A study was conducted to evaluate the effects of sludge (industrial and residential) on seed germination and growth performance of Acacia auriculiformis seedlings at the nursery of Institute of Forestry and Environm...A study was conducted to evaluate the effects of sludge (industrial and residential) on seed germination and growth performance of Acacia auriculiformis seedlings at the nursery of Institute of Forestry and Environmental Sciences, Chittagong University (IFESCU), Bangladesh. Before sowing of the seeds, different combinations of sludge were incorporated with the nutrient-deficient natural forest soils. Seed germination and growth parameters of the seedlings (shoot and root length, collar diameter, fresh and dry weight of shoot, and root and total dry biomass) were recorded after one, two and three months of seed sowing. Physio-chemical parameters (pH, organic carbon, nitrogen, phosphorus, and potassium) and heavy metals (chromium, nickel, manganese, cadmium and zinc) of each treatment were also analyzed before sowing of seeds and after harvesting of seedlings. Results show that the seed germination percentage and the seedling growth parameters varied significantly in the soil added with sludge in comparison to control. The highest germination percentage (90%) was observed in the treatment of soil with residential sludge of 2:1 compared to control. The highest growth and biomass of the seedlings as well as the maximum percentage of organic carbon and nutrients (N, P and K) were also recorded in the same combination. Soil added with industrial sludge had a higher concentration of heavy metal than that of residential sludge. The highest concentrations of heavy metals were found in soil added with industrial sludge of 1:1. It is recommended that soil added with residential sludge of 2:1 provide good condition for better seed germination and growth ofA. auriculiformis seedlings in degraded forest soil.展开更多
Dwindling supplies of bamboo resources and the increase in the demand for bamboo ha</span></span><span><span><span style="font-family:"">ve</span></span></sp...Dwindling supplies of bamboo resources and the increase in the demand for bamboo ha</span></span><span><span><span style="font-family:"">ve</span></span></span><span><span><span style="font-family:""> led to the need for better propagation techniques. This is the only way to ensure the sustainability of the bamboo resource base and improve livelihoods. Thus, this study was carried out to examine the different growth parameters of culm cuttings of <i>Bambusa vulgaris</i> in propagation beds with a substrate consisting of dark soil, manure (compost) and sand in a ratio of 1:1:1. Data on different growth parameters was collected on a daily basis over a three week period and analyzed using appropriate descriptive and inferential statistics. It was found that the different growth parameters (diameter, height, leaves and sheaths) of culm cuttings of <i>B. vulgaris</i> evolved in like manner in three propagation beds. Descriptive statistics for growth parameters of culm cuttings of <i>B. vulgaris</i> showed little or no differences across three shelter/propagation beds (shelter bed 1, shelter bed 2 and shelter bed 3) with 1.4675 ± 1.6172 cm, 93 ± 112 cm, 22 ± 30 leaves, and 4 ± 6 sheaths being the mean diameter, height, number of leaves and number of sheaths for all three propagation beds, respectively. ANOVA test showed no statistically significant variation (<i>p</i> > 0.05) between growth parameters of culm cuttings of <i>B. vulgaris</i> across the three propagation beds, implying that the different growth parameters were relatively similar. Pearson correlation showed the existence of direct and inverse relationships between the different growth parameters of culm cuttings of bamboo. The existence of these direct and inverse relationships could be attributed to the rapid growth rate of bamboo, the substrate used, and the species of bamboo used (<i>B. vulgaris</i>). The study recommends more large-scale propagation projects of this bamboo species in order to ensure the sustainability of the bamboo resource base and improve livelihoods of bamboo dependent rural communities.展开更多
The growth parameters and mortalities of five species of Synodontis in the lower river Benue at Makurdi,Benue State were studied from January,2016 to December,2018.The asymptotic length(L∞)calculated for the five spe...The growth parameters and mortalities of five species of Synodontis in the lower river Benue at Makurdi,Benue State were studied from January,2016 to December,2018.The asymptotic length(L∞)calculated for the five species ranged from 18.80cm in S.clarias females to 37.04cm in S.membranaceus females.The t0 values were all negative in the combined sexes of S.clarias,S.omias,S.gambiensis and S.membranaceus.In both combined sexes of S.membranaceus and S.schall,the t0 values were positive.The growth rate(K)was low in S.clarias and S.omias(0.301-0.497,0.171-0.310)respectively and higher in S.membranaceus(0.310-0.640),S.schall females(0.430-0.580);S.schall males(0.573),S.gambiensis(0.500-0.571).Growth performance index(Ø’)was 2.212 in S.gambiensis and 2.946 in S.schall combined.Natural Mortality(M)ranged from 0.5422 in S.omias females to 1.3340 in S.membranaceus males.Fishing Mortality(F)was 0.8214 in S.omias combined and 3.0934 in S.membranaceus females.Total mortality(Z)ranged from 1.52 in S.omias combined to 4.078 in S.membranaceus combined.Mean Exploitation(E)ratios was 0.61 in S.clarias,0.64 in S.omias,0.53 in S.gambiences,0.70 in S.membranaceus,and 0.66 in S.schall.The rate at which these species survived in the River was low(from 0.147,in S.omias combined,to 1.482 in S.membranaceus combined).展开更多
The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and...The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and annealing temperature)on the growth and properties(e.g., surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer(XRD), scanning electron microscope(SEM), and ultraviolet-visible spectrophotometer(UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the β-Ga_(2)O_(3) film are influenced by those parameters. All β-Ga_(2)O_(3) films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The I–V curves show that the Ohmic behavior between metal and β-Ga_(2)O_(3) films is obtained at 900℃. Those results will be helpful for the further research of β-Ga_(2)O_(3) photoelectric semiconductor.展开更多
Sprouts are ready-to-eat and are recognized worldwide as functional components of the human diet.Recent advances in innovative agricultural techniques could enable an increase in the production of healthy food.The use...Sprouts are ready-to-eat and are recognized worldwide as functional components of the human diet.Recent advances in innovative agricultural techniques could enable an increase in the production of healthy food.The use of light-emitting diode(LED)in indoor agricultural production could alter the biological feedback loop,increasing the functional benefits of plant foods such as wheat and lentil sprouts and promoting the bioavailability of nutrients.The effects of white(W),red(R),and blue(B)light were investigated on the growth parameters and nutritional value of wheat and lentil sprouts.In the laboratory,seeds were sown under three different LED treat-ments:white,red,and blue light,while normal incandescent light served as a control.Percentage seed germina-tion improved by 18.34%and 12.67%for wheat and 18.34%and 12.67%for lentil sprouts under LED treatments R and B,respectively.An increase in total soluble protein and sugar by 33.4%and 9.23%in wheat and by 31.5%and 5.87%in lentils was observed under the R LED treatment.Vitamin C concentrations in wheat and lentils were significantly increased by R LED compared to all other treatments.Other parameters,including potassium and sodium concentrations,were significantly increased under red and blue light compared to the control;white light,on the other hand,significantly decreased all these parameters.According to the experimental data,red and blue LED light could be beneficial in the production of functional wheat and lentil sprouts with high nutrient concentrations.展开更多
