Barrow N.J.,University of Western Australia |
Debnath A.,Bidhan Chandra Krishi Viswavidyalaya
Plant and Soil | Year: 2014
Aims: Enormous quantities of phosphate have been applied to world soils, yet we know little about effects of phosphate status on sorption properties. Methods: We measured sorption and desorption of phosphate on soils from fertilized tea plantations from northern India and compared them with unfertilized soils. We also incubated phosphate at high temperature with a previously unfertilized soil and measured the effects. Results: Sorption of phosphate was less marked on soils of high phosphate status whether derived from inherent fertility or fertilizer application. This occurred because high phosphate status made the surface charge on the reacting surfaces more negative. Phosphate status also affected desorption. The higher the phosphate status, the smaller the difference between sorption and desorption curves. This occurred because on soils of high phosphate status the pathways by which adsorbed anions diffuse were saturated and the slow reaction that follows adsorption was stopped. Conclusions: When low-phosphate soils are first fertilized, it is necessary to supply more phosphate than is removed in produce. However, after long-term phosphate fertilization, it is sufficient to only replace phosphate lost in produce. We need to find how much phosphorus it takes to reach this state and how many of the world's soils have already reached it. © 2014 Springer International Publishing Switzerland.
Patra S.K.,National Institute of Technology Rourkela |
Deb M.,National Institute of Technology Rourkela |
Patra A.,Bidhan Chandra Krishi Viswavidyalaya
Clinical Epigenetics | Year: 2011
Epigenetic regulations of genes by reversible methylation of DNA (at the carbon-5 of cytosine) and numerous reversible modifications of histones play importantroles in normal physiology and development, and epigenetic deregulations are associated with developmental disorders and various disease states, including cancer. Stem cells have the capacity to self-renew indefinitely. Similar to stem cells, some malignant cells have the capacity to divide indefinitely and are referred to as cancer stem cells. In recent times, direct correlation between epigenetic modifications and reprogramming of stem cell and cancer stem cell is emerging. Major discoveries were made with investigations on reprogramming gene products, also known as master regulators of totipotency and inducer of pluoripotency, namely, OCT4, NANOG, cMYC, SOX2, Klf4, and LIN28. The challenge to induce pluripotency is the insertion of four reprogramming genes (Oct4, Sox2, Klf4, and c-Myc) into the genome. There are always risks of silencing of these genes by epigenetic modifications in the host cells, particularly, when introduced through retroviral techniques. In this contribution, we will discuss some of the major discoveries on epigenetic modifications within the chromatin of various genes associated with cancer progression and cancer stem cells in comparison to normal development of stem cell. These modifications may be considered as molecular signatures for predicting disorders of development and for identifying disease states. © Springer-Verlag 2010.
Sarkar G.K.,Fertiliser Control Laboratory |
Chattopadhyay A.P.,Kalyani University |
Sanyal S.K.,Bidhan Chandra Krishi Viswavidyalaya
Geoderma | Year: 2013
Eight surface soil samples representing three soil orders viz., Inceptisols, Alfisols and Entisols were analyzed to characterize the non-exchangeable potassium (K) reserves. The mineralogical composition of the experimental soils varied widely. The reserves of Step-K and Constant rate K were computed by repeated extraction of soils with boiling1M HNO3. The cumulative release of non-exchangeable K by such repeated extraction followed a semi-logarithmic behavior with number of extractions, suggesting that the release of non-exchangeable K decreased with successive extractions. The threshold levels of K in soil solution below which the release of K from the initially non-exchangeable K reserves starts were also evaluated for the selected soils in terms of K activity ratio, K concentration and exchangeable K in 0.01M and 0.002M CaCl2 solution. Higher threshold value of Entisols and Inceptisols compared to Alfisols indicates less tenacity with which K is held in wedge zones of micaceous minerals. These threshold values changed considerably for all the soils as the electrolyte concentration decreased from 0.01M to 0.002M. Specifically held K, determined as exchangeable K below which the Gapon constant (KG) showed a sharp rise, varied from soil to soil in almost the same manner as noted for threshold K levels in these soils. © 2013 Elsevier B.V.
Mitra S.K.,Bidhan Chandra Krishi Viswavidyalaya
Acta Horticulturae | Year: 2016
Mango is one of the common fruit in most continents, particularly in Asia, Central and South America and Africa. Global production of mangoes is concentrated mainly in Asia and more precisely in India which produces an average of 15 million t (MT) a year. Mangoes are now growing in more than 100 countries of which more than 65 countries produce each more than 1,000 MT a year. Total world production of mangoes is about 40 MT which played an integral part in the lives of many, not only by being a rich nutrient source but also as a source of livelihood for millions of peoples in the tropics. Mangoes were not commonly known among the consumers outside the tropics before 1960s and there was virtually no trade of fresh fruit. In recent years, mangoes have become well established as fresh fruit and processed products in the global market. World demand for mango is ascertained to be increasing particularly from temperate countries where mangoes are rapidly gaining in popularity. Leading importing country is US and in the EU it are the Netherlands, France, England, Portugal, Spain, Belgium, Denmark, and Sweden. Apart from India, other major producers of mango are China, Mexico, Thailand, Indonesia, Pakistan, Philippines, Nigeria, Brazil, Peru, Australia, South Africa, Malaysia and Venezuela. India's major marketing season is April to July while harvesting continued for 8-10 months a year in Brazil, Columbia, Kenya and Venezuela. The season is also quite long in Burkina Faso, Costa Rica, Indonesia, Jamaica, Mexico, Nicaragua, and Puerto Rico. There are many mango varieties grown in different countries; India alone have nearly 1,300 mango varieties (20 grown commercially) and Thailand have about 100 varieties. This paper discussed the present state of production of mango in the world and its future prospects.
Mishra M.,Bidhan Chandra Krishi Viswavidyalaya |
Kumar S.T.P.,Bidhan Chandra Krishi Viswavidyalaya
Indian Journal of Ecology | Year: 2015
In the present investigation, trends in population dynamics of major insect pests of soybean crop have been studied through probability model. Among the major insect pests the numbers of larvae of S. litura, Thysanoplusia orichalce, Spilosoma oblique Walker and their natural enemies namely Anisoptera, Coccmellidae and spider were observed on soybean. The occurrences of the insects were grouped in the form of frequency distribution according to the number of plants. The distribution of S. litura using Polya-Aeppli distribution was known to fit well by the method of MPZC(method of proportion of zero cell) and MLE (maximum likelihood) but the distribution of Thysanoplusia orichalce using Polya-Aeppli distribution was fitted well by all the three methods of estimation, MPZC, method of moments (MM) and MLE and these methods were not fitted well to describe the frequencies of spiders. These distributions may be used for forecasting of the losses in soybean crop due to major insect pests considered here.