Plant Growth Quality Research Articles

Protein Hydrolysates Supplement in the Nutrient Solution of Soilless Grown Fresh Peppermint and Spearmint as a Tool for Improving Product Quality

The present study investigated the potential of fresh peppermint (Mentha × piperita L.) and spearmint (Menthaspicata L.) production on a floating raft system combined with a commercial protein hydrolysate supplement (Amino16®) in a nutrient solution aiming to improve plant product quality. Three levels of the protein hydrolysate solution (0, 0.25 and 0.50%) were added in the nutrient solution, and the plants were harvested after twenty-four days. Plant growth characteristics were recorded, and nutritional, essential oil and polyphenolic composition were determined in fresh tissue. The addition of protein hydrolysates did not affect the fresh or dry weight but reduced plant height. Nitrate content significantly decreased, while total chlorophyll and essential oil content increased in both species. Moreover, the protein hydrolysate solution further increased total antioxidant capacity, total soluble phenol and carotenoid contents in spearmint plants, while it did not affect the essential oil and polyphenolic composition in both species. In conclusion, protein hydrolysates solution may be added in the nutrient solution, to improve the quality of peppermint and spearmint grown in a floating system, without adverse effects on crop yield or the essential oil and polyphenolic profile.

Characteristics and Trends of Strawberry Cultivars throughout the Cultivation Season in a Greenhouse

Each strawberry (Fragaria × ananassa) cultivar has its own growth and yield characteristics. However, the characteristics of many cultivars have not been determined at a consistent time and place, making direct comparative analysis difficult. The objective of this study was to identify characteristics and trends of five Korean strawberry cultivars in the same environment during an entire season. Therefore, environmental factors such as daily average air temperature, daily average relative humidity, daily average solar radiation, daily soil temperature, daily soil water content, daily soil electrical conductivity (EC), plant growth characteristics such as the number of leaves, plant height, leaf length, leaf width, and crown diameter, and productivity characteristics such as flowering and fruiting were measured to investigate the possible correlations of the data over one season. The vegetative growth of “Seolhyang” and “Keumsil” was greater than that of “Jukhyang” and “Maehyang”. The yield of “Arihyang” was greater than that of all other cultivars. “Arihyang” also presented the greatest weight per number of fruits. Among environmental factors, higher variability in air temperature and soil water content was correlated to lower total fresh weight in the following week at different degrees for each cultivar. Among the cultivars, the time to the first flowering was delayed by about seven days when the number of leaves increased by one and was reduced by one day per 1 cm increase in plant height. The total fresh weight was enhanced up to 271 g per experimental unit, while the average number of leaves increased by one. The results indicate that the data can be used by those who need information regarding the characteristics of the strawberry cultivars through direct comparative analysis.

Effect of magnetic water irrigation on the improvement of salinized soil and cotton growth in Xinjiang

To study the effect of magnetic water irrigation on the improvement of different salinized soils and the growth of cotton in Xinjiang, field experiments were conducted in three salinity soils (slight, medium, and heavy salinity soils), with five intensities of magnetized irrigation water (0 GS (CK,G0), 1000 GS (G1), 3000 GS (G3), 4000 GS (G4), and 5000 GS (G5)). Magnetized irrigation water can change the distribution of water and salt in all salinized soils, increase the water holding capacity and salt leaching of soil, and reduce the soil salt contents in the soil profile. It is better for the improvement on slight saline soil was better than on medium and heavy saline soils; the G3 treatment had the strongest effect by increasing soil water content by 33.2%−56.2% and improving the desalination rate by 29.2%−50.4%, compared to the control. Magnetic water irrigation significantly increased cotton growth. A negative relationship was found between soil salt content and plant growth characteristics (plant height, stem diameter, leaf number, leaf area index, and chlorophyll SPAD). Under the different intensities of magnetic water treatment, cotton growth indexes showed the same trends: CK < G1 < G5 < G4 < G3 in all three salinized soils. (3) Compared with the control treatment, magnetic water treatment can increase cotton yield and water use efficiently. Maximum water use efficiency and yields were obtained when the magnetization was 3000GS, in which the water use efficiency was increased by 27.4–42.8%, and the yield was increased by 28.8–31.69% compared with control. In this region, irrigating with magnetized water with 3000GS could improve saline soil quality and cotton growth, especially in slight salinity soil.

