bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of frit fly (Oscinella frit) control measures on the establishment of seedling ryegrass (Lolium spp.)
Authors: MOWAT D. J. , JESS S. 
Published: February 2008

SUMMARYIn four experiments from 1981 to 1983 August‐sown perennial (Lolium perenne) and Italian (L. multiflorum) ryegrass were exposed to frit fly attack by oviposition on the seedlings. Responses to pesticide treatment were detected at autumn harvests. Even at low sowing rates pesticide application did not ultimately establish a better sward and, owing to a tendency towards spring reversal of autumn yield responses, even temporary returns were negligible. As frit fly numbers were unusually low the autumn response to pesticide was sufficient to suggest that frit fly is always likely to be an influential factor in ryegrass sown in early August in this area. Later sowings are less likely to be affected. The yield response was related to the numbers of adult flies present 2–7 wk after sowing. Neither grass species was consistently more affected than the other. Additional seed (compared with a sowing rate below normal commercial rates) and the inclusion of fertiliser at sowing also gave only small temporary returns and failed to establish a better sward. It is suggested that routine protection against frit fly attack is of at least equal value to the other two variables in an early August sowing.
Shoot development and bud mite infestation in hazelnut (Corylus avellana)*
Authors: BURGESS JEAN E. , THOMPSON MAXINE M. 
Published: February 2008

SUMMARYThe interaction of environmental and genetic variation in hazelnut (Corylus avellana) shoot development and the behaviour, survival, and colonisation of eriophyid bud mites (Phytoptus avellanae and Cecidophyopsis vermiformis) were studied. The distribution of galled buds on shoots indicated that mites colonised only those buds formed during the mite migration period. The point of entry is probably the growing shoot tip. Once within this structure, as the shoot develops the mites have access to a succession of newly‐formed, bud primordia that are unprotected by bud scales. The relative accessibility of the apical meristem and bud primordia may affect host susceptibility.
The use of fungicidal paints and gels to treat existing apple cankers
Authors: McCRACKEN A. R. , COOKE LOUISE R. 
Published: February 2008

SUMMARYFour paints containing mercuric oxide, octhilinone, thiophanate‐methyl or triad‐imefon and five gel formulations (carbendazim/triadimefon in sodium alginate or xanthan gum, carbendazim/triadimefon/hypophosphorous acid and thiophanate‐methyl/oxycarboxin in xanthan or PP969/alginate) were tested on natural cankers caused by Nectria galligena on apple trees. Scraping cankers decreased their size 7–9 months later due to stimulation of callus formation, even where no fungicide was applied, and decreased perithecial, but not conidial production. Only the paints were applied to scraped cankers and that containing mercuric oxide was the most effective in decreasing canker size and restricting new canker growth.All formulations except the octhilinone paint were applied to unscraped cankers. Only mercuric oxide paint and acidic carbendazim/triadimefon/xanthan gel stimulated callus formation and only the former caused a decrease in canker size. Every treatment, except triadimefon paint and PP969/alginate, reduced conidial production. Bioassay with TV. galligena showed that the carbendazim and thiophanate‐methyl gels achieved some movement of fungitoxicant into plant tissue.
Purification and partial characterisation of beet mild yellowing virus and its serological detection in plants and aphids
Authors: GOVIER D. A. 
Published: February 2008

SUMMARYBeet mild yellowing virus (BMW) was reversibly precipitated at temperatures below about 5°C and this property was used as a final step in a purification procedure which yielded about 1 mg virus/kg tissue. Purified virus was infective and had an A200/A280 ratio of about 1–8. BMW particles were isometric with a diameter of 26 nm, sedimented at 116 S, had a buoyant density in caesium chloride of 1.42 g/cm3 and a coat protein mol. wt of 25 400.An antiserum to BMW had a titre in immunodiffusion tests of 1/256 and was used in immunodiffusion tests, immunospecific electron microscopy (ISEM) and enzyme‐linked immunosorbent assay to demonstrate a close serological relationship between BMW and beet western yellows virus. BMW was readily detected by ISEM in plants and also in aphid vectors after treatment of aphid extracts with a chloroform:butanol mixture.
Viruses infecting winter oilseed rape (Brassica napus ssp. oleifera)
Authors: WALSH J. A. , TOMLINSON J. A. 
Published: February 2008

