bluuebunny/crossref_metadata_2025_split huggingface dataset:
Growth and nutrition of mycorrhizal guayule plants*
Authors: BLOSS H. E. , PFEIFFER C. M. 
Published: February 2008

SUMMARYSynthesis of mycorrhiza in guayule plants was achieved by inoculation of 8‐day‐old seedlings with hyphae and chlamydospores of an undescribed Glomus species. There was a five‐fold increase in total dry weight of 30‐day‐old mycorrhizal‐ compared to nonmycorrhizal‐guayule grown in sterile loamy‐sand without additional fertiliser. Thirty‐day‐old, inoculated‐ and uninoculated‐seedlings were transplanted to sterile or unsterile soil and grown an additional 60 days. The greatest total dry weight of guayule was attained by inoculated transplants grown in sterile soil. Inoculated transplants increased two‐ to three‐fold in total dry weight compared to uninoculated transplants, both grown in unsterile soil. After 90 days, uninoculated plants grown in unsterile soil had formed mycorrhizae with resident vesicular‐arbuscular mycorrhizal fungi to the same extent as inoculated‐plants grown in unsterile soil. Total mineral uptake increased in inoculated guayule, irrespective of soil treatment or the presence of resident VA mycorrhizal fungi.
Multiplication of the agent of X‐disease in a non‐vector leafhopper Macrostelesfascifrons
Authors: PURCELL BY ALEXANDER H. , RICHARDSON JEAN , FINLAY ALLAN 
Published: February 2008

SUMMARYThe relative titre of the causal agent of X‐disease of stone fruits in the non‐vector leafhopper Macrosteles fascifrons was tested by injecting dilutions of M. fascifrons extracts into non‐infective Colladonus montanus leafhopper vectors. The recipient C. montanus were fed on celery test plants which were then observed for X‐disease symptoms. M. fascifrons were assayed at various intervals for up to 37 days after they were fed on X‐diseased celery or injected with infectious extracts of the X‐agent. Infectivity was detected in M. fascifrons only after 25 or 37 days in separate trials. Whole body extracts but not extracts from detached heads of M. fascifrons that had fed on X‐diseased celery were infectious, whereas extracts prepared from the heads of M. fascifrons previously injected with X‐agent extracts were infectious. This infectivity was retained for up to four serial passages in M. fascifrons.Electron microscopy of M. fascifrons that had been injected with extracts of the X‐disease agent revealed mycoplasma‐like organisms (MLO) only intercellularly and appressed to various organs in the haemocoele. No MLO were observed in uninjected M. fascifrons or those injected with extracts from non‐infectious C. montanus. These results suggest that, despite multiplication of the X‐agent in vivo. barriers in the gut and salivary glands prevent its transmission to plants by M. fascifrons.
The invasion of root tips of cereals by the cereal cyst nematode Heterodera avenue
Authors: PRICE N. S. , HAGUE N. G. M. 
Published: February 2008

SUMMARYNewly germinated seedlings of susceptible cultivars of oats, wheat, barley and rye were inoculated with second‐stage juveniles of Heterodera avenae in pots of sand. Subsequent examination showed oat root tips to be more commonly invaded, and by a greater range of nematode numbers than the other cereals.A comparison of oats and barley showed that lower nematode numbers in barley were not due to a higher emigration from barley; invasion, establishment and emigration by nematodes all being greater in oats. Second‐stage juveniles were more likely to migrate prior to establishment in barley than in oats.
Effects of water shortage on the yield of winter wheat
Authors: GALES K. , WILSON N. J. 
Published: February 2008

SUMMARYThe effects of water shortage on the yield of winter wheat (cv. Maris Huntsman) were investigated in covered field plots on silt‐loam soil. Plants were subjected to drought at different stages of growth, but none of the treatments significantly decreased yield. Some treatments decreased the number of ears per unit area, and number of grains per ear, but these effects were offset by increases in individual grain weight.We estimate that the soil water deficit (151 mm) in the treatment which had the largest effect on yield, albeit non‐significant, would be expected in nature about 15 years in 100 or less.Drought also had little effect on plant water potential and stomatal conductance. The lack of effect of drought on plant water status and yield may be attributable to the large available water content of the silt loam and the deep rooting of winter wheat.On this type of soil, therefore, water shortage appears not to be an important cause of variation in the yield of winter wheat.
Inter‐plant variation in temperate crops of maize
Authors: BREEZE V. G. , MILBOURN G. M. 
Published: February 2008

