bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of spur blight (Didymella applanata) and premature defoliation on axillary buds and lateral shoots of red raspberry
Authors: WILLIAMSON B. , DALE A. 
Published: February 2008

SUMMARYNodal lesions typical of natural infections of Didymella applanata were produced on young raspberry canes when wounded petioles were inoculated with mycelium. The buds which developed in the axils of these inoculated petioles were smaller and less likely to produce lateral shoots than those in the axils of delaminated or undamaged petioles, but only when the petioles were inoculated in the field before the end of July. This effect was more pronounced in cv. Mailing Jewel than in cv. Glen Clova which suggests that the latter is more tolerant of D. applanata.Sprays to control D. applanata in the cropping region of canes will probably be effective in Scotland only if applied before the end of July.
Further evidence on the nature of the dependence of carrot mottle virus on carrot red leaf virus for transmission by aphids
Authors: WATERHOUSE P. M. , MURANT A. F. 
Published: February 2008

SUMMARYPreparations were made from chervil plants doubly infected with carrot mottle virus (CMotV) and its helper virus, carrot red leaf (CRLV), on which it depends for transmission by the aphid Cavariella aegopodii, by the procedure developed previously for CRLV. The preparations contained 25 nm isometric particles which were indistinguishable from those of CRLV but possessed aphid‐transmissible infectivity of both viruses and manually transmissible infectivity of CMotV. Only one sedimenting and buoyant density component was detected. The manually transmissible CMotV infectivity was resistant to freezing and to organic solvents, treatments that destroyed the CMotV infectivity in extracts from singly infected plants. The aphid‐transmissible CMotV infectivity in preparations from CRLV/ CMotV‐infected plants, and that in extracts from CRLV/CMotV‐carrying C. aegopodii, was abolished by treatment with CRLV antiserum but not with normal serum. These results show that transmission of CMotV by C. aegopodii is dependent on the packaging of its RNA in coats composed partially or entirely of CRLV particle protein.The aphid Myzus persicae does not transmit CRLV or CMotV from plants mixedly or singly infected with these viruses but it is a vector of beet western yellows virus (BWYV) and potato leafroll virus (PLRV) and it transmitted CMotV from plants that also contained either of these viruses. This suggests that the coat proteins of BWYV and PLRV can substitute for that of CRLV in packaging CMotV nucleic acid and thereby confer on it their own vector specificities.
The relationship of potato yield with and without nematicide to density of potato cyst nematodes, lobodera rostochiensis and G. pallida
Authors: BROWN E. B. 
Published: February 2008

SUMMARYTrials relating response to nematicide to potato cyst nematode density were conducted initially in the West Midlands and later in other Regions. Thirteen trials, only three of which were within the intensive potato growing areas, conformed to a general pattern with yield losses being largely recouped by nematicide treatment. Five trials, four within the intensive areas, gave no correlation between potato yield and nematode density and an unpredictable response to nematicide. The control of the nematode appeared to be poorer in the latter trials but other factors affecting yield and nematode multiplication may have been involved. It is speculated the main factor might be interaction with fungal organisms e.g. Rhizoctonia or Verticillium.Evidence is presented to show that on several trials the nematicide has an effect other than by controlling potato cyst nematodes.Yield losses caused by potato cyst nematodes are more variable than previous work indicated, probably due to varietal, seasonal or environmental influences.
The use of water and some inorganic salt solutions to advance sugar beet seed. I. Laboratory studies
Authors: DURRANT M. J. , PAYNE P. A. , MCLAREN J. s. 
Published: February 2008

SUMMARYThe emergence of sugar beet seedlings is often slow or irregular and insufficient plants may be established for the crop to yield fully. Treating the seed prior to sowing, such that the subsequent germination percentage is not reduced but germination is more rapid and better synchronised should be beneficial. A series of laboratory experiments was made to investigate seed treatment procedures involving water and various inorganic salt solutions. Many treatment combinations were identified which gave faster germination without decreasing germination percentage and left the seed dry and intact and suitable for sowing with conventional precision drills. No treatment was found which ‘primed’ the sugar beet seed and the term seed ‘advancement’ describes, more accurately, the effects observed. There was little difference in the performance of seeds optimally treated with water or some salt solutions generating an osmotic potential of between about –10 and –20 bars. However, the use of salt solutions, although more complicated, was preferred to water as inadvertent germination during treatment was less likely. The optimum treatment for the one bulk of sugar beet seed studied was, firstly, to wash the seeds for 3.5 h with water, then after air‐drying, to moisten them on filter paper dampened with –15 bar (0–34 M) sodium chloride solution for 6 days at 15oC followed by a final wash and air‐drying.
The use of water and some inorganic salt solutions to advance sugar beet seed. II. Experiments under controlled and field conditions
Authors: DURRANT M. J. , PAYNE P. A. , MCLAREN J. s. 
Published: February 2008

