bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of surfactants and oils on the phytotoxicity of difenzoquat to Avena fatua, barley and wheat
Authors: TAYLOR M. J. , AYRES P. , TURNER D. J. 
Published: February 2008

SUMMARYControlled drop (CDA) and conventional applications of difenzoquat to pot‐grown Avena fatua were compared. With the recommended surfactant (0.5% v/v Agral), very low volume CDA was less effective than conventional spray application. However, addition of extra Agral or various blends of paraffinic oil with Agral and the surfactants Burtemul A2 or Burtemul P2 improved the effects of the CDA treatments. When difenzoquat was absent the additives were inactive against A. fatua. They had little direct effect on wheat and barley and did not substantially increase the phytotoxicity of difenzoquat to these crops. Oil/surfactant mixtures were less viscous than high concentrations of Agral, and so easier to spray.In a pot experiment, smaller (150 μm diameter) drops of difenzoquat solution were more active against A. fatua than larger (200 μm‐300 μm) drops. Reduction of the spray volume within the range 40 litres/ha to 5 litres/ha also reduced phytotoxicity. An oil/surfactant additive improved the activity of all difenzoquat CDA treatments. There was slightly more effect at the lowest spray volume but interactions between additive and application treatments were not statistically significant.When simulated rain treatments were applied 2 h or 5 h after spraying, difenzoquat controlled drop application was much less phytotoxic than a conventional 150 litres/ha treatment. However, addition of an oil/surfactant mixture markedly improved the performance of CDA. When rain was withheld for 24 h the additive had relatively less effect.In the field an oil/surfactant mixture improved control of A. fatua by difenzoquat with both conventional and controlled drop treatments. The additive did not increase injury to the wheat crop. The oil/surfactant mixtures markedly improved the spreading and wetting properties of sprays. This reduced localised contact injury, which, it is suggested, improved uptake and translocation of difenzoquat.
Tolerance of several wild oat herbicides by a range of winter wheat varieties
Authors: TOTTMAN D. R. , LUPTON F. G. H. , OLIVER R. H. , PRESTON S. R. 
Published: February 2008

SUMMARYScreening tests exposed varietal differences in the tolerance of winter wheat to high doses of the wild oat herbicides difenzoquat and diclofop‐methyl. Subsequent yield trials at recommended and higher doses confirmed the sensitivity of Score and Sportsman to difenzoquat and showed Atou, Bouquet and Hobbit to be less tolerant than some other varieties. In most varieties, earlier spraying proved safer than treatment at or beyond the beginning of jointing. Varietal differences with diclofop‐methyl were smaller and inconsistent.Crops damage from these two herbicides was more severe in another experiment the following season, in which isoproturon at double the recommended dose also caused severe damage but flamprop‐methyl was fairly well tolerated by all varieties.
Antibiotic resistance in potato cultivars to the aphid Myzus persicae
Authors: BINTCLIFFE E. JANE B. , WRATTEN S. D. 
Published: February 2008

SUMMARYCommercially‐grown potato cultivars were assessed for antibiotic resistance to Myzus persicae in a culture room at 19°C with a 2°C range and a 16 h photoperiod. The resistant rankings obtained were consistent for the following aphid metrics: maturation time, teneral adult weight, embryo complement and the production of nymphs.Intrinsic rates of increase (rm) correlated with the above parameters of aphid growth and reproduction but this was not always the case for nymphal survival rate. The cultivars Ulster Tarn, Record and Maris Piper were relatively resistant to M. persicae and cultivars Desirée and King Edward were the most susceptible.When the aphid clone or the culture plants were changed there was no significant effect on the relative resistance of the potato cultivars under test.The relationship between the number of embryos in teneral adults and the production of nymphs by aphids was examined by grouping aphids in weight batches. There was a strong relationship between these two variables.
Tests for resistance to white clover mosaic virus in red and white clover
Authors: SCOTT S. W. 
Published: February 2008

SUMMARYA range of red and white clover cultivars was tested for immunity to white clover mosaic virus. All plants became infected although some showed no symptoms. Enzyme‐linked immunosorbent assay (ELISA) and immunosorbent electron microscopy (ISEM) revealed significant differences in virus concentration between red clover cultivars and between clones of white clover artificially infected with the virus. These differences could not, however, be related to relative yield losses.
4‐Alkoxy‐2‐methylthiopyrrolo‐[2,3‐d]‐pyrimidines. A new series of anti‐cytokinins
Authors: WILCOX E. J. , WAIN R. L. 
Published: February 2008