A field experiment was carried out at Ismailia Research Station, Ismailia Governorate from 2020-2022 to improve the growth of Khaya senegalensis and Swietenia mahagoni by using a combination of mineral fertilizer (NPK...A field experiment was carried out at Ismailia Research Station, Ismailia Governorate from 2020-2022 to improve the growth of Khaya senegalensis and Swietenia mahagoni by using a combination of mineral fertilizer (NPK) and biological fertilizer (Azotobacter chroococcum, Bacillus megatherium, and Bacillus circulant) as recommended dose under new sandy soils conditions. Split plot designed with four treatments (Control, (50% Mineral fertilizer (M.) + 50% Biological fertilizer (Bio.)), 100% M. and 100% Bio.) of each species. Vegetative growth, leaf area, tree biomass, stored carbon, basal area, tree volume, and in the soil both of microbial account and mineral content were determined. The experimental results showed no significant differences between studied species among the most studied parameters except for Khaya senegalensis which gave the highest significant difference in root biomass and below-stored carbon than Swietenia mahagoni. Evidently, the highest significant growth parameters were 100% mineral fertilizer followed by (50% M. + 50% Bio.) as compared with control. No significant difference between 100% M. and (50% M. + 50% Bio.) of shoot dry biomass (15.19 and 12.02 kg, respectively) and above-stored carbon (0.28 and 0.22 Mt, respectively). Microbial account and mineral content in soil were improved after cultivation of tree species compared to before planting and control, especially with 50% mineral fertilizer and 50% bio-fertilizer treatment. In conclusion, a treatment containing 50% mineral fertilizer and 50% bio-fertilizer has led to the ideal Khaya senegalensis and Swietenia mahagoni growth in sandy soil for cheaper and sustainable.展开更多
Plants are essential components of all ecosystems and play a critical role in environmental fate of nanoparticles. However, the toxicological impacts of nanoparticles on plants are not well documented. Titanium dioxid...Plants are essential components of all ecosystems and play a critical role in environmental fate of nanoparticles. However, the toxicological impacts of nanoparticles on plants are not well documented. Titanium dioxide nanoparticles(TiO2-NPs) are produced worldwide in large quantities for a wide range of purposes. In the present study, the uptake of TiO2-NPs by the aquatic plant Spirodela polyrrhiza and the consequent effects on the plant were evaluated.Initially, structural and morphological characteristics of the used TiO2-NPs were determined using XRD, SEM, TEM and BET techniques. As a result, an anatase structure with the average crystalline size of 8 nm was confirmed for the synthesized TiO2-NPs. Subsequently, entrance of TiO2-NPSto plant roots was verified by fluorescence microscopic images. Activity of a number of antioxidant enzymes, as well as, changes in growth parameters and photosynthetic pigment contents as physiological indices were assessed to investigate the effects of TiO2-NPs on S. polyrrhiza. The increasing concentration of TiO2-NPs led to the significant decrease in all of the growth parameters and changes in antioxidant enzyme activities. The activity of superoxide dismutase enhanced significantly by the increasing concentration of TiO2-NPs. Enhancement of superoxide dismutase activity could be explained as promoting antioxidant system to scavenging the reactive oxygen species. In contrast, the activity of peroxidase was notably decreased in the treated plants. Reduced peroxidase activity could be attributed to either direct effect of these particles on the molecular structure of the enzyme or plant defense system damage due to reactive oxygen species.展开更多
An M-shaped interface was observed in the top part of Φ76. 2 mm , (111) , dislocation-free, heavily Sb-doped Si single crystals, which is beneficial for crystals to keep dislocation-free condition at the beginning of...An M-shaped interface was observed in the top part of Φ76. 2 mm , (111) , dislocation-free, heavily Sb-doped Si single crystals, which is beneficial for crystals to keep dislocation-free condition at the beginning ofbody growth. Effects of seed rotation, crucible rotation , crown shape and growth rate on M-shaed interfacewere studied. Under proper conditions, impurity core length can be shortened from 6 cm to 1 cm , the yield israised by more than 5 %.展开更多
financially supported by the Science and Technology Develop Project of Northern Jiangsu, China (BN2015136);the Priority Academic Program Development of Jiangsu Higher Education Institution, China
Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bang...Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bangladesh. The effects of P-fertilizer on seedling growth and nodulation were comparcd to that of seedlings grown in unfertilized soil or in control at different harvesting intervals. The study revealed that, seedling growth was enhanced significantly with the application of P-fertilizer. The growth was found more pronounced in cases of A. saman and P. pinnata, whereas it was not noticeable and showed depressed growth in case of A. chinensis. The study also suggests that nodulation in terms of nodule number and size was also increased significantly with P-fertilization except in case ofP. pinnata, where higher harvesting intervals lowered the nodulation performance of that species展开更多
The stimulatory effects of atmospheric pressure cold plasma(APCP)on plant growth have attracted much attention due to its great potential as a new approach to increase crop growth and production.However,the transcript...The stimulatory effects of atmospheric pressure cold plasma(APCP)on plant growth have attracted much attention due to its great potential as a new approach to increase crop growth and production.However,the transcriptome changes of plants induced by APCP treatment are unknown.Herein,the comparative transcriptome analysis was performed to identify the transcriptional response of Arabidopsis thaliana seedlings to APCP.Results showed that APCP exhibited a dual effect(stimulation or inhibition)on Arabidopsis seedling growth dependent on the treatment time and the maximum stimulatory effects were achieved by 1 min APCP treatment.The metabolic analysis of amino acid,glutathione(GSH)and phytohormone demonstrated that 1 min APCP treatment decreased most amino acids concentrations in Arabidopsis seedling,while the accumulations of GSH,gibberellins and cytokinin were significantly increased.The RNA-Seq analysis showed that a total of218 differentially expressed genes(DEGs)were identified in 1 min APCP-treated seedlings versus the control,including 20 up-regulated and 198 down-regulated genes.The DEGs were enriched in pathways related to GSH metabolism,mitogen-activated protein kinase(MAPK)signaling transduction and plant resistance against pathogens.Moreover,most of the DEGs were defense,stimuli or stressresponsive genes and encoded proteins with oxidoreductase activity.Expression determination of six randomly selected DEGs by quantitative real-time PCR demonstrated similar pattern with the RNASeq data.These results indicated that the moderate APCP treatment may regulate the expression of stimuli/stress-responsive genes involved in GSH,phytohormone/amino metabolism and plant defense against pathogens via MAPK signal transduction pathway,accordingly enhance Arabidopsis seedling growth.This study provides a theoretical basis for the application of APCP in agriculture.展开更多