SUMMARYThe effect of seed advancement on the early growth of sugar beet was determined in two experiments made under controlled conditions and eight field experiments made between 1974 and 1978. The experiments in the growth room suggested that seed advancement increased the rate of emergence and seedling dry weight over a wide range of soil moisture contents but seedling numbers were only greater under sub‐optimal moisture conditions. Similarly, in most field experiments, seed advancement resulted in more rapid emergence and larger seedlings. In four field experiments, seed advancement gave up to 16% more plants, and in three experiments a significant increase in final sugar yield of up to 0–7 t h‐1 was detected. The plants were hand‐singled to a uniform stand and had the crops been drilled to a stand, some yield responses would have been larger. Seed advancement did not decrease the plant stand or final yield in any experiments.Results in 1977 and 1978 provided some evidence that seed advancement may help reduce the damage caused by field mice and the number of plants which bolt and, by making emergence more rapid, be particularly beneficial on soils prone to slumping or capping. There might, however, be a slightly increased risk of frost injury if advanced seed is used for early sowings.
Ontogenetic interactions between photosynthesis and symbiotic nitrogen fixation in pigeonpea
Authors: LUTHRA Y. P. , SHEORAN I. S. , SINGH RANDHIR 
Published: February 2008

SUMMARYTotal nodule nitrogenase activity (TNA, μmols ethylene plant‐1 h‐1) in pigeonpea (Cajanus cajari) increased with plant growth to reach maximum at flowering (75 days after sowing), decreasing thereafter until maturity (120 days after sowing). However, specific nodule nitrogenase activity (SNA, μmols ethylene g‐1 nodule fresh wt h‐1) reached its maximum earlier (45 days after sowing). The rate of photosynthesis and shoot and nodule respiration followed a similar pattern to TNA. However, higest rates of root respiration were observed at flowering and again immediately before final harvest. 14CO2 feeding studies showed that assimilates produced in leaves before flowering were retained in the vegetative parts. Assimilates produced after flowering were exported to the reproductive structure at the expense of the nodules. It is suggested that the decreased availability of photosynthate to nodules decreased nitrogen fixation.
The influence of wheat growth stage on yield reductions caused by the rose‐grain aphid, Metopolophium dirhodum
Authors: HOLT J. , GRIFFITHS E. , WRATTEN S. D. 
Published: February 2008

SUMMARYField caged populations of Metopolophium dirhodum were established on winter wheat (cv. Norman) during the late spring and summer of 1983. An early (G. S. 30–41), middle (G. S. 41–65) and late treatment (G. S. 65–77) were compared. Yield losses were 5, 8 and 27% respectively, although aphid indices were similar in the three treatments.For other field cage populations, all established at G. S. 38 and allowed to develop freely, a significant negative relationship existed between aphid index and yield.
Modelling mortality risks for treated insects relative to controls
Authors: ROWELL J. G. , MARKHAM P. G. 
Published: February 2008

SUMMARYA model is described for facilitating studies of insect mortality. The main feature of the model is that it includes a readily interpretable parameter which measures the mortality risk in each treatment group relative to a control group. Procedures for fitting the model are illustrated by reference to an experiment where leafhoppers were injected with spiroplasma strains; one such strain was shown to be pathogenic. Good fits have been found for data from other experiments.
Injury to and death of cabbage (Brassica oleracea) seedlings caused by vapours of di butyl phthalate emitted from certain plastics
Authors: HARDWICK R.C. , COLE R.A. , FYFIELD T.P. 
Published: February 2008

