in greenhouse conditions). Plant growth measurements and chemical analysis on edible parts (mineral tissue composition and main bioactive compounds - polyphenol, chlorophylls and carotenoids contents) were performed in order to evaluate the effects of the different substrates on growth and nutritional composition of brassica microgreens. In order to evaluate the consumer safety, daily intake, percentage of recommended daily allowance for I (RDA-I) and hazard quotient (HQ) for I intake through consumption of 50 and 100 g portions of Rapini microgreens were calculated. Posidonia in the growing media mixtures increased I and B content in edible parts of microgreens. The calculated HQ underlines the safety of these products. Results confirm the possibility to improve nutritional profile of brassica microgreens by using this natural material as a growing media component, resulting in a sustainable approach.

Seed treatment and N rate do not impact dry bean (Phaseolus vulgarisL.) plant growth or grain yield in Ontario

Application of nitrogen fertilizer and commercial seed treatments are two strategies dry bean growers in Ontario utilize to manage root rot and maximize yields. However, data solidifying these practices is absent or outdated. Experiments were conducted at the Huron Research Station, near Exeter, Ontario, from 2008 to 2010, to measure plant growth and yield responses for navy, kidney, and cranberry dry bean market classes (cv. T9905, Pink Panther, and Etna, respectively) to seed treatment (NST, no seed treatment; CMBD, Cruiser Maxx Bean + Dynasty) and N fertilizer rates of 0, 35, 70, 105, 140, and 175 kg N·ha−1. Plant measurements taken included plant emergence, vigour, height and maturity, plant and seed mass, and grain moisture and yield. Over three years, plant growth and yield responses to seed treatment and nitrogen fertilizer were very scarce. Plant emergence and vigour either improved or were not affected by seed treatment or N rate, while increasing N rates increased plant height of only Pink Panther in 2008. Plant mass was unaffected by either factor while seed treatment decreased days to maturity and grain moisture of T9905 in 2008. Nitrogen fertilizer improved the grain yield of Etna, with the highest yields occurring with 70 kg N·ha−1or more, while other cultivar site–years did not respond. Overall, these results demonstrate dry beans rarely respond to N fertilizer or seed treatment at the Huron Research Station. Additional testing over multiple years and locations would assist in predicting these responses.

The Effects of Rice Husk Biochar Rate on Arbuscular Mycorrhizal Fungi and Growth of Soursop (Annona muricata L.) Seedlings

Soursop (Annona muricata L.) is increasingly planted in Malaysia for its agronomical importance as a multipurpose plant with medicinal and health benefits. However, there is limited information on soursop cultivation in Malaysia. Soursop can be inoculated with arbuscular mycorrhizal fungi (AMF) as a sustainable approach for successful seedlings growth before transplanting to field. As a beneficial symbiotic soil microorganism, AMF has been known as biofertilizer which can improve soil conditions and plant growth. Following the need to understand the soil management using soil beneficial microorganisms for soursop cultivation, this experiment aimed to determine the effects of AMF and biochar on the growth of soursop seedlings. The polybag experiment was conducted under glasshouse conditions at Farm 15, Faculty of Agriculture, UPM Serdang, Selangor. The study was arranged in Randomised Complete Block Design (RCBD) with eight treatments comprising different rates of rice husk biochar (RHB), with and without AMF and four replications. The treatments were; T1 (Control), T2 (AMF only), T3 (−AMF with 10 t/ha RHB), T4 (+AMF with 10 t/ha RHB), T5 (−AMF with 15 t/ha RHB), T6 (+AMF with 15 t/ha RHB), T7 (−AMF with 20 t/ha RHB) and T8 (+AMF with 20 t/ha RHB). Plant growth measurement were determined upon harvesting after four months of planting. Shoot and root biomass, leaf area meter, root surface area and root length were found significantly highest in soursop seedlings grown in soils amended with 10 t/ha RHB with or without AMF as compared to control. It was concluded that RHB, either individually or when in combination with AMF, had significantly improved the growth performance of soursop seedlings at nursery stage. Therefore, earliest inoculation of soursop seedlings with AMF at nursery stage could ensure successful mycorrhizal establishment and growth performance of soursop seedlings before transplanted under field condition.

