bluuebunny/crossref_metadata_2025_split huggingface dataset:
Micro sprayers for the laboratory application of pesticides
Authors: COGGINS S. , BAKER E. A. 
Published: February 2008

SUMMARYThe microtip nozzle assembly described by Uk (1978) has been modified to provide a reliable and versatile sprayer for the laboratory application of pesticide formulations. The improved performance has been achieved through the introduction of knurled thimbles giving controlled adjustment of needle and stylus settings and by the provision of an offset liquid reservoir (0·1–2 ml) either pressurised or non‐pressurised.The device, which delivers monosize droplets (in‐flight diameter 50–500 μm) at velocities ranging from 0·5–20 m s‐1 has been used for aqueous and oil solutions, water dispersible powders and emulsifiable concentrates of varying concentration (0·1‐30g a.i. litre‐1) and is particularly suitable for the application of radiolabeled chemicals.
Characteristics of the common bean, Phaseolus vulgaris, associated with resistance to the leafhopper Empoasca kraemeri
Authors: GALWEY N. W. 
Published: February 2008

SUMMARYExperiments were conducted using the common bean, Phaseolus vulgaris, and its most important pest in Latin America, Empoasca kraemeri, in order to assess the value of insect counts and various plant characteristics as selection criteria in a plant breeding programme. The combination of insect counts with measurements of damage symptoms should make it possible to distinguish tolerance from the resistance mechanisms of antibiosis and non‐preference. By this means, and by a knowledge of the plant characteristics associated with resistance, different forms of resistance may be combined in the progeny of crosses.In a comparison of two contrasting genotypes the more severely damaged genotype was the more heavily infested at early stages of plant growth, but had the lower level of infestation at later stages. The association of high early counts with high subsequent damage was not confirmed in an experiment on six genotypes, but the association of high damage with low late counts was partially confirmed. These results indicate that the level of early infestation of E. kraemeri is not consistently reflected in the subsequent levels of damage which P. vulgaris genotypes display. This suggests that these two criteria represent distinct forms of resistance which can be combined in hybrid progeny.Resistance was also associated with late maturity, indeterminate growth habit, purple flowers and black or beige seeds. However, consumer preferences and the requirements of agricultural systems place constraints upon the use of these relationships in resistance breeding.
Studies on death of deteriorated barley seeds in soil
Authors: PERRY D. A. , ELLERTON D. R. 
Published: February 2008

SUMMARYSeeds of barley cv. Golden Promise which had been deteriorated by storing at 20% moisture content and 30 °C and which all had viabilities >85% were treated with a slurry of calcium peroxide and with dusts of a mercurial and a non‐mercurial fungicide. Calcium peroxide improved seedling emergence in wet soil conditions and deteriorated seeds benefited more than non‐deteriorated seeds. The fungicide dusts had no effects.In controlled conditions at 20 °C, deteriorated seeds in wet soil died mainly within 2 days of sowing and they were more tolerant if they were placed in moist soil for 2 days before transfer to wet soil. Application of a mercurial fungicide and sterilizing the soil and the surface of seeds improved emergence but did not restore it to the level in moist soil.Fusarium culmorum, F. equiseti, Mucor spp. and Mortierella spp. dominated the fungus flora isolated from surface sterilised dead seeds in wet soil. When the fungi were inoculated to seeds, they increased the proportion which died in wet soil but only at high inoculum levels. It was concluded that they acted primarily as saprophytes depriving seeds of oxygen and secondarily as seed colonisers.
The influence of anoxia and ethanol on barley seed death
Authors: ELLERTON D. R. , PERRY D. A. 
Published: February 2008

SUMMARYSurvival of deteriorated barley seeds in wet soil was improved by exposure to 70% oxygen compared with that in air and decreased by the imposition of anoxia. Deteriorated seeds were more sensitive to anoxia than non‐deteriorated seeds, the former died within 4 days, while the latter survived more than 7 days.Ethanol accumulated in non‐deteriorated seeds in wet soil conditions during the first 24 h and thereafter declined, while it increased to higher concentrations over 3–4 days in deteriorated seeds. High concentrations of ethanol were recorded in seeds in anaerobic conditions regardless of the level of deterioration.It was concluded that oxygen diffusion to the seeds was severely restricted in wet soil resulting in a switch to anaerobic respiration, the products of which, indicated by ethanol content, accumulated within the tissues. Non‐deteriorated seeds tolerated higher concentrations of ethanol than deteriorated seeds and the coleorhiza extruded through the covering layers more rapidly facilitating gaseous exchange, while in the latter, anaerobic products accumulated to toxic levels.
Movement, persistence and performance of fungitoxicants applied as pruning wound treatments on apple trees
Authors: GENDLE P. , CLIFFORD D. R. , MERCER P. C. , KIRK S. A. 
Published: February 2008