Sequel to complaints by cashew farmers on poor establishment rate of cashew seedlings on rehabilitated moribund cashew plantations in south western Nigeria, a fertilizer trial involving the use of organic materials (...Sequel to complaints by cashew farmers on poor establishment rate of cashew seedlings on rehabilitated moribund cashew plantations in south western Nigeria, a fertilizer trial involving the use of organic materials (cow-dung, poultry droppings, cocoa and kola pod husks) compared to NPK and control (no fertilizer) treatments was conducted on the growth performance of cashew seedlings at Ibadan, Nigeria. The fertilizers were applied to supply 15 g N seedlingl in 3 replications. Cashew seedling growth parameters and dry matter yield were determined. Fertilizers resulted to consistently general higher plant height, girth, number of leaves and leaf area compared to NPK and control. The differences in the mean values were however not significantly different for girth but it was significant (P 〈 0.5) for plant height, number of leaves and leaf area, while there was no particular regular trend for plant number of branches. Plant root lengths were significantly higher using the organic fertilizers than NPK and control. Similar trend was obtained in the dry weight values for plant leaf, stem, root and total dry matter yield. There was however no consistent significant effect on NPK usage over control for all the parameters. It was therefore deduced that optimal growth performance and better establishment of cashew seedlings could be obtained with the use of organic fertilizers rather than inorganic fertilizer. The use of cocoa pod husk followed by cow-dung and poultry droppings were outstanding in better growth and dry matter yield performance of cashew seedlings and were advised for this purpose.展开更多
We studied the effect of growth on wood anatomical dimensions and specific gravity of seed-raised plantation wood of Dalbergia sissoo with twelve trees of different diameters and similar ages. Fiber length ranged from...We studied the effect of growth on wood anatomical dimensions and specific gravity of seed-raised plantation wood of Dalbergia sissoo with twelve trees of different diameters and similar ages. Fiber length ranged from 925 to1,287 lm, fiber-diameter was 19–23 lm, wall thickness was4.2–5.4 lm, vessel-element-length was 152–188 lm, vesselelement-diameter was 152–200 lm, and specific gravity was0.59–0.72. Growth parameters including tree height, diameter at breast height, net primary productivity and net ecosystem productivity were significantly and positively correlated.Growth parameters showed non-significant positive relationships with fiber-length, fiber diameter, wall thickness, vessel element length, and vessel element diameter. The trend of wood traits increased with growth. Specific gravity showed non-significant negative relationships with growth parameters. Although the growth rate had varied relationships with wood properties, as reported by various workers, the wood element dimensions showed no significant relationship with growth parameters and there was little effect of growth rate on wood traits in seed-raised plantation of D. sissoo.展开更多
An experiment was conducted to assess the effect of Phosphorous (P) fertilizer (i.e. TSP or triple super phosphate @ 80 kg/hm^2) on seedling growth and nodulation capabilities of three potentially important agrofo...An experiment was conducted to assess the effect of Phosphorous (P) fertilizer (i.e. TSP or triple super phosphate @ 80 kg/hm^2) on seedling growth and nodulation capabilities of three potentially important agroforestry tree species (Acacia auriculiformis, Albizia lebbeck and Albizia procera) of Bangladesh. The study was conducted in nursery beds with six-month-old polybag seedlings ofA. auriculiformis, A. lebbeck and A. procera. The effects of P fertilizer on seedling growth and nodulation were compared with that of the seedlings grown in control (i.e. unfertilized soil). The observations revealed that the seedling growth was enhanced significantly with the application of P fertilizer. The growth was found more pronounced in A. auriculiformis, whereas it was not apparent and shows depressed growth in case ofA. lebbeck. The study also suggests that the nodulation in terms of nodule number and size was also increased significantly with the application of P fertilizer.展开更多
Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on differen...Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on different land uses.We quantified the growth and nutrient uptake of F.albida seedlings inoculated with AM from different sources.These efforts were based on soil and fine root samples from the rhizosphere soils of F.albida trees.AM root colonization was determined using the gridline intersect method.Spores were extracted by the wet sieving and decanting method and identified to genus level.The seedling experiment had a completely randomized onefactorial design with four treatments and five replications.Faidherbida albida seedlings were grown in a greenhouse.All in situ F.albida trees were colonized by AM fungi.AM root colonization of F.albida trees was significantly higher(P<0.0086)in area exclosures than on lands used for grazing or cultivation.Spore abundance was significantly higher(P<0.0014)in area exclosures followed by cultivated land and grazing land.Glomus was the dominant genus in all land-uses.AM-inoculated F.albida seedlings grew better(P<0.05)than non-inoculated controls.Seedlings inoculated with AM from area exclosure had significantly(P<0.05)higher growth and nutrient uptake than those inoculated with AM from grazing and cultivated land.This emphasizes the importance of the native soil AM potential for better establishment of seedlings to achieve optimum plant growth improvement and assist in rehabilitation of degraded arid lands.展开更多
The effect on the germination and seedling growth of radish(Raphanus sativus)seeds were examined employing a dielectric barrier discharge(DBD)at atmospheric pressure and room temperature for various treatment time.DBD...The effect on the germination and seedling growth of radish(Raphanus sativus)seeds were examined employing a dielectric barrier discharge(DBD)at atmospheric pressure and room temperature for various treatment time.DBD plasma using argon gas of flow rate 21 m^(-1)was employed in this study.Radish seeds were treated with DBD plasma for 1-5 min,respectively.Germination characteristics,seedling growth parameters,the contact angle of the seed coat,water uptake capacity,mass loss,the temperature of the seeds,chlorophyll,and carotenoid contents of the seedlings were measured before and after the DBD plasma treatments.Plasma treatment of radish seeds significantly increased germination-related characters,including germination percentage,fresh and dry weight,vigor index,and total carotenoids contents.However,the cumulative production rate was found to be decreased.Results from the experiment indicate an acceleration in the water uptake of the radish seeds and make the seed surface hydrophilic by plasma treatment.Scanning electron microscopy analysis showed that etching effects on the seed coat occurred after the argon plasma treatments,which affected the wettability of the radish seed.The experimental findings showed that seeds being treated by DBD plasma for 2 and 3 min had a positive effect on the germination and seedling growth of radish.展开更多
A plot of 24 m × 10 m under fallow management after several years of cultivation to maize (Zea mays) was planted to tea (Camellia sinensis) cuttings at 1.0 m ×0.6 m and treated with or without fertilizer...A plot of 24 m × 10 m under fallow management after several years of cultivation to maize (Zea mays) was planted to tea (Camellia sinensis) cuttings at 1.0 m ×0.6 m and treated with or without fertilizer. The tea cuttings were applied NPK 25:5:5 (reference fertilizer), cocoa husk, cow-dung, tea fluff and poultry droppings as manures, mixtures of the manures with urea in 3:1 ratio of N contents as organomineral and the control (no fertilizer), monitored for growth performance for two years at Kusuku (6°50'N; 11 °07'E), Nigeria. The organic based fertilizers generally outperformed NPK 25:5:5 and control in all the growth parameters. Organominerals resulted in an overall higher plant height, girth, number of leaves and branches compared to the manures in the first year of establishment, while the values were higher for manure treated plants in the second year. This trend was attributed to quicker release of nutrient by the organominerals in the first year, while the manures had undergone adequate decomposition for sufficient nutrient release to the advantage of the tea plants in the second year. However, comparative cost analysis showed that organominerals were more economical to achieve optimum tea production at minimum cost in the locality.展开更多
