bluuebunny/crossref_metadata_2025_split huggingface dataset:
Host plant reactions, physical properties and serology of three isolates of Andean potato latent virus from Peru
Authors: FRIBOURG C. E. , JONES R. A. C. , KOENIG RENATE 
Published: February 2008

SUMMARYThree isolates of Andean potato latent virus (APLV) (Caj, Hu, Ay) each infected twenty‐seven species of plants in the families Amaranthaceae, Chenopodiaceae, Cucurbitaceae and Solanaceae but differed somewhat in the symptoms they induced. Nicotiana bigelovii and N. clevelandii proved the most useful diagnostic hosts. Symptoms were sometimes produced by all three isolates in cultivated and wild potatoes. In sap from systemically infected N. bigelovii and N. clevelandii leaves, all three isolates remained infective when diluted to 10‐6 and when stored at room temperature for at least 3 wk. The thermal inactivation points were 65–70 °C for Hu and Ay, but 75–80 °C for Caj. All three isolates differed serologically from Col, the original isolate of APLV, forming spurs in gel diffusion tests. No serological difference was found between Hu and Ay, but both formed spurs in reciprocal reactions with Caj. The data from light absorption, particle morphology and protein molecular weight for Caj, Hu and Ay are similar to those reported for other tymoviruses. APLV was found widespread in Andean countries.
Effect of annual and perennial cropping regimes in microplots on the population density and vertical distribution of Xiphinema diversicaudatum and on soil porosity
Authors: COTTON J. 
Published: February 2008

SUMMARYLong‐term trends in populations of Xiphinema diversicaudatum were measured in two microplot experiments in which annual and perennial crops of seven plant families were grown in monoculture.Numbers of X. diversicaudatum increased under perennial ryegrass, raspberry and strawberry but decreased under hop, spring barley, potato, sugar beet, cabbage, winter wheat and winter beans; these effects probably reflected differences in the inherent host status of the crops. There were fewer X. diversicaudatum at 40–60 cm below annual crops than below perennial crops, and there were differences between perennial crops in nematode vertical distribution.Soil pore space did not limit nematode population density; total pore space was uniformly large under all crops and there was no detectable instability to water slaking. Under ryegrass a greater proportion of soil volume was occupied by pores too small to accommodate X. diversicaudatum, but since ryegrass supported the second largest nematode population, it seems unlikely that this was seriously limiting.
The long‐term effects of four monocultural regimes on two field populations of the nematodes Xiphinema diversicaudatum and Longidorus spp.
Authors: McNAMARA D. G. , PITCHER R. S. 
Published: February 2008

SUMMARYPopulation density changes of Xiphinema diversicaudatum and several Longidorus spp. were observed under four cultural regimes in long‐term field experiments. Numbers of X. diversicaudatum increased under strawberry and, to a lesser extent, ryegrass, but remained more or less unchanged in hop and fallow plots. A mixture of four Longidorus spp. increased in numbers under grass but stayed static, or declined slowly under the other cultural regimes.All changes in population density were slow to occur, taking 3 or 4 yr for differences to become statistically significant. Fluctuations in larval numbers were mainly responsible for overall population changes; numbers of adults showed little difference over 5 yr.
Studies on plant growth‐regulating substances XLVII. Ultrastructural studies on emergent leaves of Avena sativa treated with 3,5‐(diiodo and dibromo)‐4‐hydroxyphenylmethylsulphone
Authors: SARMA R. , FLOOD A. E. , WAIN R. L. 
Published: February 2008

SUMMARYTreatment of oat plants with the pre‐emergence herbicides ioxysone and bromoxysone leads to the production of albino leaves. Ultrastructural studies have indicated that this effect is associated with lipid‐like material outside the chloroplasts which themselves are in a proplastid state. The significance of these observations is discussed in terms of the possible mode of action of these chemicals.
Relationships, host‐ranges and symptoms of some isolates of phleum mottle virus
Authors: CATHERALL P. L. , CHAMBERLAIN JUDITH A. 
Published: February 2008

