bluuebunny/crossref_metadata_2025_split huggingface dataset:
Changes in wheat bulb fly (Delia coarctata) populations in East Anglia in relation to crop rotations, climatic data and damage forecasting
Authors: YOUNG J. E. B. , COCHRANE J. 
Published: February 2008

SUMMARYRecords of wheat bulb fly egg (Delia coarctata) population densities in fields sampled throughout East Anglia in the autumns of 1953–1990 are presented. In descending order of risk, fallow, potato, pea (mainly vining), sugar beet and oilseed rape are the main crops preceding wheat or barley which attract oviposition. A declining trend of egg populations observed over the study period may be associated with climatic changes as well as with the elimination of fallow in the rotation and the dramatic increase in the use of insecticides against the pest. Negative correlations (P < 0.05) in mean annual egg numbers were found with departures from average of July temperature and January air or soil temperature; positive correlations (P<0.05) with departure from average of August raindays. Stepwise regression analysis was used to identify the most important relationships of meteorological variables with mean annual egg numbers, or the proportion of fields sampled with egg numbers in excess of the action threshold of 2.5 million eggs/ha. Up to 59% of the variation in the annual proportion of fields above threshold was accounted for in a regression equation using departures from average of July temperature, August raindays and the percentage of average of October (preceding year) rainfall. Estimated mean annual egg populations and the proportion of fields above threshold showed a good fit with the observed values. The findings are discussed and compared with previous work. The forecasting model may be readily incorporated as a regional risk‐prediction component of a knowledge‐based system for the management of wheat bulb fly control. Regional forecasts of wheat bulb fly oviposition from this work should be tested and modified as necessary according to experience or changing climatic or agricultural factors.
Relationships between nematodes, weevils, banana and plantain cultivars and damage
Authors: SPEIJER PAUL R. , BUDENBERG WILLIAM J. , SIKORA RICHARD A. 
Published: February 2008

SUMMARYInfestation of banana and plantain suckers by nematodes (Pratylenchus good‐eyi, Radopholus similis and Helicotylenchus multicinctus) and weevils (Cosmopolites sordidus) increased with time from establishment in a field of eight different cultivars. There was a strong association between nematode and weevil infestation; suckers infested with nematodes were more than four times more likely to be infected by weevil than suckers without nematodes. Weevil damage, measured by percentage coefficient of infestation (PCI) at harvest of the bunch, was higher on a plantain (cv. Gonja) and on an east African highland cooking banana (cv. Lusumba) than on the sweet and multi‐purpose cultivars. There was a correlation between numbers of male weevils caught in a plot and the mean PCI measured in the plot, but no correlation with female numbers.
Modification of growth, yield and lodging response of lentil to phosphorus by paclobutrazol
Authors: GILL D. S. , SINGH O. S. 
Published: February 2008

SUMMARYA foliar application of paclobutrazol (1 litre a.i. ha“1) was applied before flowering of lentils grown with different levels of phosphorus (0, 20, 40, 60, 80 and 100 kg P205 ha”1). Increasing amounts of P up to 80 kg ha“1 increased plant height, crop dry matter and grain yields but also increased crop lodging. Paclobutrazol decreased plant height and lodging and increased grain yield. Maximum yields were obtained with a combination of 80 kg P ha”1 and paclobutrazol.
Rapid methods to assess the chlorophyll and carotenoid content of leaves and fruits using a microplate reader
Authors: MARTINEZ J. , DAMIDAUX R. 
Published: February 2008

SUMMARYRapid, small‐scale, accurate and inexpensive procedures have been developed to assess pigment content of leaves and tomato fruits for plant breeding programs. New formulas allowing the use of a microplate reader instead of a spectrophotometer have been computed. The theoretical background is presented for users to calibrate their own apparatus.
Evaluation of a genetically selected strain of Steinernema feltiae against the mushroom sciarid Lycoriella mali
Authors: GREWAL P. S. , TOMALAK M. , KEIL C. B. O. , GAUGLER RANDY 
Published: February 2008