To achieve optimum yield of wheat, supplementation of soil and foliar applied fertilizers with plant growth regulators is vital to assure effective assimilation of nutrients by plants. A trial was conducted at Gwebi A...To achieve optimum yield of wheat, supplementation of soil and foliar applied fertilizers with plant growth regulators is vital to assure effective assimilation of nutrients by plants. A trial was conducted at Gwebi Agricultural College Farm in Mashonaland West Province of Zimbabwe, during the 2012 winter wheat season (May to August), to evaluate the effects of differing times of application of Tianda 2116 plant growth regulator on the growth and yield of wheat (variety SC Sekuru). The trial was laid out in a Randomized Complete Block Design with three replications. The treatments were: Tianda 2116 applied at the following weeks after planting (WAP): 2 WAP, 3 WAP, 4 WAP, 5 WAP, 6 WAP, 14 WAP and no Tianda 2116 applied (control). No significant differences (P > 0.05) were noted among treatments for mean number of tillers per plant and mean number of spikes per plant. Application of Tianda 2116 at 2 and 3 WAP delayed flowering and physiological maturity. Early application of Tianda 2116 increased the number of spikelets per spike, thousand grain weight and grain yield. Conclusively, Tianda 2116 applied 2 or 3 WAP is effective in reducing growth while enhancing yield parameters in wheat production.展开更多
<span style="font-family:Verdana;">Japanese mackerel (</span><i><i><span style="font-family:Verdana;">Scomber</span></i> <i><span style="font...<span style="font-family:Verdana;">Japanese mackerel (</span><i><i><span style="font-family:Verdana;">Scomber</span></i> <i><span style="font-family:Verdana;">japonicus</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;">) is one of the important economic species in the pelagic light seine fishery in China, but few studies have been reported on the age, growth and management recommendations of Japanese mackerel in the high seas of the northwest Pacific Ocean. In this study, we fitted expressions for the relationship between fork length and body weight of Japanese mackerel based on fork length and body weight data of Japanese mackerel in the high seas of the Northwest Pacific Ocean from 2018 to 2019, and calculated growth parameters and growth characteristics of Japanese mackerel von Bertalanffy growth equation by identifying otolith age data combined with the least squares method. The results showed that the relationship between fork length and body weight of Japanese mackerel in the open sea of the Northwest Pacific Ocean was W = 2.0 × 10</span><sup><span style="font-family:Verdana;">-6</span></sup><span style="font-family:Verdana;"> L</span><sup><span style="font-family:Verdana;">3.289</span></sup><span style="font-family:Verdana;"> (r = 0.9764, n = 2833);the growth parameters were L = 447.61</span><sub><span style="font-family:Verdana;">∞</span></sub><span style="font-family:Verdana;">, K = 0.264, t = -1.06</span><sub><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"></span></span></span></sub><span style="font-family:Verdana;">;the growth rate reached the maximum when the bodyweight growth rate was 122 g/yr, at which the inflection point age was 3 years old, the inflection point body weight was 310 g, and the inflection point length was 309 mm. We recommend 2 years of age start fishing with a fork length of 250 mm (±10 mm). The growth parameters of Japanese mackerel in the open sea of the Northwest Pacific Ocean were not significantly different from those of the Japanese mackerel population on Japan’s coast (P > 0.05), Finally, based on the knowledge of biological research and resource evaluation, we suggest that the age of opening trap should be 2 years old and the length of fork should be 250 mm (±10 mm).</span>展开更多
Water deficit in arid and semiarid regions affects whole-plant sap flow and leaf-level water relations. The objectives of this study were to clarify how sap flow of Calligonum arborescens responds to different drought...Water deficit in arid and semiarid regions affects whole-plant sap flow and leaf-level water relations. The objectives of this study were to clarify how sap flow of Calligonum arborescens responds to different drought stress conditions and to understand its acclimation mechanism to drought environments. A field experiment was conducted for C. arborescens during the growing season to evaluate the effects of deficit irrigation on the daily and seasonal variations of trunk sap flow in the shelterbelt along the Tarim Desert Highway, Xinjiang, China. Three dif- ferent water regimes (2,380, 1,960 and 1,225 m3/hm2) were applied at different stages of plant growth. From 1 May to 30 October 2007, a heat-balance stem flow gauge was used to monitor the sap flow dynamics of C. arborescens under different water regimes. Atmospheric evaporation demand and soil moisture conditions for differentially irri- gated C. arborescens were also monitored. The result showed that sap flow exhibited a clear diurnal pattern re- gardless of treatments; the diurnal patterns of sap flow and vapour pressure deficit were very similar under different water regimes and growing seasons, while the slope of the linear regression of this correlation confirmed an in- creasing water regime. The sap flow decreased under reduced water regimes and there was nocturnal sap flow regardless of water regimes, which was mainly contributed to nocturnal transpiration and water recharge. The sap flow peaked before midnight and dropped afterwards with obviously higher values in summer than in other seasons. It is speculated that the water consumption of C. arborescens during the day can be supplemented through the sap flow at night, which increased with increasing irrigation amount. Net radiation was the most significant correlated factor that influenced sap flow velocity and transpiration under different water regimes (R2〉0.719). Compared with the commonly practiced water regime, the growth of C. arborescens was significantly slower in the stress deficit irrigation, but not significantly different from that in the moderate deficit irrigation. The moderate deficit irrigation would not affect the stability of the shelterbelt and was a more efficient use of water resources compared with the current watering amount.展开更多
文摘A study was conducted to evaluate the effects of sludge (industrial and residential) on seed germination and growth performance of Acacia auriculiformis seedlings at the nursery of Institute of Forestry and Environmental Sciences, Chittagong University (IFESCU), Bangladesh. Before sowing of the seeds, different combinations of sludge were incorporated with the nutrient-deficient natural forest soils. Seed germination and growth parameters of the seedlings (shoot and root length, collar diameter, fresh and dry weight of shoot, and root and total dry biomass) were recorded after one, two and three months of seed sowing. Physio-chemical parameters (pH, organic carbon, nitrogen, phosphorus, and potassium) and heavy metals (chromium, nickel, manganese, cadmium and zinc) of each treatment were also analyzed before sowing of seeds and after harvesting of seedlings. Results show that the seed germination percentage and the seedling growth parameters varied significantly in the soil added with sludge in comparison to control. The highest germination percentage (90%) was observed in the treatment of soil with residential sludge of 2:1 compared to control. The highest growth and biomass of the seedlings as well as the maximum percentage of organic carbon and nutrients (N, P and K) were also recorded in the same combination. Soil added with industrial sludge had a higher concentration of heavy metal than that of residential sludge. The highest concentrations of heavy metals were found in soil added with industrial sludge of 1:1. It is recommended that soil added with residential sludge of 2:1 provide good condition for better seed germination and growth ofA. auriculiformis seedlings in degraded forest soil.
