bluuebunny/crossref_metadata_2025_split huggingface dataset:
Translocation of 14C‐dieldrin from small droplets on cotton leaves
Authors: PHILLIPS F. T. , ETHERIDGE P. , KAVADIA V. S. , SETHI G. R. , SPARROW P. E. 
Published: February 2008

SUMMARYDieldrin (HEOD) spread from dried residues formed from droplets of emulsions and crystalline suspensions applied to the upper surfaces of cotton leaves (Gossypium species).The amounts of radiolabelled insecticide reaching defined areas of leaf‐surface bearing adhesive tape (Sellotape) were measured quantitatively by scintillation counting. Autoradiography supported these results in demonstrating the extent of insecticide movement in the leaf.Up to one‐fifth of the applied dose spread more than 8 mm across the leaf surface within a day (lateral movement).Penetration to the lower surface (vertical movement) took place within 4 days, depending on the leaf thickness, which itself was greatly affected by the growing conditions. During this process some dieldrin formed a derivative, possibly a hydroxydieldrin, and some was sorbed at the sites of the lysigenous secretory glands within the leaf.Dieldrin spreads from a deposit (representing that left by a spray droplet) on cotton leaf in all directions to a greater extent and more rapidly than previously supposed.
Physiological studies of a hybrid between populations of Dactylis glomerata from contrasting climatic regions. I. Inter population differences
Authors: EAGLES C.F. , OTHMAN OMAR B. 
Published: February 2008

SUMMARYA study of the physiological responses of a hybrid between a North European population and a colchicine‐induced autotetraploid of a Portuguese population of Dactylis glomerata subspecies lusitanica showed an intermediate response of the hybrid for many characters. However, the hybrid resembled one or other of the parents in the more favourable expression of certain characters in controlled environments at 20°C, 16 h photoperiod and 8 °C, 8 h photoperiod. Rate of dry‐matter production of the hybrid did not differ significantly from that of the northern parent at 20 °C, 16 h and that of the Portuguese parent at 8 °C, 8 h. Leaf growth of the hybrid at 8 °C, 8 h was greater than that of the northern parent and together with the high percentage survival in a freezing test may indicate a role for similar hybrids in the development of potential varieties with improved seasonal distribution of dry‐matter production.
Interactions in fireblight infections
Authors: Billing Eve , Bennett R. A. , Hutson R. 
Published: February 2008

ABSTRACTIn the host, Erwinia arnylovora (Burrill) Winslow et al. travels primarily in the inter‐cellular spaces of immature cortical tissue; progress in mature tissue is restricted. Only in the later stages of infection are saprophytic bacteria such as Erwinia herbicola (Löhnis) Dye commonly found in association with the pathogen. Their effect on the persistence of the pathogen is still uncertain though commonly assumed (with little supporting evidence) to be inhibitory.Most interaction studies have concentrated on the early stages of infection. The interactants have been inoculated prior to or together with E. amylovora and they have included avirulent E. amylovora, phyto‐pathogenic pseudomonads, E. herbicola and other saprophytes or cell components including DNA. Our experience reflects that of other workers in that interactants only inhibit at high doses or at high numbers relative to the pathogen. Prior inoculation is not always necessary for protection.In our preliminary studies of the fate of interactants, the outcome varied. Where infection progressed the interactant disappeared, persisted only at the point of inoculation or progressed alongside the pathogen. Where there was protection, both pathogen and interactant disappeared from the tissues or only the interactant persisted at the site of inoculation. Crown gall apart (possibly a special case), observations with other bacterial plant diseases have been similar to those with fireblight with an added one of stimulation of infection by the interactant.The underlying mechanisms of protection probably vary with different interacting systems and cannot always be attributed to a hypersensitivity reaction or to bacteriophage or bacteriocin activity. If a host response is involved, it seems pertinent to ask whether there are simpler ways of achieving protection of growing tissue other than by using bacteria and their products. With epiphytic bacteria two major problems are the achievement and maintenance of high enough populations at critical sites and the lack of major transmitted or translocated effects beyond the site of interaction.
Biological control of crown gall, Agrobacterium tumefaciens
Authors: Garrett Constance M. E. 
Published: February 2008