Daytime, Not Nighttime, Elevated Atmospheric Carbon Dioxide Exposure Improves Plant Growth and Leaf Quality of Mulberry (Morus alba L.) Seedlings.

Almost all elevated atmospheric CO2 concentrations (eCO2) studies have not addressed the potential responses of plant growth to different CO2 in daytime and nighttime. The present study was to determine the impact of daytime and/or nighttime eCO2 on growth and quality of mulberry (Morus alba L.), a perennial multipurpose cash plant. Six-month-old mulberry seedlings were hence grown in environmentally auto-controlled growth chambers under four CO2 concentrations: (1) ambient CO2 (ACO2, 410 μmol mol–1 daytime/460 μmol mol–1 nighttime), (2) sole daytime elevated CO2 (DeCO2, 710 μmol mol–1/460 μmol mol–1), (3) sole nighttime elevated CO2 (NeCO2, 410 μmol mol–1/760 μmol mol–1), and (4) continuous daytime and nighttime elevated CO2 (D + NeCO2, 710 μmol mol–1/760 μmol mol–1). Plant growth characteristics, nutrient uptake, and leaf quality were then examined after 120 days of CO2 exposure. Compared to control, DeCO2 and (D + N)eCO2 increased plant biomass production and thus the harvest of nutrients and accumulation of leaf carbohydrates (starch, soluble sugar, and fatty acid) and N-containing compounds (free amino acid and protein), though there were some decreases in the concentration of leaf N, P, Mg, Fe, and Zn. NeCO2 had no significant effects on leaf yield but an extent positive effect on leaf nutritional quality due to their concentration increase in leaf B, Cu, starch, and soluble sugar. Meanwhile, (D + N)eCO2 decreased mulberry leaf yield and harvest of nutritious compounds for silkworm when compared with DeCO2. The reason may be associated to N, P, Mg, Fe, and Zn that are closely related to leaf pigment and N metabolism. Therefore, the rational application of mineral nutrient (especially N, P, Fe, Mg, and Zn) fertilizers is important for a sustainable mulberry production under future atmosphere CO2 concentrations.

Determination of The Dependence of Plants Growth Characteristics on the Concentration of Petrochemicals in the Soil

Determination of The Dependence of Plants Growth Characteristics on the Concentration of Petrochemicals in the Soil

Bio-reduction of hexavalent chromium by an indigenous green alga and its impact on the germination of rice seed in chromium enriched environment

Rapid mining activities in Sukinda mining area have generated a huge amount of toxic Cr(VI) which accumulated and persisted in the soil for decades and reduced rice plant productivity in adjoining agricultural fields. Hence, for the bioremediation of rice field soil, a Cr(VI) resistant, thermotolerant and fast-growing native green algal strain SM1 was selected, which rendered resistance to 60 ppm of Cr(VI). DPC assay, ICP-OES and Raman-Spectroscopic analysis confirmed 92.765% of Cr(VI) reduction within 48 h by SM1 under optimized condition. Moreover, Cr(VI) adsorption by the green alga was also established by FTIR and SEM-EDX analysis. The alga (SM1) was identified as Chlorella thermophila by 18S rDNA sequencing (MN855377). Its application significantly improved rice (Oryza sativa var. Lalata) seed germination, seedling growth, seed vigor index, pigment and protein content. CHNS(O) and ICP-OES analysis of the algal biomass depicted the presence of several organic and inorganic compounds, which can be utilized as bio-fertilizer for the rice seedlings. Field experiments on rice plant growth characteristics should be conducted to utilize this potent algal strain in chromium contaminated rice fields for the bio-reduction of Cr(VI) and improvement of rice crop productivity.

Salinity resistance as a function of NH4+:NO3- ratio and its impact on yield and quality of tomato (Solanum lycopersicum L.)

