bluuebunny/crossref_metadata_2025_split huggingface dataset:
An assessment of a method based on intrinsic antibiotic resistance for identifying Rhizobium strains
Authors: STEIN MICHÈLE , BROMFIELD E. S. P. , DYE M. 
Published: February 2008

SUMMARYA method based on intrinsic antibiotic resistance (IAR) for identifying large numbers of Rhizobium strains was assessed and found to be unsatisfactory for R. phaseoli and isolates from Cicer arietinum (Rhizobium spp.). Our data showed that the number of different IAR patterns always exceeded the number of strains tested. With 90 nodule isolates from plants inoculated with a mixture of three strains of R. Phaseoli, the technique gave 18 different resistance patterns. When 24 strains of Rhizobium spp., each replicated three times, were examined 68 different resistance patterns were obtained. Single colony isolates from one strain also gave several different IAR patterns. All strains tested with fluorescent“ antibody were readily identified. Attempts to obtain correct strain identification with IAR by simplifying the scoring systems or allowing up to two differences in the resistance patterns were unsuccessful. We were unable to define the source of this variation although incubation time and inoculum concentration were shown to affect the IAR patterns
Regeneration of virus‐free grapevines using in vitro apical culture
Authors: BARLASS M. , SKENE K. G. M. , WOODHAM R. C. , KRAKE L. R. 
Published: February 2008

SUMMARYFragmented shoot apex culture of grapevine has been demonstrated to regenerate plants free from the graft‐transmissible diseases leafroll, yellow speckle, fleck and summer mottle. This technique in combination with heat therapy of the cultures has also produced vines free from fanleaf virus. Regenerated plants free of yellow speckle were consistently obtained if cultures were incubated at 27/20 °C but not if incubated at 35 °C. The possible ways that the in vitro elimination of these diseases was achieved are considered.
The effect of glyphosate on frond regeneration, bud development and survival, and storage rhizome starch content in bracken
Authors: AL‐JAFF D. M. A. , COOK G. T. , STEPHEN N. H. , ATCHISON T. C. , DUNCAN H. J. 
Published: February 2008

SUMMARYIn addition to very effectively suppressing bracken frond regeneration for two years at levels of 2.24 kg a. i./ha and above, glyphosate had considerable effects on the rhizome system. Dry weight of frond‐bearing rhizomes, number of living apices and developed buds, number and viability of dormant buds and starch content of storage rhizomes were all markedly reduced. The effects on dormant buds and starch content are particularly important when considering frond regeneration and as a consequence of these, glyphosate is likely to give long lasting control of bracken. Low levels of glyphosate (0.02 and 0.07 kg a. i./ha) did not stimulate bracken growth, while the addition of NH4SCN apparently inhibited the action of the sub‐lethal rate of 0.56 kg a. i./ha.
Specificity and mode of action of BTS 44584 and chlormequat chloride on wheat and soybeans
Authors: SMITH AILEEN R. , THOMAS T. H. , GARROD J. F. 
Published: February 2008

SUMMARYThe distribution and persistence of the two growth retardants chlormequat chloride and BTS 44584 were studied in wheat and soybean using radioactively labelled tracers. The chemicals were applied as seed soaks and as foliar treatments to selected leaves and root treatments. Although there were some differences in the distribution of 14C‐BTS 44584 and 14C‐chlormequat chloride, these could not be directly correlated with either the growth effects observed or the species specificity displayed by the two compounds in previous studies. Differences in the amounts of degradation of the compounds appeared to be due to differences in species, plant age and mode of application rather than any relationship between degradation and species specificity.
Distribution and abundance of adult Opomyza florum (Diptera: Opomyzidae) in cereal crops and grassland
Authors: VICKERMAN G. P. 
Published: February 2008

SUMMARYFrom 1971 to 1979 counts were made of the numbers of Opomyza florum adults found in vacuum net samples taken from cereal and grass fields on a 62‐km2 study area in West Sussex. In 2 years, 1974 and 1975, counts were made of the numbers of adults found in similar samples taken from hedgerow grasses. In all years, numbers of adults were highest in winter wheat crops; relatively few were found in other autumn‐ or spring‐sown cereals or in grass fields. Mean numbers (/m2) in winter wheat in June varied from 33.0 in 1974 to only 0.9 in 1977. In most years, the first adults were found in June in winter wheat; numbers reached a peak in July and then declined rapidly. More adults were usually found in winter wheat crops that followed winter wheat in the rotation than in those following grass. Adults were also more abundant in June in winter wheat crops sown relatively early than in those sown late. The current tendencies towards earlier drilling of winter wheat and to the growth of successive wheat crops could increase the pest status of O. florum.
The influence of potato harvesting and grading machinery on contact spread of Phoma exigua var. foveata on tubers
Authors: COPELAND R. B. 
Published: February 2008