SUMMARYA series of 4‐alkoxy‐2‐methylthiopyrrolo[2,3‐d] pyrimidines having alkoxy groups from methoxy to hexyloxy along with the parent 4‐hydroxy compound have been tested for cytokinin and anticytokinin activity using tobacco tissue culture. None of the compounds showed any cytokinin activity but several of the compounds were strongly active as anticytokinins, the most active was 4‐pentyloxy‐2‐methyl‐thiopyrrolo[2,3‐d] pyrimidine. Increasing or decreasing the chain length resulted in a lowering of activity; the hydroxy and methoxy compounds were totally inactive over the concentration range tested. The results are discussed in relation to steric and other considerations.
Resistance to binapacryl and tetradifon, and the genetic background, in fruit tree red spider mite, Panonychus ulmi, from English apple orchards
Authors: CRANHAM J. E. 
Published: February 2008

SUMMARYAssays on eggs of Panonychus ulmi held on leaf discs of Myrobalan plum were used to characterise strains (1) multi‐resistant to organophosphates (OPs) and binapacryl (strain BR), (2) multi‐resistant to OPs and tetradifon (strain TR), and (3) susceptible to OPs, binapacryl and tetradifon (strain EM). By crosses of EM females and BR males, and of EM females and TR males, and by repeated backcrossing with EM males under selection pressure of the acaricides concerned, two strains were produced in which the specific genes for resistance to binapacryl and tetradifon were isolated in the genome of the EM strain. Reciprocal crosses of the resulting backcrossed strains with EM, assays on the F1 eggs and the F2 haploid eggs, confirmed the presence of single major genes for resistance to binapacryl and tetradifon, and the absence of maternal effects. The expression of gene BR was incompletely dominant in response to binapacryl, whilst gene TR was effectively dominant in response to tetradifon.Eggs of the field‐derived strain BR showed c. 50× resistance to binapacryl, 8–19 × to dinobuton, but only c. 2× to dinocap and dinoseb. The backcrossed strain was less resistant (26 ×) to binapacryl implying that resistance in strain BR was augmented by the effects of minor genes. Resistance to tetradifon (150–200 × on eggs) involved cross‐resistance to tetrasul (23 ×) and to chlorfensulphide (27×); resistance in the field‐derived strain appeared to depend on the major gene alone.Resistance mechanisms were highly specific in their effects, so that there was no cross‐resistance to unrelated acaricides, including amitraz, dicofol, cyhexatin, formetanate, chlordimeform, and quinomethionate. Fecundity of strain BR was 44% less than that of EM; laboratory and field evidence suggest that multi‐resistant mites tend to be less fit than susceptible mites. The practical implications are discussed.
Effects of the pyrethroid deltamethrin on the acquisition and inoculation of viruses by Myzus persicae
Authors: GIBSON R. W. , RICE A. D. , SAWICKI R. M. 
Published: February 2008

SUMMARYThe pyrethroid, deltamethrin, alone or as an emulsifiable formulation, hindered infection of healthy plants with the persistent beet mild yellowing virus (BMYV) and both acquisition of, and infection with, the non‐persistent potato virus Y (PVY) and the semi‐persistent sugar beet yellows virus (BYV) by Myzus persicae in glasshouse tests.Another pyrethroid, RU‐15525, also protected against infection with PVY. Even sub‐lethal amounts of deltamethrin decreased virus transmission by rapidly incapacitating the aphids, the effect being least with aphids most resistant to organophosphorous insecticides and to certain pyrethroids including deltamethrin. Demeton‐S‐methyl hindered infection only with BMYV. This work shows that deltamethrin restricts transmission of persistent, semi‐persistent and perhaps more importantly of non‐persistent viruses in the glasshouse, and has potential for doing the same in the field.
The effects of the repellents dodecanoic acid and polygodial on the acquisition of non‐, semi‐ and persistent plant viruses by the aphid Myzus persicae
Authors: GIBSON R. W. , RICE A. D. , PICKETT J. A. , SMITH M. C. , SAWICKI R. M. 
Published: February 2008

SUMMARYFew Myzus persicae settled on polygodial (1 g litre‐1) or dodecanoic acid (5 g litre‐1)‐treated leaves and few nymphs were deposited. Polygodial decreased acquisition of the semi‐persistent beet yellows virus and the non‐persistent potato virus Y and dodecanoic acid that of the persistent potato leafroll and beet mild yellowing viruses, of beet yellows virus and of the bimodally‐transmitted cauliflower mosaic virus. However dodecanoic acid increased the acquisition of potato virus Y.
The use of ammonium fertilisers to reduce the severity of take‐all (Gaeumannomyces graminis var. tritici) on wheat in Western Australia
Authors: MACNISH G. C. , SPEIJERS JANE 
Published: February 2008