ABSTRACTBiological control of crown gall caused by Agrobacteriurn turnefaciens (Smith & Townsend) Conn, pioneered by Dr A. Kerr in South Australia, is effected through the establishment of a high population of the related non‐pathogen A. radiobacter (Beijerinck & van Delden) Conn, strain 84 in the rhizosphere of susceptible plants. Strain 84 produces a bacteriocin to which many strains of the pathogen in Australasia, North America and Britain are sensitive.The disease is present in Britain on a variety of hosts including cherry. At East Malling cherry leaf scars, invaluable as an avenue of infection for bacterial canker infectivity titrations, have been used successfully in crown gall studies. Live cells of strain 84, but neither an avirulent strain of the pathogen nor a soil bacterium highly antagonistic to A. tumefaciens in vitro, inhibited gall formation in cherry leaf scars. Heat‐killed cells had no effect.In a field experiment at East Malling hardwood cuttings of the new rootstock Colt have been dipped in strain 84 and total inhibition of crown gall is expected to ensue. The results of other experiments where the disease is already established on cherry‐rootstock layer‐beds and in blackberry plantations are less predictable. In time we hope to solve this problem. Only time will show whether this method of biological control is long lasting or will eventually break down.
Lignification in wheat roots parasitised by Gaeuntannomyces graminis and Phialophora radicicola
Authors: Cowan M. C. 
Published: February 2008

ABSTRACTPreliminary results suggest a possible relationship between lignin synthesis in wheat roots and the observed interaction between Gaeumannomyces graminis (Sacc.) Arx & Olivier and Phialophora radicicola Cain var. graminicola Deacon when they parasitise wheat roots. It was found that colonisation of wheat roots by P. radicicola resulted in a qualitative change in the lignin of the root, such that the content of the p‐hydroxy type of aromatic nucleus was reduced almost to zero. It was also found that some of the metabolic precursors of lignin were inhibitory to the growth of G. graminis in Petri‐dish culture. Most inhibitory of these precursors was caffeic acid, which reduced the growth rate of G. graminis by half at a concentration of 37 ppm. It is tentatively suggested that colonisation by P. radicicola results in an increased activity of polyphenol oxidase in the root tissues. This would lead to a more rapid synthesis of caffeic acid, with a depletion of the level of p‐coumaric acid, and probably an increase in the levels of ferulic acid and sinapic acid. As well as bringing about a change in the composition of the lignin of the root, as the results show, the possible accumulation of caffeic acid in the root tissues might explain the greater resistance to infection by G. graminis observed in roots colonised first by P. radicicola.
Interactions between seed‐borne wheat pathogens
Authors: Odebunmi‐Osikanlu Y. K. 
Published: February 2008

ABSTRACTFusarium nivale Auct., Fusarium culmorum (W.G.Sm.) Sacc. and Septoria nodorum Berk. were used to inoculate wheat seed either singly or in mixtures. Data collected from glasshouse and field experiments suggest that less pre‐emergence death of seedlings and fewer seedlings with lesions occur when F. nivale and F. culmorum are present on the seed together than when F. culmorum only is present. There is also clear evidence that this reduction in disease cannot be attributed to the halving of the spore concentration of each species in the mixture used.
Interactions between Rhizoctonia tuliparum and soil microorganisms
Authors: Gladders P. , Coley‐smith J. R. 
Published: February 2008

ABSTRACTRhizoctonia tuliparum Whetzel & Arthur is a winter active soil‐borne pathogen, which causes the grey bulb rot of tulips and Dutch irises. The fungus survives by means of sclerotia.It was found that the sclerotia only germinated in unsterile soil at low temperatures (0–10 °C). Germination in sterile soil occurred over a wider range of temperatures (0–25 °C) but was inhibited at 20 °C after the addition of a suitable bacterial inoculum.An unidentified pyrone antibiotic was leaked by sclerotia which had been air‐dried and re‐wetted. This could be detected in vitro using an agar medium seeded with a spore suspension of Bacillus subtilis Cohn emend Prazmowski. In soil, however, material leaked by sclerotia stimulated both bacteria and fungi.Undried, air‐dried and oven‐dried (non antibiotic) sclerotia persisted equally well in soil over 2 yr. This suggests that the resistance to lysis of sclerotial cell walls may be important in the long term survival of this organism.
A rapid technique for analysing diets of invertebrate predators by electrophoresis
Authors: MURRAY R. A. , SOLOMON M.G. 
Published: February 2008