SUMMARYThe incidence of wounds infected by Phoma exigua var. foveata was increased if freshly damaged tubers (recipients) were shaken in a bag with diseased tubers (donors) to simulate the tuber‐to‐tuber contact that occurs during potato handling. An increase in the number of gangrene rots on damage points also occurred if the recipient tubers were wounded after contact with the diseased tubers, rather than before, and when the donor tubers were heavily infested with P. exigua var. foveata but were free of gangrene lesions. Increasing the proportion of donor to recipient tubers increased the percentage of infected wounds on recipients.Increased incidences of infection in recipient tubers also occurred after they had been passed over an elevator digger when it was lifting stocks of tubers heavily infested with P. exigua var. foveata. When spores of an E +ve isolate of P. exigua var. foveata were sprayed onto the webs of manned potato harvesters, tubers harvested immediately after developed gangrene rots from many of which the E +ve isolate was cultured. An E +ve isolate was also used to demonstrate the transfer of P. exigua var. foveata inoculum from tubers onto soil on riddles of a potato grader and from these soil‐coated surfaces onto other tubers during grading.
Host range, purification and some properties of two carlaviruses from hop (Humulus lupulus): hop latent and American hop latent
Authors: ADAMS A. N. , BARBARA D. J. 
Published: February 2008

SUMMARYHop latent virus (HLV) occurs in virtually all commercial hop plants in England, without causing apparent symptoms. It was transmitted between hop plants in a non‐persistent manner by the aphid Phorodon humuli, but was not seed‐borne in hop. The virus infected six species in four families out of 40 in 13 families which were inoculated, but infection was systemic only in Dianthus deltoides and hop. Only Phaseolus vulgaris and Chenopodium murale developed symptoms. Purification of HLV from hop extracts was hampered by aggregation of virus particles but this was minimised either by resuspending pellets in phosphate‐buffered saline containing Tween 20 or by avoiding ultra‐centrifugation. Virus was purified from extracts treated with Triton X‐100 by precipitation with polyethylene glycol (PEG) followed either by centrifugation through sucrose density gradients or by exclusion chromatography through columns of Sephadex G‐25 and Sepharose 4B. Purified preparations contained filamentous particles c. 675 × 14 nm composed of c. 6% single stranded RNA of mol. wt c. 2.9 × 106 and a single protein species of mol. wt c 33 000. Immunosorbent electron microscopy (IEM) decoration tests suggested that HLV was serologically related to carnation latent, Helenium virus S, lily symptomless and Nerine latent viruses.American hop latent virus (AHLV) was found in two introductions to England from Corvallis, USA in 1975 and 1976. It was transmitted between hop plants in the non‐persistent manner by P. humuli. The virus infected 17 species in seven families out of 41 species in 13 families which were mechanically inoculated and was systemic in nine species. It did not cause symptoms in any of five English hop cultivars. C. quinoa was a convenient propagation host and countable local necrotic lesions and ringspots occurred in leaves of Datura stramonium. AHLV was purified by PEG precipitation and centrifugation in sucrose density gradients. Preparations contained filamentous particles c. 680 × 15 nm composed of c. 6% single‐stranded RNA of mol. wt c. 3.0 × 106 and a single protein species of mol. wt c. 33 000. In IEM decoration tests AHLV was serologically related to Nerine latent virus but did not react with antisera to 14 other carlaviruses.
The influence of form of deposit on the phytotoxicity of MCPA, paraquat and glyphosate applied as individual drops
Authors: MERRITT C. R. 
Published: February 2008

SUMMARYMCPA, paraquat and glyphosate were applied as individual drops (200–400 μm) to pot‐grown plants of radish (Raphanus sativus) or wild oat (Avena fatua), using concentrations appropriate to very low volume applications of these herbicides. For a given dose per plant, herbicide activity was unaffected by concentration of MCPA or paraquat but was enhanced as the concentration of glyphosate was increased. The activity of all three herbicides on both species was affected by variation of the site of application but not by drop size. On radish the greatest activity resulted when paraquat was applied to the cotyledons, glyphosate to the interveinal areas of true leaves and MCPA to the veins of true leaves. This is discussed in relation to herbicide mobility and local toxicity following applications at high concentration.
Efficacy of benzimidazole and related fungicides against Rhizoctonia solani and R. bataticola
Authors: TANEJA M. , GROVER R. K. 
Published: February 2008

