Bio-Fertilizer Improved Oil Palm Seedling Growth

In most farming systems newly introduced commercial fertilizers to be accepted, adopted and used by farmers, their effectiveness and appropriate application rates must be exhibited. This study was conducted to validate the effect and rates of a bio-fertilizer (super agric) on oil palm seedling growth. The trial was laid out in a randomized complete block design (RCBD) with three application rates of 0, 4 and 8 ml/L of water (treatments) replicated thrice. Following the application of super agric to oil palm seedlings for a period of six months, observations drawn from the analysis of growth data were as follows: Three months after treatment, super agric significantly (P < 0.05) increased the height and breadth of oil palm seedling compared to those which were not applied with super agric. The results also showed that when super agric was applied at a rate of 4 ml/L, the leaf length and breadth were higher compared to the control were super agric was not used. Furthermore, applications of super agric improved oil palm seedling nitrogen uptake by 31% in treatment groups as compared to the control which explained the height and breadth increase in the oil palm seedlings that were applied with super agric. On the other hand, the effect of super agric application on phosphorus uptake by seedlings was not significant. Although the height, breadth, leaf width and length were all significantly affected by super agric application, the number of oil palm leaves and spears were not affected for the period the experiment was conducted. Six months after application of super agric the growth of oil palm seedlings was favorably impacted, hence we recommend super agric to be promoted among oil palm seedling growers.

Effects of Biostimulant NEAU10 on Growth of Rice Seedlings and Soil Physicochemical Parameters

The process of rice(Oryza sativa L.)seedling cultivation is often subjected to adverse environmental stress.Biostimulants regulate the robust growth of rice seedlings and play a crucial role in promoting the green and ecological development of agriculture.In this study,1.0 and 2.0 g•m^(-2) of the biostimulant were applied to soil in rice seedbeds.Growth indicators of rice,antioxidant enzyme activities and soil physicochemical characteristics were assessed at the 2.5-leaf and 4-leaf stages of rice.The results indicated that applying 2.0 g•m^(-2) of the biostimulant at both the 2.5-leaf and 4-leaf stages had the most significant promoting effect on rice growth.At the 2.5-leaf and 4-leaf stages,the number of fibrous roots increased by 23.43%and 22.25%,stem base width increased by 19.05%and 19.58%,above ground dry weight increased by 18.09%and 16.47%,root dry weight increased by 19.67%and 18.28%,leaf peroxidase(POD)activity increased by 34.44%and 42.94%,superoxide dismutase(SOD)activity increased by 37.24%and 56.79%,malondialdehyde(MDA)content decreased by 18.60%and 27.67%,and chlorophyll content increased significantly by 28.31%and 34.24%,respectively.At the 4-leaf stage of rice,urease,phosphatase and cellulase activities in the seedbed soil increased by 42.13%,25.96%and 33.59%,respectively,while soil alkaline nitrogen,available phosphorus and available potassium content decreased by 19.76%,19.02%and 17.88%,respectively.The application of biostimulants played a crucial role in promoting the growth of rice seedlings and enhancing soil nutrient absorption.

Seedling dynamics differ between canopy species and understory species in a tropical seasonal rainforest,SW China

We used 11 years of census data from 450 seedling quadrats established in a 20-ha forest dynamics plot to study seedling dynamics in tree species of a tropical seasonal rainforest in Xishuangbanna,southwestern China.We found that overall seedling recruitment rate and relative growth rate were higher in the rainy season than in the dry season.Both the recruitment rate of seedlings from canopy tree species(two species)and the relative growth rate of seedlings from understory species(nine species)were higher in the rainy season than in the dry season.However,in the rainy season,the recruitment rate of seedlings was higher for canopy tree species than for understory tree species.In addition,relative growth rate of seedlings was higher in the canopy species than in understory seedlings in the dry season.We also observed that,in both rainy and dry seasons,mortality rate of seedlings was higher for canopy species than for understory species.Overall,canopy tree species appear to have evolved a flexible strategy to adapt to the seasonal changes of a monsoon climate.In contrast,understory tree species seem to have adopted a conservative strategy.Specifically,these species mainly release seedlings in the rainy season and maintain relatively stable populations with a lower mortality rate and recruitment rate in both dry and rainy seasons.Our study suggests that canopy and understory seedling populations growing in forest understory may respond to future climate change scenarios with distinct regeneration strategies.

