bluuebunny/crossref_metadata_2025_split huggingface dataset:
Field techniques for assessing the reaction of winter wheat cultivars to Septoria nodorum
Authors: SCOTT P. R. , BENEDIKZ P. W. 
Published: February 2008

SUMMARYMethods of assessing the reaction of winter wheat cultivars to Septoria nodorum were compared in nine field trials. Plots were inoculated either by scattering naturally infected wheat debris or by spraying with a suspension of conidia at different growth stages, and were subsequently kept damp by several methods. Disease development was monitored by assessing the percentage cover of different organs by lesions, or by measuring the maximum height of lesions above ground. Major differences between cultivars were evident with all methods of inoculation and assessment, but time of assessment was critical for best differentiation. Inoculation with conidia soon after ear emergence, followed by assessment of lesions on flag leaves and ears, was a simple and effective method.Yield loss due to disease was measured by making comparisons either between inoculated and uninoculated plots, with various degrees of separation, or between inoculated plots with and without fungicidal treatment: the first of these methods was more effective in maintaining a disease differential. Yield loss was positively correlated with severity of disease and there was little evidence that cultivars differed in tolerance of disease. Disease was measured more easily and with less error than yield loss.
Studies on the fungicidal control of stem lesions caused by Botrytis cinerea on glasshouse tomatoes
Authors: CHANNON A. G. , THOMSON MOIRA C. 
Published: February 2008

SUMMARYIn glasshouse pot experiments, uptake of benomyl, thiophanate‐methyl and carbendazim from equivalent soil applications (in the range 0–003– 0–035 %a‐i‐ atarateof 2&4 ml/plant) gave equal levels of control of Botrytis lesions developing from inoculations of freshly exposed leaf scars on tomato stems. Spray applications of benomyl to exposed leaf scars controlled infection at concentrations down to 0025 % a.i. The effect of lower concentrations of the stem spray could be markedly enhanced either by the addition of a mineral oil (2 % Actipron) or by a prior soil application of benomyl at a low rate which on its own had little effect on lesion development. Protectant spray applications of glycophene and vinclozolin gave levels of control quite comparable to that of benomyl at equivalent concentrations.Evidence was obtained that the lesions formed at the artificially‐inoculated leaf scars at the top of the stems of young pot‐grown tomato plants were larger than those lower down. In spite of this, the level of disease control with soil applications of fungicides containing or generating carbendazim (MBC) was greater at the top than at the bottom, probably because of the normal migration of the fungicides and their accumulation at the extremities of the plant.In an observation trial in a commercial crop of tomatoes, benomyl applied either as five soil drenches at approximately monthly intervals, or as two drenches followed by five sprays at three‐weekly intervals, or as five sprays alone gave marked reductions in plant loss and number of Botrytis stem lesions in both cvs Eurocross BB and Cudlow Cross. Those stem lesions which did develop, however, were generally as large as those on untreated control plants. Five sprays of dichlofiuanid gave similar levels of disease control. All the treatments gave apparently higher yields (statistically untested) in Eurocross BB, but less consistent responses were recorded in Cudlow Cross.
Principles of insecticide action on mushroom cropping: incorporation into compost
Authors: WYATT I. J. 
Published: February 2008

SUMMARYA series of cropping experiments has demonstrated that mushroom yields show an approximate logistic response to a range of insecticide concentrations incorporated in the compost. This principle applies only to the cumulative yield at any flush, and the response of an individual flush is, therefore, related to the difference between two logistic curves. Increases in crop can thus occur in later flushes, partially compensating for earlier losses. With diazinon treatments, but not thionazin, some of this compensation was due to increases in the size of mushrooms.It is concluded that commercial applications of 50 ppm diazinon could cause up to 2–5 % reduction in crop and that 10 ppm thionazin may cause a 6% loss which must be weighed against the advantages of treatment. Suggestions are made for the design and interpretation of future trials.
Electrophoretic studies on populations of Myzjus persicae in Scotland from March to July, 1976
Authors: BAKER J. P. 
Published: February 2008