SUMMARYThe control potential of a strain (ScP) of Steinernema feltiae genetically selected against the mushroom sciarid Lycoriella solani, was evaluated for the management of L. mali. Trials were conducted at two commercial mushroom farms with high and low levels of fly infestation. The efficacy of the ScP strain was compared with the SN strain of S. feltiae and the chitin synthesis inhibitor, diflubenzuron. At low densities of L. mali, the two strains did not differ in efficacy and caused 85–94% reduction in fly populations. At high fly densities with a mixed infestation of the phorid fly, Megaselia halterata, the ScP stain caused 56–83% reduction in L. mali populations whereas the SN strain caused 51–73% reduction. Two doses of the improved strain (0.5 times 106 and 1.0 times 106 infective juveniles per m2 cropping area) did not differ in efficacy from diflubenzuron which caused 80% reduction in L. mali populations. The lower dose (0.5 times 106) of the SN strain was less effective than diflubenzuron. The ScP strain had a major advantage over the SN strain in persistence in casing material. Nematodes had no significant effect on mushroom yields.
Effect of fluchloralin on protein synthesis, free amino acids and hydroxyproline content in groundnut (Arachis hypogaea L.)
Authors: DURGESHA M. 
Published: February 2008

SUMMARYCultivar TMV‐2 of groundnut plant {Arachis hypogaea L.) was grown in a nutrient solution containing fluchloralin at the rate of either 2 mg litre‐1 or 4 mg litre“1. Protein synthesis and hydroxyproline content in the cell walls of roots, stem and leaves were determined. Free amino acids content and total ammonia in leaves and roots were also analysed. Presence of fluchloralin did not adversely affect protein synthesis. No significant effect of herbicide was observed on hydroxyproline content of a purified cell wall fraction of groundnut roots, stem and leaves. The total amount of ammonia increased in roots and leaves of plants which received the higher concentration of fluchloralin. With the exception of aspartic acid, asparagine, glutamic acid and glutamine, free amino acids content decreased considerably with herbicide treatment. Alanine and glycine were strongly reduced. It is suggested that transamination reactions could be affected and the process of senescence may be enhanced.
Effect of annual and biennial burning of seed alfalfa (Lucerne) stubble on populations of lygus (Lygus spp.), and alfalfa plant bug (Adelphocoris lineolatus (Goeze)) and their predators1
Authors: SCHABER B D , ENTZ T 
Published: February 2008

SummaryThe effects of six burning treatments combined with two insecticide treatments of alfalfa (Medicago sativa L.) stubble on alfalfa plant bug, Adelphocoris lineolatus (Goeze) and Lygus spp. populations were evaluated over an 8‐yr period (1982–1989). The burn treatments were: burning every spring and autumn, burning in alternate springs, burning at 50–100 mm and 150–200 mm of spring growth, and an unburned control. Alfalfa plant bug, which overwinters in the egg stage in alfalfa stems, were reduced by the spring burns. First generation populations of Lygus spp., were enhanced by the burn treatments before spring growth appeared, but were reduced when alfalfa was burned over 50 mm of spring growth. Counts of the minute pirate bug, Onus tristicolor White, were enhanced in 1983 by all burn treatments, and in 1985 by some of the burn treatments. Of all the predators, only spiders were significantly reduced and only in 1986 by the burned every autumn and spring treatments.
The efficiency of a new lightweight suction sampler for sampling aphids and their predators in arable land
Authors: MACLEOD A , WRATTEN S D , HARWOOD R W J 
Published: February 2008

SummaryA petrol driven machine, normally used to collect leaf litter, was modified to be used as a suction sampler for polyphagous predators in cereals and grassy habitats and aphids in cereals. Recovery efficiency of Araneae, Carabidae and Staphylinidae did not differ significantly between winter sampling from Agrostis stolonifera, Dactylis glomerata, Festuca rubra, Holcus lanatus or Lolium perenne although the structure of these grasses was very different. Summer sampling of aphids and their predators in winter wheat showed that the new sampler captured significantly more target organisms per unit area than did a traditional suction sampler. The machine was also lighter, cheaper and much easier to use than a traditional machine.
Limited degree of serological variability in pepper strains of potato virus Y as revealed by analysis with monoclonal antibodies
Authors: SOTO M J , ARTEAGA M LUIS , FERERES A , PONZ F 
Published: February 2008

SummaryThe degree of serological variability among pepper strains of potato virus Y (PVY) was assessed through the analysis of samples of infected pepper collected in three main pepper producing regions of Spain. Samples corresponding to the period 1980–1991 were analysed by ELISA with five different monoclonal antibodies (MAbs) produced against potato strains of the virus. The results obtained show a limited degree of epitope variability among pepper PVY‐isolates, since only eight out of 32 possible serological profiles were found. Most isolates are not recognised by a MAb directed towards an epitope reported to be present in all potato‐PVY isolates. The overall serological behaviour of pepper isolates with these MAbs places them as closer to the group O, of the three groups into which the potato isolates of PVY have been subdivided.
Effect of mulching with cereal straw and row spacing on spread of bean yellow mosaic potyvirus into narrow‐leafed lupins (Lupinus angustifolius)
Authors: JONES R A C 
Published: February 2008