SUMMARYMaize grown at northern latitudes suffers from variation in the yield from individual plants, as well as uneven uniformity in the stage of maturity. The contributions of genotype, environment and some seed characteristics to phenotypic variation of weight and stage of development were studied in maize from experiments that included treatments of sowing date, density and planting arrangement, and which used hybrids with differing uniformity of genotype. It was not possible to divide the variation simply into genotypic or environmental components, and the performance of varieties was inconsistent.Single cross material was only slightly more uniform than a double cross variety Using large sized seed led to 1–2 days earlier silking but to little effect on final yields. The size of plants was not influenced by the size of neighbouring plants along the row and spacing in a square arrangement only had a small effect on improving uniformity of plants. More variation occurred at a high density planting.Inter‐plant variation appeared to occur either in dry weight or in the stages of development, but also there was an association between the two, e.g. the largest plants tended to be the most advanced. There was a tendency for the first emerged plants to silk first and to produce the highest grain yield (although this was not consistent in the double cross INRA 200). The first plants to silk in a crop were up to 7 days earlier than the average at harvest and yielded double the grain weight.As reliability of harvest limits the acceptance of grain maize in north‐west Europe, it is suggested that one method that could improve the uniformity in stage of maturing, without seriously reducing final grain yield, is to use a somewhat lower planting density (6 plants/m2 for grain) than has hitherto been recommended.
Grass scorch due to pot ale
Authors: NAYLOR ROBERT E. L. , SHORTREED K. 
Published: February 2008

SUMMARYGrass scorch sometimes occurs when pot ale, a waste product of malt whisky distilling, is used as a liquid fertiliser. Experiments performed on grass turves show that a high concentration of solids in the pot ale, and a large amount of foliage on the sward result in higher amounts of scorch, as determined by visual assessment. Sward yield is independent of the amount of leaf scorch but appears to be linked to the proportion of dead tillers or plants in the sward. It is suggested that leaf scorch itself does not limit yield, but if the scorching compound runs off foliage and acts against roots then tiller or plant death may occur, accompanied by a yield loss. This interpretation may help to explain some conflicting evidence on scorch effects in the literature.
Black tea manufacture.
Authors: HARRIS N. , ELLIS R. T. 
Published: February 2008

SUMMARYA comparison of the structure of the leaf manufactured by different processing systems has been made by transmission and scanning electron microscopy. A single harvest of clonal leaf was divided into batches and commercially manufactured by Orthodox, Rotorvane only, Rotorvane combined with Cutting, Tearing and Curling and the Lowrie Tea Processor methods. The different manufactures produced leaf with characteristically different damage patterns. The relationship of the different forms of damage to the qualities of made tea is discussed.
Brown spot disease of citrus caused byPhaeoisariopsissp.
Authors: EMECHEBE A. M. 
Published: February 2008

SUMMARYBrown spot disease ofCitrusspp. was shown to be caused byPhaeoisariopsissp. It severely affects all varieties of sweet orange, tangerine, grapefruit, lime and rough lemon, smooth lemon being relatively resistant. Fruits and leaves are much more susceptible than stems on which symptoms are rare. On the young fruit circular, slightly sunken, brown necrotic lesions are often associated with a surrounding ring of raised epicarp, giving the fruit a blistered appearance. Lesions on older fruits are usually flat and brown and surrounded by yellow haloes. Premature abscission, especially of young fruits, is common. Leaf symptoms start as greenish yellow patches and a fully formed leaf spot consists of light brown or greyish centre which is surrounded by a dark brown margin bordered by a yellow halo. Generalised foliar chlorosis, caused by coalescence of several lesions, culminates in premature defoliation. During wet weather, centres of both fruit and foliar lesions sporulate and become black. Stem lesions, dark brown and mostly occurring as extensions of petiole lesions, may coalesce causing stem die‐back or resulting in the formation of corky internodal lesions.In artificial culture, the fungus sporulated only on media containing an extract of citrus leaf or fruit peel. The characteristics of the fungus mostly based on examination of structures formed on naturally infected parts of the plant, are described. This is probably the first report of aPhaeoisariopsissp. on citrus.
Properties of Scottish isolates of cocksfoot mild mosaic virus and their comparison with others
Authors: TORRANCE LESLEY , HARRISON B. D. 
Published: February 2008