SUMMARYFive formulations of four benzimidazole derived fungicides, carbendazim, benomyl, thiophanate methyl and methyl 4‐[2‐(2‐dimethylamino acetamide) phenyl]‐3‐thioallophanate were compared for their toxicity towards two pathogenic isolates of Rhizoctonia solani and three of R. bataticola. The isolates of two fungi showed significant differences in mycelial growth inhibition by the five fungicides. Benomyl and carbendazim were most inhibitory to all isolates of both fungi while the sesame isolate of R. bataticola was least sensitive to all fungicides.Disease control (90%) was obtained with low concentrations of benomyl against root rot of cowpea caused by R. solani, and with thiophanate methyl against root rot of sesame and sunflower, and leaf blight of mung bean caused by R. bataticola. The spread of stalk‐end rot of sunflower heads was best checked with a spray of thiophanate methyl. The results suggest that benzimidazole fungicides having similar toxophores act differently for disease control in different host‐parasite combinations.
The effects of dazomet, fenaminosulf, and soil ridges on red core disease of strawberry
Authors: MONTGOMERIE ISABEL G. , KENNEDY DIANA M. 
Published: February 2008

SUMMARYFenaminosulf applied as a single soil drench soon after planting and growing plants on ridges 305 mm high decreased the incidence and severity of red core (Phytophthora fragariae). Pre‐plant treatment with dazomet and growing plants on raised rows 100 mm high were ineffective.The % number of diseased roots was the most useful estimate of disease in evaluating the efficacy of treatments and the interaction of disease and yield. The relationship between disease and yield was highly significant, negative and apparently linear. Disease accounted for a higher proportion of the variation in yield in the first fruiting year than in the second. There was a close correlation between plant size in June and yield in July.
Susceptibility of different developmental stages of the root‐knot nematode, Meloidogyne incognita, to the nematicide oxamyl
Authors: WRIGHT DENIS J. , ROWLAND AMANDA J. 
Published: February 2008

SUMMARYOxamyl (6.25 μg ml‐1 soil water) was applied to cucumber roots containing Meloidogyne incognita at different stages of nematode development. Oxamyl was more effective in reducing the proportion of juveniles which developed into females when applied soon after infection to second stage juveniles than when applied later (to third and fourth stage juveniles). Early application of oxamyl also significantly reduced the proportion of females with egg masses, whereas late application had no such effect. However, the number of eggs per egg mass and the size of the young adult females was significantly reduced by all oxamyl treatments ‐ the earlier the application the greater the effect. These results support the hypothesis that actively feeding second stage juveniles of Meloidogyne spp. are more susceptible to systemic nematicides than are the non‐feeding third and fourth stage juveniles.
The effect of temperature and water stress on the timing of leaf death in Vicia faba
Authors: FINCH‐SAVAGE W. E. , ELSTON J. 
Published: February 2008

SUMMARYThe timing and pattern of leaf death was studied in three field experiments from observations of the area and dates of death of individual leaves. Two linear regression lines adequately described the pattern of leaf death on the plant in all experiments and treatments. These represented an initial phase with a slow rate of leaf death changing to a second phase with a more rapid rate of leaf death. The change from the first to second phase of leaf death occurred when the maximum seed dry weight was reached. The rates of both the first and second phases of leaf death increased with temperature. This was confirmed in an experiment in growth rooms. The rate of leaf death in both phases of plants grown at three constant temperatures increased linearly with temperature from 14 °C to 22 °C. The rate of leaf death in phase 2 increased with increasing solar irradiance and vapour pressure deficit. The rate of leaf death in both phases increased with increasing water stress in three irrigation treatments in the field.
Control of glasshouse whitefly, Trialeurodes vaporariorum, by an ‘aphid’ strain of the fungus Verticillium lecanii
Authors: KANAGARATNAM P. , HALL R. A. , BURGES H. D. 
Published: February 2008