SUMMARYThe systemic fungicides triadimenol, fenpropimorph, furmecyclox and carben‐dazim, applied to pruning wounds as solutions in a non‐aqueous solvent containing N‐methyl–2‐pyrrolidone moved predominantly towards the trunk. Coriolus versicolor, introduced deliberately, moved both proximally and distally irrespective of whether it was introduced in the dormant or growing season. Natural resistance to damage by chemical or C. versicolor appeared to be greater in the growing than in the dormant season and was inhibited when a cationic surfactant was used to aid penetration of fungitoxicant into the wood.Against C. versicolor the non‐systemic fungicide captafol was ineffective, furmecyclox or fenpropimorph gave some protection and triadimenol was very effective. Carbendazim, although inactive against wood‐rotting basidiomycetes, moved extensively within the wood and persisted well, and so could be an effective treatment for ascomycete pathogens. It also stimulated callus formation.The mercuric oxide preparation Santar was effective in these experiments and also stimulated callus formation.
Bioassay of a purified nuclear polyhedrosis virus against Heliothis armigera
Authors: FLATTERY K. E. 
Published: February 2008

SUMMARYA precise bioassay method, which is not limited by lack of field applicability, as are peroral administration techniques, is described. Purified nuclear polyhedrosis virus (NPV) suspensions were assayed against third and fourth instar Heliothis armigera larvae to provide standards for additive and field testing. Third instar larvae proved to be approximately one hundred times more susceptible to the NPV disease than fourth instar larvae. The minimum time to mortality was 4 days.
The relation between cowpea golden mosaic and its vector, Bemisia tabaci
Authors: ANNO‐NYAKO F. O. , VETTEŃ H. J. , ALLEN D. J. , THOTTAPPILLY G. 
Published: February 2008

SUMMARYAdult whiteflies (Bemisia tabaci) acquired the agent of cowpea golden mosaic (CGM‐A) within 7 min and transmitted during 2 min inoculation access. Nymphs also acquired CGM‐A and retained it through the pupal stage. Efficiency of transmission reached 90% when the acquisition period was increased to 36 h. The minimum latent period of CGM‐A in B. tabaci was 8 h, and the median latent period (LP50) about 12 h. Transmission was generally intermittent and declined throughout the period of 21 days which was the maximum time insects remained infective. Female whiteflies were more efficient vectors than males. B. tabaci acquired CGM‐A from plants inoculated only 60 h previously. The epidemiological implications of these findings are discussed.
Tolerance of potato to potato cyst nematodes (Globodera rostochiensis and G. pallida) in relation to the growth and efficiency of the root system
Authors: TRUDGILL D. L. , COTES L. M. 
Published: February 2008

SUMMARYPotato cyst‐nematode (Globodera rostochiensis) was shown to damage potato plants in several ways. A major cause of damage, affecting all cultivars to a similar extent, was a reduction in the top to root weight ratio. Intolerant cultivars also suffered a reduction in the weight and length of their root systems when grown in heavily infested soil, the combined damage resulting in a marked decrease in nutrient uptake and top growth. In addition intolerant cultivars tended to senesce prematurely when heavily infested, further decreasing their leaf area duration and yield.Cultivars tolerant of potato cyst‐nematode (PCN) differed from intolerant cultivars in that their root systems tended to grow larger in heavily infested soil than in lightly infested or nematicide‐treated soil, so partly compensating for the reduction in the top/root ratio. In a growth cabinet experiment Maris Anchor was more severely damaged at a soil temperature of 10 than at 15 °C. In a glasshouse, without temperature control, differences were obtained between cultivars in small pots (10 cm) in the effect of PCN on root growth which correlated well with differences in tolerance obtained in field trials.
The microflora of ripening barley grain and the effects of pre harvest fungicide application
Authors: HILL R. A. , LACEY J. 
Published: February 2008