SUMMARYMany items made of flexible plastic contain the plasticiser di butyl phthalate (DBP). When the plastic is in an enclosed volume, such as a glasshouse, vapours of DBP can reach toxic concentrations and kill cabbage (Brassica oleracea) seedlings. The phenomenon, which varies in severity between varieties, accounts for recent crop losses in certain glasshouses in which the flexible plastic used to cushion the glass, i.e. the glazing strip, was plasticised with DBP. Concentrations of DBP up to 2010 pg litre‐1 were recorded in such a glasshouse. The problem was cured by replacing the glazing strip with a strip plasticised with di iso‐decyl phthalate (DIDP). A residual DBP concentration of 120 pg litre‐1 was traced to DBP contaminants in the DIDP strip.Other plastic items used in glasshouses such as hosepipes and flexible pots have also been examined, and the results of chemical analyses and bioassays are reported.
Pollination activity by blowflies and honeybees on onions in breeders' cages
Authors: CURRAH LESLEY , OCKENDON D. J. 
Published: February 2008

SUMMARYHoneybees (Apis mellifera) and three species of blowflies (Calliphora vomitoria, Lucilia caesar and L. sericata) were observed on mass‐pollinated populations of onions (Allium cepa) in 4·4 × 3·6 m × 2‐2·5 m cages in June‐August 1977. Pollination activity at temperatures from 14° to 28°C was compared on the basis of mean time per flower touched on each umbel visit.Honeybees did not forage below 16°C. Above 16°C their mean time per flower was short (1·4 s) and varied little with temperature. For blowflies, it decreased markedly from 12·1 s at 14–15·5°C to 2·7 s at 26°C and above, largely because at low temperatures flies spent long periods quiescent or grooming rather than actively feeding.When flowering was not completely synchronous between cultivars, honeybees were more selective than blowflies, but where flowering was synchronous, both types of pollinator visited the two cultivars at random.For the size of cage used, neither type of insect had a distinct advantage as a pollinator of onions, despite their different behaviour patterns.
The susceptibility of Heliothis armigera larvae to three nuclear polyhedrosis viruses
Authors: WILLIAMS CERIS F. , PAYNE C. C. 
Published: February 2008

SUMMARYQuantitative bioassay techniques were used to measure the susceptibility of Heliothis armigera to three nuclear polyhedrosis viruses (NPVs): H. armigera singly‐enveloped NPV (HaSNPV), H. zea SNPV (HzSNPV) and H. armigera multiply‐enveloped NPV (HaMNPV). Viruses were identified by EcoRI restriction endonuclease analysis. Electrophoretic profiles of DNA fragments revealed that the HaSNPV isolate was a previously undescribed genotypic variant. Bioassays with neonate and 6‐day‐old larvae measured small but significant differences in virulence between the three viruses. HzSNPV was the most virulent for neonate larvae with a median lethal dose (LD50) of five polyhedra. HaMNPV was least virulent for 6‐day‐old larvae, with a LD50 of 1400 polyhedra compared with 640–670 polyhedra for HaSNPV and HzSNPV. In addition, the median lethal time (LT50) for infection with HaMNPV in neonate larvae was approximately 1·7 days longer than for the other viruses. Although they varied in virulence, each of the three viruses was sufficiently virulent to have considerable potential as a microbial control agent of H. armigera.
A model for estimating infection levels of anthracnose disease of mango
Authors: FITZELL R. D. , PEAK C. M. , DARNELL R. E. 
Published: February 2008

SUMMARYAnthracnose disease of mango caused by Colletotrichum gloeosporioides var. minor, spreads by water‐borne conidia from vegetative parts of the tree to attack inflorescences and prevent fruit set. An analysis of data from laboratory studies demonstrated that infection by conidia during wet periods was related both to the temperature and to the duration of the wet period. A model was used to estimate infection levels of anthracnose disease in two mango orchards over three seasons.The number of infection periods recorded and the estimated percentage of conidia forming appressoria in these periods matched disease development during flush growth and flowering. In 1980, only two infection periods were detected during flowering in one of these orchards and blossom blight did not prevent fruit set. In 1981 and 1982 however, higher estimated levels of infection were recorded more frequently during the same time and severe blossom blight developed. A second orchard, situated in an area less favourable to disease, was also monitored during 1982. Nine infection periods were recorded during flowering in this orchard compared to 14 in the first. A moderate level of blossom blight developed in this orchard.
The influence of foliar diseases and their control by selective fungicides on a range of groundnut (Arachis hypogaea L.) genotypes
Authors: SUBRAHMANYAM P. , WILLIAMS J. H. , McDONALD D. , GIBBONS R. W. 
Published: February 2008