文摘Dwindling supplies of bamboo resources and the increase in the demand for bamboo ha</span></span><span><span><span style="font-family:"">ve</span></span></span><span><span><span style="font-family:""> led to the need for better propagation techniques. This is the only way to ensure the sustainability of the bamboo resource base and improve livelihoods. Thus, this study was carried out to examine the different growth parameters of culm cuttings of <i>Bambusa vulgaris</i> in propagation beds with a substrate consisting of dark soil, manure (compost) and sand in a ratio of 1:1:1. Data on different growth parameters was collected on a daily basis over a three week period and analyzed using appropriate descriptive and inferential statistics. It was found that the different growth parameters (diameter, height, leaves and sheaths) of culm cuttings of <i>B. vulgaris</i> evolved in like manner in three propagation beds. Descriptive statistics for growth parameters of culm cuttings of <i>B. vulgaris</i> showed little or no differences across three shelter/propagation beds (shelter bed 1, shelter bed 2 and shelter bed 3) with 1.4675 ± 1.6172 cm, 93 ± 112 cm, 22 ± 30 leaves, and 4 ± 6 sheaths being the mean diameter, height, number of leaves and number of sheaths for all three propagation beds, respectively. ANOVA test showed no statistically significant variation (<i>p</i> > 0.05) between growth parameters of culm cuttings of <i>B. vulgaris</i> across the three propagation beds, implying that the different growth parameters were relatively similar. Pearson correlation showed the existence of direct and inverse relationships between the different growth parameters of culm cuttings of bamboo. The existence of these direct and inverse relationships could be attributed to the rapid growth rate of bamboo, the substrate used, and the species of bamboo used (<i>B. vulgaris</i>). The study recommends more large-scale propagation projects of this bamboo species in order to ensure the sustainability of the bamboo resource base and improve livelihoods of bamboo dependent rural communities.
文摘The growth parameters and mortalities of five species of Synodontis in the lower river Benue at Makurdi,Benue State were studied from January,2016 to December,2018.The asymptotic length(L∞)calculated for the five species ranged from 18.80cm in S.clarias females to 37.04cm in S.membranaceus females.The t0 values were all negative in the combined sexes of S.clarias,S.omias,S.gambiensis and S.membranaceus.In both combined sexes of S.membranaceus and S.schall,the t0 values were positive.The growth rate(K)was low in S.clarias and S.omias(0.301-0.497,0.171-0.310)respectively and higher in S.membranaceus(0.310-0.640),S.schall females(0.430-0.580);S.schall males(0.573),S.gambiensis(0.500-0.571).Growth performance index(Ø’)was 2.212 in S.gambiensis and 2.946 in S.schall combined.Natural Mortality(M)ranged from 0.5422 in S.omias females to 1.3340 in S.membranaceus males.Fishing Mortality(F)was 0.8214 in S.omias combined and 3.0934 in S.membranaceus females.Total mortality(Z)ranged from 1.52 in S.omias combined to 4.078 in S.membranaceus combined.Mean Exploitation(E)ratios was 0.61 in S.clarias,0.64 in S.omias,0.53 in S.gambiences,0.70 in S.membranaceus,and 0.66 in S.schall.The rate at which these species survived in the River was low(from 0.147,in S.omias combined,to 1.482 in S.membranaceus combined).
基金Project supported by the Science and Technology Major Project of Shanxi Province,China (Grant No.20181102013)the “1331 Project” Engineering Research Center of Shanxi Province,China (Grant No.PT201801)the Natural Science Foundation of Shanxi Province,China (Grant No.201801D221131)。
文摘The Ga_(2)O_(3) films are deposited on the Si and quartz substrates by magnetron sputtering, and annealing. The effects of preparation parameters(such as argon–oxygen flow ratio, sputtering power, sputtering time and annealing temperature)on the growth and properties(e.g., surface morphology, crystal structure, optical and electrical properties of the films) are studied by x-ray diffractometer(XRD), scanning electron microscope(SEM), and ultraviolet-visible spectrophotometer(UV-Vis). The results show that the thickness, crystallization quality and surface roughness of the β-Ga_(2)O_(3) film are influenced by those parameters. All β-Ga_(2)O_(3) films show good optical properties. Moreover, the value of bandgap increases with the enlarge of the percentage of oxygen increasing, and decreases with the increase of sputtering power and annealing temperature, indicating that the bandgap is related to the quality of the film and affected by the number of oxygen vacancy defects. The I–V curves show that the Ohmic behavior between metal and β-Ga_(2)O_(3) films is obtained at 900℃. Those results will be helpful for the further research of β-Ga_(2)O_(3) photoelectric semiconductor.
基金Supported by Researchers Supporting Project Number(RSP2024R410)King Saud University,Riyadh,Saudi Arabia.
