1,458 research outputs found
Sugarcane white leaf and sugarcane grassy shoot diseases: biology and taxonomic characterization of the associated phytoplasmas
No full textSugarcane white leaf (SCWL) and sugarcane grassy shoot (SCGS) are yellows and decline diseases of sugarcane (Saccharum officinarum L.) associated with phytoplasma infection. Both diseases occur only in Asia and not in other sugarcane growing areas of the world. Sequence and restriction fragment length polymorphism (RFLP) analysis of ribosomal DNA (rDNA), which was amplified by polymerase chain reaction (PCR), revealed that the SCWL and SCGS agents are closely related organisms. They form, together with the rice yellow dwarf (RYD) phytoplasma and strain BVK obtained from the leafhopper Psammotettix cephalotes in Germany, the phylogenetic SCWL group. Differentiation of the SCWL and SCGS phytoplasmas is possible by RFLP analysis of PCR-amplified rDNA, using HpaII and MspI restriction endonucleases
Fusarium rhizome rot of ginger in Queensland
Get PDFA rhizome rot of ginger in Queensland is shown to be caused by a strain of Fusarium oxysporum and is considered to be a distinct form referred to F. oxysporum f. zingiberi Trujillo. Control of the disease in artificially inoculated ginger rhizomes was obtained with ethoxyethyl mercury chloride (6% Hg) at 1 lb in 40 gal for 30 min or 2 lb in 40 gal for 10 min. Control was not obtained with a dip treatment with captan, with dust treatments with captan or chloranil, or by curing rhizome pieces for five days before inoculation
Technical notes. A lucerne root rot caused by Pythium myriotylum
Get PDFEach of three isolates of P. myriotylitm proved virulently pathogenic to lucerne seedlings under the conditions of the test. The stems and leaves of inoculated plants became shrivelled, wilted and curled. The most practicable way of reducing losses from root rot caused by Pythimn niyriotylimi appears to be to correct unsatisfactory cultural conditions as far as possible
Technical notes. Puccinia argophylli sp. N. on Argophyllum nullumense in Queensland
No full textIn January 1957 a collection of inconspicuously rusted leaves of the scrub tree Argophyllum nullumense R. T. Baker was made on "The Lost World," a small rain-forest plateau in the rugged McPherson Range of southeastern
Queensland. Argophyllun is a genus of the family Saxifragaceae, tribe Escallonieae. No rust has been recorded from this genus or the related Quintinia, Abrophyllum, Cuttsia, Polyosma and Anopterus. The rust is therefore considered to be an unnamed species, and is described below
Papaw root rot caused by Phytophthora palmivora Butl.
Get PDFA severe root rot of papaw (Carica papaya Gaertn.) in Queensland is caused by Phytophthora palmivora Butl. Waterlogging is an important predisposing factor in the occurrence of the disease. In the Brisbane area, soil temperatures are favourable for growth and sporulation of P. palmivora, except during June, July and August. Field evidence suggests that crop rotation reduces the severity of attack. P. palmivora isolated from roots proved capable of rotting green papaw fruit, but a similar fruit rot has not been found naturally in Queensland
Abiotic transmission of southern bean mosaic virus in soil
No full textWhen soil in pots was infested with southern bean mosaic virus (SBMV), it became infective for highly susceptible Phaseolus vulgaris bait plants. Soil could be infested by adding either infected plant tops or roots or by growing infected plants in it. Release of SBMV by roots of P. vulgaris cv. Red Kidney reached a maximum at flowering and thereafter declined, but some virus was still recovered in drainage water when the plants were dead. When grown in infested soil P. vulgaris cv. Bountiful was more susceptible to infection at 26°C than at 21 or 32°C, temperatures which were less favourable for plant growth. The addition to virus-infested soil of tomato roots carrying nematodes (Meloidogyne sp.), fungi and other soil biota did not increase virus infection in bait plants. It is concluded that SBMV resembles tobacco mosaic virus in being able to infect plant roots abiotically in infested soil
Species of Pythium in Queensland
Get PDFFourteen species of Pythium have been recorded in Queensland. Notes are given on the morphological and cultural characters found useful in identifying these species. Growth-temperature studies confirm that maximum temperature can be used as an aid to morphology in identification. An annotated host index for Queensland is presented
New (Probabilistic) Derivation of Diaz-Metcalf and Pólya-Szegő Inequalities and Consequences
No full textClassical inequalities of Diaz - Metcalf and Pólya - Szegő are generalized to
probabilistic setting which covers the initial deterministic (both discrete and integral) variants.
From these two inequalities, by the probabilistic derivation method further well -
known inequalities are obtained (that ones by Kantorovich, Rennie and Schweitzer)
Mouvance and the medieval author: re-editing Ancrene Wisse
No full textThe paper discusses the theoretical and practical problems of editing the early thirteenth-century guide for anchoresses, Ancrene Wisse, which (in Paul Zumthor's phrase) is an 'oeuvre mouvante', modified repeatedly from an early stage by its author and others
Tele-operated climbing and mobile service robots for remote inspection and maintenance in nuclear industry
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