SUMMARYSpecimens of Myzus persicae have been collected from field populations in Scotland and scored electrophoretically for their phenotypes at three polymorphic loci. These phenotypes were almost invariably present in individuals in one of a small number of favoured combinations, suggesting that these populations may be oligogeneous, that is, composed of large numbers of copies of a few favoured combinations of alleles.Temporal and spatial sampling at sites in East and West Scotland in 1976 has shown that different allele combination types were present in the two areas. Populations in E. Scotland contained very few specimens belonging to the organophosphorus (OP) resistant clone types (using esterase activity to infer resistance); instead there were large numbers of an OP susceptible type which has not been detected in England, but which came to predominate on cabbage and potato host plants at every site sampled during the period of rapid population increase. In contrast, populations in W. Scotland were characterised by substantial numbers of specimens belonging to OP resistant clone types and by an almost complete absence of this susceptible type. Two other distinguishable OP susceptible types were found to be common to both areas. The W. Scotland populations closely resemble N. England populations while those in E. Scotland appear to be unique to that area. Specimens of OP resistant types were only detected in E. Scotland after the beginning of June and in such relative proportions as to strongly suggest that they were migrants from W. Scotland or N. England.
The life‐history and bionomics of Epitrimerus piri (Acarina: Eriophyidae) on pear
Authors: EASTERBROOK M. A. 
Published: February 2008

SUMMARYThe majority of Epitrimerus piri on pear, cv. Williams' Bon Chretien, moved from their hibernation sites in small permanently dormant buds on spurs and under loose bark to fruit buds between the stages of green cluster and petal fall. Peak numbers of mites occurred in mid‐June on fruit and early August on leaves with the return to hibernation beginning in July. Development time from egg hatch to adult was 17–1, 6–9 and 4–8 days at 10, 16 and 22 °C, respectively. Mites were dispersed by wind. They were found only on species in the genera Pyrus, Cydonia and Pyronia.Mite feeding caused browning on the ventral, sides of leaves and russet on fruit which was confined to the calyx end on Williams'. Populations of over 2000 mites/leaf reduced the length and dry weight of new shoots on potted pears by 8 and 14% respectively.
The incidence of stalk rot (Fusarium spp.) on maize hybrids and its effect on yield of maize in Britain
Authors: COOK R. J. 
Published: February 2008

SUMMARYStalk rot was present in each of 78 maize crops and six hybrid maize trials examined between 1971 and 1975. Fusarium culmorum was the main cause of the disease and was isolated from 67 of the 82 samples from which isolates were made. Lodging was found to be related to, and a natural succession of, the earlier wilting symptom caused by infection with F. culmorum. Yield losses were estimated in 39 crops between 1973 and 1975 and the disease caused a mean reduction of 18‐7% in cob weight and 11‐2% in 1000‐grain weight of infected plants over the 3 yr of the survey.
Preservation of baled hay with propionic and formic acids and a proprietary additive
Authors: LACEY J. , LORD K. A. , KING H. G. C. , MANLOVE ROSEMARY 
Published: February 2008

SUMMARYField‐baled hay was incompletely preserved using propionic or formic acids. Results were most satisfactory, although moulding by Aspergillus glaucus group was still frequent, when die hay contained less than 30% water and propionic acid was used. However, much more propionic acid was needed than in laboratory experiments probably because poor distribution of acid in the bale, resulted in under‐treated pockets of hay where moulds tolerant to propionic acid could grow and then spread to areas that would otherwise have been adequately treated.In Dewar flasks, moulds, particularly Paecilomyces varioti and the A. glaucus group, could spread from untreated hay into hay containing 2% w/w of propionic acid. Addition of 4 or 10% of propionic acid protected adjacent untreated hay from moulding. The concentration of propionic acid necessary to prevent flasks from heating and moulding increased with thickness of the untreated layers and with water content. Redistribution of acid in the bale after treatment was slow and much variation in acid levels occurred even between adjacent 1 cm segments of grass following storage. Spontaneous heating of moulding hay could cause migration of propionic acid in hay, assisting the spread of fungi. A proprietary additive did not prevent moulding at any hay water content tested.
Oxamyl sprays for the control of potato spraing disease caused by nematode‐transmitted tobacco rattle virus
Authors: ALPHEY T. J. W. 
Published: February 2008

