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Home > Influence of Silicon on Wheat Grown under Saline Environments

Influence of Silicon on Wheat Grown under Saline Environments

Thesis Info

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Author

Anser Ali

Program

PhD

Institute

University of Agriculture

City

Faisalabad

Province

Punjab

Country

Pakistan

Thesis Completing Year

2009

Thesis Completion Status

Completed

Subject

Applied Sciences

Language

English

Link

http://prr.hec.gov.pk/jspui/handle/123456789/520

Added

2021-02-17 19:49:13

Modified

2024-03-24 20:25:49

ARI ID

1676726463514

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Salinity often causes decrease and instability in wheat production that occupies a supreme position in food grains of Pakistan. Recently, wheat has been designated as silicon (Si) accumulator which can alleviate the salinity damage, a major constraint to agricultural crop production. With the objective to combat salinity stress in wheat by Si applications using calcium silicate, a series of experiments were conducted on two contrasting wheat genotypes (salt sensitive; Auqab-2000 and salt tolerant; SARC-5), under normal and saline conditions. Initially five different levels of Si (0, 50, 100, 150 and 200 mg L -1 ) were optimized for salinity tolerance on the basis of plant morphological characters especially dry weight in hydroponics and 150 mg L -1 was selected as an optimized level. Optimized Si-level was further used to investigate its effect on wheat in hydroponic and pot culture under normal (2 dS m -1 ) and saline (10 dS m -1 for hydroponics and 12 dS m -1 for pots study) conditions. The evaluation was done on the basis of various morphological, physiological, biochemical, growth and yield traits during these experiments. Silicon supplementation into the solution culture and soil medium significantly improved the K + : Na + with reduced Na + and increased K + uptake. Plant water relations with higher water potential and relative water content, increase in chlorophyll fractions and its ratios, enhanced stomatal conductance and better defense system with stimulated activities of superoxide dismutase (SOD) and catalase (CAT) were observed. Nevertheless, the activity of peroxidase (POD) was reduced and root growth remained unaffected by silicon application. The final field studies were conducted at two sites (within a radius of less than 500 m): Normal field with EC < 4 dS m -1 and saline field with EC~10-13.8 dS m -1 . Silicon was applied @ 0, 75 (half of optimized dose) and 150 mg kg -1 (optimized dose). Plants were harvested at maturity and concomitant increase in number of tillers, number of grains per spike, grain yield, and biological yield were observed due to silicon application both under optimal and salt affected field conditions. It was concluded that SARC-5 is better than Auqab-2000 under salt stress and silicon inclusion into the any growth medium is beneficial for wheat and can improve crop growth by maintaining plant water status, better K + : Na + and recovering the plant defense system adversely influenced by salt stress.
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اصطلاحات سازی کے فروغ میں انجمن ترقیِ اردو پاکستان کا کردار

اصطلاحات سازی کے فروغ میں انجمن ترقیِ اردو پاکستان کا کردار

ڈاکٹر محفوظ احمد ثاقب

1857ء کی جنگِ آزادی نے جہاں برصغیر پاک وہند کی تاریخ میں ان مٹ اثرات مرتب کیے وہاں اردو زبان و اب پر بھی گہرے نقوش چھوڑے۔ 1857ء کی جنگِ آزادی کے سبب پیدا ہونے والی ابتری حالت، مایوسی اور ناامیدی کا ایک ہی حل تھا کہ ایک طرف تو انگریز سرکار سے مثبت تعلقات کشید کیے جائیں تو دوسری طرف جدید علوم و فنون پر مضبوط گرفت حاصل کی جائے۔ مذکورہ اغراض کے تحت  سرسید احمد خاں نے محمڈن ایجوکیشنل کانفرنس منعقدہ علی گڑھ کی بنیاد ڈالی۔  محمڈن ایجوکیشنل کانفرنس میں مذید توسیع کے لیے علی گڑھ میں 31 دسمبر 1902ء کو تیرھویں  سالانہ کانفرنس منعقد کی گئی ۔ یہ کانفرنس  مورخہ 31 دسمبر 1902 تا 4 جنوری 1903 جاری رہی۔اس کانفرنس میں متفقہ طور پر محمڈن ایجوکیشنل کانفرنس کے مذید تین شعبہ جات( سیکشن سوشل ریفارم، سیکشن امورِ متفرقات ، لٹریری سیکشن )کی منظوری دی گئی۔ ان تین نئے شعبہ جات میں سے لٹریری سیکشن کو  بعد میں انجمن ترقیِ اردو  ھند( دھلی) کے نام سے جانا جانے لگا۔ انجمن ترقی اردو کے قیام کے بارے میں مولانا شبلی نعمانی لکھتے ہیں کہ :

"انجمن 4 جنوری 1903 ء کو سالانہ محمڈن ایجوکیشنل کانفرنس میں قائم ہوئی " (1)

ابتداء میں تو یہ محض ایک علمی شعبہ تھا مگر تاریخ نے یہ ثابت کیا کہ یہ ایک متحرک مجلس تھی جس نے اردو زبان و ادب اور دیگر جدید  علوم میں کے فروغ میں اہم کردار ادا کیا۔ انجمن ترقی ِ اردو کو دھلی صدر مقام پر جنوری 1903 میں قائم کیا گیا ۔

            انجمن ترقیِ اردو بنا کسی مذہبی  یا علاقائی تعصب...