SUMMARYNewly‐emerged ears of barley soon became colonised by micro‐organisms with numbers increasing to 5·8 × 105 viable propagules/g dry weight by harvest. Bacteria were numerically predominant throughout. Yeasts and yeast‐like fungi were also numerous during the early stages of grain development but were exceeded by propagules of filamentous fungi during ripening, with Cladosporium spp., Alternaria alternata, Epicoccum purpurascens and Verticillium lecanii most abundant. Numbers of most micro‐organisms were greatest in a wet season but Alternaria was equally abundant in hot dry weather. Application of fungicides at or after anthesis modified the grain microflora. Captafol was most effective overall in decreasing numbers of fungi. However, benomyl decreased Cladosporium inoculum more than catpafol but was ineffective against Alternaria which became more numerous on benomyl‐treated grain than on untreated. Yield increases of up to 4% were obtained by late fungicide treatment, least in a hot, dry year. Germination was also increased by some treatments by up to 5%.
Necrosis in field beans (Vicia faba) induced by interactions between bean leaf roll, pea early‐browning and pea enation mosaic viruses
Authors: COCKBAIN A. J. , WOODS R. D. , CALILUNG V. C. J. 
Published: February 2008

SUMMARYMixed infections with two or three viruses ‐ bean leaf roll (BLRV), pea early‐browning (PEBV) and pea enation mosaic (PEMV) ‐ were detected in plants showing leaf curling, stunting and necrosis in a crop of field beans grown for seed in 1980. In glasshouse tests, field bean plants infected with any one of these viruses showed no necrosis, and plants infected with PEBV and PEMV together showed symptoms of PEMV only. However, mixed infection with BLRV and PEMV almost invariably induced severe stunting and leaf necrosis, and infection with BLRV and PEBV often induced both leaf and stem necrosis and sometimes caused early death. Thus it seems that the necrotic symptoms seen in the field were induced by interactions between BLRV and the other viruses.No transmission of PEBV was detected through seed harvested from the crop, but up to 5% transmission was detected through seed from experimentally‐infected plants. The infected seedlings were symptomless.
Seed survival and periodicity of seedling emergence in ten species of annual weeds
Authors: ROBERTS H. A. , BODDRELL JUNE E. 
Published: February 2008

SUMMARYSeeds or fruits of 10 species of annual weeds were collected in each of 3 years and mixed with the top 7 · 5 cm of sterilised soil (confined in cylinders sunk in the ground outdoors and cultivated three times yearly. The numbers of seedlings emerging were recorded for 5 yr and the numbers of viable seeds remaining then determined. Emergence of Anagallis arvensis, Anchusa arvensis, Chaenorrhinum minus and Euphorbia peplus was mainly in spring; Lamium amplexicaule and Myosotis arvensis also had a spring peak but emergence continued in summer and autumn. Seedlings of Aphanes arvensis appeared almost entirely in autumn and those of Lamium purpureum between May and October. Veronica arvensis had spring and autumn peaks, while Fumaria densiflora showed no definite pattern. Except for Anagallis arvensis and F. densiflora, in which there was apparent innate dormancy due to the seed coat, most seedlings appeared in the first year with a decrease, usually exponential, from year to year. This was most rapid in C. minus and E. peplus, of which few viable seeds remained after 5 yr. Seed survival for the other species ranged from 2·6% of those sown for Anchusa arvensis to 14·8% for F. densiflora.
Germinability and enforced dormancy in seeds of species of indigenous grassland
Authors: WILLIAMS E. D. 
Published: February 2008

SUMMARYGermination of seeds of a range of species from indigenous grassland was tested at an alternating temperature regime in incubators, soon after they were shed in 1978 and also after various intervals of dry storage at outdoor ambient temperatures. Concomitant investigations were made of seedling emergence from and seed survival at different depths of soil in pots; Poa annua and Poa trivialis were investigated separately in 1979.Almost all seeds of Lolium perenne, Cynosurus cristatus, Festuca rubra and Holcus lanatus germinated readily, but c. 30% of Deschampsia caespitosa seeds and c. 15% of fresh, early‐shed Agrostis capillaris did not germinate until they were also given gibberellic acid. However, more late‐ than early‐shed seed of the latter two species germinated and their seeds became more germinable with increasing length of storage. Of the dicotyledonous species tested, germination of Cerastium fontanum ssp. glabrescens was rapid and complete, but that of Ranunculus spp. was particularly protracted. All Ranunculus repens seeds and a large proportion of Ranunculus acris seeds were highly dormant.Species differed greatly in their ability to emerge from and persist at different depths in pots. The most persistent species after 15 months were R. repens (69%), A. capillaris (39%), Luzula campestris (37%), C. fontanum ssp. glabrescens (30%), P. trivialis (8%), D. caespitosa (7%) and H. lanatus (3%). A mean of 42% of P. annua and 16% of P. trivialis seeds persisted from autumn 1979 until late spring 1980, but pre‐imbibing the seeds decreased seed persistence to 12% and 4% respectively.The results are discussed in relation to previously published information on the germination biology of the species and to the different abilities of the species to become part of the soil seed population.
Cavity spot of carrots ‐ observations on a commercial crop
Authors: SCAIFE M. A. , TURNER MARY K. , BARNES A. , HUNT J. 
Published: February 2008