SUMMARYField trials on sites infested with trichodorid nematodes in Scotland tested the effects of dichloropropene‐dichloropropane mixture (D‐D), thiofanox, and granules and foliar sprays of oxamyl on the incidence of spraing disease in potato (cv. Pentland Dell) tubers. D‐D was effective in controlling spraing on all three sites, thiofanox was ineffective on the one site tested. On two sites oxamyl granules and sprays, alone and together, significantly decreased the amount of spraing. Those treatments including a spray were more effective than granules alone. At the third site different rates and times of application of sprays were tested.
Principles of insecticide action on mushroom cropping: incorporation into casing
Authors: WYATT I. J. 
Published: February 2008

SUMMARYThe incorporation of organophosphorous insecticides into the casing layer of mushroom beds reduces the numbers of mushrooms, according to a logistic relationship with log10 (dose). The cumulative numbers at any flush are affected in this way, and the response of individual flushes may, therefore, be represented by the difference between two logistic curves. This explains the observed increases in numbers in the second and third flushes following diazinon treatment and in the fourth following thionazin, pirimiphos‐methyl and pirimiphos‐ethyl. No compensation in numbers followed chlorfenvinphos treatment. This decreasing response pattern reflected the increasing residual action of the insecticides.Mushroom size was inversely related to numbers but even when numbers in any flush were unaffected by the treatment, there was usually an increase in size. Thus yield increases occurred in most flushes at commercial concentrations of four insecticides (thionazin compensated only in the fourth flush) and total yields were increased by 8 to 13%.
The effect of inoculation with an attenuated mutant strain of tobacco mosaic virus on the growth and yield of early glasshouse tomato crops
Authors: CHANNON A. G. , CHEFFINS N. J. , HITCHON G. M. , BARKER J. 
Published: February 2008

SUMMARYIn trials in 1973‐5 at the Glasshouse Investigational Unit for Scotland, the yield of fruit from tomato cv. Eurocross BB inoculated at the seedling stage with the Mil‐16 attenuated strain of tobacco mosaic virus was 5–8‐9‐4% greater than that from uninoculated plants which became naturally infected with a severe indigenous strain of the virus within 7–8 wk of planting. The increase in fruit yield, particularly of better grades, resulted in higher gross financial returns (up to 25p/plant) from inoculated plants. The yields from the Mil‐16 protected plants were up to 14% greater than those from plants artificially inoculated at the seedling stage with the indigenous severe virus.Inoculation with Mil‐16 had little adverse effect on early growth or the rate of fruit development on the first five trusses, but in 1973 the final yield of inoculated plants was depressed c. 5% compared with that from plants substantially free from infection for 14 wk after planting.In 1 year's test no benefit from inoculation with Mil‐16 was recorded in cv. Cudlow Cross.
Incidence, field spread, seed transmission and effects of broad bean stain virus and Echtes Ackerbohnenmosaik‐Virus in Vicia faba in eastern Scotland
Authors: JONES A. T. 
Published: February 2008

SUMMARYIn eastern Scotland seed‐borne infection with broad bean stain virus (BBSV) and/or Echtes Ackerbohnenmosaik‐Virus (EAMV) was detected in five of 39 seed lots of field bean in 1975 and in four of 21 commercial crops of field bean or broad bean sampled in 1975 or 1976. Tests failed to detect the main weevil vector of these viruses, Apion vorax, in 1975 and 1976 but Sitona weevils were found in most crops and were numerous in many, reaching maximum numbers in August. No spread of BBSV and EAMV was detected in commercial crops containing seed‐borne infection. In experimental field bean crops containing plants manually inoculated with virus, no virus spread was detected in 1975, and only 0–015% uninoculated plants became infected with EAMV in 1976. Sitona, therefore, was an inefficient vector.The percentage of virus infection in seed harvested from field bean plants manually inoculated 3, 5, 7 and 11 wk after emergence in the field was 1–5, 2–7, 0–4 and 0–06 for BBSV and 0–5, 2‐1, 0–6 and 0 for EAMV respectively. Seed harvested from unrogued and rogued plots of field bean grown from seed containing 3–4% seed‐borne infection produced 0–05% and no infected plants, respectively. Yield losses in field bean plants manually inoculated with virus before flowering were up to 20% but were much greater in plants infected through the seed. Loss in yield was largely caused by a decrease in number of seeds per pod.The absence of A. vorax, the late arrival of Sitona weevils in the crop and their inefficiency as vectors, and the smaller effects of BBSV and EAMV on crop yield than in southern England appear to make eastern Scotland very suitable for the production of bean seed free from BBSV and EAMV.
Effects of host resistance on the development of haustoria and colonies of oat mildew
Authors: CARVER T. L. W. , CARR A. J. H. 
Published: February 2008

