Seasonal disease: Foamy bark canker of Citrus maxima in the delta region of Tamil Nadu

The Citrus maxima, commonly called pummelo, are a Rutaceae family. The Canker disease recently had an issue on Citrus species in the Delta region of Tamil Nadu. This disease is appeared by foamy oozes from the bark. The infected plant dies slowly in a short period. This study was identified the microorganism causes of foamy disease from bark and infected area. Totally 19 fungi were isolated. Among these 16 fungi were isolated from uninfected bark, 3 fungal species belonging to Ascomycetes, 2 fungal species belonging to Coelomycetes, and 10 species be classed Hyphomycetes and one sterile form, though 11 fungal species were isolated from infected bark foamy ooze, eight Hyphomycetes, one Oomycete, and two sterile forms were isolated. The RPO statistical analysis resulted, the bark fungi have been separated a group fungus from foamy fungi such a few fungi as the Fusarium, Phytophthora, and yeast have isolated in the foam. Also, the Jaccard’s similarity showed 42.105% and dissimilar among to the bark and foamy fungus. The plant was decay, branch dieback and tree death may induce by fungi also that the Canker disease on Citrus may be caused by Phytophthora fungal species.

Search for the “missing” α-decay branch in 239Cm

SummaryA search for the α-decay of

Progress and Challenges in K-Ar and40Ar/39Ar Geochronology

K-Ar and more recently the40Ar/39Ar variant are well established dating methods. The40Ar/39Ar method requires irradiation with neutrons, posing some complications that are greatly outweighed by the benefits. The40Ar/39Ar method is particularly powerful due to the availability of internal reliability criteria, the ability to analyze single crystals, and the amenability of the analyses to automation.40Ar/39Ar dating has the capability for unsurpassed precision and is applicable to the broadest range of geologic environments and time scales of any radioisotope dating technique. For chronostratigraphic applications,40Ar/39Ar is most important in the Cenozoic, becoming progressively less useful into the early Phanerozoic due to alteration and loss of radiogenic argon. Precision and accuracy of40Ar/39Ar dating have been improved considerably in recent years, but an uncertainty of about 1% in the decay constant for40K, probably mainly in the electron capture decay branch, still limits accuracy at about this level. Inconsistent use of standards (neutron fluence monitors) and attribution of variable ages to standards is still a source of confusion, but straightforward recalculation procedures can overcome the underlying problems provided that appropriate standards are used.