SUMMARYA technique has been developed for the rapid determination of some species of prey consumed by mites and insects. The method detects prey enzymes within the gut of a predator by polyacrylamide gradient gel electrophoresis and subsequent staining for esterase activity. It is sufficiently sensitive to detect fruit tree red spider mite (Panonychus ulmi) esterases within the gut of a single predacious mite (Typhlodromus pyri) for at least 31 h after feeding. The method has been used to demonstrate feeding relationships among a range of insect and mite predator and prey species in the laboratory and in the field.
Predisposing effects of Eyespot (Pseudocercosporella herpotrichoides) on Septoria nodorum infection of winter wheat
Authors: JONES D. GARETH , JENKINS P. D. 
Published: February 2008

SUMMARYPlants of two cultivars of winter wheat were inoculated with Pseudocercosporella herpotrichoides at Growth Stage 4 and with Septoria nodorum at Growth Stage 9 or 10.5. Significantly higher levels of S. nodorum developed on the leaves of eyespot infected plants but there was no significant interaction in terms of grain yield. Eyespot infection markedly predisposed the developing seed to infection by S, nodorum.The significance of these results is discussed with reference to the epidemiology of S. nodorum and in relation to the strategy for fungicide control of cereal diseases.
Evaluation of fungicides for control of South American leaf blight of Hevea brasiliensis
Authors: CHEE K. H. 
Published: February 2008

SUMMARYOf 43 fungicides tested in vitro, 19 showed strong, seven moderate and 17 weak inhibition of germination of conidia and ascospores of Microcyclus ulei. The formation of lesions on Hevea brasiliensis leaf discs was also suppressed by the first category of fungicides as well as by the five adjuvants tested. Ascospores were not released when perithecia were treated with urea, thiabendazole or alcoholic mercury chloride at 10.00, 0.10, 1.00 g/1 respectively; other fungicides had no such inhibitory effect.In field trials, thiophanate methyl (0.07% a.i.) and benomyl (0.025% a.i.) were most effective in controlling leaf infection, followed by chlorothalonil (0.15% a.i.) and mancozeb (0.32% a.i.). Benomyl suppressed conidial sporulation, whereas one application of thiophanate methyl (0.14% a.i.) to perithecia inhibited ascospore release; half of this concentration applied to conidial lesions or pycnidia caused the perithecia formed subsequently to abort. Thiophanate methyl thus shows promise for SALB control and elimination and benomyl may be valuable as a supplement in later rounds of spraying to control conidial sporulation.After 6 days of showery rain (2 mm for 17 min per day), water collected from sprayed leaves still gave complete inhibition of spore germination. However, inhibition was markedly reduced after 6 days of heavy rain (over 8 mm for 24 min per day).
Effects of some surfactant fungicides on Rhizobium trtfolii and its symbiotic relationship with white clover
Authors: FISHER D. J. , HAYES ANN L. , JONES CHRISTINE A. 
Published: February 2008

SUMMARYEffects of the surfactant apple mildew eradicants Manoxol OT, Alk 3, Triton X45, PP 222, Ethylan CP, Hyamine 3500, Aromox DMMCDW and Aromox C12W on growth and respiration of R. trifolii in vitro and on its symbiotic nitrogen fixation in association with white clover were measured. Most treatments reduced growth up to 8 wk; after 12 wk plant weight and nitrogenase activity were significantly reduced (P = 0.01) by Triton X45, Manoxol OT and PP 222 at concentrations of 1000, 2500 and 5000 μg/gram of soil respectively.Electron microscopy showed that bacteroids in root nodules where nitrogen fixation was inhibited had contracted away from the host membrane leaving an intracellular space. Damage to the bacteroid membrane was apparent. Surfactants had no demonstrable effect on adhesion of the bacteria to root hairs.In apple orchards run‐off of surfactant fungicides, applied to apple trees at the recommended rates is unlikely to have adverse effects on Rhizobium nodulated white clover.
Distribution of carbon‐14 assimilated by wheat awns
Authors: OLUGBEMI L. B. 
Published: February 2008

SUMMARYThe pattern of distribution of carbon assimilated by awns was investigated in two lines of Triticum aestivum. Single awns on basal florets of spikelets in the central part of the ear were dosed with 14CO2. Five days after dosing, 99% of the carbon‐14 recovered was in the spikelet bearing the awn. Of the carbon‐14 exported from the treated awn 57% went to the grain of the first floret, 1% to the second, 28% to the third and 7% to the fourth.
Modelling canopy net photosynthesis by isolated blocks and rows of chrysanthemum plants
Authors: ACOCK B. , CHARLES‐EDWARDS D. A. , FITTER D. J. , HAND D. W. , WILSON J. WARREN 
Published: February 2008

