bluuebunny/crossref_metadata_2025_split huggingface dataset:
Control of Aphelenchoides composticola in mushroom compost with nematicides
Authors: MCLEOD R. W. , KHAIR G. T. 
Published: February 2008

SUMMARYMushroom compost was treated with nematicides and infested with Aphelenchoides composticola at the time of filling into growing containers. Yields of mushrooms from infested untreated control composts were reduced to 40–60% of yields from uninfested control compost. Yields from infested compost treated with fenamiphos emulsifiable concentrate (e.c.) at 10 or 20 mg a.i./kg, thiabendazole wettable powder at 40 or 60 mg a.i./kg or oxamyl granules at 20 mg a.i./kg were as high as from uninfested controls. Compost treated with granules of AC 64,475 up to 20 mg a.i./kg or ethoprophos or thionazin up to 80 mg a.i./kg gave yields significantly lower than uninfested controls.Numbers of nematodes rose to about 106/20 g of compost in untreated compost and then fell, and a similar peak occurred in treatments in which yields were substantially reduced by nematode damage. Treatments which yielded as well as the uninfested controls held maximum nematode numbers down to about 10V20 g of compost but populations stayed at this level or tended to rise while numbers in untreated compost fell. Incorporation of fenamiphos in casing or its application to the surface of beds 3 wk after cropping began gave lower yields than the uninfested control but mushrooms were being produced late in the cropping cycle.Fenamiphos e.c. at 20 mg ai./kg incorporated in compost is considered a practical preventive measure for control of A. composticola.
Symptomatologically distinct strains of pepper veinal mottle virus from four West African solanaceous crops
Authors: BRUNT A. A. , KENTEN R. H. , PHILLIPS SUE 
Published: February 2008

SUMMARYSevere diseases of pepper (Capsicum annuum), tomato (Lycopersicon esculentum), eggplant (Solanum melongena) and tomato eggplant (Solanum integrifolium) in West Africa were induced by pepper veinal mottle virus (PVMV). Five selected virus isolates were serologically similar and readily transmissible by aphids in the non‐persistent manner, but they differed in host range and/or symptoms induced in some susceptible species. One isolate from eggplant failed to infect pepper, Chenopodium quinoa and C. amaranticolor, and induced only local infections in tomato. An isolate from tomato failed to infect eggplant, and an isolate from tomato eggplant induced severe stunting in Physalis floridana. The type strain, like the isolate from tomato, failed to infect Nicotiana tabacum systemically, but each caused severe systemic leaf and stem necrosis in tomato. None of the isolates infected S. melongena cv. Long Purple, suggesting that PVMV might be controlled in this and perhaps other crop species by the use of immune or tolerant cultivars.All five isolates were serologically related to potato virus Y and some to six of 12 other potyviruses.
Incidence, and effects on yield, of virus diseases of taro (Colocasia esculenta) in the Solomon Islands
Authors: GOLLIFER D. E. , JACKSON G. V. H. , DABEK A. J. , PLUMB R. T. 
Published: February 2008

SUMMARYTwo virus diseases, alomae and bobone, both of which are spread by the planthopper Tarophagus proserpina affect taro (Colocasia esculenta) on Malaita, Solomon Islands. Where the diseases were endemic, plants of 284 of 297 cultivars died from alomae infection; the remaining 13 showed bobone symptoms on three to five leaves and then recovered, but symptoms later recurred on 12–13% of plants. Loss of yield due to alomae infection was directly proportional to the percentage of plants infected. Losses due to bobone of c. 25% could not be reliably detected unless insect pests were controlled. Frequent sprays with 0–1% malathion had no appreciable effect on the incidence of alomae, but fewer plants (30%) were infected when planted in November or December than when planted in May, June or August (64–94%).Because new taro crops are traditionally grown close to infected crops, insecticidal control of the vectors will probably be of limited use in decreasing spread of the diseases.
Effect of virus yellows on yield of some monogerm cultivars of sugar beet
Authors: HEATHCOTE G. D. 
Published: February 2008