SummaryTwo field experiments examined the effect of straw spread on the soil surface on the incidence of bean yellow mosaic potyvirus (BYMV) in plots of narrow‐leafed lupin (Lupinus angustifolius) sown at narrow (17.5 cm) vs wide (35 cm) row spacing and low (25–30 kg/ha) vs medium (50–60 kg/ha) seeding rates. Virus ingress was by vector aphids flying from adjacent pastures dominated by subterranean clover. In Expt 1, in which BYMV infection was extensive, straw greatly decreased the rate and amount of virus spread regardless of row spacing or plant density, decreasing infection more than 70% by the final assessment date. This effect of straw was attributed to decreased landing rates of incoming vector alates. In the plots without added straw, narrow row spacing decreased BYMV % infection by 38% by the last assessment date. Sowing at the medium seeding rate also decreased infection. The effect of wide row spacing seemed due to delayed canopy closure between rows which is likely to have increased the landing of aphids while the effect of medium seeding rate was attributed partly to the dilution effect of greater plant numbers and partly to the effects of partial canopy development in decreasing landing rates. In Expt 2, in which the incidence of BYMV infection was low, added straw again decreased BYMV spread, but by only 25–27% at final assessment; there were no effects of row spacing or seeding rate. In both experiments, an additional “reference” treatment was included which had a high (90–100 kg/ha) seeding rate, narrow rows and no straw. The dense canopy it developed also decreased BYMV incidence but less than in the plots with added straw in Expt 1.In Expt 1, adding straw and the resulting decrease in plants killed by BYMV, were associated with an overall increase in lupin grain yield of 20%. The greater plant densities resulting from the medium seeding rate also increased grain yield but row spacing did not affect it significantly.These results indicate that retaining stubble on the soil surface at seeding will assist in management of BYMV infection in lupin crops but that wide row spacing in the absence of retained stubble is undesirable.
Comparative host tissue Réactions of Musa acuminate (AAA group) cvs Poyo and Gros Michel roots to three banana‐parasitic nématodes
Authors: MATEILLE THIERRY 
Published: February 2008

SummaryIn a comparative histopathological investigation, Poyo and Gros Michel cul‐tivars of Musa acuminata (AAA triploid) were inoculated with Radopholus similis, Helicotylenchus multicinctus or Hoplolaimus pararobustus and were grown in a greenhouse under tropical conditions. R. similis infected all the cortical parenchyma layers of the roots, reaching the vascular cylinder, but it stayed more superficial in Gros Michel roots. Red‐brown cytoplasmic globules appeared in the cortical parenchyma cells of Gros Michel only. H. multicinctus infected much of the outer cortical parenchyma in roots of both cultivars with a few phenolic cells occurring around the superficial lesions. H. pararobustus penetrated only the immediate sub‐epidermal tissues in both cultivars. The differences observed between nématodes and cultivars reflect specific host‐nematode interactions on bananas.
Effects of nitrogen fertiliser on tree/ pasture competition during the establishment phase of a silvopastoral system
Authors: CAMPBELL C D , ATKINSON D , VIS P G JAR , NEWBOULD P 
Published: February 2008

SummaryThe establishment phase of an upland silvopastoral system was studied to examine the growth and nutrition of wild cherry (Prunus avium L.) trees under different nitrogen fertiliser treatments. High rates of nitrogen fertiliser exacerbated competition between trees and pasture in a dry year when low fertiliser treatments produced faster tree height growth. When herbicides were not used to control grass growth after the third growing season, tree growth was significantly reduced showing that below‐ground competition may be a significant factor on stony upland soils. Tree growth was correlated with foliar nitrogen concentrations and not soil water, suggesting competition for soil nitrogen reduced tree growth. The importance of the interaction of fertiliser use with competition is considered in relation to successful establishment.
Salt tolerance of pigeon pea (Cajanus cajan (L.) Millsp.) at three growth stages
Authors: ASHRAF M 
Published: February 2008