Application of Genomics and Phenomics in Plant Breeding for Climate Resilience

Advances in the fields of genomics and phenomics are currently creating significant foundations for the sustainable intensification of plant breeding initiatives targeting climate resilience. Genomics is a biological study that focuses on architecture, function, editing, mapping, and evolution of genomes. It can be applied extensively in climate resilience breeding for cost-effective, rapid, and high-through put genotyping, phenotyping, and trait mapping. The efficacy of genomics-assisted breeding (GAB) is strongly hinged on the high resolution and robustness of Next Generation Sequencing (NGS) and CRISPR/Cas9-based Gene Editing systems. The integration of genomics and phenomics in crop improvement can upscale the efficiency of breeding systems targeting climate resilience and hasten cultivar release cycle. Phenomics is an interdisciplinary field that focuses on the enhanced measurement of plant performance, growth, and composition. Similarly, phenomics has revolutionized the efficacy of plant breeding off-trial initiatives established to phenotypically characterize and study diversity levels of collected germplasm. Field phenomics tools such as the phenonet, phenomobile, and phenonetwork have proven to be efficient in capturing large sums of multiscale and multidimensional experimental data. The main purpose of this review article is to present a summarized account of the probable applications of integrated systems of genomics and phenomics in plant breeding for climate resilience in major crops.

The effect of water activated by nonthermal air plasma on the growth of farm plants: Case of maize and barley

AbstractThe effects of plasma‐activated water (PAW) generated by nonthermal air plasmas of transient spark with water electrospray or atmospheric glow discharge were investigated on maize (Zea mays L. var Saccharata) and barley (Hordeum vulgare L.) seedlings. PAW is characterized by measuring concentrations of reactive oxygen and nitrogen species (H2O2, , ). After 4 weeks of plants growth, the effects of PAW are analyzed by measuring plant growth and physiological parameters: plant length and fresh weight, photosynthetic pigments concentration and photosynthesis rate, total soluble proteins, antioxidant enzyme activity, and DNA damage. The results suggest that PAW, depending on chemical composition, has the potential to improve the plant growth and influence the physiological parameters, while causing no harmful DNA damage.

Phosphate Solubilization and Plant Growth Promoting Actinobacteria from Rhizosphere Soil

Background: Phosphorus has been considered as the key element as it is directly involved in most of the life processes including in plants. Soil contains both organic and inorganic forms of phosphorus. Phosphate solubilization is the important property of soil bacteria to develop them as plant growth promoting bacteria in the agricultural field. The present study report the phosphate solubilizing and plant growth promoting properties of selected actinobacteria isolated from rhizosphere soil.Methods: Actinobacterial strains were isolated from rhizosphere soil and screened for in vitro phosphate solubilizing properties using agar plate method. The efficiency of phosphate solubilization and phosphatase activity of isolated actinobacterial strains were tested using Pikovskaya broth. Result: In the present study phosphate solubilization and phosphatase activity of isolated actinobacteria, Streptomyces sp. CTD-2 was comparatively higher in lab conditions. In pot trial experiment strain CTD-2 showed higher growth when compared to the control plant. The chlorophyll content of leaves in the experimental plants were found maximum with actinobacteria strain CTD-2 treated plant. Plant growth measurements such as root length, shoot length, leaf length, total plant growth measurements, quick yield production were also observed.

Effects of earthworms and warming on tree seedling growth: a small-scale microcosm experiment

Warming global temperatures are expected to strongly influence plant communities, yet there is limited knowledge of how these changes will interact with stressors such as the invasion of exotic earthworms. We conducted a small-scale microcosm experiment to assess the individual and interactive effects of warming and exotic anecic earthworms (Lumbricus terrestris L.) on the growth of sugar maple (Acer saccharum Marsh.) seedlings. After 50 days, the elevated-temperature chamber created warmer and drier soil conditions and increased several measures of plant growth, including stem width, ratio of stem width to stem height, stem biomass, and fine-root biomass. Earthworms did not have any clear impacts on plant growth on their own nor in interactions with the temperature chambers. However, earthworms both reduced surface leaf litter cover and exposed soils, which could exacerbate evaporative losses and moisture stress in field soils resulting from a warming climate under different growing conditions. Future studies should consider the long-term effects of earthworm–temperature interactions on sugar maple growth, as well as diurnal and seasonal changes in temperature.