Relationship between Seed Priming Mediated Seedling Vigor and Yield Performance of Spring Wheat

Seed priming is a pre-germinated technique that can enhance seed germination percentage,faster and synchro-nized germination,better seedling growth,and yield under stress conditions.To ascertain the most effective seed priming method that would ensure the potential yield of wheat in Bangladesh,two experiments were carried out from December 2021 to March 2022 at the Department of Agronomy,Bangladesh Agricultural University.Two wheat varieties namely BARI Gom-28 and BWMRI Gom-1 were subjected to a range of priming chemicals in both lab and pot tests.These compounds included the following:control(no priming),hydropriming(distilled water),10000 ppm KNO_(3),15000 ppm KNO_(3),40000 ppm Mannitol,60000 ppm Mannitol,10000 ppm NaCl,20000 ppm NaCl,100 ppm PEG,150 ppm PEG,500 ppm NaOCl,1000 ppm NaOCl,10000 ppm CaCl_(2),20000 ppm CaCl_(2),10000 ppm KCl and 20000 ppm KCl.A complete randomized design(CRD)with three repli-cations was used to set up the experiments.The results showed that BARI Gom-28 and BWMRI Gom-1 responded best to KCl priming in terms of rapid seed germination and strong seedling development.On the other hand,the best priming agents for plant growth and productivity turned out to be CaCl_(2) and KCL.The results of this study support the possibility of using seed priming as a technique to improve wheat plant development and output by raising seed emergence and survival rates.

BEAR1, a bHLH transcription factor, controls seedling growth by regulating gibberellins biosynthesis in rice

The genetic pathways of rice seedling growth have a major impact on seedling emergence from soil and development.In this study,we identified a new bHLH transcription factor,BEAR1,from rice RNAi mutant library.Both the BEAR1-RNAi and bear1 CRISPR mutants had accelerated seedling growth.Histological section of leaves showed accelerated development of lacuna and vascular bundles in bear1 mutant.GUS staining revealed that BEAR1 was highly expressed in coleoptiles and leaves at seedling stage.Expression analysis of gibberellin(GA)biosynthesis and metabolic genes and content determination of active GAs indicated that the expression of GA biosynthesis genes,especially OsKS4 and OsCPS2,were upregulated and the GAs content were significantly increased in bear1,which correlated with the seedling phenotype of bear1 mutant.Molecular and biochemical assays revealed that BEAR1 directly binds to the promoter of OsKS4,thereby repressing its expression.Haplotypes analysis showed clear differentiation in indica and japonica rice varieties,and a strong correlation with seedling height.These findings provide novel insights into the regulation of seedling growth in rice.

ZmDRR206 functions in maintaining cell wall integrity during maize seedling growth and defense response to external stresses

Plants adaptively change their cell wall composition and structure during their growth,development,and interactions with environmental stresses.Dirigent proteins(DIRs)contribute to environmental adaptations by dynamically reorganizing the cell wall and/or by generating defense compounds.A maize DIR,ZmDRR206,was previously reported to play a dominant role in regulation of storage nutrient accumulation in endosperm during maize kernel development.Here we show that ZmDRR206 mediates maize seedling growth and disease resistance by coordinately regulating biosynthesis of cell wall components for cell-wall integrity(CWI)maintenance.Expression of ZmDRR206 was induced in maize seedlings upon pathogen infection.ZmDRR206 overexpression in maize resulted in reduced seedling growth and photosynthetic activity but increased disease resistance and drought tolerance,revealing a tradeoff between growth and defense.Consistently,ZmDRR206 overexpression reduced the contents of primary metabolites and down-regulated genes involved in photosynthesis,while increasing the contents of major cell wall components,defense phytohormones,and defense metabolites,and up-regulated genes involved in defense and cell-wall biosynthesis in seedlings.ZmDRR206-overexpressing seedlings were resistant to cell-wall stress imposed by isoxaben,and ZmDRR206 physically interacted with ZmCesA10,which is a cellulose synthase unit.Our findings suggest a mechanism by which ZmDRR206 coordinately regulates biosynthesis of cell-wall components for CWI maintenance during maize seedling growth,and might be exploited for breeding strong disease resistance in maize.