SUMMARYA model describing the response of canopy net photosynthesis by isolated blocks and rows of chrysanthemum plants to incident light flux density is reported. The model combines a description of the light environment within an isolated array of plants with a description of the response of leaf net photosynthesis to light flux density.The leaf parameters in the model were estimated by analysis of data for the response of canopy net photosynthesis by a closed crop of chrysanthemum plants to incident light flux density at two carbon dioxide concentrations. These leaf parameter values were then used to simulate the response of canopy net photosynthesis to incident light flux density by an isolated block and double row of chrysanthemum plants. The simulated responses were found to be in close agreement with the measured responses.
Effects of irradiance and water supply on grain development in wheat
Authors: BROCKLEHURST P. A. , MOSS J. P. , WILLIAMS WATKIN 
Published: February 2008

SUMMARYThe effects of two levels of irradiance and of water supply on grain development in two cultivars of winter wheat were studied by imposing treatments during the phases of cell production and cell expansion in the endosperm. The storage capacity of the grain was determined by cell number in the endosperm, which was reduced by both treatments during the cell production phase. Changes in cell number caused by the treatments were due to changes in the rate of production of cells; the duration of the cell production phase was constant. Weight per grain at maturity was proportional, both within and between cultivars, to the number of endosperm cells, except when treatments altered the supply of assimilate to the grain during the cell expansion phase.Reducing irradiance and water during the cell expansion phase decreased the rate of accumulation of dry matter in the grain and reduced weight per grain at maturity, with no effect on the duration of grain filling. Shrivelled grain resulted from a failure of the endosperm cells to fill completely, and was characterised by a reduction in the number of ‘B’‐type starch granules.
A wilt disease of coconuts from Trinidad associated with Phytomonas sp., a sieve tube‐restricted protozoan flagellate
Authors: WATERS HENRY 
Published: February 2008

SUMMARYA wilt disease of coconut palms in Trinidad has been responsible for the death of more than 15 000 palms in the last 2 years. Symptoms of the disease include: loss of nuts, premature browning of successively younger leaves, necrosis of open and unopened inflorescences and of the young unexpanded leaves at the centre of the crown; rotting of the growing point, stem apex and roots.Samples from each of 10 diseased palms contained flagellates which were classified as trypanosomatid protozoans of the genus Phytomonas. The protozoans, which by squeezing could be expressed easily from tissues for observation by phase contrast light microscopy, were 1–1.5 μm wide and 27 μm long including the flagellum which was approximately 7 μm long.Sections of inflorescence rachillae from diseased palms revealed that the phytomonads were restricted to the sieve tubes. Phytomonas was always associated with diseased palms but it was never found in healthy palms.A brief description of the ultrastructure of the presumed pathogen of wilt disease is also given.
The effect of carbendazim‐generating fungicides with and without a mineral oil additive on tomato stem lesions caused by carbendazim‐sensitive and tolerant strains of Botrytis cinerea
Authors: CHANNON A. G. , THOMSON MOIRA C. 
Published: February 2008

SUMMARYIsolates of Botrytis cinerea were obtained from tomatoes in several localities in the West Scotland. Some isolates grew on agar containing 100 mg/1 benomyl (carbendazim‐tolerant), while others did not (carbendazim‐sensitive).Pot‐grown tomato plants treated with benomyl and other carbendazim‐generating fungicides, applied either as sprays or soil drenches, were inoculated on the leaf scars with some of these isolates. On treated plants the carbendazim‐tolerant isolates formed lesions which were about as large as those on untreated plants. Sensitive isolates formed much smaller lesions on treated plants.There was evidence that the increase in lesion size during the period 7–14 days after inoculation with a carbendazim‐sensitive isolate was less on plants sprayed with benomyl or carbendazim with added mineral oil (2% Actipron) than on plants to which the fungicides alone had been applied. No such effect was recorded with thio‐phanate‐methyl. There was also an indication that the addition of Actipron to a benomyl spray improved the effect of the fungicide against two tolerant isolates, though there was no effect on the relative increase in lesion size during the second week after inoculation.In two tests the addition of 2% and 4% Actipron to benomyl soil drenches did not improve the level of leaf scar lesion control.
Distribution, host range, properties and purification of cassava latent virus, a geminivirus
Authors: BOCK K. R. , GUTHRIE E. J. , MEREDITH GINA 
Published: February 2008