文摘Sprouts are ready-to-eat and are recognized worldwide as functional components of the human diet.Recent advances in innovative agricultural techniques could enable an increase in the production of healthy food.The use of light-emitting diode(LED)in indoor agricultural production could alter the biological feedback loop,increasing the functional benefits of plant foods such as wheat and lentil sprouts and promoting the bioavailability of nutrients.The effects of white(W),red(R),and blue(B)light were investigated on the growth parameters and nutritional value of wheat and lentil sprouts.In the laboratory,seeds were sown under three different LED treat-ments:white,red,and blue light,while normal incandescent light served as a control.Percentage seed germina-tion improved by 18.34%and 12.67%for wheat and 18.34%and 12.67%for lentil sprouts under LED treatments R and B,respectively.An increase in total soluble protein and sugar by 33.4%and 9.23%in wheat and by 31.5%and 5.87%in lentils was observed under the R LED treatment.Vitamin C concentrations in wheat and lentils were significantly increased by R LED compared to all other treatments.Other parameters,including potassium and sodium concentrations,were significantly increased under red and blue light compared to the control;white light,on the other hand,significantly decreased all these parameters.According to the experimental data,red and blue LED light could be beneficial in the production of functional wheat and lentil sprouts with high nutrient concentrations.
文摘A field experiment was carried out at Ismailia Research Station, Ismailia Governorate from 2020-2022 to improve the growth of Khaya senegalensis and Swietenia mahagoni by using a combination of mineral fertilizer (NPK) and biological fertilizer (Azotobacter chroococcum, Bacillus megatherium, and Bacillus circulant) as recommended dose under new sandy soils conditions. Split plot designed with four treatments (Control, (50% Mineral fertilizer (M.) + 50% Biological fertilizer (Bio.)), 100% M. and 100% Bio.) of each species. Vegetative growth, leaf area, tree biomass, stored carbon, basal area, tree volume, and in the soil both of microbial account and mineral content were determined. The experimental results showed no significant differences between studied species among the most studied parameters except for Khaya senegalensis which gave the highest significant difference in root biomass and below-stored carbon than Swietenia mahagoni. Evidently, the highest significant growth parameters were 100% mineral fertilizer followed by (50% M. + 50% Bio.) as compared with control. No significant difference between 100% M. and (50% M. + 50% Bio.) of shoot dry biomass (15.19 and 12.02 kg, respectively) and above-stored carbon (0.28 and 0.22 Mt, respectively). Microbial account and mineral content in soil were improved after cultivation of tree species compared to before planting and control, especially with 50% mineral fertilizer and 50% bio-fertilizer treatment. In conclusion, a treatment containing 50% mineral fertilizer and 50% bio-fertilizer has led to the ideal Khaya senegalensis and Swietenia mahagoni growth in sandy soil for cheaper and sustainable.
文摘Plants are essential components of all ecosystems and play a critical role in environmental fate of nanoparticles. However, the toxicological impacts of nanoparticles on plants are not well documented. Titanium dioxide nanoparticles(TiO2-NPs) are produced worldwide in large quantities for a wide range of purposes. In the present study, the uptake of TiO2-NPs by the aquatic plant Spirodela polyrrhiza and the consequent effects on the plant were evaluated.Initially, structural and morphological characteristics of the used TiO2-NPs were determined using XRD, SEM, TEM and BET techniques. As a result, an anatase structure with the average crystalline size of 8 nm was confirmed for the synthesized TiO2-NPs. Subsequently, entrance of TiO2-NPSto plant roots was verified by fluorescence microscopic images. Activity of a number of antioxidant enzymes, as well as, changes in growth parameters and photosynthetic pigment contents as physiological indices were assessed to investigate the effects of TiO2-NPs on S. polyrrhiza. The increasing concentration of TiO2-NPs led to the significant decrease in all of the growth parameters and changes in antioxidant enzyme activities. The activity of superoxide dismutase enhanced significantly by the increasing concentration of TiO2-NPs. Enhancement of superoxide dismutase activity could be explained as promoting antioxidant system to scavenging the reactive oxygen species. In contrast, the activity of peroxidase was notably decreased in the treated plants. Reduced peroxidase activity could be attributed to either direct effect of these particles on the molecular structure of the enzyme or plant defense system damage due to reactive oxygen species.
文摘An M-shaped interface was observed in the top part of Φ76. 2 mm , (111) , dislocation-free, heavily Sb-doped Si single crystals, which is beneficial for crystals to keep dislocation-free condition at the beginning ofbody growth. Effects of seed rotation, crucible rotation , crown shape and growth rate on M-shaed interfacewere studied. Under proper conditions, impurity core length can be shortened from 6 cm to 1 cm , the yield israised by more than 5 %.
基金financially supported by the Science and Technology Develop Project of Northern Jiangsu, China (BN2015136)the Priority Academic Program Development of Jiangsu Higher Education Institution, China
文摘financially supported by the Science and Technology Develop Project of Northern Jiangsu, China (BN2015136);the Priority Academic Program Development of Jiangsu Higher Education Institution, China
文摘Triple Super Phosphate, TSP fertilizer, was applied @ 80 kg·ha^-1 as the source of phosphorous on six months old polybag seed- lings of Albizia chinensis, Albizia saman and Pongamia pinnta in nursery beds in Bangladesh. The effects of P-fertilizer on seedling growth and nodulation were comparcd to that of seedlings grown in unfertilized soil or in control at different harvesting intervals. The study revealed that, seedling growth was enhanced significantly with the application of P-fertilizer. The growth was found more pronounced in cases of A. saman and P. pinnata, whereas it was not noticeable and showed depressed growth in case of A. chinensis. The study also suggests that nodulation in terms of nodule number and size was also increased significantly with P-fertilization except in case ofP. pinnata, where higher harvesting intervals lowered the nodulation performance of that species
基金supported by National Natural Science Foundation of China(Nos.11605159,11405147)Chinese Postdoctoral Science Foundation(No.2017M612412)+2 种基金the Foundation of Key Technology Research Project of Henan Province(No.182102311115)Key Discipline Construction Project of Zhengzhou University(No.32410257)Youth Innovation Project of Key Discipline of Zhengzhou University(No.XKZDQN202002)。
文摘The stimulatory effects of atmospheric pressure cold plasma(APCP)on plant growth have attracted much attention due to its great potential as a new approach to increase crop growth and production.However,the transcriptome changes of plants induced by APCP treatment are unknown.Herein,the comparative transcriptome analysis was performed to identify the transcriptional response of Arabidopsis thaliana seedlings to APCP.Results showed that APCP exhibited a dual effect(stimulation or inhibition)on Arabidopsis seedling growth dependent on the treatment time and the maximum stimulatory effects were achieved by 1 min APCP treatment.The metabolic analysis of amino acid,glutathione(GSH)and phytohormone demonstrated that 1 min APCP treatment decreased most amino acids concentrations in Arabidopsis seedling,while the accumulations of GSH,gibberellins and cytokinin were significantly increased.The RNA-Seq analysis showed that a total of218 differentially expressed genes(DEGs)were identified in 1 min APCP-treated seedlings versus the control,including 20 up-regulated and 198 down-regulated genes.The DEGs were enriched in pathways related to GSH metabolism,mitogen-activated protein kinase(MAPK)signaling transduction and plant resistance against pathogens.Moreover,most of the DEGs were defense,stimuli or stressresponsive genes and encoded proteins with oxidoreductase activity.Expression determination of six randomly selected DEGs by quantitative real-time PCR demonstrated similar pattern with the RNASeq data.These results indicated that the moderate APCP treatment may regulate the expression of stimuli/stress-responsive genes involved in GSH,phytohormone/amino metabolism and plant defense against pathogens via MAPK signal transduction pathway,accordingly enhance Arabidopsis seedling growth.This study provides a theoretical basis for the application of APCP in agriculture.