SUMMARYTwenty groundnut genotypes were grown with various spray treatments which controlled either, only rust, or only leaf spot diseases, or all of these diseases or none of them. The genotypes varied in their resistance to these diseases, some having resistance to only one disease and some having resistance or susceptibility to all the diseases. Chemical control of the diseases resulted in variations in leaf area protection and in yield which were specific to each genotype. For some genotypes the diseases had little influence on yield and foliage, while for others yield and remaining green leaf were varied greatly by the control of diseases. For many of the genotypes the yield achieved was well related to variations in the green leaf remaining at maturity as a result of the spray treatments. Genotypes with good levels of genetic resistance did not have high yield potentials while those with the best yields when diseases were controlled were the most susceptible to these diseases.
Development of a hand tool to test the degree of retting of flax straw
Authors: SEABY D. A. , MERCER P. C. 
Published: February 2008

SUMMARYTo determine the optimum conditions for inducing retting of flax, by the application of glyphosate herbicide, it is necessary to have an easily portable tool which will give a rapid, accurate assessment of the stage that retting has reached. Such a tool, which can be used to test individual stems, is described and the estimates of retting obtained compared with those from other methods.
The selection of pupation sites by the stalk‐eyed fly Diopsis thoracica (Diptera: Diopsidae) and pupal parasitism in some rice cultivars
Authors: ALGHALI ALIYAGEEN M. 
Published: February 2008

SUMMARYSix rice cultivars (lines (TKM6, OS6, ADNY 11, IR28, Rexero and IR579‐48‐1) were used to determine the pupation sites of Diopsis thoracica and their effects on pupal parasitism. There was a general preference for pupation on the first three outer leaf sheaths. Preference was also observed for healthy tillers compared with damaged ones, except in OS6 where there was no significant difference between pupation on healthy and damaged tillers. Pupae on the first two outer leaf sheaths were heavily parasitised by the eulophid Tetrastichus (Neotrichoporoides) sp. (Hymenoptera). The level of parasitism ranged from 17·6% in OS6 to 58·8% in Rexero, with an overall mean of 38·9% for the entire experimental plot. The number of parasites per pupa ranged from 0·5 in OS6 to 3·0 in Rexero, with an overall mean of 1·37. There was a strong relationship between (a) parasitism (%) (r = 0·68); (b) number of parasites per pupa per variety (r = 0·90) and pupal length. The relationship between parasitism (%) and parasite density was very strong (r = 0·89), but a marginal improvement in relationship was obtained when parasitism (%) was correlated with log parasite density (r = 0·94), thus possibly suggesting weak interaction between the parasites.
Crop and weed emergence patterns in relation to time of cultivation and rainfall
Authors: ROBERTS H. A. 
Published: February 2008

SUMMARYIn experiments over 3 years, separate field plots were cultivated once only at 2‐wk intervals. Cultivation resulted in a flush of weed seedlings, representing usually less than 6% of the apparently viable seeds in the top 10 cm of soil and with a species composition which varied with the time of year. Subsequent flushes coincided in timing and extent with those on soil which had been undisturbed and were related to significant rainfall events. In each year there were periods when lack of soil moisture restricted emergence. At these times, seeds were released from dormancy by cultivation but germination of some or all of them was delayed. There was a general correspondence in the emergence patterns of weeds and of carrot and onion sown after each cultivation. On occasions when the seedbed was drying out, establishment of the comparatively rapidly‐germinating radish and cabbage was greater than that of carrot, onion or weeds. Effective initiation of germination of both crops and weeds was traceable to rainfall events. Emergence was reduced or delayed on more than half of the 45 cultivation occasions during the three growing seasons, and the results emphasise the importance of soil moisture in determining the extent and timing of seedling emergence.
The response of pigeon pea (Cajanus cajan) to the application of fertilisers
Authors: TAYO T. O. , TOGUN A. O. 
Published: February 2008