SUMMARYA single field of commercially‐grown carrots was sampled in September at 16 points for cavity spot incidence. Carrot tops, root core and peel were analysed for N, P, K, Ca and Mg, and soils were analysed for organic C, total N, available P, K, Ca, Mg and Na, pH, conductivity and chloride.The incidence of the disorder varied from 0–96% within a small area of field, thus tending to rule out explanations for cavity spot based entirely on weather, genotype etc.Several types of lesion were recorded in addition to ‘typical’ cavity spot, and their incidence was found to be mutually correlated. Most of these (including splitting) were positively correlated with cavity spot, and tended to be positively related to concentrations of macroelements in the carrot peel (especially N and Ca): however, ‘scabs’ were very strikingly dissociated from cavities (both on a plot and individual root basis). This dissociation appeared to be connected with soil pH, in that scabs were most common above pH 6‐5, whereas cavities were most frequent below this pH.
Association of viruses with two protozoal pathogens of the honey bee
Authors: BAILEY L. , BALL BRENDA V. , PERRY J. N. 
Published: February 2008

SUMMARYUndisturbed honey bee colonies near Rothamsted were commonly infected with a filamentous DNA virus (FV) which was usually associated with Nosema apis in infected adult individuals and occurred most frequently about June. No symptoms were caused by FV, which appeared less harmful than either black queen‐ceil virus (BQCV) or bee virus Y (BVY), two isometric RNA viruses also associated with N. apis. Bee virus X, another isometric RNA virus distantly related to BVY, was not associated with N. apis, but prevailed in winter and was then associated significantly with Malpighamoeba mellificae in dead individuals, although it frequently multiplied alone. Results of laboratory experiments supported conclusions made from the field observations about these relationships and their pathology.
Control of ergot in pearl millet through pollen management*
Authors: THAKUR R. P. , WILLIAMS R. J. , RAO V. P. 
Published: February 2008

SUMMARYFour pearl millet F, hybrids, ICH‐118, ICH‐220, BJ‐104, and ICH‐206, which are highly susceptible to ergot, were grown one/season in isolation plots and in a demonstration plot during the four rainy seasons of 1978‐81, respectively, alone and mixed with an early flowering variety SC‐2(M)5‐4, which is less susceptible to ergot (less than 10% severity) to test the hypothesis that increased pollen availability at the early stages of flowering in hybrids protects the hybrids from ergot infection. In 1978, the hybrid was grown with the pollen donor in a seed mixture (4 parts hybrid and 1 part pollen donor) and in other years one row of the pollen donor was planted between two, four, or eight rows of the hybrid. Ergot inoculations were made 3–4 times at protogyny flowering stage of the hybrids. Significant reductions in ergot infection and considerable increase in grain yields occurred in the hybrids when grown with the pollen donor line. The possible application of this control measure in farmers' fields is discussed.
Infection of lucerne (Medicago sativa) by Fusarium species
Authors: PEGG G. F. , PARRY D. W. 
Published: February 2008