پاکستان کا مسئلہ نمبر 1 کرپشن: اسباب اور خاتمہ تعلیمات نبویﷺ کے آئینے میں

The word corruption is very comprehensive. It is  the  synonym   of   bribery, demoralization, sinfulness, wickedness,   impurity, dishonesty, fraud, falsehood, embezzlement, illegal  and  criminal,   etc.  Currently  in  pakistan government & private  sectors,   high rank  government  employees,   bureaucracy and political institutions,   are  involved  in  different  kinds  of  corruption.  Consequently, the economy of the courntry has  been effected  extremly.  Therefore,   there  is  no peace in the counrtry. CALVIN COOLIDGE said in his speech, in 1923: "Economy is always a guarantee of peace". (1) In this  research article  it  would be   searched that  how the  corruption  in the country   could   be   eradicated,    in the  light of  Islamic teachings.  So that the economy of the the country can make progress smoothly and easily.

Nonlinear Phenomenon in Plasmas With Generalized R, Q Distribution

In this thesis, we have studied the propagation of nonlinear electrostatic waves in a nonMaxwellian plasma in which electrons follow the generalized (??,??) distribution function which has the advantage that it mimics most of the distribution functions observed in space plasmas. Generally spectral index ?? corresponds to the flatness and ?? corresponds to the high energy tail in the profile of the distribution. The generalized (??,??) distribution function is the generalized form of kappa and Maxwellian distribution function and can be reduced to these in the limits ??=0,??=(??+1) and ??=0,??→∞, respectively. First we studied the propagation of nonlinear ion acoustic waves in a (??,??) distributed plasma and derived the Korteweg-de Vries (KdV) equation. In the past, KdV equation has been derived for ion acoustic waves with Boltzmannian or kappa distributed electrons and only compressive solitary structures were obtained. We have shown that when electrons are modelled by (??,??) distribution, the nonlinear ion acoustic waves admit both humps and dips in the perturbed potential. We found that for positive values of ??, which correspond to flat-topped distribution, the nonlinear ion acoustic waves admit compressive solitary structures or density humps. And for negative values of ??, which correspond to a spiky distribution, the nonlinear ion acoustic waves admit rarefactive solitary structures or density depletions. It has also been shown that the generalized (??,??) distribution function provides another way to explicate the density depletions observed by Freja and Viking satellites previously explained by proposing Cairns distribution function. In the third chapter, we have studied the propagation of nonlinear electron acoustic waves (EAWs) by deriving the KdV equation in a plasma comprising of cold and hot electron populations in which the ions form the neutralizing background. The hot electrons have been assumed to follow the generalized (??,??) distribution. Interestingly, it has been found that unlike Maxwellian and kappa distributions, the electron acoustic waves admit not only rarefactive structures but also allow the formation of compressive solitary structures for generalized (??,??) distribution. Using the plasma parameters, typically found in the Saturn’s magnetosphere and the Earth’s auroral region, where two x populations of electrons and electron acoustic solitary waves have been observed, we have given an estimate of the scale lengths over which these nonlinear waves are expected to form and how the size of these structures would vary with the change in the shape of the distribution function and with the change of the plasma parameters. In chapter-4, we then derived the modified Korteweg-de Vries (mKdV) equation to study nonlinear ion acoustic waves in a plasma in which electrons follow generalized (??,??) distribution. The spectral index ?? in the distribution corresponds to the flat top at low energy and by increasing its value flat top in the distribution increases. The spectral index ?? can also have negative values due to which distribution becomes spiky at low energies. Such flat topped or spiky distributions have been frequently observed in space plasmas. By employing (??,??) distribution, it has been shown that solitary structures are much influenced by the spectral index ??. This study highlighted the effect of low energy particles on the propagation characteristics of the solitary structures which could not be done by employing Maxwellian or kappa distributions and be helpful in explaining the underline physics in those regions where such flat top distributions are observed. In the chapter 5, we have studied the propagation of nonlinear ion acoustic shock waves in unmagnetized and collisionless plasma in the presence of electrons that follow the generalized (??,??) distribution. The Burger and Korteweg-de Vries–Burger (KdV-Burger) equations have been derived through reductive perturbation technique and via tangent hyperbolic method shock like solutions have been presented analytically for both Burger and KdV-Burger equations. It has been found that the strength and steepness of shock waves are affected by the flatness parameter ??, tail parameter ?? and the nonlinear propagation velocity ??. It is found that the shock strength of KdV–Burger is less than simple Burger equation’s shock. We concluded that propagation of nonlinear electrostatic waves strongly dependent on the profile of the distribution function and the results obtained are of great importance as they interpret those observations which could not be predicted on the basis of Maxwellian or kappa distribution functions.