SUMMARYColony development of Erysiphe graminis f.sp. avenae race 2 was studied on detached leaf segments of a range of Avena hosts with different levels of resistance, none of which possesses known specific gene resistance to this race. Resistance affected the length attained by mature primary haustoria, and also colony size as assessed by numbers of haustoria and conidiophores produced per colony 5 days after inoculation. A more accurate assessment of the size of mature haustoria was provided by the total length of their digitate processes. At the primary haustorium stage resistance affected not only haustorial size, but also haustorial efficiency measured as colony growth per unit size. Adult plant resistance of some hosts decreased haustorial size and/or efficiency in colonies on the fifth in comparison with the first formed leaf.
A technique for measuring the susceptibility of wheat bulb fly larvae to insecticides in the laboratory
Authors: SMITH CLARA , GRIFFITHS D. C. 
Published: February 2008

SUMMARYA simple assay is described for measuring the toxicity of insecticides to larvae of wheat bulb fly (Delia coarctata) in the laboratory. The method should be suitable for other small soil insect larvae that cannot be obtained in large numbers and are difficult to treat and confine. A limitation of the technique is that it works only with insecticides that are soluble enough to be toxic in aqueous solution.
Comparison of fungicides for the control of Rhizoctonia solani causing datnping‐off of mung bean (Phaseohis aureus)
Authors: KATARIA H. R. , GROVER R. K. 
Published: February 2008

SUMMARYOf 41 fungicides tested in the laboratory, copper carbonate, copper sulphate, mercuric chloride, Agrosan GN, quintozene, kasugamycin, carboxin, pyracar‐bolid, carbendazim, chloroneb, benomyl, Ohric, RH 893 (2‐n‐octyl‐4‐isothiazole‐3‐one) and Terrazole were most inhibitory to the mycelial growth of Rhizoctonia solani on Czapek's agar plates and had EC50 values of less than 1 μg a.i./ml, while copper oxychloride, Udonkor, zineb, ziram, F 319 (3‐hydroxy‐5‐methyl isoxazole) and anilazine were much less toxic, ziram being least inhibitory with an EC50 of 214 μg a.i./ml.Of 17 fungicides tested in the greenhouse as seed treatments, thiabendazole, carbendazim, benomyl, thiophanate‐methyl, dichlozoline and Ohric gave 80–90% control of damping‐off of mung bean seedlings. A single soil drench with thiophanate‐methyl and two drenches with benomyl gave about 90% disease control, More seedlings with R. solani infection survived when thiophanate‐methyl was used as a post‐inoculation soil drench than when benomyl or chloroneb were used.
Nematodes in Scottish forest nurseries
Authors: BOAG B. 
Published: February 2008

SUMMARYSeven hundred soil samples from 41 forest nurseries were collected between 1972 and 1975 and examined for plant parasitic and predatory nematodes. Rotylenchus goodeyi, Trichodorus primitivus, Cephalenchus emarginatus and Tylenchus davainei occurred in most nurseries but their numbers were generally lower than those of R. robustus and Paratrichodorus pachydermus. In a glasshouse experiment as few as 10 R. robustus decreased the growth of Sitka spruce seedlings. It was estimated that Rotylenchus and trichodorid nematodes probably retarded the growth of some seedling trees in eight of the nurseries sampled. During the survey, Trichodorus sparsus was found for the first time in Great Britain and Paralongidorus maximus for only the third time. Since both these species were found in nurseries they were probably introduced and are ideally situated to be more widely disseminated.
Effect of gibberellic acid on senescence of isolated petals of carnation
Authors: GARROD J. F. , HARRIS G. P. 
Published: February 2008