An arbuscular mycorrhizal fungus alters switchgrass growth, root architecture, and cell wall chemistry across a soil moisture gradient.

The abiotic environment can dictate the relative costs and benefits of plant-arbuscular mycorrhizal fungi (AMF) symbioses. While the effects of varying light or soil nutrient conditions are well studied, outcomes of plant-AMF interactions along soil moisture gradients are not fully understood. It is predicted that mycorrhizal associations may become parasitic in extreme soil moisture conditions. Under low soil moisture stress, costs of maintaining a mycorrhizal symbiont may outweigh benefits for the host plant, whereas under high soil moisture stress, the host plant may not need the symbiont. In a factorial growth chamber study, we investigated the effects of a plant-arbuscular mycorrhizal fungus symbiosis along a soil moisture gradient on growth, cell wall chemistry, and root architecture of a biofuel crop, Panicum virgatum (switchgrass). Regardless of soil moisture conditions, we found an increase in the number of tillers, number of leaves, root biomass, and amount of cellulose and hemicellulose in response to root colonization by the arbuscular mycorrhizal fungus. The fungus also increased aboveground biomass and changed several root architectural traits, but only under low soil moisture conditions, indicating a reduction in benefits of the mycorrhizal association under high soil moisture. Results from this study indicate that an arbuscular mycorrhizal fungus can increase some key measures of plant growth and cell wall chemistry regardless of soil moisture conditions but is most beneficial in low soil moisture conditions.

RTIP: A FULLY AUTOMATED ROOT TIP TRACKER FOR MEASURING PLANT GROWTH WITH INTERMITTENT PERTURBATIONS.

RTip is a tool to quantify plant root growth velocity using high resolution microscopy image sequences at sub-pixel accuracy. The fully automated RTip tracker is designed for high-throughput analysis of plant phenotyping experiments with episodic perturbations. RTip is able to auto-skip past these manual intervention perturbation activity, i.e. when the root tip is not under the microscope, image is distorted or blurred. RTip provides the most accurate root growth velocity results with the lowest variance (i.e. localization jitter) compared to six tracking algorithms including the top performing unsupervised Discriminative Correlation Filter Tracker and the Deeper and Wider Siamese Network. RTip is the only tracker that is able to automatically detect and recover from (occlusion-like) varying duration perturbation events.

Influence of nutrient solution concentration on growth and tissue mineral content of Panax ginseng seedlings cultured in a root medium containing peat and perlite

There is an increasing trend of producing seedlings of Panax ginseng in amended root media in raised beds. Precise control of the fertility of root media is essential for raising healthy seedlings, especially when inert media with a low buffering capacity are used. The objective of this study was to investigate the influence of fertility (as measured by EC) of the nutrient solution used for seedling production. One thousand eight hundred seeds were sown for five treatments and a control (300 seeds per treatment, 3 × 3 cm spacing) using root medium [composed of peat moss + perlite (7:3, v/v)] on raised beds with measurements, 120 × 60 × 25 cm (L × W × H) on Mar 9, 2018. Five nutrient solutions with different strengths (0.4, 0.6, 0.8, 1.0, 1.2 dS m−1 EC) were prepared with ground water (0.25 dS m−1) and a fertilizer stock solution (2 mM NH4+-N, 12 mM NO3−-N, 1 mM H2PO4−, 8 mM K+, 2 mM Ca2+, 1 mM Mg2+, 1 mM SO42−). Fertigation of the beds started on May 21 using each of six nutrient solutions and fertigation frequencies were controlled using an EC5 soil moisture sensor. The stock solutions were automatically supplied for 30 min when the volumetric water content decreased to 36%. Plant growth measurement and soil analyses were carried out twice: first at 144 days and subsequently at 197 days (from the day of seeds sown). For the first growth measurement, elevated EC in the fertilizer solution resulted in enhanced growth, but statistical differences among treatment solutions were not significant except for the case of ground water. In the second measurement, the seedling growth in terms of dry weight of above- and below-ground plant parts increased significantly in plants treated with the 1.0 dS m−1 EC solution and decreased in plants treated with the (1.2 dS m−1 EC) solution. In both the first and second measurements, the ground tissue nutrient content (T-N, P, K and Ca) was significantly different among treatments. The EC of root media in the case of 1.0 dS m−1 treatment, where the seedling growth was the highest among treatments, was 0.54 dS m−1 at the first measurement and 0.82 dS m−1 at the second measurement. In summary, a root medium with a mixture of peat moss + perlite (7:3, v/v), a leaching percentage of 20–30%, and a nutrient solution with a concentration of 1.0 dS m−1 EC is suitable for the healthy growth of ginseng seedlings.