SUMMARYTurnip mosaic virus (TuMV) and cauliflower mosaic virus (CaMV) have been found infecting field crops of winter oilseed rape (Brassica napus ssp. oleifera) in South Warwickshire. Other viruses found include broccoli necrotic yellows virus (BNYV) and a member of the beet western yellows virus group.Systemic leaf symptoms caused by TuMV varied within and between cultivars; the three predominant reaction types were classified as necrotic, mosaic and immune. Some recently introduced cultivars of oilseed rape were more severely affected by TuMV infection than older cultivars. Reactions to CaMV were less varied and immunity was not found. The seed yield from TuMV and CaMV‐infected plants was less than that of healthy control plants. This effect was due to infected plants producing either fewer seeds, smaller seeds or both. Germination of seeds from infected plants was unaffected if sown soon after harvest. After storage for one year the germination of seed from a virus infected plant was significantly less than that of seed from a virus‐free plant.All commercial cultivars tested were experimentally susceptible to turnip yellow mosaic virus (TYMV) and some American strains of cucumber mosaic virus (CMV).
An infra‐red photographic technique for the rapid assessment of weed and crop seedlings in field experiments
Authors: MAY M. J. , HARVEY R. N. , WRIGHT KATHRYN J. 
Published: February 2008

SUMMARYThe construction and procedures for use of a camera box are described. Infrared film was used to record weed and/or crop growth stages in the field. The equipment allowed fast assessment of experiments in the field and more detailed assessments in the laboratory. Counts, ground cover, plant growth and healthy plant material were all satisfactorily recorded by the technique.
Uptake, translocation and metabolism of fluazifop‐butyl in Setaria viridis
Authors: CARR JANE E. , DAVIES L. G. , COBB A. H. , PALLETT K. E. 
Published: February 2008

SUMMARYThe uptake and translocation of fluazifop‐butyl was investigated in Setaria viridis. Young plants (three to four leaves) with a portion of the second, third or fourth leaf covered, were sprayed with a dose equivalent to 0.25 kg a.i. ha‐1. 14C‐fluazifop‐butyl was subsequently applied to the unsprayed area and the treatment resulted in plant death within 2 wk. Uptake by leaf 3 was rapid, with less than 5% of the applied dose remaining on the leaf surface after 24 h. The highest proportion of 14C‐activity was retained in the treated portion of the leaf. Only 2% of the applied dose was translocated from leaf 3 and 0. 76% accumulated in the apical meristem.Uptake by the younger leaf 4 was more rapid and the pattern of translocation differed in that more 14‐‐activity accumulated in apical meristematic tissue. 6–30% of the applied dose was undetected and this was greatest when foliar uptake was slow. Artificial leaf surface experiments indicated that this undetected activity may have been due to volatility of fluazifop‐butyl or degradation to volatile products. 14C‐activity extracted from treated leaves was identified as fluazifop‐butyl, fluazifop acid and polar conjugates. The major 14C‐activity extracted from the apical meristem was fluazifop acid and no fluazifop‐butyl was detected in this extract.
Yield losses caused by potato cyst nematodes: a review of the current position in Britain and prospects for improvements
Authors: TRUDGILL D. L. 
Published: February 2008

SUMMARYStudies of the yield losses caused by potato cyst nematodes (PCN) in Britain are reviewed.The main conclusions either drawn from or supported by the literature, are:‐ 1) The models/equations used to relate yield losses to pre‐planting densities of PCN are not entirely satisfactory. 2) There is considerable variation between sites in the damage caused by PCN and hence the yield response to nematicide treatment cannot be reliably predicted. 3) Oximecarbamate nematicides, if well applied and if other damaging pests are absent, will prevent most of the loss at infested sites but do not increase yields at most uninfested sites. 4) PCN decreases yields by reducing the effectiveness of the root system, and hence leaf area duration and the amount of light intercepted by the crop canopy: in some circumstances PCN may also decrease the efficiency of assimilation. 5) Several factors interact either to increase or to decrease the damage caused by PCN; some of the more important are soil type, interactions with micro‐organisms, differences in husbandry, differences between cultivars in their tolerance of damage, the weather and differences in yield potential between sites. 6) Both the yield losses caused by Globodera pallida and the amounts of nematicide used may be decreased by planting tolerant and partially resistant cultivars.New results are used to show that yield losses may be decreased by applying extra fertiliser and that low rates of nematicides may be adequate to prevent damage to tolerant cultivars. Further research may lead to an improved basis for advice relating to the control of PCN and the damage it causes.
Effects of fluorescent pseudomonads on the potato blackleg syndrome
Authors: RHODES D. J. , LOGAN C. 
Published: February 2008