SUMMARYThe yield of plants of monogerm cultivars of sugar beet artificially infected with both beet yellows and beet mild yellowing viruses was, on average, depressed 2–7% for every 100 ‘infected plant weeks’, equivalent to c. £25/ha at 1976 prices. The cv. Vytomo, previously recommended to growers as being tolerant of infection by virus yellows, had a high sugar content and abundant foliage but in field trials its actual yield of sugar was no greater when infected, and lower when virus‐free, than that of some other monogerm cultivars.
Degradabflity and phenolic components of cell walls of wheat in relation to susceptibility to Puccinia striiforntis
Authors: HARTLEY R. D. , HARRIS P. J. , RUSSELL G. E. 
Published: February 2008

SUMMARYCell walls of tips and bases of laminae of flag leaves from 11 cultivars of winter wheat of varying susceptibility to Puccinia striiforntis yellow rust) were compared by examining their phenolic components released by treatment with a commercial cellulase. Isolated cell walls of both susceptible and resistant cultivars released water‐soluble carbohydrate esters of phenolic acids, the major acid detected being trans‐ferulic. There was no relationship between the amount of phenolic esters released by cellulase and susceptibility to yellow rust.The leaf lamina tips, which were much more susceptible to yellow rust than the corresponding bases, had lower cell wall contents than the bases and their walls were more degradable by cellulase. Examination of transverse sections of leaf laminae of cv. Little Joss showed that cells whose walls contained phenolic groups that gave a red colour reaction with p‐nitrobenzene diazonium tetrafluoroborate, occupied a larger area of leaf lamina bases than of the tips. A greater percentage of the abaxial epidermal cells of the bases, compared with the tips, had walls that gave this red colour reaction. We suggest that the presence of phenolic groups in these walls may be related to the greater resistance of the bases to P. striiforntis.
Preliminary studies of carrot susceptibility to carrot fly attack
Authors: ELLIS P. R. , WHEATLEY G. A. , HARDMAN J. A. 
Published: February 2008

SUMMARYEleven carrot cultivars were tested to compare their susceptibility to carrot fly attack at Wellesbourne and at Mepal, Cambridgeshire in 1969. Significant differences in the percentages of unattacked roots were observed but not all the cultivars behaved consistently in this respect at the two sites. Foliage height and the percentage unattacked roots were not significantly correlated for these cultivars.Four of the cultivars representing the different levels of susceptibility were retested in fen and in mineral soil in microplots at Wellesbourne in 1970. Soil type significantly affected plant growth but not the relative susceptibilities of the cultivars to carrot fly attack. Plant size was positively correlated with insect attack and accounted for most, but not all, of the differences in susceptibility between the cultivars. In 1971 also, cv. Royal Chantenay was significantly less attacked than Speed's Norfolk Giant from August to December even after allowing for the large differences between the two cultivars in plant size.The experiments demonstrated a consistent difference in the relative susceptibilities of cvs Royal Chantenay and Speed's Norfolk Giant. The difference was correlated with plant size but allowances for foliage and root size failed to account for all of the difference. The results suggested a more fundamental basis for part of the difference in the susceptibility of the cultivars to carrot fly attack.
Specialisation of crown rust on highly and moderately resistant plants of perennial ryegrass
Authors: WILKINS P. W. 
Published: February 2008

SUMMARYFrom two field samples of crown rust, isolates were selected for increased aggressiveness on four of 10 resistant perennial ryegrass clonal lines. Two lines which were formerly highly resistant became highly susceptible to the selected isolates but two which were formerly moderately resistant became only moderately susceptible. Thus, moderate resistance, although no less likely to be race‐specific, was more stable than a high level of resistance.Cultures from highly resistant lines did not show increased aggressiveness on the varieties from which the resistant lines had been selected; hence individual genes of major effect were unimportant in determining varietal resistance. In contrast, cultures from moderately resistant lines were substantially more aggressive on their corresponding varieties. Three varieties contained many genes which tended to buffer changes in virulence of the rust.
The effect of sowing pre‐germinated seeds of lettuce (Lactuca sativa) on seedling emergence
Authors: GRAY D. 
Published: February 2008