Pumpkin seed protein hydrolysate treatment alleviates salt stress effects on Phaseolus vulgaris by elevating antioxidant capacity and recovering ion homeostasis

Pumpkin seed protein hydrolysate (PH) is a biostimulant product that contains high antioxidant activities, peptides and amino acids. This biostimulant is able to improve plant tolerance to abiotic stresses, including salinity. A pot experiment was conducted during summer season of 2018, with the aim of determining growth and productivity, physio-biochemical attributes, and antioxidant system components in salt (3.9 or 7.8 dS m−1 using NaCl)-stressed Phaseolus vulgaris plants treated with PH (1000 or 2000 μL L‒1). Salt stress was applied in irrigation water, and PH was applied three times as foliar application. Under 7.8 dS m−1, Na+ content was significantly increased, however, PH application at 1000 or 2000 μL L‒1 reduced it by 11 or 13%, respectively. The negative impacts of salinity on essential nutrients (e.g., N, P, K+, Ca2+, and Mg2+) contents, leaf photosynthetic pigments contents, and tissue health (in terms of relative water content, membrane stability index, and excised leaf water retention) were considerably mitigated by PH application. Increase in malondialdehyde (MDA) content was associated by increases in proline, soluble sugars, and glutathione contents, and antioxidant enzyme activities under salt stress, however, PH application further improved these parameters along with a worthy reduction in MDA content in salt-stressed plants. PH can maintain plant anatomical features, growth and yield measurements, which were disrupted by salt stress. Results of this study recommend the use of PH as foliar application, especially at 2000 μL L‒1 to obtain satisfactory growth and yield of Phaseolus vulgaris plants grown under salt stress up to 7.8 dS m−1.

Chemical Composition and Plant Growth of Centaurea raphanina subsp. mixta Plants Cultivated under Saline Conditions.

The aim of this report was to study the effect of salinity (control: 2dS/m, S1: 4 dS/m and S2: 6 dS/m) and harvest time (first harvest on 9 May 2018 and second harvest on 19 April 2018) on the growth and the chemical composition of Centaurea raphanina subsp. mixta plants. The plants of the first harvest were used for the plant growth measurements (fresh weight and moisture content of leaves, rosette diameter, number and thickness of leaves), whereas those of the second harvest were not used for these measurements due to the flowering initiation, which made the leaves unmarketable due to their hard texture. The results of our study showed that C. raphanina subsp. mixta plants can be cultivated under mild salinity (S1 treatment) conditions without severe effects on plant growth and yield, since a more severe loss (27.5%) was observed for the S2 treatment. In addition, harvest time proved to be a cost-effective cultivation practice that allows to regulate the quality of the final product, either in edible form (first harvest) or for nutraceutical and pharmaceutical purposes as well as antimicrobial agents in food products. Therefore, the combination of these two agronomic factors showed interesting results in terms of the quality of the final product. In particular, high salinity (S2 treatment) improved the nutritional value by increasing the fat, proteins and carbohydrates contents in the first harvest, as well as the tocopherols and sugars contents (S1 and S2 treatments, respectively) in the second harvest. In addition, salinity and harvest time affected the oxalic acid content which was the lowest for the S2 treatment at the second harvest. Similarly, the richest fatty acid (α-linolenic acid) increased with increasing salinity at the first harvest. Salinity and harvest time also affected the antimicrobial properties, especially against Staphylococcus aureus, Bacillus cereus and Trichoderma viride, where the extracts from the S1 and S2 treatments showed high effectiveness. In contrast, the highest amounts of flavanones (pinocembrin derivatives) were detected in the control treatment (second harvest), which was also reflected to the highest antioxidant activity (TBARS) for the same treatment. In conclusion, C. raphanina subsp. mixta plants seem to be tolerant to medium salinity stress (S1 treatment) since plant growth was not severely impaired, while salinity and harvesting time affected the nutritional value (fat, proteins, and carbohydrates) and the chemical composition (tocopherols, sugars, oxalic acid, fatty acids), as well as the bioactive properties (cytotoxicity and antimicrobial properties) of the final product.