AbstractBackground: Adequate regulation of plant nutrients may constitute a promising approach to overcome the deleterious effects of salinity on plant growth and development. Among these nutrients, nitrogen (N) can be a stand out option to improve plant adaptation to saline environment. However, plant response to N under salinity stress may vary depending upon ratio in the growth medium.Aims: The present study aimed to determine the efficiency of different ratios for improving salt resistance of tomato under alkaline conditions.Methods: Experimental plan comprised of five ratios 100:0, 75:25, 50:50, 25:75, and 0:100, and three salinity levels (no salinity, moderate salinity of 7 dS m−1, and high salinity of 10 dS m−1), with five replications. Plants were grown up to maturity and fruits were harvested for quality analysis.Results: ratios produced a differential response in ameliorating salinity toxicity. Plant growth and fruit yield characteristics reduced with salinity but the extent of reduction varied significantly with ratio under both salinity levels compared to respective ratio without salinity. Physiological characteristics viz. chlorophyll, photosynthesis, malondialdehyde, glutathione, electrolyte leakage and relative water content were also got optimized in favor of the high plant growth and yield by ratio of 50:50 under salinity stress. Among different ratios, 50:50 had greater potential not only to reduce Na+ and Cl− but also to promote N, K+, and Ca2+ accumulation in roots, shoots, and fruits, and thus gave more protection against the deleterious effects of salinity. Fruit quality characteristics improved with salinity, except for vitamin C. Shoot N correlated positively with photosynthesis (R2 = 0.94) and fruit yield (R2 = 0.98).Conclusions: Overall, ratios ranked in order of 50:50 &gt; 0:100 &gt; 25:75 &gt; 75:25 &gt; 100:0 to regulate the growth, yield and physiological characteristics of tomato under salinity stress, however best fruit quality characteristics were recorded in 100:0 ratio.

Arbuscular Mycorrhizal Fungi Improve Tolerance of the Medicinal Plant Eclipta prostrata (L.) and Induce Major Changes in Polyphenol Profiles Under Salt Stresses.

Eclipta prostrata (L.) is an important and well-known medicinal plant due to its valuable bioactive compounds. Microorganisms, including arbuscular mycorrhizal fungi (AMF), and salinity could directly impact plant metabolome, thus influencing their secondary metabolites and the efficacy of herbal medicine. In this study, the role of different single AMF species (Funneliformis mosseae, Septoglomus deserticola, Acaulospora lacunosa) and a mixture of six AMF species in plant growth and physio-biochemical characteristics of E. prostrata under non-saline conditions was investigated. Next, the most suitable AM treatment was chosen to examine the impact of AMF on physio-biochemical features and polyphenol profiles of E. prostrata under saline conditions (100 and 200 mM NaCl). The findings indicated that AMF mixture application resulted in more effective promotion on the aboveground part of non-saline plants than single AMF species. AM mixture application improved growth and salt tolerance of E. prostrata through increasing the activity of catalase, peroxidase (at 4 weeks), proline, and total phenolic content (at 8 weeks). Such benefits were not observed under high salinity, except for a higher total phenolic concentration in mycorrhizal plants at 8 weeks. Through high-performance liquid chromatography, 14 individual phenolic compounds were analyzed, with wedelolactone and/or 4,5-dicaffeoylquinic acid abundant in all treatments. Salinity and mycorrhizal inoculation sharply altered the polyphenol profiles of E. prostrata. Moderate salinity boosted phenolic compound production in non-AM plants at 4 weeks, while at 8 weeks, the decline in the content of phenolic compounds occurred in uncolonized plants subjected to both saline conditions. Mycorrhization augmented polyphenol concentration and yield under non-saline and saline conditions, depending on the growth stages and salt stress severity. Plant age influenced polyphenol profiles with usually a higher content of phenolic compounds in older plants and changed the production of individual polyphenols of both non-AM and AM plants under non-stress and salt stress conditions. A better understanding of factors (involving mycorrhiza and salinity) affecting the phenolic compounds of E. prostrata facilitates the optimization of individual polyphenol production in this medicinal plant.