SUMMARYIn field experiments in Western Australia ammonium fertilisers significantly reduced the severity of root damage to wheat (Triticum aestivum) caused by Gaeumannomyces graminis var. tritici. A series of response lines depicting the effect of sources and rates of nitrogen on take‐all are presented. In general, the higher the rate of ammonium nitrogen used, the greater the reduction in the severity of take‐all. Ammonium sulphate and ammonium sulphate/mono‐ammonium phosphate mixture were more effective in reducing disease than di‐ammonium phosphate, urea or ammonium nitrate. Sodium nitrate did not reduce take‐all.
Overwintering of Venturia inaequalis, the causal agent of apple scab, on different cultivars
Authors: JEGER M. J. , SWAIT A. A. J. , BUTT D. J. 
Published: February 2008

SUMMARYA maturation index summarising pseudothecial development of Venturia inaequalis was devised. The index demonstrated differences in overwintering on 10 apple cultivars and the crab apple Malus toringo in experiments over two winters. At about the green cluster stage, when there is a high proportion of susceptible foliage, there were 50–100 fold differences in the yield of ascospores from these hosts, due mainly to different rates of pseudothecial maturation. These rates were shown to be independent of cultivar differences in colony numbers on leaves in the previous autumn.Cultivar differences in the timing of fruit bud development were independent of differences in the overwintering of V. inaequalis. These findings confirm the importance of considering cultivar identity in apple scab management.
Tolerance in Botrytis squamosa to iprodione
Authors: PRESLY A. H. , MAUDE R. B. 
Published: February 2008

SUMMARYCultures of B. squamosa when grown in concentrations from 4–2500 μg/ml of iprodione in agar, produced iprodione‐insensitive isolates distributed at random over the concentration range. Thirty of the 37 isolates when subsequently transferred to fungicide‐free agar were slower growing than the parent cultures. Similar results were obtained with single spore and multispore isolates. Iprodione insensitivity occurred in cultures derived from benomyl tolerant and sensitive field isolates. Insensitive isolates grown on agar, containing 500 μg/ml iprodione, did not revert to sensitivity after several cultural cycles on fungicide‐free agar. Spores of iprodione insensitive isolates generally proved less infective than spores from sensitives isolates when sprayed onto untreated onion leaves. In general, protectant sprays of iprodione did not enhance the infectivity of insensitive isolates. Inoculation of glasshouse and field raised plants indicated that although selected aggressive iprodione‐insensitive isolates, from treatments with low and high concentrations of the fungicide, readily infected onion leaves, they were less capable of sporulation than the sensitive parent forms of the fungus.Iprodione‐insensitive isolates were cross‐tolerant to the chloronitrobenzene fungicides quintozene and tecnazene and to the dichloroaniline fungicide dicloran.
The effect of prunus necrotic ringspot virus on field‐grown roses
Authors: THOMAS B. J. 
Published: February 2008

SUMMARYThe effect of prunus necrotic ringspot virus (PNRSV; cherry serotype) on field‐grown maiden rose bushes cv. Fragrant Cloud was assessed in two trials during 1979 and 1980. PNRSV delayed the onset of flowering, reduced the size and number of blooms and increased the proportion of deformed flowers but had no effect on flower pigmentation or scent. Autumnal leaf‐fall was generally earlier in diseased bushes, which lacked vigour and re‐established less readily after transplanting. Although all healthy plants conformed to the British Standards Institution specifications for maiden bush roses, c. half of diseased plants were sub‐standard because the total diameter of the shoots produced at the bud union was less than 20 mm.The significance of these results is discussed in relation to the commercial production of field‐grown rose bushes in the UK.
The development and yield of autumn‐ and spring‐sown barley in south east Scotland
Authors: RUSSELL G. , ELLIS R. P. , BROWN J. , MILBOURN G. M. , HAYTER A. M. 
Published: February 2008