SUMMARYEleven isolates of phleum mottle virus, each from a different grass species, were grouped into five distinct strains: phleum mottle (PM), holcus transitory mottle (HTM), festuca mottle (FM), cocksfoot mild mosaic (CMM) and brome stem‐leaf mottle (BSM). Their interrelationship was expressed three‐dimensionally using serological differentiation indices.When 105 species of Gramineae were inoculated with each strain, eighty‐one in forty genera became infected. These included festucoid, chloridoid, panicoid and andropogonoid species. Electron microscopy was more reliable than back‐inoculation for detecting infection in plants that remained symptomless. Annual species were usually more severely affected than perennials. PM, HTM, FM, CMM and BSM did not appear to differ in host range, but sometimes differed in the symptoms induced in a given host. Each was symptomless in some hosts, caused a mild or severe mottle in others and mottling plus necrosis in a few. HTM was symptomless in most, and BSM in fewest species: BSM caused necrosis in most and HTM in fewest hosts.
Changes in the oxygen consumption of cysts of Globodera rostochiensis associated with the hatching of juveniles
Authors: ATKINSON H. J. , BALLANTYNE A. J. 
Published: February 2008

SUMMARYThe oxygen consumption of single cysts (90–110 /tg dry wt) was measured with an oxygen electrode microrespirometer. The mean oxygen consumption of nine cysts after 7 days in tap‐water, was 0–48 + 0–05 mm3 02 mg dry wt‐1 h‐1. After transfer to potato root diffusate for 1 day the mean oxygen consumption of the same cysts showed a significant increase to 159±7% of the rate recorded before they were removed from water. After 3 and 7 days in diffusate the corresponding means were 131±9% and 127±12% respectively. Cysts that remained in water throughout the experiments did not show any significant change in their oxygen consumption from the rate recorded after 7 days. The initial increase in oxygen uptake after the addition of diffusate was shown not to be due to the presence of microorganisms.Comparison of hatching data with the changes in oxygen consumption of similar cysts after 24 h in diffusate suggests that the increased oxygen uptake cannot be attributed solely to locomotor activity of the juveniles during the hatching process. The increased rate of respiration may precede other known changes that follow after the juveniles within a cyst are stimulated to hatch.
Changes in the adenine nucleotide content of cysts of Globodera rostochiensis associated with the hatching of juveniles
Authors: ATKINSON H. J. , BALLANTYNE A. J. 
Published: February 2008

SUMMARYThe content of AMP, ADP and ATP within single cysts of Globodera rostochiensis (60–80 fig dry weight) was determined as ATP to an accuracy of ± 10‐11 mol by a bioluminescent technique, after microenzymic methods had been used to phosphorylate AMP and ADP to ATP.Results for a total of 120 cysts showed that a change occurs in the adenylate energy charge of their contents after they have been exposed to potato root diffusate. Cysts in water had a mean adenylate energy charge of 0–63 (s.E. ± 0–04), but a randomly selected group of cysts after 24 h treatment with potato root diffusate had a significantly lower mean of 0–49±0–04. In a second, similar experiment, cysts in diffusate for only 8 h had an energy charge of 0*55 ± 0–03, but this value was not significantly less than the corresponding mean of o‐6i ±0–03 of cysts that remained in water.The results indicate an effect on the metabolism of the unhatched juveniles that occurs too soon after the addition of diffusate to be directly due to any increase in locomotor activity. Apparently, the primary action of the hatching factor had affected many juveniles within 24 h of the addition of potato root diffusate to the cyst.
The effect of partial defoliation on yield of sugar beet
Authors: FRENCH S. A. W. , HUMPHRIES E. C. 
Published: February 2008

SUMMARYSugar‐beet plants were defoliated during growth in seven experiments from 1968 to 1974 either (1) by removing each leaf as it became fully expanded or (2) by removing with scissors as soon as possible all leaves except certain groups up to leaf50, but mainly 6 to20, or (3) by treating the growing point chemically or mechanically in an attempt to stop the production of leaves after the twentieth.Removing mature leaves decreased yields considerably, but removing all leaves except 6–20 did not decrease significantly total dry matter yield of the whole plant and in one experiment increased it by 7% and root weight by 15%. Remaining leaves had a greater photosynthetic efficiency as measured by growth analysis and a 14C02 feeding technique because they were less shaded or there was reduced competition for some nutrient or essential growth component.Additional leaves formed beyond the twentieth resulted in a proportionately lower photosynthetic efficiency of all leaves, but attempts to treat the plant to stop production of new leaves beyond the twentieth were inconclusive.
Host‐ranges of cocksfoot mottle and cynosurus mottle viruses
Authors: CATHERALL P. L. , ANDREWS P. A. , CHAMBERLAIN J. A. 
Published: February 2008