Quantifying Changes in Surface Elevation in Conjunction with Growth Characteristics of Incipient and Foredune Vegetation

McGuirk, M.T.; Kennedy, D.M.; Konlechner, T., and Chiaradia, A., 2021. Quantifying changes in surface elevation in conjunction with growth characteristics of incipient and foredune vegetation. Journal of Coastal Research, 37(1), 216-224. Coconut Creek (Florida), ISSN 0749-0208. Vegetation is critical for the initiation and growth of incipient dunes and foredunes by providing structure to entrap and store sand. Vegetation characteristics (leaf length, width, height, and quantity) directly influence the rate and volume of sand deposition and therefore the final dune morphology. This paper describes a low-cost and highly portable method to quantify changes in sand surface elevation in relation to plant growth character. A sediment elevation platform was constructed from steel and Perspex, from which surface elevation and plant character can be measured with a movable wooden dowel. This was used in conjunction with a point intercept pin frame to quantify leaf height and number of touches, from which leaf density and frequency were calculated. The system is collapsible, lightweight, and costs AUD 360. It may be operated by a single person. It was tested in a pilot study conducted at Phillip Island, Australia. Plant attributes of two dominant coastal grasses (Spinifex sericeus and Thinopyrum junceiforme) were quantified in December 2018 and January 2019, and sand elevation changes were quantified in January and February 2019. Data collected during the measurement period displayed the influence of plant growth on sand accumulation on a monthly scale. Measurements showed an increase in sand surface elevation from January to February. The average vertical sand accretion for the quadrant with T. junceiforme in January was 29 mm and in February was 89 mm, whereas S. sericeus had an average vertical sand accretion for January of 95 mm and for February of 162 mm. The number of leaves of S. sericeus increased from December (48) to January (169). This new method enables tracking of changes in sand morphology, along with the specific plant growth characteristics. This knowledge may enable the planning of specific dune morphologies using specific plant species and assist in dune recovery after erosion.

Management of Root-Knot Nematode (Meloidogyne incognita) on Bell Pepper (Capsicum annuum L.) under Green House Condition

A trial was conducted under green house condition to study the efficacy of some chemicals as soil fumigation and soil application on plant growth characters and reproduction of M. incognita infecting bell pepper. In this study, chemicals viz. metham sodium at 20 ml/m2, 30 ml/m2, 40 ml/m2, fluensulfone at 5 g/m2, 10 g/m2, 15 g/m2 and carbofuran at 20 g/m2 were applied and suitable control was also maintained for comparison. Observations on plant growth characters (shoot and root length, shoot and root weight) and nematode reproduction factors (number of galls per 5g root, number of egg masses per 5g root, nematode population/200 cc soil) and yield kg/plant were recorded. Results showed that metham sodium @ 40ml/m2 was best treatment to improve the plant growth characters, yield and reducing nematode reproduction on bell pepper.

Effect of some Amino Acids and Yeast on Root-knot Disease on Tomato Plants

Three amino acids (AAs) viz. glycine, L-proline and L- tryptophan plus yeast fungus, Saccharomyces cerevisiae, were tested against root knot disease, RKD, caused by root-knot nematode, Meloidogyne incognita on tomato cv. Super Strain-B. All AAs and yeast showed significant reduction in the number of galls, developmental stages, egg masses and fecundity of the treated plants associated with corresponding positive response in plant growth characters. tryptophan gave significantly higher response in reducing the final nematode population followed by L-proline and glycine at high concentrations compared with yeast and check plants. In most cases, the soil drench application was more effective than foliar spray in reducing nematode build-up. The inhibitory effect of all treatments on nematode reproduction was positively correlated with increasing the concentration used. Plant growth was also promoted by all treatments used. generally, All AAs gave significant impact in suppressing the development of the nematode pathogen and sequentially reliving the disease severity. Results of this research offered environmentally safe approaches for combating root-knot disease. Further researches are needed to determine the proper doses, and concentrations of tested AAs and yeast under semi-field and field conditions. Investigations must include the impact on plant yield, before recommending them for managing root-knot disease or promoting plant growth on a wide scale.

Effect of seedling age and different levels of fertilizer on growth and yield of transplanted finger millet (Eleusine coracana L.)