Comparing the Seedling Growth of Six Precious Species in Southern China

Seedling stage is an important period for forestry.The aim of this study was to estimate the growth trend of six local precious species and consider their implications for silviculture on forestry.We assessed height,diameter near ground and crown width at 1,4,6 and 8-month.The variance analysis indicated that there were significant differences between species on all traits except diameter near ground and crown width at 8-month.There were no significant differences on height and crown width at all ages among replicates whereas there were significant differences on diameter near ground at 1 and 4 months,differences on diameter near ground at 6 months and no difference on diameter near ground at 8-month.The significant differences among interaction of species and replicates on diameter near ground at 1-months,4-month,6-month and crown width at 8-month were also found.Dalbergia odorifera had a higher growth period after 6-month.Aquilaria sinensis(Lour.)Spreng,Swietenia mahagoni(L.)Jacq.,Hopea hainanensis Merr.et Chun,Homalium hainanense Gagnep.and Cassia siamea Lam.had the same growth trend on all traits at the whole time.

Effects of Sand Burial on the Survival, Growth, and Biomass Allocation in Semi-shrub Hedysarum laeve Seedlings

Hedysarum laeve Maxim. (Leguminosae) is one of the major species used frequently in revegetation of dune_field in the sandlands of the northern part of China by means of aerial sowing. Seedlings of the species after emergence above the sand surface may be buried in sand to various depths during its establishment in late spring and early summer. A study was made to examine the effects of sand burial at different levels of 0 (control), 33%, 67%, 100% and 133% of their shoot height, on the survivorship, growth, and biomass allocation pattern of H. laeve seedlings (one and two weeks old after emergence). When burial depth was up to 100% of their shoot height, about 70% seedlings died; and the burial at depth of 133% of their shoot height led to death of all seedlings. When seedlings was buried at depth of 33% and 67% of their shoot height, respectively, after six_week growth, their biomass of whole plant, blade, and root and relative growth rate were higher than the unburied counterparts. The seedlings in both 33% and 67% sand burial treatments did not significantly change their biomass allocation pattern comparing with the unburied ones. Furthermore, the number of leaves and shoot height of the seedlings in both 33% and 67% sand burial treatments were not significantly different from those of unburied individuals, respectively. The newly born leaves of the surviving seedlings, in 33%, 67%, and 100% burial treatments, during the period of experiment, were significantly more than those in control.

Effects of peat and weathered coal on the growth of Pinus sylvestrisvar. mongolica seedlings on aeolian sandy soil

The experiment was conducted at the Ganqika Sandy Land Ecological Station in Ke抏rqinzuoyihouqi County, Inner Mongolia, in a growing season from April 28 to October 28, 2001. Peat and weathered coal were added to the aeolian sandy soil in different ratios. Two-year-old Pinus sylvestris var. mongolica seedlings and plastic pots were used in the experiment. The experimental results indicated that: 1) the peat and weathered coal could significantly improve the physical and chemical prop-erties of aeolian sandy soil, and thus promoted the growth of seedlings; 2) the effect of peat on seedling growth, including height, base diameter, root length and biomass, presented an order of 8%>10%>5%>2%>0 in terms of peat contents, and the effect of weathered coal on seedling growth presented an order of 5%>8%>10%>2%>0 in terms of weathered coal contents for height and basal diameter, 5%>8%>2% >10%>0 for root length, and 5%>2%>8% >10%>0 for biomass; 3) the effects of peat were generally greater than that of weathered coal. Meanwhile, 8% peat was the best treatment to promote the growth of P. sylvestris var. mongolica seedlings.