SUMMARYHeavy infestations of whitefly on glasshouse cucumber plants were controlled below the level of economic crop damage by fortnightly or monthly sprays of Verticillium lecanii spores. The fungus did not spread from glasshouse to glasshouse, or from plant to plant, and often not from diseased whitefly scales bearing fungal spore heads to nearby healthy scales. Some scales survived and the resulting adults laid eggs on new leaves bearing no infected scales, creating another, healthy, generation. This makes regular spraying of new leaves essential. Blastospores were as effective as conidia in controlling scales when sprayed to ‘run off’ at concentrations near 107 spores ml‐1 sprayed on to the undersurfaces of leaves. A fivefold increase in spore concentration at levels near 107 spores ml‐1 usually caused significant improvement in mortality, but increase above this concentration is likely to be unrewarding. Thorough coverage of leaves was found to be vital. Control was impaired by dry conditions and by prolonged air temperatures above 25 °C. The fungicide dimethirimol, used against cucumber mildew, did not impair whitefly control by V. lecanii.
Experiments on soil drenching with fungicides against take‐all in wheat
Authors: BATEMAN G. L. , NICHOLLS P. H. 
Published: February 2008

SUMMARYIn short term pot experiments benomyl, iprodione and KWG 0599 applied as soil drenches in several types of soil significantly suppressed take‐all symptoms from inoculum placed just below wheat seeds planted 1×5 cm deep, and in sand but not other soils when seeds were 5 cm deep. Benomyl was, however, effective against inoculum below seed planted 5 cm deep in a loam‐sand mixture when the drench contained an alcohol ethoxylate surfactant. Computer simulations of fungicide distributions in the soils correlated well with disease control observations.In long term outdoor pot experiments two drenches with benomyl (without surfactant) controlled disease significantly for at least 3 months against inoculum placed 15 cm deep.The significance of these results for the practical control of take‐all by fungicides is discussed.
Tests for transmission of four potato viruses through potato true seed
Authors: JONES R. A. C. 
Published: February 2008

SUMMARYThe Andean potato calico strain of tobacco ringspot virus (TRSV‐Ca) was detected in 2–9% of potato seedlings grown from true seed from plants of cv. Cara and clone G5998(6) infected with TRSV‐Ca. Similarly, a potato isolate of the oca strain of arracacha virus B (AVB‐O) was detected in 4–12% of progeny seedlings of cv. Cara and clone D42/8 infected with AVB‐O. Potato virus T (PVT) passed through 33–59% of seed from PVT‐infected cv. Cara, but only 0–2% infection was detected in seedlings from seed of PVT‐infected clone D42/8. By contrast, no infection was detected in seedlings grown from seed from plants of G5998(6), D42/8 or cv. Cara infected with Andean potato latent virus strains Hu (APLV‐Hu) or Caj (APLV‐Caj), although both strains passed through seed of Nicotiana clevelandii.AVB‐O, PVT and TRSV‐Ca were detected in all tests of pollen from flowers of infected potato plants, but APLV‐Hu and APLV‐Caj were detected less frequently. AVB‐O and PVT were transmitted through 2% and 8% respectively, of seed from healthy potato plants pollinated with pollen from infected plants. However, no transmission through seed was detected when pollen from TRSV‐Ca infected plants was used. None of the four viruses were transmitted to healthy potato plants pollinated with pollen from infected plants.APLV‐Hu caused exceptionally severe symptoms in the cv. Cara plants used for seed production, but the Bolivian strain of PVT induced only mild symptoms rather than the severe systemic necrosis previously reported for the type of strain of PVT in this cultivar. No symptoms developed in potato seedlings infected with TRSV‐Ca, AVB‐O or PVT through the seed.
Interaction between barley yellow dwarf virus and rust in wheat, barley and oats, and the effects on grain yield and quality
Authors: POTTER L. R. 
Published: February 2008