The experiment was carried out for the evaluation of seedling age and different levels of fertilizer on growth and yield of transplanted finger millet Co (Ra) 15during rabi season of 2019-2020 at Agricultural College and Research Institute, Killikulam. The experiment was laid in split plot design and replicated thrice. The main plot consists of different age of seedlings viz., 15, 18 and 21 days old seedlings raised with nutrient media. Simultaneously 17 days old seedlings also raised as conventional method. In subplot different levels of recommended fertilizer dose viz., 75, 100 and 125% were imposed. During the cropping, various plant growth characters such as plant height and drymatter production were recorded at harvest stage and number of tillers hill-1 was recorded at 60 DAT. The yield characters like number of productive tillers, number of earheads m-2, number of filled grains earhead-1, grain and straw yield were also recorded. The experimental result shows that planting 15 days old seedlings from nutrient media along with application of 125% RDF recorded significantly higher plant height (108.5 cm), number of tillers hill-1 (8.9), drymatter production (9524 kg ha-1), number of productive tillers hill-1 (6.9), number of earheads m-2 (153), number of filled grains earhead-1 (1696), grain (3602 kg ha-1) and straw yield (6484 kg ha-1) and it was on par with15 days old seedlings from nutrient media along with 100% RDF.

The effect of the nanosilica/oligochitosan hybrid material on the growth of lettuce (Lactuca sativa L. var. longifolia)

A nanostructured hybrid material prepared from eco-friendly natural materials such as nanosilica (nSiO2) extracted from rice husk and oligochitosan (OS) isolated from shrimp shells is material of high promise with special properties to be applied in various fields, especially in agriculture. In this study, hybrid nanosilica material based on oligochitosan (SOS) with a concentration of 50 mg/L as nutrient source was supplied to the lettuce (Lactuca sativa) at different stages of growth. The two-week-old lettuce (H2W2) supplied with the hybrid material had an increase in leaf length by 17.24% and root length by 5.26% in comparison with those of the control lettuce. Additionally, the fresh weight and leaf number of the hybrid-supplied plant were 20.39% heavier and 9.09% higher than those of the control samples, respectively. Moreover, the chlorophyll measurement indicated that the total chlorophyll content of H2W2 was 7.61% higher than that of the control, and the plant growth characteristics also increased by 20.39% compared with the control plant. The SOS hybrid material could be seen as a green agrochemical with a great promise of being applied in the modern agriculture. This kind of renewable material also contributes to replacing and declining the numbers of the type of toxic chemical fertilizers and plant protection products used on the market today.

不同密度猪毛菜形态结构性状及生物量分配策略的异速关系

植物的生长特性随环境条件的变化具有可塑性，而不同的环境因素对植物可塑性的影响也不尽相同。利用异速分析的方法，通过模拟退化草地恢复过程中猪毛菜（Salsola collina）的不同种群密度（16、44、100、400株/m²），研究其形态结构性状及生物量分配策略的异速关系在种群密度间的差异。结果表明，种群密度增大能抑制猪毛菜的生长，而且对猪毛菜的株高、根长、一级分枝数、二级分枝数、三级分枝数以及总分枝长均产生了极显著的影响，表明种群密度的变化使得植物的高生长和侧向生长发生了显著变化。种群密度的变化也引起了植物生物量的变化，其中植物根、茎、叶间的生物关系是一种表观可塑性，植物的生长策略未发生改变，只是植物个体大小发生改变引起的生物量分配的变化。植物株高、总分枝长、一级分枝数及繁殖分配的变化，是由种群密度变化引起的，植物的适应策略发生了改变，是真正的可塑性。种群密度改变了植物的繁殖分配策略，而未改变植物叶的分配策略，说明当环境发生变化时，植物调整了其繁殖策略以适应环境因素的改变，以保证种群的生存繁衍。;Plant growth characteristics have plasticity in response to changes of environmental conditions, and different environmental factors have different effects on plant plasticity. The allometric method was used to analyze the morphological-structural traits and biomass allocation strategies by simulating population densities of S. collina (16, 44, 100 and 400 plants/m²) during the restoration of degraded grassland. The results showed that the increased population density could inhibit the growth of S. collina. population density had significant effects on plant height, root length, primary branch number, second-level branch number, third-level branch number, and total branch length, indicating that population density changes have caused significant changes in vertical and lateral growth of S. collina. Population density changes also influenced on the biomass of plant. The biological relationships between roots, stems, and leaves are an apparent plasticity, and the growth strategy has not changed at all, only the variation of biomass allocation were caused by the change of individual plant size. Changes in plant height, total branch length, primary branch number and reproductive biomass allocation were significantly influenced by population density, representing true plasticity. The results showed that variation of population density caused the strategy change of the reproductive allocation rather than the leaf allocation, indicating that when environment changes, plant would adjust the reproductive strategy to adapt to surrounding environmental factors, to ensure the survival and reproduction of the population.