文摘Sequel to complaints by cashew farmers on poor establishment rate of cashew seedlings on rehabilitated moribund cashew plantations in south western Nigeria, a fertilizer trial involving the use of organic materials (cow-dung, poultry droppings, cocoa and kola pod husks) compared to NPK and control (no fertilizer) treatments was conducted on the growth performance of cashew seedlings at Ibadan, Nigeria. The fertilizers were applied to supply 15 g N seedlingl in 3 replications. Cashew seedling growth parameters and dry matter yield were determined. Fertilizers resulted to consistently general higher plant height, girth, number of leaves and leaf area compared to NPK and control. The differences in the mean values were however not significantly different for girth but it was significant (P 〈 0.5) for plant height, number of leaves and leaf area, while there was no particular regular trend for plant number of branches. Plant root lengths were significantly higher using the organic fertilizers than NPK and control. Similar trend was obtained in the dry weight values for plant leaf, stem, root and total dry matter yield. There was however no consistent significant effect on NPK usage over control for all the parameters. It was therefore deduced that optimal growth performance and better establishment of cashew seedlings could be obtained with the use of organic fertilizers rather than inorganic fertilizer. The use of cocoa pod husk followed by cow-dung and poultry droppings were outstanding in better growth and dry matter yield performance of cashew seedlings and were advised for this purpose.
文摘We studied the effect of growth on wood anatomical dimensions and specific gravity of seed-raised plantation wood of Dalbergia sissoo with twelve trees of different diameters and similar ages. Fiber length ranged from 925 to1,287 lm, fiber-diameter was 19–23 lm, wall thickness was4.2–5.4 lm, vessel-element-length was 152–188 lm, vesselelement-diameter was 152–200 lm, and specific gravity was0.59–0.72. Growth parameters including tree height, diameter at breast height, net primary productivity and net ecosystem productivity were significantly and positively correlated.Growth parameters showed non-significant positive relationships with fiber-length, fiber diameter, wall thickness, vessel element length, and vessel element diameter. The trend of wood traits increased with growth. Specific gravity showed non-significant negative relationships with growth parameters. Although the growth rate had varied relationships with wood properties, as reported by various workers, the wood element dimensions showed no significant relationship with growth parameters and there was little effect of growth rate on wood traits in seed-raised plantation of D. sissoo.
文摘An experiment was conducted to assess the effect of Phosphorous (P) fertilizer (i.e. TSP or triple super phosphate @ 80 kg/hm^2) on seedling growth and nodulation capabilities of three potentially important agroforestry tree species (Acacia auriculiformis, Albizia lebbeck and Albizia procera) of Bangladesh. The study was conducted in nursery beds with six-month-old polybag seedlings ofA. auriculiformis, A. lebbeck and A. procera. The effects of P fertilizer on seedling growth and nodulation were compared with that of the seedlings grown in control (i.e. unfertilized soil). The observations revealed that the seedling growth was enhanced significantly with the application of P fertilizer. The growth was found more pronounced in A. auriculiformis, whereas it was not apparent and shows depressed growth in case ofA. lebbeck. The study also suggests that the nodulation in terms of nodule number and size was also increased significantly with the application of P fertilizer.
基金supported by the Steps towards sustainable forest management with the local communities in Tigraynorthern Ethiopia at Mekelle University funded by NORAD/NORHED(ETH 13/0018)program+1 种基金Mekelle UniversityNORADⅢproject
文摘Poor land use management and practice inhibit the growth and establishment of tree seedlings in dryland areas.We assessed arbuscular mycorrhizal fungi(AM)status of Faidherbia albida(Del.)A.Chev.trees grown on different land uses.We quantified the growth and nutrient uptake of F.albida seedlings inoculated with AM from different sources.These efforts were based on soil and fine root samples from the rhizosphere soils of F.albida trees.AM root colonization was determined using the gridline intersect method.Spores were extracted by the wet sieving and decanting method and identified to genus level.The seedling experiment had a completely randomized onefactorial design with four treatments and five replications.Faidherbida albida seedlings were grown in a greenhouse.All in situ F.albida trees were colonized by AM fungi.AM root colonization of F.albida trees was significantly higher(P<0.0086)in area exclosures than on lands used for grazing or cultivation.Spore abundance was significantly higher(P<0.0014)in area exclosures followed by cultivated land and grazing land.Glomus was the dominant genus in all land-uses.AM-inoculated F.albida seedlings grew better(P<0.05)than non-inoculated controls.Seedlings inoculated with AM from area exclosure had significantly(P<0.05)higher growth and nutrient uptake than those inoculated with AM from grazing and cultivated land.This emphasizes the importance of the native soil AM potential for better establishment of seedlings to achieve optimum plant growth improvement and assist in rehabilitation of degraded arid lands.
基金Nepal Academy of Science and Technology(NAST),Khumaltar,Lalitpur,Nepal for providing financial and technical support。
文摘The effect on the germination and seedling growth of radish(Raphanus sativus)seeds were examined employing a dielectric barrier discharge(DBD)at atmospheric pressure and room temperature for various treatment time.DBD plasma using argon gas of flow rate 21 m^(-1)was employed in this study.Radish seeds were treated with DBD plasma for 1-5 min,respectively.Germination characteristics,seedling growth parameters,the contact angle of the seed coat,water uptake capacity,mass loss,the temperature of the seeds,chlorophyll,and carotenoid contents of the seedlings were measured before and after the DBD plasma treatments.Plasma treatment of radish seeds significantly increased germination-related characters,including germination percentage,fresh and dry weight,vigor index,and total carotenoids contents.However,the cumulative production rate was found to be decreased.Results from the experiment indicate an acceleration in the water uptake of the radish seeds and make the seed surface hydrophilic by plasma treatment.Scanning electron microscopy analysis showed that etching effects on the seed coat occurred after the argon plasma treatments,which affected the wettability of the radish seed.The experimental findings showed that seeds being treated by DBD plasma for 2 and 3 min had a positive effect on the germination and seedling growth of radish.