Effects of Shading Treatment on the Growth of Bischofia javanica Seedlings

With annual Bischofia javanica seedlings as experimental material, the plasticity and comprehensive evaluation methods were employed to investigate the effects of different shading degrees （100% NS （natural sunshine）, 41.3% NS, 14.6% NS and 3.6% NS） on B. javanica seedlings growth, so as to obtain the shade toler- ance in B. javanica. The results showed that with the shading degree increasing, the seedling height increment, diameter increment, leaf area, fresh weights （above- ground part, underground part and whole plant） and dry weights （aboveground part, underground part and whole plant） of B. javanica seedlings all increased first and then decreased, and reached peak values under 41.3% NS, while the total root length, average root diameter, total surface area, total root volume and total root number all presented a decreasing trend. Also the comprehensive evaluation by subordinate function value method and plasticity analysis were carried out on these growth indexes. It was concluded that B. javanica seedlings have medium shade tol- erance from the comDrehensive analysis of growth indexes.

Branching and growth of plantings in fifth year of a seedling seed orchard of Masson pine (Pinus massoniana Lamb.)

The features of branching and growth studied included height, diameter at breast height (DBH), total number of branches, annual height growth, annual branch elongation in the year of elongating, annual branch number for four consecutive years, diameter of branches of different ages, and diameter of stem where branch-whorl originates. For features of total growth and overall branching, no significant differences were found between families, except for DBH. For annual features, no significant differences were found in annual stem height growth, annual branch elongation in the year of elongation and diameter of branches. In the last four years, differences in number of branches were not significant in the first two years but were significant in the last two year; differences in stem diameter where branch-whorls grow were significant for the four consecutive years. Trend of annual growth and branching features of families can be divided into three types as increasing type, stable type and fluctuating type. Most of families have an increasing type with respect of annual height growth and annual branch elongation, while most families belong to a fluctuating type with annual branch number. The results indicated that in the fifth year after planted in seedling seed orchard, differences between families were mostly insignificant. This result may have two main explanations: one is the growth rhyme in early ages of Masson pine, the other one is the complex paternal components to form the open-pollinated families. Family selection seemed to be not useful based on the result. It is suggested to select some of families in the nursery instead of to use all the families when establishing seedling seed orchards with open-pollinated families from plus-trees.

Effects of Pb Stress on Seed Germination and Seedling Growth of Two Weed Species Seeds

Objective] The aim was to investigate the effects of Pb stress on seed germination and seedling growth of Chenopodium glaucum and Chenopodium serot-inum L. [Method] With C. glaucum and C. serotinum as the study objects, the ef-fects of different concentrations of Pb on their seed germination and seedling growth, as wel as on the leaf SOD, POD and CAT activity were studied primarily. [Result] The germination potential of both the two kinds of weed seeds increased first and then decreased with the increase of Pb concentration. The germination po-tential of C. serotinum and C. glaucum seeds reached the peak at Pb concentration of 25 and 50 mg/L, respectively. With the increase of Pb treatment concentration, the germination rate, germination index and vigor index of C. serotinum and C. glaucum seeds decreased, and their bud length and root length also reduced gradu-al y. ln overal , the leaf SOD, POD and CAT activity of C. glaucum and C. serot-inum_ seedlings increased first and then decreased with the increased treatment concentration of Pb. The leaf SOD and POD activity of C. glaucum and C. serot-inum seedlings reached the maximum at Pb concentration of 200 and 100 mg/L, respectively, and the leaf CAT activity reached the maximum at Pb concentration of 100 mg/L. [Conclusion] The two Chenopodium species had strong tolerance to Pb stress, and they could be used as alternative accumulator plants of soil Pb contami-nation.