SUMMARYTwo isolates of cocksfoot mild mosaic virus obtained from cocksfoot (Dactylis glomerata) in Scotland differed in symptomatology, and apparently in host range, from isolates obtained in Germany and Wales. They were serologically more closely related to a Dutch isolate from cocksfoot, and to a Scottish isolate from timothy (Phleum pratense), than was the German isolate from cocksfoot. The Scottish isolate from timothy was somewhat more virulent than, but serologically closely related to a Welsh isolate from timothy.Particles of Scottish isolates from cocksfoot and timothy were best preserved for electron microscopy by fixation with osmium tetroxide. In 1.0 m KCl or 0.01 m ethylene diamine tetraacetate they were stable at pH 5.2–5.3 but unstable above pH 7; they were disrupted by 0.5% sodium dodecyl sulphate. The particles contained major and minor RNA components of mol. wt c. 1.5. 106(RNA‐1) and 0.5. 106(RNA‐2) respectively, together with polydisperse RNA of intermediate mol. wt and protein of mol. wt c. 27 000. In CsCl gradients, major and minor nucleoprotein components of density 1.39 and 1.38 g/ml respectively were distinguished. The less dense particles contained a larger proportion of intermediate‐sized RNA molecules and of RNA‐2, and a smaller proportion of RNA‐1, than did the denser particles. Particles seem to contain either RNA‐1 or various combinations of smaller RNA molecules.Despite the differences in antigenic constitution, symptomatology and particle stability between virus isolates obtained from cocksfoot and timothy in different countries, these isolates seem sufficiently similar to be considered one virus.
Techniques for distributing non‐fumigant nematicides in soil to control potato cyst‐nematodes, Globodera rostochiensis and G. pallida
Authors: WHITEHEAD A. G. , TITE D. J. , BROMILOW R. H. 
Published: February 2008

SUMMARYPotato cyst‐nematodes can be controlled and potato yields increased by applying aldicarb or oxamyl in vertical bands 12.5 or 25 cm apart in the top 15 cm of infested soil and incorporating it by rotary harrowing. This new ‘Vertical Band‐Roterra’ technique spreads the nematicides almost as uniformly in the soil as does spreading them on the soil surface and incorporating them by rotary cultivation, and gives equally effective nematode control. It is also faster, does not mix weathered with unweathered soil and does not smear the soil. The nematicide, or any other substance requiring incorporation in the top 15 cm of the soil, can be applied in either granule or liquid form by the new technique. Merely spreading the nematicide on the soil surface and incorporating it by rotary harrowing leaves most of the substance in the top 5 cm of the soil, lessening nematode control. Spreading the nematicide on the soil surface and in horizontal layers 5 and 10 cm deep, followed by rotary harrowing, controls the nematodes as well as does the rotary cultivation method, but is inconvenient.
Aspects of the laboratory production of mushroom phorid flies (Megaselia halterata) parasitised by the nematode Howardula husseyi
Authors: RICHARDSON P. N. , CHANTER D. O. 
Published: February 2008

SUMMARYEconomic mass‐production of mushroom phorids parasitised by Howardula husseyi is essential if the release of parasitised Megaselia halterata on farms is to become a practicable alternative to insecticidal control of the pest. The effects on parasite incidence in the succeeding fly generation of two methods of spawning mushroom compost, and of three initial levels of parasitism (numbers of parasitised parental flies), were studied in the laboratory. In emerging flies percentage parasitism, and mean number of adult parasites per fly, were significantly affected by the original number of parasitised females. Estimates showed that for every 10 additional parasitised parental flies there was an increase of 0.166 adult parasites per fly in the next generation. ‘Top spawning’ resulted in a significantly higher percentage parasitism than ‘through spawning’. Emerging female progeny were significantly more highly parasitised than males. Statistical models, used to assess the ability of H. husseyi infectives to parasitise M. halterata larvae in compost, indicated that even at very high host densities > 20% of the potential parasites successfully invaded a phorid larva. The results suggest that unless an in vitro method of rearing H. husseyi can be developed the nematode will not be of practical use in phorid control.
The effect of introducing aphid‐pathogenic Entomophthoraceae into field populations of Aphis fabae
Authors: WILDING BY N. 
Published: February 2008