文摘A plot of 24 m × 10 m under fallow management after several years of cultivation to maize (Zea mays) was planted to tea (Camellia sinensis) cuttings at 1.0 m ×0.6 m and treated with or without fertilizer. The tea cuttings were applied NPK 25:5:5 (reference fertilizer), cocoa husk, cow-dung, tea fluff and poultry droppings as manures, mixtures of the manures with urea in 3:1 ratio of N contents as organomineral and the control (no fertilizer), monitored for growth performance for two years at Kusuku (6°50'N; 11 °07'E), Nigeria. The organic based fertilizers generally outperformed NPK 25:5:5 and control in all the growth parameters. Organominerals resulted in an overall higher plant height, girth, number of leaves and branches compared to the manures in the first year of establishment, while the values were higher for manure treated plants in the second year. This trend was attributed to quicker release of nutrient by the organominerals in the first year, while the manures had undergone adequate decomposition for sufficient nutrient release to the advantage of the tea plants in the second year. However, comparative cost analysis showed that organominerals were more economical to achieve optimum tea production at minimum cost in the locality.
文摘To achieve optimum yield of wheat, supplementation of soil and foliar applied fertilizers with plant growth regulators is vital to assure effective assimilation of nutrients by plants. A trial was conducted at Gwebi Agricultural College Farm in Mashonaland West Province of Zimbabwe, during the 2012 winter wheat season (May to August), to evaluate the effects of differing times of application of Tianda 2116 plant growth regulator on the growth and yield of wheat (variety SC Sekuru). The trial was laid out in a Randomized Complete Block Design with three replications. The treatments were: Tianda 2116 applied at the following weeks after planting (WAP): 2 WAP, 3 WAP, 4 WAP, 5 WAP, 6 WAP, 14 WAP and no Tianda 2116 applied (control). No significant differences (P > 0.05) were noted among treatments for mean number of tillers per plant and mean number of spikes per plant. Application of Tianda 2116 at 2 and 3 WAP delayed flowering and physiological maturity. Early application of Tianda 2116 increased the number of spikelets per spike, thousand grain weight and grain yield. Conclusively, Tianda 2116 applied 2 or 3 WAP is effective in reducing growth while enhancing yield parameters in wheat production.
文摘<span style="font-family:Verdana;">Japanese mackerel (</span><i><i><span style="font-family:Verdana;">Scomber</span></i> <i><span style="font-family:Verdana;">japonicus</span></i><span style="font-family:Verdana;"></span></i><span style="font-family:Verdana;">) is one of the important economic species in the pelagic light seine fishery in China, but few studies have been reported on the age, growth and management recommendations of Japanese mackerel in the high seas of the northwest Pacific Ocean. In this study, we fitted expressions for the relationship between fork length and body weight of Japanese mackerel based on fork length and body weight data of Japanese mackerel in the high seas of the Northwest Pacific Ocean from 2018 to 2019, and calculated growth parameters and growth characteristics of Japanese mackerel von Bertalanffy growth equation by identifying otolith age data combined with the least squares method. The results showed that the relationship between fork length and body weight of Japanese mackerel in the open sea of the Northwest Pacific Ocean was W = 2.0 × 10</span><sup><span style="font-family:Verdana;">-6</span></sup><span style="font-family:Verdana;"> L</span><sup><span style="font-family:Verdana;">3.289</span></sup><span style="font-family:Verdana;"> (r = 0.9764, n = 2833);the growth parameters were L = 447.61</span><sub><span style="font-family:Verdana;">∞</span></sub><span style="font-family:Verdana;">, K = 0.264, t = -1.06</span><sub><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;">0</span></span></span><span style="font-family:Verdana;"><span style="font-family:Verdana;"><span style="font-family:Verdana;"></span></span></span></sub><span style="font-family:Verdana;">;the growth rate reached the maximum when the bodyweight growth rate was 122 g/yr, at which the inflection point age was 3 years old, the inflection point body weight was 310 g, and the inflection point length was 309 mm. We recommend 2 years of age start fishing with a fork length of 250 mm (±10 mm). The growth parameters of Japanese mackerel in the open sea of the Northwest Pacific Ocean were not significantly different from those of the Japanese mackerel population on Japan’s coast (P > 0.05), Finally, based on the knowledge of biological research and resource evaluation, we suggest that the age of opening trap should be 2 years old and the length of fork should be 250 mm (±10 mm).</span>
基金financially supported by the International Science and Technology Cooperation Program of China (2012DFR30830)the National Natural Science Foundation of China (41261047)+1 种基金the Gansu Science and Technology Support Program(1204NKCA084)the Project of Knowledge Innovation of the Chinese Academy of Sciences(KZCX3-SW-342)
文摘Water deficit in arid and semiarid regions affects whole-plant sap flow and leaf-level water relations. The objectives of this study were to clarify how sap flow of Calligonum arborescens responds to different drought stress conditions and to understand its acclimation mechanism to drought environments. A field experiment was conducted for C. arborescens during the growing season to evaluate the effects of deficit irrigation on the daily and seasonal variations of trunk sap flow in the shelterbelt along the Tarim Desert Highway, Xinjiang, China. Three dif- ferent water regimes (2,380, 1,960 and 1,225 m3/hm2) were applied at different stages of plant growth. From 1 May to 30 October 2007, a heat-balance stem flow gauge was used to monitor the sap flow dynamics of C. arborescens under different water regimes. Atmospheric evaporation demand and soil moisture conditions for differentially irri- gated C. arborescens were also monitored. The result showed that sap flow exhibited a clear diurnal pattern re- gardless of treatments; the diurnal patterns of sap flow and vapour pressure deficit were very similar under different water regimes and growing seasons, while the slope of the linear regression of this correlation confirmed an in- creasing water regime. The sap flow decreased under reduced water regimes and there was nocturnal sap flow regardless of water regimes, which was mainly contributed to nocturnal transpiration and water recharge. The sap flow peaked before midnight and dropped afterwards with obviously higher values in summer than in other seasons. It is speculated that the water consumption of C. arborescens during the day can be supplemented through the sap flow at night, which increased with increasing irrigation amount. Net radiation was the most significant correlated factor that influenced sap flow velocity and transpiration under different water regimes (R2〉0.719). Compared with the commonly practiced water regime, the growth of C. arborescens was significantly slower in the stress deficit irrigation, but not significantly different from that in the moderate deficit irrigation. The moderate deficit irrigation would not affect the stability of the shelterbelt and was a more efficient use of water resources compared with the current watering amount.