Effects of combining Renlon with Renbarb1 and Renbarb2 on resistance of cotton (Gossypium hirsutum L.) to reniform nematode (Rotylenchulus reniformis Linford and Oliveria)

The upland cotton (Gossypium hirsutum L.) germplasm lines BARBREN-713, having the Renbarb1 and Renbarb2 quantitative trait loci (QTL), and LONREN, carrying the Renlon QTL, have introgressed resistance to reniform nematode (Rotylenchulus reniformis Linford and Oliveria). Stunting has been observed in the LONREN source of resistance when subjected to heavy nematode pressure but not for BARBREN-713. To investigate the potential to reduce stunting in the LONREN source of resistance, cotton lines were developed with different combinations of reniform nematode resistance QTL from LONREN and BARBREN-713. Marker assisted selection was conducted to identify the following QTL combinations: (1) Renbarb1 + Renbarb2, (2) Renbarb1 + Renbarb2 + Renlon, (3) Renbarb2 + Renlon, (4) Renbarb1 + Renlon, (5) Renbarb1 alone, (6) Renbarb2 alone, (7) Renlon alone, and (8) a Null susceptible genotype. QTL combinations were inoculated with 0, 2300, or 5000 reniform nematodes per 120 cm3 soil in growth chamber tests. Plants were harvested at 60 days after inoculation, plant growth measurements made, and the nematode reproduction factor calculated. In this study, the Renbarb1 genotype was scored as susceptible to reniform nematode. Combining Renlon with Renbarb2 did not improve resistance to reniform nematode; however, the Renbarb2/Renlon combination showed improved growth compared to LONREN-1, BARBREN-713, and the susceptible null check.

Barnacle colonization on Spartina alterniflora in Georgia salt marshes

The distribution of barnacles within a habitat is influenced by numerous biotic and abiotic factors that impact barnacle recruitment and/or settlement. In Georgia salt marshes, barnacles (specifically Chthamalus fragilis) have been observed colonizing leaves and stems of S. alterniflora, which is the dominant plant species in marshes along the Gulf and East Coast. The aims of this study were to: 1) identify spatial and short-term monthly patterns of barnacle colonization within individual S. alterniflora as well as across sites of varying marine influence during peak barnacle recruitment and plant growth and 2) determine the effect of barnacle settlement on S. alterniflora growth and productivity. Patterns of barnacle settlement and measurements of plant growth and productivity were assessed through a field survey and field experiment in three salt marshes of varying proximity to oceanic inputs. Two marsh sites were dominated by tall-form S. alterniflora and one was composed of short-form plants. Results suggested spatial and short-term monthly patterns in barnacle settlement both across sites and within individual plants. Specifically, there was significantly greater barnacle density on stems and leaves of plants in salt marshes with greater marine influence. Furthermore, there was a decrease in barnacle settlement on S. alterniflora leaves and increase in settlement on stems from June to August, suggesting short-term monthly patterns in the portion of the plant colonized. Within individual plants, there was a significantly greater density of large barnacles on the middle segments of the stem and greater barnacle colonization in the non-axils of the stems compared to leaf axils. A potential negative impact of barnacle settlement on S. alterniflora was observed at the site with the greatest barnacle density and marine influence, which was also the site dominated by short-form S. alterniflora. These plants showed significantly lower photosynthetic efficiency in August, but it is unclear whether this was related to barnacle settlement, edaphic conditions, or both. Information on the patterns of barnacle settlement and its impact on S. alterniflora will be vital to coastal managers in salt marsh conservation strategies.