SUMMARYGlasshouse and field experiments were conducted to investigate the effects of sowing both untreated and pre‐germinated seeds, with or without a gel carrier, and also pelleted seeds into soils of different moisture contents and at different temperatures on seedling emergence of lettuce cvs Cobham Green and Avondefiance.Pre‐germinated seeds with radicles 1–2 mm long gave, on average, 15 and 4% higher final percentage emergence than untreated and pelleted seeds respectively. Sowing pre‐germinated seeds having radicles longer than 2 mm gave more variable levels of emergence and often reduced emergence, particularly when they were sown into dry or drying seedbeds. Increasing the rate of gel carrier from 0 to 30 ml m_1 of row reduced emergence progressively from 67 to 30%. Pre‐germinated seeds emerged 2–5 and 3‐0 days earlier than untreated and pelleted seeds, respectively, at a soil temperature of 10 oC; at 15 oC the corresponding figures were 0–5 and 3–5 days. Sowing pre‐germinated seeds reduced the spread (i.e. variability) of emergence by an average of 37 and 47% compared with untreated and pelleted seeds, respectively.
The effect of transfer from low to high temperatures on losses of stored bulb onions (Allium cepa)
Authors: STOW J. R. , WARD C. M. 
Published: February 2008

SUMMARYThe effect of transferring onion bulbs from low to high temperatures during storage was investigated. It was found that the later transfer was made the lower was the weight loss per bulb but the greater the loss from sprouting. The lowest total loss observed was 37% by May following transfer in January.
An analysis of some effects of light and soil temperature on clubroot disease
Authors: BUCZACKI S. T. , OCKENDON J. G. , FREEMAN G. H. 
Published: February 2008

SUMMARYIn a glasshouse study, 54 batches of cabbage seedlings were each grown for 6 wk in clubroot inoculated soil. The batches were sown at weekly intervals during the experiment which lasted 60 wk. Soil temperature and light were monitored throughout the study while other potential variables were maintained as constant as possible. Records of clubroot incidence, severity and plant weights were kept and causal relationships for disease severity and percentage infected plants sought among the light and temperature data by regressions. It was found that clubroot severity was influenced most by the light level in the second and third weeks, while the percentage of diseased plants was most influenced by temperature, that in the second week probably being the most important. The optimum light value in the second and third weeks for expression of maximum clubroot severity was c. 600 Wh m‐2 day‐1 and a mean daily temperature of not less than c. 19‐5 oC was required to give close to 100% infection. Possible reasons for the findings are discussed.
Candidate insecticides for the control of larvae of Mamestra brassicae (Lepidoptera) (Noctuidae)
Authors: LEDIEU M. S. 
Published: February 2008

SUMMARYFifteen insecticides were tested in the laboratory against larvae of Mamestra brassicae, a chrysanthemum pest. Seven of these, methomyl, chlorpyrifos, leptophos, iodofenphos, methamidophos, mephosfolan and fenitrothion were significantly more potent than carbaryl, the standard adopted.The performance of the insecticides is discussed in relation to selective action against insects and to mammalian toxicity, to identify those which might be suitable for integrated control or chemical control of noctuid larvae under glass.A technique for monitoring the amount of pesticide deposited on to a target by a Potter Tower sprayer is described.
Pre‐flowering and post‐flowering insecticide applications to control Aphis fabae on field beans: their biological and economic effectiveness
Authors: BARDNER R. , FLETCHER K. E. , STEVENSON J. H. 
Published: February 2008

SUMMARYMost spring‐sown field beans are treated with insecticides to control Aphis fabae, but there is usually a risk of toxicity to pollinating honeybees if insecticides are applied during flowering. An experiment was repeated at Rothamsted for 6 consecutive years, comparing treatments before and after flowering.It is concluded that (1) pre‐flowering treatments (demeton‐S‐methyl spray at 0–25 kg a.i. ha‐1 or phorate granules at 1–12 kg a.i. ha‐1) were more effective and profitable than post‐flowering treatments, (2) application of phorate granules before flowering gave the greatest economic return, and minimised the danger to foraging bees and (3) aphid populations varied considerably from year to year, as did the relationship between aphid infestation and yield, but our evidence supports the suggestion that insecticide spray treatments are profitable if 5% or more of the plant stems are infested at the end of primary aphid migration.
The mildew resistance of Hordeum bulbosum and its transference into H. vulgare genotypes
Authors: JONES I. T. , PICKERING R. A. 
Published: February 2008