SUMMARYDuring two warm, dry seasons (1975 and 1976) aphid‐pathogenic species of Entomophthoraceae introduced into Aphis fabae populations on field beans established briefly but failed to spread. In cool moist seasons (1977 and 1978), the fungi, principally Erynia neoaphidis and Neozygites fresenii, spread more rapidly in treated than untreated plots. In 1977, the maximum aphid population in plots treated with fungi reached a mean of 9000/plant on 19 July compared with 16 000/plant 1 wk later in untreated plots. The corresponding yield of beans in treated plots was twice that in untreated plots though only half that in plots kept free of aphids with pirimicarb. In two experiments in 1978, the maximum aphid population in treated areas was 700/plant, half that in untreated areas and 1 to 2 wk earlier. Yields from treated plots, however, were not significantly different from those from untreated plots. In nature, the fungi attack A. fabae populations in England only after they have become damaging, partly because fungal inoculum is sparse when the aphid population is small.
Lindane‐resistant strains of the leather beetle Dermestes maculatus in the United Kingdom
Authors: BINNS T. J. , PEMBERTON G. W. 
Published: February 2008

SUMMARYAdult Dermestes maculatus were tested for resistance by exposing them to films of lindane in oil on filter papers. Insects which survived a discriminating dose, designed to knock down 100% of susceptible insects, were classed as resistant. Of 42 strains intercepted on imports or collected from infested poultry houses, 34 were found to be resistant when first tested. The F1 progeny of survivors from 19 of these resistant strains were also exposed to the discriminating dose. Significant increases in survival confirmed the presence of resistance in 18 strains.
Effects of vernalisation and aphid culture history on the relative susceptibilities of wheat cultivars to aphids
Authors: KAY D. J. , WRATTEN S. D. , STOKES SUZANNE 
Published: February 2008

SUMMARYThe weight and embryo number of adults of the cereal aphid Metopolophium dirhodum were compared on vernalised and unvernalised seedlings of six winter wheat cultivars. Aphids were smaller when reared on vernalised plants and contained fewer embryos than those reared on unvernalised material. Resistance rankings of the cultivars also changed markedly; cultivars at the extremes of the resistance sequence when vernalised were not separable statistically when unvernalised. When Sitobion avenae was tested on five of the six unvernalised cultivars, results agreed with earlier work on this species but the ranking differed from that for M. dirhodum. The plant species on which the test aphid's parent had been reared markedly affected the level of resistance and this and the vernalisation effects are discussed in relation to earlier work on aphid resistance in cereals.
The tolerance of black currant flowers to induced frosts
Authors: DALE A. 
Published: February 2008

SUMMARYFlower buds on potted plants of 17 varieties of black currant were frosted to ‐3.3, ‐4.5 and ‐5.2 °C between the grape stage and full flower in 1979 and 1980. In all varieties more flower buds died after the ‐5.2 °C frosts and at full flower, and less after the ‐3.3 °C frosts and at the grape stage. Varieties related to Ben More and Ojebyn tolerated the ‐4.5 °C frosts until after first flower while Baldwin and Magnus became susceptible at the grape stage. Seabrooks Black, Greens Black and Ben Lomond and its relatives were intermediate. In both years flower buds tolerated frosts to similar growth stages but in 1980 the varieties flowered about 2 wk earlier than in 1979 and suffered more frost damage at full flower. The frosted plants had slightly larger fruits than the unfrosted ones in 1979. The immature fruit drop was similar in frosted and unfrosted plants in both years except when it was increased after ‐5.2 °C in 1980. It is pointed out that for reliable cropping, varieties should flower late as well as tolerate spring frosts and that tests of frost tolerance should be done for at least three growth stages.
A new strain of the rust fungus Puccinia chondrillina for biological control of skeleton weed in Australia
Authors: HASAN BY S. 
Published: February 2008