SummarySalt tolerance of pigeon pea (Cajanus cajan (L.) Millsp.) was determined at three growth stages following observations by a number of workers that degree of salt tolerance of different crops varies with their ontogeny. The salt tolerance of three accessions, Local arhar, ICPL‐151 and ICPL‐850014 of pigeon pea was assessed at the germination, seedling and adult stages.There was no positive correlation between tolerance at the early growth stages and at the adult stage since no clear difference in salt tolerance of the three accessions was observed at the germination and the seedling stages, whereas accessions differed considerably at the adult stage.Although increasing salt concentrations adversely affected the growth of all three accessions, ICPL‐151 was superior to the other two accessions in fresh and dry biomass, yield and yield components when tested at the adult stage. The tolerant accession, ICPL 151, accumulated significantly lower Na+and CI in shoots. By contrast it was higher in shoot and root K+, K/Na ratios, K vs Na selectivity, soluble sugars, free amino acids and proline compared with the other two accessions.
Distribution and prevalence of the predatory planarian Artioposthia triangulata (Dendy) (Trieladida: Terricola) in Scotland
Authors: BOAG B , PALMER L F , NEILSON R , CHAMBERS S J 
Published: February 2008

SummaryThe distribution of the New Zealand flatworm (Artioposthia triangulata) in Scotland was surveyed between July 1991 and February 1993. There were 348 records from domestic gardens, 56 from botanic gardens, garden centres and nurseries, with only 13 from farms. Although most of the records came from around the major cities the flatworm was found to have become established throughout the Scottish mainland and some of the Islands, e.g. Bute, Gigha, Orkney and Skye.The impact of the flatworm on earthworm populations in agricultural land in Scotland was, as yet, found to be minimal but the fact that seven adjacent farms near Dunoon were infected suggested it could be spread from farm to farm and that in the West of Scotland it could become widespread in agricultural land.
Effects of previous cropping and fungicide timing on the development of light leaf spot (Pyrenopeziza brassicae), seed yield and quality of winter oilseed rape (Brassica napus)
Authors: FIGUEROA L , SHAW M W , FITT B D L , McCARTNEY H A , WELHAM S J 
Published: February 2008

SummaryLight leaf spot, caused by Pyrenopeziza brassicae, was assessed regularly on double‐low cultivars of winter oilseed rape during field experiments at Rothamsted in 1990‐91 and 1991‐92. Previous cropping and fungicide applications differed; seed yield and seed quality were measured at harvest. In each season, both the initial incidence of light leaf spot and the rate of disease increase were greater in oilseed rape crops sown after rape than those sown after cereals. The incidence of diseases caused by Phoma lingam or Alternaria spp. was also greater in second oilseed rape crops. In 1991‐92 there was 42% less rainfall between September and March than in 1990‐91, and much less light leaf spot developed. However, P. lingam and Alternaria spp. were more common. Only fungicide application schedules including an autumn spray decreased the incidence of light leaf spot on leaves, stems and pods, as indicated by decreased areas under the disease progress curves (AUDPC) and slower rates of disease increase. Summer sprays decreased incidence and severity of light leaf spot on pods only. In 1990‐91, all fungicide treatments which included an autumn spray increased seed and oil yields of cv. Capricorn but only the treatment which included autumn, spring and summer sprays increased yields of cv. Falcon. No treatment increased the yields of cv. Capricorn or cv. Falcon in 1991‐92. Fungicide applications decreased glucosinolate concentrations in the seed from a crop of cv. Cobra severely infected by P. brassicae in 1990‐91, but did not increase yield.
Properties of an unusual isolate of raspberry ringspot virus from grapevine in Germany and evidence for its possible transmission by Paralongidorus maximus
Authors: JONES A T , BROWN D J F , McGAVIN WENDY J , RÜDEL MARIA , ALTMAYER B 
Published: February 2008