Effects of Exogenous GA_3 on Seed Germination and Seedling Growth of Salicornia europaea L. under Salt Stress

[Objective] The paper was to study the effects of exogenous GA3 on seed germination and seedling growth of Salicornia europaea L.under salt stress.[Method] With the combination of different concentrations of NaCl（50,100,150,200,250,300,350,400 mmol/L）with 10 μmol /L GA3 treatments,the effects of exogenous GA3 on seed germination and seedling growth of S.europaea under salt stress were studied.[Result] Exogenous GA3 promoted the seed germination rate,germination capacity,germination index and seed vigor index of S.europaea under salt stress.Under the treatment of exogenous GA3,the root system vigor,the lengths of roots and stems and the salt-tolerance of S.europaea were higher than that of single salt stress treatment.[Conclusion] Within a certain concentration range,exogenous GA3 could alleviate the inhibition effects of salt stress on seed germination and seedling growth of S.europaea.

Effects of Cadmium Stress on Seed Germination and Seedling Growth of Brassica napus L.

To investigate the effects of the heavy metal cadmium （Cd） on seed ger- mination and seedling growth of Brassica napus L., 25 B. napus lines with different genetic background were treated with four concentrations （0, 1, 5 and 10 mg/L） of Cd, and then, their germination potential, germination rate, seedling length, main root length, seedling fresh weight, and seedling dry weight were measured. The re- sults showed that the response of the B. napus lines to Cd stress was different. With the increase of Cd concentration, the relative germination potential and relative seedling rate increased first and then decreased, and reached the maximum levels when the Cd concentration was 5 rag/L. The inhibitory effects of Cd stress on seedling growth indices in a decreasing order were root length〉seedling length〉 seedling fresh weight〉seedling water content. There were extremely significant differ- ences in the relative root length, relative seedling length, relative seedling fresh weight and relative seedling water content among the B. napus lines treated by dif- ferent concentrations of Cd, while there were no significant differences in the rela- tive germination potential and relative seedling rate among the lines, except that the relative seedling rate was significantly different among the lines treated by 5 mg/L Cd. The results suggested that seedling growth was more sensitive than seed ger- mination to heavy metal stress.

Effect of trace elements on growth of Pinus tabulaeformis seedling

The stimulative effect of trace elements on seed germination and seedling growth of Pinus tabulaeformis was tested. The experiments were carried out on seed soak and topdressing with different trace elements and varied concentrations at the nursery of Gardens Research Institute, Harbin, in 2000-2001. The experimental results showed that soaking seed with 1% and 0.2% concentrations of Mn element produced best result for seed germination, and the germination rate was increased by 9%~19% for the seeds treated with 1% concentration and 12%~14% for the seeds treated with 0.2% concentration compared with the control group. The seeds treated with boron element had lowest germination rate. For trace element topdressing, Mn and Mo elements presented good result for seedling growth and the treatment with low concentration was even better. The height or chlorophyll content of the seedlings with spray of low-concentration Mn and Mo element was much higher than that of untreated ones. In the contrast to the treating method of seed soak, topdressing (application of spraying on foliage) had evident effect on seedling growth.

Effects of Liquid Seaweed Bio-organic Fertilizer on Seed Germination and Seedling Growth of Vegetables

[Objective] This study aimed to investigate the effects of liquid seaweed bio-organic fertilizer on seed germination and seedling growth of different vegetables. [Method] Serial dilution concentrations of liquid seaweed bio-organic fertilizer were prepared for seed soaking and pot incubation of cucumber, tomato and chili, to ob- serve the effects of liquid seaweed bio-organic fertilizer on seed germination and seedling growth of vegetables. [Result] Compared with the control, germination rate of cucumber and tomato seeds applied with 600-fold liquid seaweed bio-organic fer- tilizer varied significantly; germination rate of chili seeds applied with 400-fold liquid seaweed bio-organic fertilizer varied significantly; germination energy and germination index of chili seeds applied with different dilution concentrations of liquid seaweed bio-organic fertilizer presented no significant differences. In addition, 200-fold and 400-fold liquid seaweed bio-organic fertilizer significantly improved the root length, plant height, plant fresh weight, plant dry weight, chlorophyll content and leaf area of cucumber, tomato and chili seedlings; after treated with 600-fold liquid seaweed bio-organic fertilizer, root length, chlorophyll content and leaf area of cucumber seedlings varied significantly compared with the control, but no significant differences were observed in plant height, plant fresh weight and plant dry weight; after treated with 600-fold liquid seaweed bio-organic fertilizer, root length, chlorophyll content, plant height, plant fresh weight and plant dry weight of chili and tomato varied sig- nificantly compared with the control, but no significant differences were observed in leaf area. [Conclusion] Soaking vegetable seeds with liquid seaweed bio-organic fer- tilizer can significantly improve seed generation rate and seedling growth.