Development of agroforestry oil palm for peatland restoration in Jambi Province: establishing process and initial results

Rapid degradation of peatland forest in Indonesia is caused by conversion into plantation forest and agriculture land, including oil palm plantation by farmers. Restoration of peatland is then needed with involvement of local farmers as main stakeholder. This paper presents establishment process and initial result from an action research on peatland restoration using biodiversity enrichment experiment in existing oil palm smallholder plantation to develop oil palm agroforestry. The experiment was established in Sinar Wajo Village, Tanjung Jabung Timur Regency, Jambi Province in which 30 plots in sizes of 25m2, 100 m2, and 400 m2 placed systematically over about 21 ha oil palm plantation belong to a group of farmers. There were 1,180 trees of 6 species, i.e. blangeran (Shorea blangeran), pinang (Areca pinanga), petai (Parkia speciosa), durian (Durio zibethinus), jengkol (Archidendron pauciflorum), and kopi liberika (Coffea liberica) with 0, 3, and 6 diversity levels, created tree island on the sea of oil palms. Approach to local leaders was very important for the initiation of the action research. Focus group discussion with farmer group, provision of seedlings and labour wages were conducted to ensure farmer willingness of participation. Capacity building, such as training on tree cultivation, bio-fertilizer production and study tour was conducted as incentive for farmers. The initial result of plant growth measurement from experiment plots showed 21 months after planting many planted trees grew well. Blangeran as native species of peatland forest showed the best growth performance. Pinang, Kopi Liberika and Durian were also showed relatively good growth performance. Only Petai and Jengkol showed less growth performance. High farmer participation on the establishment of oil palm agroforestry as peatland restoration model was mostly driven by provision of incentives. Oil palm agroforestry is a promising model for restoration of already planted by oil palm peatland area, and involving farmers is important factor for the success of peatland restoration through appropriate social approaches.

Adaptation and productivity of kaliandra for biomass energy source

The development of wood energy forest plantations is one of the government’s strategies to meet national energy needs. Kaliandra (Calliandra calothyrsus) is one tree/shrub species that is potential for biomass energy source due to its rapid growth and high calorific value. This study aims to analyze the level of adaptation and productivity of kaliandra planted in 3 spacing treatments in the Production Forest Management Unit (KPHP) Puncak Ngengas - Batulanteh, Sumbawa. The treatment of spacing applied is 4 m x 1 m or density of 2, 500 trees/ha (J1), 4 m x 2 m or density of 1, 250 trees/ha (J2), and 4 m x 2 m with stripe or density of 1, 850 trees/ha (J3). Measurements of adaptation and plant growth were carried out until 6 months after planting. The results of this study indicate that the J2 treatment showed the best level of adaptation with a survival rate of 89.3%, followed by treatments J3 and J1 with a survival rate of 85.9% and 84.4% respectively. The J3 treatment resulted in the best growth rate of Kaliandra plants with an average diameter of 18.1 mm, an average height of 244.9 cm and the volume of individual trees of 0.00085 m3/tree. The J3 treatment also produced the highest total volume, estimated biomass production and energy productivity compared to other treatments, which were 3.5 m3/ha, 2.7 tons/ha and 51.9 Gj/ha, respectively. Treatment of spacing indicates the influence on the level of tree adaptation and growth and estimation of biomass production and calorific value. However, the treatment of spacing does not show a clear pattern related to the effect of initial spacing on growth and productivity of Kaliandra at the beginning of the year.