SUMMARYCocksfoot mottle virus (CfMV) and cynosurus mottle virus (CyMV) had similar, but not identical, host‐ranges within the Gramineae. Each infected fifteen out of forty‐one species tested, considerably fewer than phleum mottle virus (PMV), but unlike PMV both infected Triticum aestivum (wheat), causing a lethal mottle. The species most useful for differentiating CfMV, CyMV and PMV are listed. Some species appear especially susceptible to virus infection.
Control of clubroot by soil partial sterilization with particular reference to the treatment of small natural foci of infection
Authors: WHITE J. G. , BUCZACKI S. T. 
Published: February 2008

SUMMARYExperiments were made on field plots with four soil partial sterilants applied at different dose rates or as combination treatments. The effects of treatments on clubroot were assessed by growing cabbages on the field plots or in a glasshouse in soil removed from the plots. In two experiments, no plants grown on plots or seedlings grown in soil samples from plots treated with Dowfume M.C.2 or Telone were infected with clubroot, whilst only one infected seedling was found in soil samples from those plots treated with chloropicrin. Although relatively few infected plants were recovered from Basamid treated plots, many infected seedlings were found in soil samples from those plots. The effectiveness of these treatments as indicated by seedling survival was Dowfume M.C.2 < chloropicrin < Telone < Basamid. At five sites a combination of Dowfume M.C.2 at 98 g/m2 with 40 g/m2 Basamid resulted in all cabbage seedlings grown in soil samples being disease free.
The effect of Benlate and cytokinins on the content of tobacco mosaic virus in tomato leaf disks and cucumber mosaic virus in cucumber cotyledon disks and seedlings
Authors: BAILISS K. W. , COCKER F. M. , CASSELLS A. C. 
Published: February 2008

SUMMARYTomato leaf disks were inoculated with tobacco mosaic virus (TMV) and floated for 7 days on solutions of kinetin and benzyladenine in the range 20‐0‐002 mg/1. Virus content was reduced at the higher and increased at the lower concentrations. Benlate and benomyl showed a peak of cytokinin activity in the Amaranthus betacyanin bioassay equivalent to c. 0–002 fig/l kinetin. At concentrations above 25 and 100 mg a.i./l for Benlate and benomyl respectively, both compounds increased the TMV content of tomato leaf disks.Cucumber mosaic virus (CMV) content in cucumber cotyledon disks was increased by Benlate and benomyl treatment (50–100 mg/1). Applied as a soil drench (50–500 mg a.i./l) when the plants were inoculated, Benlate increased the CMV content of infected seedlings. The number of starch‐iodide lesions (a measure of susceptibility) was unaltered in cotyledons treated with Benlate 7 days before or immediately after inoculation. Infectivity of crude infective cucumber sap was unaffected by benomyl incorporation, whereas Benlate reduced infectivity at higher concentrations (1000–5000 mg/1).Under the experimental conditions described, Benlate, benomyl, benzyladenine and kinetin had no effect on the chlorophyll content of tomato leaf disks, and intact seedlings.
Regeneration from rhizome fragments of Agropyron repens
Authors: LEAKEY R. R. B. , CHANCELLOR R. J. , VINCE‐PRUE D. 
Published: February 2008

SUMMARYSingle‐node rhizome fragments from four swards of Agropyron repens were grown without added nutrients in Perspex growth‐boxes in the dark. Mean values for shoot length; shoot, root and rhizome dry weights; soluble sugar, starch, soluble nitrogen and total nitrogen contents were determined monthly, and the occurrence of ‘late spring dormancy’ noted. Regenerative capacity was greatest in winter and least in summer and often could be related to the rhizomes' total nitrogen content, as there was a correlation between total nitrogen content and shoot dry weight throughout the year. The amount of gibberellic acid in i‐yr‐old rhizomes was less than o‐i figjg in April and June, the months with the two extremes of regenerative capacity.
Regeneration from rhizome fragments of Agropyron repens
Authors: LEAKEY R. R. B. , CHANCELLOR R. J. , VINCE‐PRUE D. 
Published: February 2008