SUMMARYMildew from susceptible genotypes (SI and S2) of Hordeum bulbosum was found to be avirulent on all H. vulgare genotypes tested, including such cultivars as Proctor with no known genes for resistance to mildew.The H. bulbosum genotype SI (2n =14) proved resistant to all isolates of mildew from H. vulgare. The mildew isolates used for these tests possessed most of the common virulence factors which attack the current ‘vulgare’ cultivars in Western Europe.Some H. bulbosum genotypes were resistant to the ‘bulbosum’ mildew. Attempts at combining resistance from both species are presented and discussed.
Studies on plant growth‐regulating substances. XLIX. Phenoxyalkenes
Authors: RIUS‐ALONSO C. , WAIN R. L. 
Published: February 2008

SUMMARYA series of phenoxyalkenes has been examined in a number of tests for plant growth‐regulating and selective herbicidal properties. Some of these compounds were found to possess high activity. The results are discussed in terms of chemical structure/biological activity relationships and mode of action.
Effect of sodium fertiliser on water status and yield of sugar beet
Authors: DURRANT M. J. , DRAYCOTT A. P. , MILFORD G. F. J. 
Published: February 2008

SUMMARYEffects of sodium fertiliser on growth, water status and yield of sugar beet crops were measured in 1974 and 1975. Sodium increased leaf area index early in the growing period, the water content of the leaves and the final yields of root dry matter and sugar in both years. In 1974, it increased leaf relative water content and diffusive conductance under conditions of moderate soil moisture deficit in August but had no effect in June or September when soil moisture deficits were low. There was also no effect in June 1975 but later, when there was a severe drought, sodium decreased leaf water potential. Further evidence of an interaction between sodium and soil moisture on leaf water status was obtained from a reappraisal of results of field experiments made between 1965 and 1976. Sodium increased sugar yield through at least two different physiological mechanisms; it improved interception of radiation by the crop by increasing leaf area early in the season and it improved the efficiency of leaves under conditions of moderate water stress.
Breeding bird communities on Scottish farms
Authors: Batten L. A. , Cousins S. 
Published: February 2008

ABSTRACTThe Common Birds Census, begun by the British Trust for Ornithology has now been monitoring bird population levels on a nationwide basis since 1962. Separate indices were constructed for Scotland and the rest of Great Britain for 12 of the commonest species.Of the species examined blue tit (Parus caeruleus), wren (Troglodytes troglodytes), song thrush (Turdus philomelos), lapwing (Vanellus vanellus), chaffinch (Fringilla coelebs) and skylark (Alauda arvensis) have increased since 1963 and show very similar population trends to the rest of Great Britain. Whitethroat (Sylvia communis), willow warbler (Phylloscopus trochilus) and swallow (Hirundo rustica) have all declined nationally, the decline in the swallow appears to have begun earlier in Scotland. The blackbird (Turdus merula) and dunnock (Prunella modularis) showed similar upward trends until 1972 when the Scottish population started to decline; a much more noticeable decline in the Scottish robin (Erithacus rubecula) population began in 1966.The total density of territory‐holding males has not increased but the biomass has and this is due to more, bigger birds but fewer passerines. The species diversity measured by the Shannon Wiener index (H.) has improved a little since 1971 and it is concluded that during the study period the farmland plots censused in Scotland have on average not shown evidence of deterioration as habitats for territory‐holding birds.
Distribution and analysis of cabbage root fly pupal populations
Authors: FINCH S. , SKINNER G. , FREEMAN G. H. 
Published: February 2008