SUMMARYApplication of gibberellic acid (GA3) to isolated petals of carnation growing in agar or a liquid medium resulted in a delay in senescence by up to 4 days. Sucrose and 8‐hydroxy‐quinoline sulphate were also effective in delaying senescence but combined effects with GA3 were not additive.
A method for the extraction and enumeration of resting spores of Plasmodiophora brassicae from infested soil
Authors: BUCZACKI S. T. , OCKENDON JEAN G. 
Published: February 2008

SUMMARYA technique is described for the extraction of the resting spores of Plasmodiophora brassicae from soil. After deflocculation, coarse mineral matter was filtered from soil samples and the remainder mixed with 40% sucrose. The mixture was allowed to stand for 2–5 days; this enabled most mineral particles to settle out leaving the spores in suspension. The spores were counted optically on a microscope using Nomarski interference contrast optics, although preliminary studies had indicated that electronic image analysis was a more satisfactory method. Good recovery of spores was achieved from artificially infested soils containing 106 spores/g but the technique can be satisfactorily applied to less heavily infested soils. Clubroot symptoms developed on seedlings dipped in suspensions of spores recovered in this way.
Effects of chemical treatments for mildew control at different times on the growth and yield of spring barley
Authors: JENKYN J. F. 
Published: February 2008

SUMMARYExperiments in 1973 and 1974 tested the effects of ethirimol seed treatment and the timing of single sprays of ethirimol or tridemorph, on mildew control and the growth and yield of spring barley. These treatments were compared with selected combinations of two treatments designed to give longer protection. In 1973, combinations of seed treatment and spray, or two sprays, did not yield better than the best component treatment applied alone or the most effective single spray of tridemorph applied on 1 June. In 1974, mildew developed usually early and yields were increased by applying ethirimol to the seed plus a tridemorph spray or two tridemorph sprays. However, barley sprayed once with tridemorph on 20 May, the expected best date, yielded more than barley receiving a seed treatment of ethirimol plus a tridemorph spray applied on either 3 or 12 June. Sprays of captafol and tridemorph, applied as separate treatments, successively to the same plots on three occasions, gave the best yields in both years. Treatments most affected ear number but they did have some effect on all components of yield. In 1974 there was a significant relationship between ear number and the variance of the number of grains per ear.
Field experiments on sugar‐beet powdery mildew, Erysiphe betae
Authors: BYFORD W. J. 
Published: February 2008

SUMMARYSugar‐beet powdery mildew, Erysiphe betae appeared in East Anglia in late July 1976 and became wide‐spread in eastern England during August and September but was scarce in crops in the north and west of England. Fentinhydroxide, sulphur, benomyl and ethirimol controlled the disease but benomyl applied once only and ethirimol were less effective than the other materials. In heavily infected crops two sulphur sprays, the first applied at the onset of the mildew attack, increased sugar yield by 13%. A single early sulphur spray increased yield on average by 9% giving a return of six to seven times the cost of treatment. When the first spray was delayed, mildew control was less effective.
Effect of machine‐harvester wounds and Leptosphaeria coniothyrium on yield of red raspberry
Authors: HARGREAVES A. J. , WILLIAMSON B. 
Published: February 2008

SUMMARYWhen wounds on raspberry canes caused by machine harvesting in the previous year were infected by Leptosphaeria coniothyrium the potential yield per cane was reduced by 45% compared with that of uninfected hand harvested canes. However, the corresponding reduction per plot was less (c. 25%) because the yield of wounded but uninfected canes was not reduced and some canes were not wounded. The advantages and disadvantages of recording potential yield per cane are discussed.
Capsulation and virulence in Erwinia amylovora
Authors: BENNETT R. A. , BILLING EVE 
Published: February 2008

SUMMARYEvidence is presented that capsulation may be one virulence determinant for Erwinia amylovora, the fireblight pathogen.When 15 virulent and seven avirulent strains were grown on a medium containing asparagine as the only source of carbon and nitrogen, or yeast peptone agar, or on a sugar medium containing an inorganic source of nitrogen, capsule production and virulence were not correlated. However, if a sugar or sugar alcohol was added to the asparagine medium or to yeast peptone agar all the virulent strains produced some or many capsulated cells whereas six of the avirulent ones did not. Capsules were also produced by all the virulent strains during infection. The existence of a seventh avirulent strain which was capsulated on all media except unsupplemented asparagine agar, suggested that capsule production was not the only virulence determinant.