SUMMARYExperiments were done with rhizome fragments of Agropyron repens with or without ‘late spring dormancy’. Increasing concentrations of KN03 from 1 to 210 ppm successively increased the percentage of buds released from dormancy, but the restriction of shoot extension was significantly lessened only when concentrations of nitrogen were 50 ppm or more. Solutions of sodium nitrite, ammonium chloride and glutamic acid with equal nitrogen contents were equally effective in releasing buds from dormancy. Larger amounts of nitrogen were required to stimulate growth in basal buds, than in apical buds. GA3, and chilling at – 2 oC slightly increased the percentage of buds growing but did not significantly affect the amount of extension growth, while ethephon (2‐chloroethylphosphonic acid) had no effect. The restoration of regenerative capacity was associated with increased utilization of rhizome sugars.In single‐node rhizome fragments with ‘late spring dormancy’, chilling for 2 wk slightly increased the regenerative capacity but chilling for longer periods decreased it, possibly because respiration during the protracted period of chilling depleted rhizome reserves. Chilling also increased the utilization of rhizome carbohydrates during subsequent growth. Node position affected regenerative capacity: buds from the apical end of the rhizomes were found to have the highest regenerative capacity, this being associated with their greater nitrogen content.Because the name ‘late spring dormancy’ seems to be inappropriate for this phenomena, the term ‘Restricted Regenerative Capacity’ is proposed.
The relative hardening of roots and shoots and the influence of day‐length during hardening in perennial ryegrass
Authors: LAIDLAW A. S. , BERRIE A. M. M. 
Published: February 2008

SUMMARYThe influence of long and short days during the hardening period on the cold hardiness of perennial ryegrass seedlings was studied as was the relative hardiness of roots and shoots. Hardiness was assessed by the electrolyte release method which was a measure of the amount of damage subsequent to low temperature treatment.Long days promoted hardiness in shoots of Pax 0tofte plants and in one case under short days the roots were found to be hardy. Generally roots were less hardy than shoots in Pax 0tofte and S23 plants hardened under long days for 2 wk. When hardened at the fourth leaf stage for 2 wk at + 5 oC under long day conditions, Pax 0tofte plants were more hardy than those of S23.The long day effect on hardiness was arrived at more rapidly, there being no difference in hardiness after 3 wk in Pax 0tofte hardened under long or short days, whereas a significant degree of hardening was observed after 1 wk of hardening under long days at – 4 oC.The results obtained are discussed in relation to winter kill of grasses in the West of Scotland, and it is considered that root damage is not an important factor in causing winter kill. The promotive effect of long days on hardiness when hardening commences in late autumn is considered an advantage in temperate regions as it may also allow early frosts to be withstood.
A comparison of the effects of a new quaternary ammonium growth retardant with those of other growth retarding chemicals on the pot chrysanthemum (Chrysanthemum morifolium)
Authors: MENHENETT ROGER 
Published: February 2008

SUMMARYA new quaternary ammonium growth retardant, i‐allyl‐i‐(3,7‐dimethyl‐octyl)‐piperidinium bromide (ADOPB), was compared with daminozide, ancymidol and chlorphonium chloride for its effectiveness in reducing lateral stem length in the pot chrysanthemum (Chrysanthemum morifolium). Single foliar sprays of ADOPB applied at 100 to 250 ppm active ingredient (a.i.) gave excellent height control without phytotoxicity in cv. Bright Golden Anne throughout the year. Similar results were obtained in two trials with cvs Purple Anne and Regal Anne. As much as 10 to 50 times this concentration of daminozide was required to achieve a similar degree of height control. However, under summer conditions even high concentrations of daminozide did not adequately reduce stem length. Foliar sprays of ancymidol (50–100 ppm a.i.) also gave good control of stem length but this chemical was more effective when applied as a compost drench. Compost drenches of ADOPB reduced stem extension but a greater quantity of a.i. was required compared to a foliar spray. Foliar sprays of dikegulac‐sodium (100 to 5000 ppm a.i.) were very phytotoxic. Reductions in thelength of lateral stems were associated with marked decreases in their fresh and dry weights.Growth retardants delay the flowering of pot chrysanthemums by inducing a slower rate of flower bud development. Foliar sprays of ADOPB generally delayed flowering by 2–3 days more than did sprays of daminozide, but this was comparable with that associated with the use of compost drenches of chlorphonium chloride. High concentrations of all the retardants reduced the diameter of open flowers. Only daminozide caused a loss of flower colour in cv. Regal Anne.The results are discussed in relation to the mode of action of growth retardants, with particular reference to the effects of gibberellins on stem extension and flower development in the chrysanthemum.
Economics of forecasting for chemical control of the black bean aphid, Aphis fabae, on the field bean, Vicia faba
Authors: CAMMELL M. E. , WAY M. J. 
Published: February 2008