Research Progress on Growth Characteristics of Invasive Plants in Different Habitats

Biological invasion generates serious threats to global biodiversity. Exotic species usually have high environmental adaptability and tolerance, which is one of the bases of their invasion. Except for biological invasion threats, other serious environmental problems like extreme cold or hot events, soil drought, saline-alkali and flood are emerging constantly on a global scale. In the background of multiple environmental problems interfering with existing habitats, exploring the growth characteristics of invasive plants in different habitats, and grasping the reasons why the invasive plants can obtain growth superiorities are in favor of propelling the understanding of their invasion mechanism. This paper gives an overview of research progress on the invasive plants’ morphological characteristics and physiological characteristics in deferent habitats, summarizes the growth specialties of invasive plants which are affected by high temperature, low temperature, drought and flood, and discusses the reasons why the invasive plants prevail in the growth competitions, which provided theoretical and realistic signification to relieve the biological invasion current status.

Effect of addition of lanthanum-modified bentonite(Phoslock&lt;sup&gt;&amp;#174;&lt;/sup&gt;) in sediments on growth of &lt;i&gt;Hydrilla verticillata&lt;/i&gt; under different water nutrient concentration

轮叶黑藻（Hydrilla verticillata）是我国浅水湖泊常见的沉水植物，经常用于湖泊生态修复工程.然而在生态修复中后期，轮叶黑藻又往往会过度繁殖，影响其他湖泊功能的发挥.镧改性膨润土（锁磷剂）可以有效地降低沉积物中生物可利用磷含量，近年来被用于控制湖泊沉积物磷释放，其对轮叶黑藻生长和形态的影响还有待阐明.本研究在2种不同上覆水营养盐浓度条件下，设置添加和不添加锁磷剂2种处理，探究沉积物添加锁磷剂对轮叶黑藻生长及形态特征的影响.结果表明：1）沉积物添加锁磷剂之后，铁锰结合态磷、有机磷、铝结合态磷等生物可利用磷浓度显著降低，而生物不可用磷，如钙结合态磷浓度显著升高；2）沉积物添加锁磷剂显著降低了轮叶黑藻的生物量和生长率.添加锁磷剂的处理组植物的株高、地上部分生物量均明显低于无锁磷剂组；相反，添加锁磷剂显著增加了植物的根长和地下部分生物量，进而提高了植物的根冠比；3）锁磷剂对轮叶黑藻生长的影响程度与水体营养盐浓度有关，在低营养盐浓度水体中锁磷剂对植物生长和形态特征的影响更为显著.本研究表明，锁磷剂的添加能降低沉积物中生物可利用磷浓度，抑制轮叶黑藻的生长，同时这种影响程度与在水体营养盐浓度有关.;Hydrilla verticillata is a common submerged plant in shallow lakes in China, and is often used as a pioneer species in lake ecological restoration projects. However, the Hydrilla verticillata tends to overgrowth, forming a canopy which affects other functions of lakes. Lanthanum-modified bentonite (Phoslock^®) can effectively reduce the bioavailable phosphorus content in sediments. In recent years, it has been used to control phosphorus release from lake sediments. Its impact on the growth and morphology of Hydrilla verticillata remains to be clarified. In this study, two treatments with and without Phoslock^® in the sediments were set up to investigate the effects of Phoslock^® on the growth and morphological characteristics of Hydrilla verticillata under two different water nutrient concentrations. The results show that:1) After adding Phoslock^® to the sediments, the bioavailable phosphorus concentration, such as Fe/Mn combined phosphorus (BD-P), organic phosphorus (Org-P), Aluminum-bound phosphorus (Al-P), is significantly reduced, while the non-bioavailable phosphorus concentration, such as Calcium-bound phosphorus (Ca-P), is significantly increased. 2) The addition of Phoslock^® in the sediments significantly reduced the biomass and growth rate of the Hydrilla verticillata. The plant height and aboveground biomass of Phoslock^® group were significantly lower than those without Phoslock^®; on the contrary, the addition of Phoslock^® significantly increased the root length of the plant and the underground biomass, and increased the plant's root-shoot ratio. 3) The effect of Phoslock^® on the growth of Hydrilla verticillata is related to the concentration of nutrients in the water, and the effect of Phoslock^® on plant growth and morphological characteristics is more significant in low-nutrient water. Overall, this study shows that the addition of Phoslock^® can effectively reduce the concentration of bioavailable phosphorus in sediments and inhibit the growth of Hydrilla verticillata, and this effect is more significant when the concentration of nutrients in the water is reduced.