SUMMARYThe distribution of cabbage root fly pupae around roots of brassica plants was studied from 1971 to 1977.Different distributions of the first and overwintering generations of pupae demonstrated that the two should be considered separately. The number of plant roots to be sampled for a given level of precision was greater for the first than for the overwintering generation. Sampling plans for the range of pupal populations normally encountered during the two generations are illustrated. They were unaffected by changes in plant species, plant cultivar and plant density and were also suitable for use in both untreated and insecticide‐treated crops. No attempts were made to obtain a plan for the second generation of pupae because of the difficulty in accurately predicting the occurrence of this generation in the field. Taylor's power law gave a good description of the distribution of pupae. Although many factors changed between generations the value of the power remained constant at 1–3, apparently the index of aggregation characteristic of the pupal stage of the cabbage root fly in Canada as well as in England.
The occurrence, hosts and properties of lilac chlorotic leafspot virus, a newly recognised virus from Syringa vulgaris
Authors: BRUNT A. A. 
Published: February 2008

SUMMARYLilac chlorotic leafspot virus (LCLV), a hitherto undescribed virus, was isolated from three of 65 lilacs (Syringa vulgaris) with chlorotic leafspotting symptoms growing in S.E. England. The virus was transmitted readily by sap‐inoculation to 21 of 52 species from eight of 20 families, but it was not seed‐borne in four hosts or transmitted in the semi‐persistent manner by any of four aphid species. The virus was moderately stable in vitro; sap from Chenopodium quinoa was infective after 10 min at 60 but not 65 oC, after 8–16 days at 20 oC or 25–30 wk at 2 oC, and after dilution to 10‐3 but not 10‐4.Up to 180 mg of purified virus per kg leaf tissue were obtained from C. quinoa by clarification of buffered leaf extracts with 8% (v/v) n‐butanol, followed by one cycle of differential centrifugation and molecular permeation chromatography on controlled pore glass beads (700 Å, 120–200 mesh). LCLV has fragile flexuous filamentous particles which, when intact, mostly measured c. 12‐5 times 1500–1600 nm; the helical substructure (pitch c. 3–7 nm) was clearly visible on some particles mounted in uranyl acetate. The particles sedimented as a single component (sedimentation coefficient 96 S; buoyant density 1–302 g cm‐3) and contained c. 5% nucleic acid and a single polypeptide of mol. wt 27 times 103. Although these properties place LCLV in the closterovirus group, the virus showed no serological relationship to any of six closteroviruses (beet yellows, beet yellow stunt, carnation necrotic fleck, apple chlorotic leafspot, apple stem grooving and potato virus T) and differed from other recognised or possible members of this group in host range and/or symptoms induced in indicator species.The infrequent occurrence of LCLV in lilac in S.E. England indicates that the virus could probably be eradicated by selecting only virus‐free plant material for propagation.
Detection of resistance to aphids in cereals
Authors: LOWE H. J. B. 
Published: February 2008

SUMMARYResistance to Sitobion avenae and Metopolophium dirhodum was assessed by caging aphids on the upper part of mature tillers. Despite variation in the results, considered to be due mainly to differences amongst plants of different ages, certain cultivars consistently supported fewer aphids. Winter wheats Anna Migliori and Marsters Al and Indian spring barleys EB 921 and DL 107 were identified as resistant cultivars useful for reference in further work.
Aseptic cultivation of sapling trees for studies of nutrient responses with particular reference to phosphate
Authors: PELHAM J. , MASON P. A. 
Published: February 2008

SUMMARYPlantlets of Betula verrucosa and B. pubescens, originally obtained from seeds surface sterilised in hydrogen peroxide, were grown on slopes of mineral nutrient agar, modified Ingestad, in plastic tubes kept at room temperatures (26 °C) with supplementary lighting. Cuttings taken from plants grown in this way rooted readily on media supplemented with 0–1 mg/1 naphthalene acetic acid and 10 g/1 sucrose.In replicated experiments to determine the optimal conditions for growth, the effects of varying salt concentrations, the addition of charcoal and changes in ventilation and amounts of phosphate were studied. It was found necessary to ‘confound’ variations attributable to the sources of seedlings/cuttings in the experimental designs.The method has facilitated the detection of clones in both B. verrucosa and B. pubescens, which, although growing equally well with large amounts of readily available phosphate, differed greatly when phosphate was in short supply. Low phosphorus ‘tolerant’ and ‘intolerant’ types were identified.