Effects of Various Phytohormones on Seed Germination and Seedling Growth of Leymus Chinensis

[Objective] To explore the effects of various phytohormones at different concentrations on the seed germination and seedling growth of Leymus Chinensiss （ L. chinensis）. [ Method ] The seeds of two varieties of L. chinensis were respectively treated with four kinds of phytohormone [ gibbereUin （ GA ）, 2,4-D, naphthalene acetic acid and 6-benzyl aminopurine （6-BA） ] for the observation of seed germination. The seedling growth of natural L. chinensis was observed after the seedlings were respectively treated with these phytohormones. [Result] The germination percentage of L. chinensis was promoted by the GAs and 6-BA at low concentration and inhibited by these two kinds of phytohormone at high concentration. Moreover, they promoted the seedling growth of L. chinensis, and the GA3 had better effect. However, the NAA and 2,4-D at any concentration inhibited the seed germination and seedling growth of L. chinensis. [ Conclusion] The various phytohormones have different effects on the seed germination and seedling growth of L. chinensis.

Study on Cadmium Tolerance of Seed Germination and Seedlings Growth of Different Rice Varieties

The research used bioassay method to explore seed tolerance of Cd in terms of seed germination and seedling growth. Specifically, 12 rice varieties of three types were investigated under Cd stress, covering germination rate, shooting index, vigor index, seedling and shoot lengths, and fresh weights. The results showed that as Cd concentration grew, seed germination and seedling growth kept increasingly inhibited; germination index, vigor index, root length, shoot length and fresh weights went down; inhibition effects on seed germination and seedling growth were conventional rice〉two-line hybrid rice〉three-line hybrid ,rice. Shanyou 9588, Tianyou 998, Chuanxiang 8, and Y Liangyou 1 performed ~rongly in Cd tolerance; C Liangyou 651, Nei 5 You 263, Xiangwanxian 16, Huanghuazhan, Xiangwanxian 13, and Zhunliangyou 527 performed poorly in Cd tolerance, and Cd tolerance of rest treatments were moderate.

Effects of Farming and Seedling-raising Methods on Population Growth and Grain Yield of Mechanized Transplanting Rice

The effects of farming method, rice variety and seedling-raising method were studied on the population growth quality and grain yield of the mechanized transplanting rice by way of three-factor split plot design. The results showed that the no-tillage mechanical transplanting treatment was poorer than the conventional mechanical transplanting treatment in transplanting quality in general, but the former was similar to the latter in population growth quality. In regard to grain yield, the no-tillage mechanical transplanting treatment was lower than the conventional me- chanical transplanting treatment. Raising both pot-mat seedling and plastic-tray seedling did not make much difference in population growth and grain yield of mechanized transplanting rice, so both of the seedling-raising methods can be adopted according to practical conditions.

Effect of Different Treatments on the Germination and Seedling Growth of Firmiana simplex

With Firmiana simplex （L.） W. F. Wight as an experiment material, the effects of different concentrations of GA3 （Gibberellin A3）, SA （Salicylic acid） and NAA （1-Naphthalene acetic acid） and stratification on the germination rate of seeds were studied firstly, and then the effects of GA3 and NAA on seedling growth were analyzed. The results showed that the germination rate could be improved by 0.075 g/L SA and stratification markedly. It was indicated by the experiment that the growth of the main root and main stem could be promoted by 0.050 g/L and 0.077 g/L NAA, respectively. However, the leaf length and leaf width decreased significantly in the GA3 and NAA treatments.