SUMMARYIn four field trials in 1983 and 1984 potato tubers were inoculated by dipping them at planting in a suspension of Erwinia carotovora subsp. atroseptica and then treated with a powder formulation of two strains of fluorescent pseudomonads (B 10 and I 13) isolated from potatoes. lnoculation with E. carotovora increased blackleg and reduced emergence, plant growth, tuber size and weight compared with uninoculated controls. These effects were partially reversed by treatment of tubers with fluorescent pseudomonads which also reduced contamination by E. carotovora and the soft‐rot potential of progeny tubers. In some trials a mixture of both pseudomonad isolates delayed the breakdown of the mother tuber although individual treatments did not.
The host‐plant relationships of apterous virginoparae of the grass aphid Metopolophiurn festucae cerealium
Authors: DENT D. R. , WRATTEN S. D. 
Published: February 2008

SUMMARY Metopolophium festucae cerealium has at various times caused damage to both grass and cereal crops. Despite this, little work has been done on the relative susceptibility of different grass and cereal cultivars to this aphid. The present work showed that for the cultivars examined the most common ley pasture species (Lolium perenne and Lolium multiflorum) exhibited relatively low levels of antibiotic resistance to M. f. cerealium and that wheat is more susceptible than any of the grass species tested. This enigma, in view of the aphid's low pest status on wheat, is discussed. The resistance in the grasses was greater at the stem elongation stages than at the seedling stage but the ranking was consistent between growth stages. M. f. cerealium exhibited a preference for feeding on emerging and senescing leaves of 10‐wk‐old grass but on wheat it distributed itself evenly between all available green leaves.
Heat treatments for the control of sprouting of potatoes during storage
Authors: RAMA M.V. , NARASIMHAM P. 
Published: February 2008

SUMMARYPotatoes were given hot water dip and vapour heat treatments at temperatures ranging from 50 to 80°C and 60 to 70°C respectively for various durations to control sprouting.Hot water treatment at its effective temperatures and durations resulted in undesirable physical damage to tubers. On the other hand, vapour heat treatment at 60°C with 95 ° 5 r.h. for 60 min suppressed sprouting, when given to tubers at the sprout emergence stage, without causing any deleterious side effects. The treatment, when repeated after 3 wk further reduced sprout yield during storage at ambient conditions (22–35°C, 50–80 r.h.).Comparative studies on the efficacy of vapour heat treatment and manual de‐sprouting showed that vapour heat was superior to manual de‐sprouting.
Effect of a calcium peroxide seed coating on germination of perennial ryegrass seeds
Authors: NAYLOR ROBERT E. L. , PRENTICE C. G. 
Published: February 2008

SUMMARYA seed coating containing calcium peroxide improved germination and emergence of perennial ryegrass in wet conditions. This was attributed to the oxygen supplying capability of the coating. In dry soil, coated seeds performed less well than uncoated seeds, possibly because the coating selectively absorbed water and prevented its passage to the caryopsis.
Variation in growth attributes of contrasting populations of Trifolium repens
Authors: EAGLES C. F. , OTHMAN O. B. 
Published: February 2008