SUMMARYAs part of a study of the relationship between plant development and grain yield, winter and spring barleys were sown in the autumn and spring. Apical development and leaf area development were monitored and the final yield was partitioned into grain weight and grain number. The photosynthetically active radiation (PAR) absorbed was calculated.The main differences found were between sowings rather than between genotypes within sowings. The autumn sowing outyielded the spring sowing because the grains were heavier, although the autumn sowing tended to have fewer grains m‐2. In the autumn sowing the rate of initiation of spikelet primordia was slower, due to the lower temperatures encountered, but the initiation phase lasted longer and a larger proportion of primordia survived. However, the increased proportions of tillers to mainstem reduced the mean number of grains/ear.The numbers of grains m‐2 and the yield were related to the PAR absorbed. In this analysis the earlier anthesis of the autumn‐sown plants could be seen to be reducing the PAR absorbed and consequently the grains m‐2.
Effect of osmotic potential on the growth of Gaeumannomyces graminis and Phialophora spp.
Authors: WONG P. T. W. 
Published: February 2008

SUMMARYThe linear growth of 10 isolates each of Gaeumannomyces graminis var. graminis, G. graminis var. tritici and Phialophora graminicola and five isolates each of G. graminis var. avenae and a lobed‐hyphopodiate Phialophora sp. was studied on osmotically adjusted agar at 20 °C. While most isolates of G. graminis var. avenae ceased growing at osmotic potentials of ‐60 bars (1 bar = 105 Pa), six out of 10 isolates of G. graminis var. tritici grew at that potential. The growth of all isolates of G. graminis var. tritici and var. avenae ceased at ‐70 bars. In contrast, four out of 10 isolates of P. graminicola grew at ‐70 bars, but all stopped growing at ‐80 bars. Most of the isolates of G. graminis var. graminis and the lobed‐hyphopodiate Phialophora sp. grew at ‐70 bars while three out of 10 isolates of G. graminis var. graminis and one out of five isolates of the lobed‐hyphopodiate Phialophora sp. were capable of growth at ‐80 bars. None of the fungi grew at ‐90 bars.Detailed studies of the growth of two or three isolates each of the five fungi at 10, 20, 30 and 35 °C were carried out on osmotic agar controlled by the addition of either sodium chloride or potassium chloride. In general, similar reductions in growth occurred with decreasing osmotic potential regardless of the solute used. At 10 and 20 °C., all three isolates of P. graminicola showed optimal growth at about ‐5 bars while the other fungi grew fastest at ‐12middot; bars. At 30 °C., one isolate of the lobed hyphopodiate Phialophora sp. and two isolates each of P. graminicola, G. graminis var. tritici and G. graminis var. avenae grew optimally at osmotic potentials of ‐10 to ‐15 bars. The other isolate of the Phialophora sp. and two isolates of G. graminis var. graminis studied grew optimally at the highest potential (‐1·2 bars). However, at 35 °C the last three fungi exhibited optimal growth at osmotic potentials of‐10 to ‐20 bars. The ecological significance of these results is discussed in relation to cross‐protection against the take‐all fungi by the avirulent fungi.
The response of tomato seedling roots to infection by Verticillium albo‐atrum or Fusarium oxysporum f. sp. lycopersici
Authors: HUTSON R. A. , SMITH I. M. 
Published: February 2008

SUMMARYThe response of seedling roots of near‐isogenic tomato varieties to infection by Verticillium albo‐atrum or Fusarium oxysporum f. sp. lycopersici was investigated. Studies of the infection of seedling roots not artificially damaged indicated that there was an extra‐vascular expression of resistance towards V. albo‐atrum but not to F. oxysporum. Roots of resistant tomato seedlings infected by V. albo‐atrum contained the fungus in the epidermis and outer cortex while susceptible roots became heavily colonised. Observations made by transmission electron microscopy showed that the fungus appeared to be abnormal in growth and appearance in the epidermal and cortical cells of resistant seedling roots but normal in susceptible roots. Two preformed antifungal terpenoids were detected in seedling roots in greater amounts in resistant that in susceptible varieties. The possible mechanisms of seedling root resistance to vascular wilts are discussed.
Susceptibility of tobacco blue mould (Peronospora hyoscyami) to metalaxyl
Authors: JOHNSON G. I. , SHEPHERD R. K. 
Published: February 2008