SUMMARYA strain of the rust fungus Puccinia chondrillina introduced into Australia in 1971 for the biological control of skeleton weed, Chondrilla juncea, attacked only the narrow‐leaf form of this weed. Studies were, therefore, undertaken in the Mediterranean region to discover strains of the rust which will attack the other two Australian forms of skeleton weed, intermediate‐ and broad‐leaf. Several strains of the rust were found to be highly virulent against the intermediate form. One of these strains from Manisa, western Turkey, was both highly specific to its host and safe for use as a biological control agent. This strain has recently been introduced into Australia for the control of the intermediate form of Chondrilla.
Isolation of corn stunt spiroplasma in Jamaica, and probable dual infection with maize mosaic virus
Authors: EDEN‐GREEN BY S. J. , WATERS HENRY 
Published: February 2008

SUMMARYSpiroplasma isolated from naturally diseased corn (Zea mays) plants in Jamaica, produced symptoms typical of the Rio Grande strain of corn stunt spiroplasma (CSS) following experimental transmission to corn by Dalbulus maidis. Isolates were serologically closely related to a reference culture of CSS. Bacilliibrm virus‐like particles associated with a related disease condition were transmitted experimentally to a small proportion of plants by D. maidis. Both virus‐like particles and CSS were detected in one experimentally infected plant, suggesting that this leafhopper could acquire both agents and transmit then simultaneously to corn.
Chemical suppression of virus in cultured plant tissues
Authors: SIMPKINS I. , WALKEY D. G. A. , NEELY HEATHER A. 
Published: February 2008

SUMMARYThe concentrations of cucumber mosaic (CMV) and alfalfa mosaic viruses, present in various types of cultured plant tissues, were significantly less when ribavirin (syn. Virazole) at 50 or 100 mg/litre was present in the culture medium. CMV concentrations decreased within 24 days in infected cultures treated with ribabirin, but incubation periods of up to 127 days were required before the virus was undetectable. However, virus‐free cultures were obtained from CMV‐infected meristem‐tips irrespective of the presence or absence of ribavirin. Kinetin at concentrations up to 25.6 mg/litre had no persistent antiviral effect.
A Neoaplectanid nematode in the larch sawfly Cephalcia lariciphila (Hymenoptera: Pamphiliidae)
Authors: GEORGIS R. , HAGUE N. G. M. 
Published: February 2008

SUMMARYA nematode parasitic on prepupae of larch sawfly (Cephalcia lariciphila) appears to be indistinguishable from Neoaplectana carpocapsae. Of three temperatures tested the optimum for development was 25 °C at which most eggs were produced in both the first and second generations. Infective nematodes entered sawfly prepupae through the anus and mouth, but the preferred mode of entry was through the spiracles; prepupal hosts were extremely attractive to infective nematodes. Nematodes overwintered in prepupal hosts and in the soil. Dauerlarvae penetrated 10 cm of packed moist soil to infect prepupae constrained at the bottom of a vertical tube, sawfly mortality decreasing with depth. Dauerlarvae may also migrate 8 cm horizontally, and 5 cm upwards, to invade the host.It is suggested that the nematode could be used to supplement biological control of Cephalcia lariciphila.
Control of whitefly, Trialeurodes vaporariorum and cotton aphid, Aphis gossypii in glasshouses by two isolates of the fungus, Verticillium lecanii
Authors: HALL R. A. 
Published: February 2008

SUMMARYThe abilities of two isoiates of the entomopathogenic fungus, Verticillium lecanii (one isolated from whitefly and one from aphids), to control both aphids and whitefly on glasshouse cucumbers was investigated. Control of homologous hosts was better than that of heterologous hosts. A single spray of a commercial substrate‐containing formulation of the ‘whitefly’ isolate controlled established whitefly populations satisfactorily on sprayed foliage and also when the whitefly moved up to younger untreated foliage. In addition, because the substrate permitted growth and sporulation of the fungus on leaf surfaces, whitefly populations introduced after a V. lecanii application were also controlled. Control of whitefly by the ‘aphid’ isolate alone was unsatisfactory although control could be obtained in conjunction with the hymenopterous parasite Encarsia formosa. Control of Aphis gossypii by the ‘aphid’ isolate was obtained by spraying a commercial formulation containing a substrate but not by spraying pure spore suspensions. The ‘whitefly’ isolate did not control aphids satisfactorily. The difference between the two isolates in pathogenicity for aphids and whitefly was supported by laboratory infectivity experiments.