SUMMARYA range of growth attributes was measured in seedlings of 10 Trifolium repens populations, differing in leaf size and origin, grown in three temperature and two glasshouse environments.Growth rates of large leaf types of Mediterranean origin were higher than those of smaller leaf types at 10°C. However, the greater temperature response of the smaller leaf types resulted in higher growth rates for S.100 and S.184 than for a large leaf type from Israel at 20°C.The increase of growth rate with temperature was associated with changes in leaf area ratio and net assimilation rate between 10° and 15°C but only with changes in net assimilation rate between 15° and 20°C. Within each temperature environment, population differences in growth rate were related to differences in net assimilation rate rather than leaf expansion.At low temperature a greater proportion of dry matter was distributed to leaf tissue in large leaf types particularly those of Mediterranean origin but they showed a proportionately smaller increase in allocation to leaves with increasing temperature compared with small leaf types.In the glasshouse environments growth rates in spring were more than double those in the autumn. This difference was associated with net assimilation rates which were about five times greater in the spring environment. However, leaf area ratios in the spring were only half those in the autumn. These differences in leaf area ratio between the glasshouse environments were closely related to differences in specific leaf area but not to differences in distribution of dry matter to leaf tissue which was greater in the spring environment.
Effect of temperature, irradiance and photoperiod on morphological characters of seedlings of contrasting white clover populations
Authors: EAGLES C. F. , OTHMAN O. B. 
Published: February 2008

SUMMARYSeedlings of 10 contrasting white clover populations differing in leaf size and origin were grown in a glasshouse in spring and autumn, and in controlled environments in which temperature (10°, 15°, 20°C), photoperiod (8, 16‐h) and irradiance (13, 47, 57 Wm‐2) were varied. There were large effects of these environmental variables on a range of morphological characters. Population differences were closely related to classification of the populations by leaf size. Within the large leaf types there was also an effect of origin. In particular, Mediterranean types differed from those of northern origin.Rate of leaf appearance increased with temperature but was less affected by photoperiod. Population differences were greater at lower temperatures.Petiole length was more sensitive to temperature than was leaflet length, particularly in the range 10° to 15°C. Similarly, petiole length increased appreciably with photoperiod extension; smaller leaf types responded more than large leaf types with the result that there were no population differences in the 16‐h photoperiod. Population differences in the other environments were closely related to leaf size classification.The onset of stolon production was delayed by lower temperatures and by short photoperiods but stolon number at the sixth leaf stage of development was not closely related to this character in the temperature environments since stolon numbers increased at lower temperatures.In low temperature and short day conditions the large leaf types including those of Mediterranean origin showed a desirable combination of long petioles and large leaves compared with the smaller leaf types. However, these differences between the two groups were eliminated for petiole length, and much reduced for leaflet length, by the greater response to temperature and photoperiod of the smaller leaf types. The implications of these responses for seasonal production are discussed.There were large effects of irradiance on the lengths of leaflets and petioles with longer ones at higher irradiance levels. There were also faster rates of leaf appearance at higher light levels. Stolon production was faster at 57 Wm‐2 than at 47 Wm‐2 while at 13 Wm‐2 no stolons were produced. After an extended period in the lowest light environment there was some plant mortality.
Effects of osmotic priming and ageing on onion seed germination
Authors: DEARMAN JANE , BROCKLEHURST P. A. , DREW R. L. K. 
Published: February 2008

SUMMARYOnion seeds were osmotically primed in polyethylene glycol solution (342 g/kg water) either for 14 days before accelerated ageing at 40°C. 18% m.c. for 0, 24, 48, 72 or 96 h, or for 10, 14 or 17 days after ageing. Priming improved the rate of germination compared with non‐primed seed. Priming before ageing delayed the loss of viability due to ageing, but priming after ageing had no effect on viability.Primed and dried onion seed was stored for 18 months at 10°C, 9% m.c. with no effect on viability; improvements in germination rate due to priming were maintained over the storage period.Conductivity measurements of seed leachates were not a consistently reliable indicator of germination performance.
Environmental factors affecting seed germination of gray birch (Betula populifolia) collected from abandoned anthracite coal mine spoils in northeast Pennsylvania
Authors: PRATT CARL R. 
Published: February 2008