THE ROLE OF COMPOST, AMINO ACIDS, SILICON AND SEAWEEDS EXTRACT IN ENHANCING THE GROWTH, YIELD AND ACTIVE INGREDIENTS OF ROSELLE PLANTS

This investigation was conducted at the Experimental Farm Faculty of Agriculture, Al-Azhar Univ., Assiut during the two successive seasons of 2018 and 2019 to determine the influence of compost as organic fertilization and foliar Spray with stimulant substance namely (amino acids [tryptophan + methionine + phenylalanine], silicon and seaweeds extract), as well as their interactions on plant growth traits, sepals. yield / plant and fed. and active ingredients of roselle (Hibiscus sabdariffa, L.) C.V. "Sabahia 17" dark line plants. Compost was applied at 0, 8, 16 and 24 m³/ fed., and spraying the plants with the three examined stimulant substances as follows: control (no sprayed plants), amino acids at 300 ppm, silicon at 1 ml/L, seaweeds extract at 3 ml/L, amino acids + silicon, amino acids + seaweeds extract, silicon+ seaweeds extract, amino acids + silicon + seaweeds extract. The revealed results indicated that the use of compost at all levels led to a significant increase in plant growth traits (plant height, branch number / plant and herb dry weight/ plant) and also sepals dry yield/ plant and /fed., as well as % anthocyanin. In addition, all levels of compost significantly augmented acidity % except for the low one of compost (8 m³/ fed.) in the second season. The highest values of these traits were detected by applying the high level of compost (24 m³/ fed.). It could be noticed. That foliar spray with stimulant substances either single or together resulted a significant augment in these studied parameters, except for silicon treatment, mostly and, also amino acids treatment concerning acidity % in the second season. The application of the triple combined treatment (amino acids + silicon + seaweeds extract), followed, by the double combined one (amino acids + seaweeds extract) gave the highs values of plant growth characteristics. In connection, the highest values of sepals yield/ plant and fed., % acidity and anthocyanin % were given by foliar spray with the triple combined treatment (amino acids + silicon + seaweeds extract). The data showed that all studied traits were significantly affected by interaction treatments. Most combined treatments caused a significant increase in all examined parameters. In most cases, the addition of compost at the high level (24 m³/ fed.) with foliar spray with the triple combined treatment (amino acids + silicon + seaweeds extract), followed by the double combined one (amino acids + seaweeds extract).

Effect of Humic Acid, Biofertilizers and Mineral Phosphate on Soil Microbial Activity and Productivity of Pea Plants under Toshka Conditions

Two field experiments were conducted during the winter season of 2015/2016 & 2016/2017, at Toshka Research Station - Desert Research Center. The aim of the study was to investigate the effect of humic acid (HA) at rates of 0, 4 and 8 kg / fed. combined with phosphate dissolving bacteria(PDB) and mineral phosphate fertilizer at rates of 100, 90, 80 and 70% P2O5 of the recommended dose in commercial production on pea plants. Treatment with humic acid at 8 kg / fed. combined with inoculation of PDB and 100% of mineral phosphate fertilizer significantly increased the total microbial count, Bacillus megaterium count, CO2 evolution , organic carbon and phosphatase and dehydrogenase enzymes activities. The bio-fertilizer treatments (PDB) showed a clear superiority when added in combination with the phosphate fertilizer and humic acid compared to the results of using a mixture of humic acid and superphosphate only. Adding of humic acid and superphosphate with the presence of phosphate dissolving bacteria improved most of the vegetative growth characteristics of plants. Yield components had the highest positive response to humic acid combined with mineral fertilizer percentage with phosphate-dissolving bacteria. The highest concentration of N, P, and K were with the use of humic acid at (8 kg), phosphate-dissolving bacteria and 100% phosphate fertilization P2O5. The study revealed that using 8 kg HA/fed in combination with PDB and high level of P2O5 as a fertilizer application to improve soil properties, vegetative growth, mineral content and yield of pea plants in new soils was recommended.