SummaryAn isolate of raspberry ringspot nepovirus (RRV‐P) commonly found infecting grapevine in localised areas of the German Palatinate, was serologically closely related to, but distinguishable from, the English type strain of this virus (RRV‐E) which is transmitted by Longidorus macrosoma. However, unlike RRV‐E, RRV‐P had a restricted herbaceous host range and produced symptoms reliably in only two hosts, Chenopodium quinoa and Nicotiana occidentalis‐accession 37B: these symptoms were a faint systemic vein clearing which, on most occasions in C. quinoa, was transient. In in vitro studies with herbaceous plant sap, RRV‐P infectivity was lost after diluting 1/100 ‐1/500, after storage at 20oC for 1–3 days and at 4oC for 45 days: for similar studies with RRV‐E, the values were 1/125 000, and more than 15 days at 20oC and 4oC, respectively. RRV‐P was difficult to purify in quantity and in most preparations seemed to sediment as a single component corresponding to ‘bottom’ component of RRV‐E. Purified particles of RRV‐P, like those of RRV‐E, contained a major polypeptide and two RNA species of Mr 54 000, 2.6 times 106and 1.6 times 106respectively. There was no evidence from RNA preparations from purified virus particles or, from analysis of dsRNA from infected plants, that RRV‐P contained a satellite RNA. The incidence of RRV‐P in vineyards was not associated with the presence in soils of Longidorus nematodes, but was associated with the distribution in the Palatinate of Paralongidorus maximus. Furthermore, results from an experiment in Germany in a vineyard planted with healthy grapevines in soil fumigated to destroy nematodes, showed spread of RRV‐P into these plants from an adjoining source of infected grapevines and soil infested with P. maximus. In laboratory studies, RRV‐P was transmitted by P. maximus at a very low level between grapevines (used as the virus source and test plants) but not to, or between, herbaceous hosts.
Transfer of resistance to potato leafroll virus, potato virus Y and potato virus X from Solarium brevidens to S. tuberosum through symmetric and designed asymmetric somatic hybridisation
Authors: VALKONEN J P T , XU Y‐S , PULLI S , PEHU E , ROKKA V‐M 
Published: February 2008

SummaryResistance to potato leafroll virus (PLRV), potato virus Y (PVYo) and potato virus X (PVX) was studied in symmetric and asymmetric somatic hybrids produced by electrofusion between Solanum brevidens (2n=2×=24) and dihaploid S. tuberosum (2n=2×=24), and also in regenerants (B‐hybrids) derived through protoplast culture from a single somatic hybrid (chromosome number 48). All of the somatic hybrids between 5. brevidens and the two dihaploid lines of potato cv. Pito were extremely resistant to PLRV and PVYoand moderately resistant to PVX, irrespective of their chromosome number and ploidy level (tetraploid or hexaploid). Most (56%) of the asymmetric hybrids of irradiated S. brevidens and the dihaploid line of potato cv. Pentland Crown (PDH40) had high titres of PVYosimilar to those of PDH40, whereas the rest of the hybrids had PVYotitres less than a tenth of those in PDH40. Three B‐hybrids had a highly reduced chromosome number (27, 30 and 34), but were however as resistant to PLRV, PVYoand PVX as 5. brevidens. Two asymmetric hybrids and one B‐hybrid were extremely resistant to PLRV but susceptible to both PVY and PVX. The results suggested that resistance to PLRV in 5. brevidens is controlled by a gene or genes different from those controlling resistance to PVY and PVX, and the gene(s) for resistance to PVY and PVX are linked in S. brevidens.
Seasonal growth of tree lupins (Lupinus arboreus) and the effect of defoliation on leaf production
Authors: MARRIOTT CAROL A , SMITH MORAG A 
Published: February 2008

SummaryThe growth of tree lupins was investigated in two experiments. In the first, two ages of plant, 4‐wk‐old seedlings and 1‐year‐old plants, were transplanted into a ryegrass sward in an upland environment. Growth, in terms of leaf production, branching and stem elongation, was measured over two successive growing seasons. Plant dry matter and nutrient contents were determined at the beginning and end of each growing season. In the first summer, the rate of production of new leaves on the main stem of seedling plants averaged 1.8 leaves per wk and main stem length increased from 5 to 67 cm. On older plants, where floral apices had been initiated on main and primary stems, there was a 3–10 fold increase in secondary branch length. In the second season, there was no effect of plant age on rates of leaf appearance or stem extension; dry matter production was higher than in the first season.In the second experiment, the effect of removal of 0%, 50% or 100% of fully expanded leaves on the subsequent growth of 23‐wk‐old plants was investigated. During the 7‐wk growth period, defoliation promoted the rate of production of mature leaves, and area and dry weight of new laminae were slightly higher in defoliated plants. Defoliation did not affect the concentrations of N, P or K in the new laminae, but P and K concentrations in petioles of defoliated plants were significantly higher than those in intact plants.The results from the experiments are discussed in relation to the potential use of tree lupins as nurse species and biomass crops in hill and upland environments of the UK.