Measuring plant growth characteristics using smartphone based image analysis technique in controlled environment agriculture

High plant number per unit area makes it challenging to monitor plant growth in controlled environment agriculture (CEA) systems. Our objective was to develop and validate image analysis technique that uses a smartphone connected to local desktop computer for non-destructive measurement of growth characteristics of several species commonly grown in CEA. Using mobile apps, an iPhone-6 was remotely connected to a local computer containing image-processing software (MATLAB) and script. Smartphone was used to capture images of plants belonging to several species including basil, leaf lettuce, tomato, and zinnia. The images were moved to a folder on cloud storage and remotely processed on a local computer to derive estimated leaf area (LAestimated) of plants. Regression analysis indicated a near perfect linear relation between measured leaf area (LAmeasured) and LAestimated (r2 = 0.98) and shoot dry weight (SDW) and LAestimated (r2 = 0.94) when data were pooled from all species. No significant differences were observed when relative growth rate (RGR) was measured using either SDW or LAestimated values. Further, results indicated that real-time and non-invasive LAestimated measurements can be used to track plant growth differences over time. This method was able to identify plant growth differences more accurately than visual assessments on plants. Our findings indicate that LAestimated can be used for accurate and non-invasive measurement of growth characteristics of plants in academic research. The technique can also aid in maximizing productivity, minimizing resource wastage and harvesting crops timely in commercial production.

Influence of drought stress on bioactive compounds, antioxidant enzymes and glucosinolate contents of Chinese cabbage (Brassica rapa)

This study investigated the effects of drought stress on Chinese cabbage (Chcab) by measuring plant growth responses, total antioxidant enzyme activities, the contents of bioactive compounds including glucosinolates (GLS, aliphatic and indolic), and binding with human serum albumin (HSA). Forty-day-old Chinese cabbage (Brassica rapa L. ssp. pekinensis) seedlings were transplanted into pots and maintained for three weeks at 10% (drought-treated, D-T) and 30% (control, C) soil water. The total leaf number, leaf area, and fresh and dry weights were significantly lower in D-T Chcab than in controls. Total GLSs and catalase activities were found to be significantly higher in D-T Chcab than in controls. Indolic GLSs were significantly higher than aliphatic GLSs in D-T Chcab. These results show that D-T Chcab reduced growth parameters and binding properties with HSA and influenced total contents of GLSs, polyphenols, flavonoids, total antioxidant enzyme activities, catalase and peroxidase.

Vision Based Modeling of Plants Phenotyping in Vertical Farming under Artificial Lighting.

In this paper, we present a novel method for vision based plants phenotyping in indoor vertical farming under artificial lighting. The method combines 3D plants modeling and deep segmentation of the higher leaves, during a period of 25–30 days, related to their growth. The novelty of our approach is in providing 3D reconstruction, leaf segmentation, geometric surface modeling, and deep network estimation for weight prediction to effectively measure plant growth, under three relevant phenotype features: height, weight and leaf area. Together with the vision based measurements, to verify the soundness of our proposed method, we also harvested the plants at specific time periods to take manual measurements, collecting a great amount of data. In particular, we manually collected 2592 data points related to the plant phenotype and 1728 images of the plants. This allowed us to show with a good number of experiments that the vision based methods ensure a quite accurate prediction of the considered features, providing a way to predict plant behavior, under specific conditions, without any need to resort to human measurements.

All roads lead to growth: imaging-based and biochemical methods to measure plant growth.

Plant growth is a highly complex biological process that involves innumerable interconnected biochemical and signalling pathways. Many different techniques have been developed to measure growth, unravel the various processes that contribute to plant growth, and understand how a complex interaction between genotype and environment determines the growth phenotype. Despite this complexity, the term 'growth' is often simplified by researchers; depending on the method used for quantification, growth is viewed as an increase in plant or organ size, a change in cell architecture, or an increase in structural biomass. In this review, we summarise the cellular and molecular mechanisms underlying plant growth, highlight state-of-the-art imaging and non-imaging-based techniques to quantitatively measure growth, including a discussion of their advantages and drawbacks, and suggest a terminology for growth rates depending on the type of technique used.