SUMMARYThe effects of fertilisers on the performance of three cultivars of pigeon pea, Cita‐1, Cita‐2 and Cita‐4, were measured in a pot experiment and a field trial from February to August 1982. The fertilisers were either applied as complete NPK (15‐15‐15) to the soil at a rate of 50 kg/ha in single or split doses within 4 wk of sowing, or as solutions containing 100 mg/litre each of N, P and K sprayed on to the plants 4 wk after sowing or at anthesis.The growth of pigeon pea was only enhanced significantly by fertiliser application in the field experiment but yields and their components were changed by fertilisers in both experiments. The magnitudes of the effects on growth and yield were similar with both methods of application.
Identifying soybean lines differing in gas exchange sensitivity to humidity
Authors: BUNCE JAMES A. 
Published: February 2008

SUMMARYThe ratios of root length and root weight to leaf area differed within and between cultivars of soybean. Plants with low ratios of root length or weight to leaf area had leaf conductances and net photosynthetic rates more reduced by a given increase in the leaf to air water vapour pressure difference around a single leaf than plants with high ratios. Plant and root system conductances to water were estimated as transpiration rate per unit leaf area divided by the difference between substrate and leaf water potentials, and by the rate of water flow through pressurised root systems. These conductances were greater in plants with large, as compared with small, root systems per unit leaf area. Cultivar rankings in sensitivity of gas exchange to humidity were consistent in controlled environment chambers and in field tests.
An appraisal of ear, leaf and stem 14CO2 assimilation, 14C‐assimilate distribution and growth in a reproductive seed crop of amenity Lolium perenne
Authors: CLEMENCE T. G. A. , HEBBLETHWAITE P. D. 
Published: February 2008

SUMMARYIn seed crops of Lolium perenne, yield may be reduced by competition for a limited assimilate supply from sinks other than the ear. This study was undertaken to evaluate the priorities for allocation of assimilate within the crop from all photosynthetic sites on the main reproductive tiller after anthesis.Ear, stem and leaves were fed with 14CO2 on two occasions; the assimilatory efficiency of these sources and the magnitude and pattern of 14C‐assimilate export from each was determined. The growth of each part of the main tiller and subtending tillers was also measured.Stem elongation apparently dominated the current assimilate resource and the ear did not become a net importer of assimilate until this process had ceased. Assimilate allocation to the tillers was high throughout.The nature of any competition between these sinks is discussed. When crop growth was contrasted with that in a previous year, environmental factors were implicated as determinants of priority for assimilate allocation to each sink. Sources of carbon for seed filling are also discussed as is the relevance of these findings to seed crop management.
Biological effectiveness of electrostatically charged rotary atomisers.
Authors: ARNOLD A. J. , CAYLEY G. R. , DUNNE Y. , ETHERIDGE P. , GRIFFITHS D. C. , JENKYN J. F. , PHILLIPS F. T. , PYE B. J. , SCOTT G. C. , WOODCOCK C. M. 
Published: February 2008

SUMMARYElectrostatically charged rotary atomisers deposited greater amounts of pesticides on wheat plants than did a conventional hydraulic sprayer and improved the effectiveness of pirimicarb against aphids, benomyl against eyespot, and dimethoate against wheat bulb fly. Although deposits of triadimefon on barley plants were increased (and soil residues decreased) by the use of the electrostatic sprayer, mildew control was about equivalent to that obtained with the hydraulic sprayer. Similar amounts of herbicide were deposited, and similar biological effects obtained, when electrostatic or hydraulic sprayers were used to control Amsinckia intermedia in winter barley.
Biological effectiveness of electrostatically charged rotary atomisers.
Authors: ARNOLD A. J. , CAYLEY G. R. , DUNNE Y. , ETHERIDGE P. , GREENWAY A. R. , GRIFFITHS D. C. , PHILLIPS F. T. , PYE B. J. , RAWLINSON C. J. , SCOTT G. C. 
Published: February 2008

SUMMARYIn 1982 seven trials on non‐cereal crops examined the effectiveness of electrostatically charged rotary atomisers with different crop‐pest combinations. Compared with conventional hydraulic sprays electrostatically applied sprays deposited much more chemical on potatoes, field beans, oilseed rape and peas, and gave better control of the pea and bean weevil (Sitona lineatus) on field beans, the pea moth (Cydia nigricana) and of fungal diseases of oilseed rape. However on swedes, sugar beet and Brussels sprouts deposits of pesticide were increased only on some parts of the plant. The control of mildew (Erysiphe cruciferarum) on swede and Erysiphe betae on sugar beet) and of caterpillars (Pieris spp.) living within the central whorl of leaves on Brussels sprouts was not as great as when a high‐volume hydraulic sprayer was used.