SUMMARYA limited field survey of lucerne crops on four Kent farms showed infection by Fusarium species to be widespread. Plants selected at random were for the most part free from aerial symptoms, but 90–100% showed browning of the lower stem and tap root. Fusarium avenaceum was most commonly isolated exceeding Verticillium albo‐atrum in four out of six sites. Other species isolated included F. culmorum, F. equiseti, F. graminearum, F. oxysporum, F. solani and F. tabacinum. Phoma medicaginis and Cylindrocarpon destructans were also found in roots and stems.Isolates of F. avenaceum were either pathogenic or non‐pathogenic on a range of lucerne cultivars, some reducing leaf area and shoot dry weight. One isolate showed differential pathogenicity to cvs Europe, Vertus, Sabilt and Dupuits. No evidence was found to suggest that natural infection by Fusarium spp. was limiting to growth. The possible significance of lucerne as a reservoir for cereal fusaria is discussed.
Interaction between the fungicide metalaxyl and soil microorganisms on survival of Phytophthora cinnamomi
Authors: MALAJCZUK N. , BOUGHTON T. J. , CAMPBELL N. A. , LITCHFIELD R. T. 
Published: February 2008

SUMMARYIn soil leachates the fungicide, metalaxyl, eliminated sporangia production by Phytophthora cinnamomi as well as enhancing hyphal lysis. There was a marked interaction between lytic soil microorganisms, fungicide application and hyphal lysis.
A comparison of Australian bean yellow mosaic virus isolates using molecular hybridisation analysis
Authors: ABU‐SAMAH NORANI , RANDLES J. W. 
Published: February 2008

SUMMARYTwenty‐nine isolates of bean yellow mosaic virus (BYMV), obtained over 5 yr by sampling of a limited area in south‐eastern South Australia and western Victoria (Collection I), resembled each other in host range and symptomatology. Three reference isolates and nine other isolates (Collection E) from across southern Australia differed in host range and symptomatology from each other, and from the members of collection I.Molecular hybridisation analysis (MHA) using 3H‐complementary DNA specific to the RNA of the three reference isolates of BYMV (BYMV‐G, ‐Q and ‐S) showed that the isolates of collection I were more closely related to BYMV‐S, which originated from the same region, than to ‐G, or ‐Q which came from outside the region. None of the isolates in collection E were related by MHA to BYMV‐S. Only one showed low but significant homology with Q, and none showed homology with G, despite some similarities in host range and symptomatology to the reference isolates.Neither host of origin nor the propagation host influenced percentage homology to reference isolates. The percentage hybridisation values obtained with the RNA of isolates showed no significant variation in homology during regular transfer by mechanical inoculation for 2 yr. We conclude that percentage homology as determined by MHA has an advantage over assessments of biological properties for discriminating between strains or variants of BYMV; it appears to be a stable property which can be determined semiquantitatively.
Insecticidal control of aphids and the spread of potato leafroll virus in potato crops in eastern Scotland
Authors: WOODFORD J. A. T. , HARRISON B. D. , AVEYARD C. S. , GORDON S. C. 
Published: February 2008

SUMMARYField experiments were carried out in eastern Scotland in 1976‐78 to test the ability of granular insecticides, applied to soil at planting, and of insecticide sprays applied to the foliage, to control aphids and spread of potato leafroll virus (PLRV) in potatoes. The three years provided contrasting opportunities for virus spread. In 1976, the main vector of PLRV, Myzus persicae, arrived in early June and multiplied rapidly in untreated plots, and PLRV spread extensively. In 1977, M. persicae arrived 4–6 wk later than in 1976 and most spread of PLRV, which was less than in 1976, occurred after the end of July. In 1978, few M. persicae were recorded but the potato aphid, Macrosiphum euphorbiae, arrived early and very large populations developed in untreated plots. However, little spread of PLRV occurred in 1978, supporting other evidence that M. euphorbiae is an inefficient vector of PLRV in field conditions.In each year, granular insecticides decreased PLRV spread to a quarter or less of that in control plots. Thiofanox gave somewhat better and longer‐lasting control of aphid populations than disulfoton, especially of M. persicae, but did not give greater control of PLRV spread. Application of three (1976) or five (1977) sprays of demeton‐S‐methyl to plots treated with granular insecticides further improved the control of M. euphorbiae but had less or no effect on M. persicae, especially where organophosphorus resistant aphids (R1 strain) were found. These supplementary sprays of insecticide did not further improve the control of PLRV but, in 1978, four sprays of demephion or pirimicarb to plots not treated with granular insecticide decreased PLRV spread.These data, together with previous findings, indicate that the amount of virus spread depends on the date of arrival and rate of multiplication of M. persicae in relation to the timing and effectiveness of removal of PLRV sources in crops. It is concluded that in Scotland insecticide granules should be used routinely only in crops of the highest grade of seed potato. Their use for other grades need be considered only in years following mild winters, when aphids can be expected to enter crops earlier and in larger numbers.