SUMMARYThe lethal dose (LC50) of metalaxyl for a wild isolate of Peronospora hyoscyami f. sp. tabacina was determined using a bioassay. Infection levels were recorded using 5‐wk‐old tobacco seedlings that had been treated with foliar sprays of metalaxyl (Ridomil®) 24 h prior to inoculation. Plants were maintained in a controlled environment cabinet. LC50 estimates determined by probit analysis of the data from three independent experiments ranged between 0–46 and 0–58 μg/ml. Pooling the results for all three experiments, probit analysis gave a slope of 8·733 (S.E. 0·805) with an LC50 of 0·51 μg/ml (95% fiducial limits 0·45, 0·57). This determination will be useful as a guide to future monitoring of P. hyoscyami for resistance to metalaxyl.
Further studies on a spiroplasma isolated from coconut palms in Jamaica
Authors: EDEN‐GREEN S. J. , ARCHER D. B. , TULLY J. G. , WATERS HENRY 
Published: February 2008

SUMMARYThe pathogenicity of a spiroplasma isolated from coconut palms was tested by (1) transmission experiments to palms and other plants susceptible to infection by mycoplasmas, using the suspected vector of lethal yellowing, Myndus crudus, and vectors of the agents of other yellows diseases and (2) enzyme‐linked immunosorbent assay (ELISA) to detect spiroplasma antigens in diseased palm tissues. Results of both these tests were negative and, as earlier attempts to repeat the isolations from lethal yellowing diseased palms had also been unsucessful, it was concluded that this organism was not the causal agent of lethal yellowing disease. Further analysis by serological tests and by polyacrylamide gel electrophoresis (PAGE) of spiroplasma proteins confirmed that the coconut isolates were related to members of the Spiroplasma citri serogroup but were distinct from other strains tested.
Influence of the soil conditioner cellulose xanthate on the activity and persistence of nine acetanilide herbicides
Authors: WALKER A. , ROBERTS H. A. , BROWN P. A. , BOND W. 
Published: February 2008

SUMMARYApplications of cellulose xanthate equivalent to 25 kg cellulose/ha increased the numbers of weed seedlings by up to 23% compared with untreated controls. With propachlor and prynachlor, weed control was poorer in the presence of cellulose xanthate and analyses of soil samples demonstrated that the rate of herbicide loss from the soil was enhanced. Although the soil conditioner increased the rate of loss of some other acetanilide herbicides, weed control was not greatly affected. The results suggest that interactions between cellulose xanthate and acetanilide herbicides are only important with those compounds which are normally of very short persistence.
An analysis of the seasonal variation in the dry seed yields of eleven cultivars of Phaseolus vulgaris
Authors: ANDREWS D. J. , HARDWICK R. C. , HARDAKER J. M. 
Published: February 2008

SUMMARYNine determinate and two indeterminate‐bush dry seed cultivars of P. vulgaris were grown in trials for four successive years. Mean annual yield of air dry seed (15% moisture content) varied between 222 and 398 g/m2. Most of the annual variation in yield was accounted for by differences in the quantity of nitrogen fertiliser applied and in the duration of bright sunshine during August. The annual mean harvest date varied between 20 September and 9 October. There was a significant negative correlation between the mean harvest date and the number of Ontario heat units accumulated between 20 May and 20 July.There were significant interactions between genotype and environment for both yield and harvest date; joint regression analysis of the interactions showed that five of the cultivars, which had previously been identified as cold tolerant in laboratory tests, all showed greater stability of yield and of maturity date than standard navy bean types. Environmental variation in the yield components of the cold tolerant selections tended to be compensatory, while that of the standard navy beans was additive in its effects on yield.
Effects of adding plant nutrients to the gel carrier used for fluid drilling germinating lettuce and onion seeds
Authors: FINCH‐SAVAGE W. E. , COX C. J. 
Published: February 2008

SUMMARYFluid drilled germinating lettuce seeds gave earlier production of larger heads than dry sown natural seeds. The addition of sodium phosphate to the gel with germinating seeds increased seedling growth rate which further advanced maturity and increased head weight. Sodium, ammonium and potassium phosphate added to the gel increased seedling dry weight of onions compared to the germinating seed control which produced larger seedlings than dry seed. However, these early improvements in onion seedling size diminished with time.
Fusarium oxysporum f. sp. fatshederae, a new forma specialis causing wilt of x Fatskedera lizei
Authors: TRIOLO E. , LORENZINI G. 
Published: February 2008

SUMMARYA Fusarium oxysporum sensu Snyder & Hansen was pathogenic in the vascular tissue and caused a severe wilt and dieback of ×Fatshedera lizei, Fatsia japonica and Hedera helix.The fungus appeared nonpathogenic on plants of 29 species in numerous genera.Benomyl soil drenches were effective in preventing infection.A new forma specialis, Fusarium oxysporum f. sp. fatshederae, f. sp. nov. is proposed for this pathogen.