SUMMARYGermination of gray birch (Betula populifolia) seed collected from anthracite mine spoils in northeastern Pennsylvania was studied. Environmental conditions of the spoil banks are such that high mortality may occur at seed and germination stages because of low moisture availability and thermal stress. The mine spoil banks are harsh environments with respect to key seed germination factors: percent soil moisture as low as 1.8% and soil surface temperatures reaching 59°C. In the field, gray birch typically germinated in mid‐April prior to severe environmental stress. Trends in germination success were inversely related to rising soil temperature and decreasing soil moisture availability. Although seeds were capable of survival and germination under laboratory conditions of constant temperatures in excess of 55°C, dramatic decline in germination was observed under fluctuating temperature regimes likely to be experienced in the field. No germinations occurred under fluctuating temperatures in excess of 30°C. Germinations in the field were seen to end after mid‐June when substrate temperatures exceeded 30°C.
Effects of high temperatures on the ripening responses of bananas to acetylene
Authors: SMITH N. J. S. , SEYMOUR G. B. , THOMPSON A. K. 
Published: February 2008

SUMMARYUnripe bananas were exposed to 1 ml litre‐1 of acetylene gas in air for different periods of time and different temperatures and then ripened at 20°C. It was found that exposure of fruits to acetylene for 4 h at 20, 25 and 30°C, or 8 h at 20°C did not initiate ripening. Some fruits which had been exposed to acetylene for 4 h at 35°C or 8 h at 25°C and all fruit exposed for 8 h at 30° and 35°C ripened. These results indicate that bananas became more sensitive to ripening by acetylene as temperatures increased within the range of 20 to 35°C.
The effect of sciarid larvae (Lycoriella auripila) on cropping of the cultivated mushroom (Agaricus bisporus)
Authors: WHITE P. F. 
Published: February 2008

SUMMARYSignificant linear relationships between the mean number of sciarid, Lycoriella auripila, larvae/125 g‐sample of casing and yield, numbers of mushrooms and weight/mushroom were demonstrated at all stages of a mushroom crop. Negative relationships were obtained for yield throughout the cropping period. There was no injury threshold for this pest, although an economic threshold of one larva/sample was deduced. Loss in yield was mostly due to the destruction of mushroom primordia and presumed interruption of nutrient supply to the developing sporophores.Numbers of mushrooms were severely reduced in the first, second and third flushes, more so than yield, although a large increase in numbers was demonstrated in the fourth flush. The size of mushroom was inversely related to numbers, although the increases in size in the first three flushes were insufficient to compensate for the reduction in numbers. A reduction in size was evident in the fourth flush.
Predator density manipulation and its effects on populations of Rhopalosiphumpadi (Horn.: Aphididae) in spring barley
Authors: CHIVERTON PHILIP A. 
Published: February 2008

SUMMARYExperiments were carried out in 1981‐83 to assess the impact of polyphagous predators (e.g. Carabidae, Staphylinidae and Araneae) on populations of cereal aphids in spring barley in Sweden. Barriers were erected around mid‐field and field‐edge plots at different times during the aphids' establishment phase in order to manipulate the predation pressure during the aphid pre‐peak period; predators were emigrating from field boundaries. Rhopalosiphum padi was the dominant species of cereal aphid in 1981 and 1982, and was abundant in both years. Reduction of the predation pressure resulted in R. padi populations that were two to six times larger compared with those in unenclosed control plots. Aphid populations were much larger when the predation pressure was reduced earlier in June than when this was done later, in both years, since late erection of barriers excludes fewer predators because most had already entered the enclosed areas. In 1983, R. padi and Sitobion avenae were equally common but occurred in low numbers, and the effects of reducing the predation pressure were less obvious. Bembidion spp. (B. lampros and B. quadrimaculatum) and linyphiid spiders were the most abundant predators during the early establishment phase of aphid populations in each year, and significant inverse correlations were found between peak numbers of R. padi per shoot and numbers of predators from these taxa in 1981 and 1982. Similar relationships were found between total aphids and numbers of Staphylinidae, B. quadrimaculatum and Coccinella septempunctata in 1983.It was concluded that differences between the manipulated numbers of polyphagous predators caused the observed differences in peak population levels of R.padiin 1981,1982 and to a lesser extent, 1983. Apparent levels of parasitism and fungal disease were low during the pre‐peak period. Aphid specific predators, abundant after the peak, were considered partly responsible for the decline of aphid populations each year.The results are compared with those from similar experiments elsewhere with S. avenae and Metopolophium dirhodum in winter wheat. Reasons why the effects of polyphagous predators are greater, and occur over a much shorter period of time in Sweden are discussed.