Design of an Unmanned Ground Vehicle and LiDAR Pipeline for the High-Throughput Phenotyping of Biomass in Perennial Ryegrass

Perennial ryegrass biomass yield is an important driver of profitability for Australian dairy farmers, making it a primary goal for plant breeders. However, measuring and selecting cultivars for higher biomass yield is a major bottleneck in breeding, requiring conventional methods that may be imprecise, laborious, and/or destructive. For forage breeding programs to adopt phenomic technologies for biomass estimation, there exists the need to develop, integrate, and validate sensor-based data collection that is aligned with the growth characteristics of plants, plot design and size, and repeated measurements across the growing season to reduce the time and cost associated with the labor involved in data collection. A fully automated phenotyping platform (DairyBioBot) utilizing an unmanned ground vehicle (UGV) equipped with a ground-based Light Detection and Ranging (LiDAR) sensor and Real-Time Kinematic (RTK) positioning system was developed for the accurate and efficient measurement of plant volume as a proxy for biomass in large-scale perennial ryegrass field trials. The field data were collected from a perennial ryegrass row trial of 18 experimental varieties in 160 plots (three rows per plot). DairyBioBot utilized mission planning software to autonomously capture high-resolution LiDAR data and Global Positioning System (GPS) recordings. A custom developed data processing pipeline was used to generate a plant volume estimate from LiDAR data connected to GPS coordinates. A high correlation between LiDAR plant volume and biomass on a Fresh Mass (FM) basis was observed with the coefficient of determination of R2 = 0.71 at the row level and R2 = 0.73 at the plot level. This indicated that LiDAR plant volume is strongly correlated with biomass and therefore the DairyBioBot demonstrates the utility of an autonomous platform to estimate in-field biomass for perennial ryegrass. It is likely that no single platform will be optimal to measure plant biomass from landscape to plant scales; the development and application of autonomous ground-based platforms is of greatest benefit to forage breeding programs.

Effects of different planting approaches and site conditions on aboveground carbon storage along a 10-year chronosequence after moso bamboo reforestation

Moso bamboo (Phyllostachys pubescens) is widely used for afforestation and reforestation in subtropical China because of its high carbon (C) sequestration rate and ability to control soil erosion in degraded areas; it also plays an important role in mitigating climate change. To satisfy the requirements of carbon trading systems, methodologies for estimating changes in C storage under different planting approaches and site conditions are needed. A 10-year field monitoring study of a moso bamboo reforestation area was carried out to research the effects of different planting approaches and site conditions on stand structure dynamics and aboveground C storage accumulation (AGCSA). The bamboo was transplanted in groups of 3 plants (3-PG) or as individual plants (IP). The site conditions were classified into three categories (poor, fair and excellent). The bamboo diameter at breast height (DBH) and height exhibited a slow-fast-slow growth rate trend under both planting approaches. The DBH and height peaked in the 9th year under the 3-PG approach, but maximum DBH and height values were not reached under the IP approach during the study period. The density (D) of new culms (NCs) peaked at five years after reforestation under both planting approaches, and the aboveground C storage (AGCS) of NCs peaked seven years after reforestation. Both planting approaches exhibited clear on-year and off-year plant growth characteristics. The different planting approaches and site conditions significantly influenced AGCSA. Growth models for DBH, height and AGCSA under the specific silvicultural approaches and site conditions were established on the basis of the identified correlations. Ten years after reforestation under the 3-PG approach, the AGCSA was only 3.71 Mg C ha−1 under poor site conditions, while under excellent site conditions, the AGCSA reached 14.71 Mg C ha−1. An optimized management model that considers soil factors has great potential for improving C sequestration in moso bamboo forests.