SUMMARYIn three separate experiments, the upper leaf surface of the fifth formed leaf of wheat cv. Highbury, the fourth and fifth leaves of barley cv. Julia and the third and fourth leaves of oat cv. Mostyn were inoculated in a spore settling tower with wheat brown rust (Puccinia recondita f. sp. tritici), barley brown rust (P. hordei) or oat crown rust (P. coronata f. sp. avenae), respectively. Fewer pustules developed on distal portions of leaves of plants infected with barley yellow dwarf virus (BYDV) than on similar portions of leaves from virus‐free plants. There were no significant differences in the number of pustules on proximal leaf portions. In barley and oats, the number of pustules on distal leaf portions was negatively correlated with the amount of yellowing of the leaf areas scored. In wheat, symptoms of BYDV were mild and leaves were little affected by yellowing. The latent period of rust on wheat and oats was not affected by BYDV. In barley, BYDV reduced the latent period of rust on leaf 5, but not on leaf 4, and reduced it on proximal, but not distal, leaf portions.In other experiments, BYDV reduced the yield of wheat and oats by 44% and 66%, respectively, while BYDV‐infected barley was almost sterile. The appropriate rust reduced the yield of wheat, barley and oats by 33%, 13% and 86%, respectively. When infected with both BYDV and rust, yield of wheat and oats was reduced by 63% and 91%, respectively. Neither BYDV nor rust affected the percentage crude protein content of wheat grain, nor did rust affect that of barley. In oats, BYDV and rust each significantly increased crude protein of grain, but rust infection of BYDV‐infected plants tended to reduce it.
An investigation of the host range of the carrot fly
Authors: HARDMAN J. A. , ELLIS P. R. 
Published: February 2008

SUMMARYThe historical records of the earliest reports of umbelliferous and other hosts of carrot fly (Psila rosae) are presented and their validity discussed. In addition, the results are reported of tests made between 1972 and 1980 on 27 species of Umbelliferae and three sub‐species of Daucus carota to determine whether they would support the carrot fly. Techniques were developed for identifying plant species as hosts by determining the number of adult flies that emerged from root and soil samples obtained from plants exposed to carrot fly in the field. Experiments in 1979 and 1980 indicating the importance of co‐ordinating the life cycles of plant and insect. The results showed that certain annual species of Umbelliferae were unsuitable as hosts in the autumn when they has flowered and senesced. Valid records could only be obtained for these species by exposing the plants to first generation carrot fly attack. Of the 27 species tested, Anthriscus sylvestris, Ferula communis, and Smyrnium olusatrum failed to support carrot fly and the following 13 species were new host records: Aethusa cynapium, Anthriscus caucalis, Apium inundatum, Apium nodiflorum, Bupleurum tenuissimum, Chaerophyllum temulentum, Cicuta virosa, Daucus capillifolius, Daucus glochidiatus, Heracleum mantegazzianum, Ligusticum scoticum, Oenanthe crocata and Sison amomum. From two species, Chaerophyllum temulentum and Torilis japonica, more than two carrot flies/root were recovered. These species are numerous and widespread in carrot‐growing districts. The significance of these and other wild host plants in relation to the ecology and control of carrot fly is discussed.
Cereal aphids on maize in southern England
Authors: HAND S. C. , CARRILLO J. R. 
Published: February 2008

SUMMARYIn 1978, 1979 and 1980, counts were made of the numbers of cereal aphids on a maize crop near Fordingbridge, Hampshire, England. Maize plants were selected away from the edge of the crop and the number, morph, species and feeding site of the aphids were recorded. Metopolophium dirhodum and Rhopalosiphum padi were found at densities that exceeded those found on small‐grain cereals and grasses at the same time of the year. Sitobion avenae and Macrosiphum euphorbiae were found at relatively low densities, and Rhopalosiphum maidis and Metopolophium festucae were observed rarely. Unlike other species, the numbers of R. padi continued to increase throughout the summer and reached a peak in September/October; at this time of the year, R. padi constituted over 98% of the aphids found on maize. M. dirhodum and S. avenae were found mostly on the leaves whereas R. padi appeared to favour the cob until populations became too large to be supported. If the area of maize grown in the UK increases, the crop will probably play an important role in the life cycle of cereal aphids (especially R. padi). It is suggested that further work should be carried out on the pest status of aphids on maize and on the role that maize may play in the ecology of cereal pests.
Control of dark leaf spot (Alternaria brassicicola) of Brassica oleracea seed production crops with foliar sprays of iprodione
Authors: HUMPHERSON‐JONES F. M. , MAUDE R. B. 
Published: February 2008

SUMMARYThree sprays of iprodione (Rovral 50% w. p.) at 0.5‐1 kg a. i./ha applied to Brassica oleracea seed crops in experimental plots and field trials at 3‐wk intervals from the young green pod stage until cutting controlled pod infection caused by A. brassicicola in seasons 1976–1979. As a result few seeds were infected, seed yields were increased and their germination was improved. Sprays of Bordeaux mixture were as effective as iprodione in years when disease levels were low but were ineffective when infection pressure was severe.