SUMMARYThe economics of a forecasting scheme for predicting the need for chemical control of the black bean aphid, Aphis fabae, on spring‐sown field beans, Vicia faba, are compared with alternative control strategies, namely no treatment, eradicant treatment and routine preventive treatment. Two criteria are assessed. First, the ‘risk’ of lost revenue from wrong control decisions and, secondly, the overall profitability of the strategy. A wrong decision is made when a profitable treatment is not applied or when an unprofitable one is applied. These constitute ‘risk’ for the grower. The forecasting scheme involves least risk of monetary loss and the most acceptable alternative strategy is the routine preventive treatment. Relative to the routine treatment, a gain averaging £3.78/ha of bean crop would have been made between the years 1970‐5 by adopting control based on the forecasting scheme.There was considerable year‐by‐year and area‐to‐area variation in monetary benefits, with the largest gains in areas where economic damage occurred least frequently and where relatively large areas of beans are grown, as in East Anglia. Other benefits of using the forecasting scheme, e.g. correct timing of chemical application, are discussed but not evaluated.
Chemical control of the cabbage stem flea beetle, Psy Modes chrysocephala, on winter oil‐seed rape
Authors: ALFORD D. V. 
Published: February 2008

SUMMARYIn East Anglia, from 1974 to 1976, field experiments were carried out on the chemical control of the cabbage stem flea beetle (PsyModes chrysocephala). Carbofuran, 5% granules, proved an outstanding autumn preventive and mid‐winter eradicant treatment under both wet and dry conditions, with 1–5‐2‐24 kg a.i./ha giving virtually 100% control of larvae. Fonofos and phorate granules at 2–24 kg a.i./ha were also effective. AC 92 100 and thiofanox granules were less extensively tested but both gave good control of P. chrysocephala. Several materials showed little or no activity against the pest. The effective preventive granule treatments were all superior to a standard spray of gamma‐HCH.
The infection of apples by Phytophthora syringae
Authors: EDNEY K. L. 
Published: February 2008

SUMMARYContamination with infected soil has led to high wastage of apples in storage due to rotting by Phytophthora syringae. At 3‐3 oC lesions formed 3–4 wk after inoculation with zoospores; the percentage infection fell if the suspensions dried after 48 h at this temperature and after 22 h at 15 oC. Infected soil rotted fruit only if kept moist; at 3‐3 oC a 3‐day period of wetness resulted in 37‐5% rotting after 8 wk. Fruit dipped in soil slurry remained wet in some parts of a 4361(12 bushel) bin for at least 3 wk. There was a 10‐fold increase in rotting by contact between sound and rotting fruit after 11 wk at 3‐3 oC. Captan gave effective protection against rotting derived from zoospores or infected soil; it had no eradicant action.
The effect of harvest date and duration of wound healing conditions on the susceptibility of damaged potato tubers to infection by Phoma exigua (gangrene)
Authors: ADAMS M. J. , GRIFFITH R. L. 
Published: February 2008

SUMMARYIn experiments extending over 3 yr, King Edward tubers harvested on various dates from early September until early November were uniformly wounded and kept at 15 oC and c. 95% r.h. for periods of up to 21 days for wounds to cure. When tubers were subsequently inoculated with Phoma exigua var.foveata and incubated at 5 oC for 12 wk, curing for 3 and 7 days decreased gangrene incidence to respectively c. 13 and 4% of the non‐cured controls. When tubers were inoculated before curing and immediately after wounding, curing for 7 days decreased gangrene incidence to only c. 68% of the non‐cured controls. Curing was also progressively less effective the later the date of harvesting, suggesting that there would be advantages in harvesting potato crops early in the autumn.
Investigations on fungicides. XX. The fungitoxicity of analogues of the phy toalexin 2‐(2‘ ‐methoxy‐4’ ‐hydroxyphenyl)‐6‐methoxybenzofuran(vignafuran)
Authors: CARTER G. A. , CHAMBERLAIN K. , WAIN R. L. 
Published: February 2008

SUMMARYA series of hydroxy‐and methoxy‐2‐phenyl benzofurans, structurally related to the phytoalexin vignafuran, have been synthesised and their antifungal activity assessed both as inhibitors of spore germination in vitro and as protective foliar sprays against three pathogens. All fungitoxic compounds have a hydroxy group in the molecule although most di‐ and tri‐hydroxy compounds were inactive. Methoxy compounds were inactive but substituting methoxy groups into the molecule of monohydroxy compounds sometimes enhanced their fungitoxicity. No close correlation was established between antifungal activity and either Hansen n values or the n.m.r. chemical shift of the phenolic protons.