SUMMARYCassava latent virus (CLV) is almost entirely confined in East Africa to upland cassava‐growing areas west of the Rift Valley, where it is often associated with cassava mosaic disease (it was isolated from 27 of 38 cassava plants with mosaic, but not from 24 without mosaic). However, it is not the causal agent, because it was not recovered from any of 31 mosaic‐diseased plants in coastal districts. All attempts to return CLV to cassava failed.The host range of CLV appears to be limited to Euphorbiaceae (Manihot) and Solanaceae (Nicotiana, Datura, Nicandra, Solanum). N. clevelandii proved the most useful assay and propagation host. The dilution end‐point of CLV was about 10‐3, thermal inactivation point about 55°C, and longevity in vitro about 3 days.CLV was purified by clarification of leaf extracts with butanol/chloroform mixtures. Purified preparations (A 260/A 280 ratio c. 16) contained numerous 30 20 nm paired particles with a sedimentation coefficient (s20w) of 76 S. Treatment with RNase and DNase showed that the viral nucleic acid is DNA; CLV closely resembles maize streak virus but is not related to it serologically. The cryptogram for CLV is D/1: 0.8/*: S/S: S/*, geminivirus group.
Host plan preferences of Oscinella spp. (Diptera: Chloropidae) in the laboratory
Authors: Vickerman G. P. 
Published: February 2008

SUMMARYThe oviposition preferences of Oscinella frit, O. vastator, O. nitidissima, O. albiseta andO. nigerrima for differenct Gramineae were investigated in the laboratory. O. frit, laid most eggs on oats, Lolium multiflorum and Festuca rubra, relatively few eggs were laid on barley and virtually none on Dactylis glomerata None of the other Osinella species oviposted on cereals. Of the other species, O. vastator appeared to be the most polyphagous and the preferred hosts were L. multiflorum, Lolium perenne and Festuca pratensis; few eggs were laid on either F. rubra, Agrostis tenuis or Poa pratensis. The host ranges of the remaining species were much more limited. Although a few eggs were laid by O. nitidissima on Lolium, the preferred host was A. tenuis. Oscinella albiseta oviposited only on D. glomerata whilst nearly all the eggs laid by O. nigerrima were deposited on shoots of Arrhenatherum elatius. The distribution of eggs by O. frit on L. multiflorum and A. tenuis was different from that on oats; on grasses most eggs were laid inside withered leaf sheaths whereas on oats most were deposited inside the coleoptile. The oviposition sites of O. nitidissima, O. nigerrima and O. albiseta on their respective host grasses were similar to those of O. frit on grasses. O. frit laid most eggs on grasses which were at the five‐leaf stage and tailoring.
Evalutiaon of four isomers of 3‐butyl‐5‐methloctahydroindoliz, a component of the trail pheromone of pharaoh's ant, Monomorium pharaonis
Authors: Edwards J. P. , Pinniger D. B. 
Published: February 2008

SUMMARYFour isomers of 3‐butryl‐methyloctahydroindolizine (monomorine 1), a major component of the trail pheromone of Monomorium pharaonis, was tested for attractant and trail‐initiating activity, One isomer showed attractancy and, under colony condition, tow initiated trail‐following bahaviour. Only the all‐cis isomer (monomorine 1a) had both attractant and trail‐initiating activity. The results indicated that these compounds may have only limited potential for use in control measures against this species.
Host and environmental effects on the infection of maize by Puccinia sorghi. II. Post‐penetration development
Authors: Mahindapala Ranjith 
Published: February 2008

SUMMARYThe numbers of pustules which subsequently developed on maize seedlings incubated at 5, 10, 15, and 20 °C and 100% r.h. were directly related to the temperature and length of incubation.The generation time was 16 days at 10 °C, 10 days at 15 °C, 7 days at 20 °C and 5 days at 25 °C. Increase in urediniospore production was observed with increase in temperature.Increase in the inoculum concentration up to 5 × 104 urediniospores/ml increased the number of resultant uredinia. However, further increases did not increase uredinia‐formation.