bluuebunny/crossref_metadata_2025_split huggingface dataset:
Acquisition and transmission of corn stunt spiroplasma by its leafhopper vector Dalbulus maidis
Authors: ALIVIZATOS A. S. , MARKHAM P. G. 
Published: February 2008

SUMMARYAs the acquisition access period of Dalbulus maidis on infected maize increased from 15 min to 7 days, the incubation period of corn stunt spiroplasma (CSS) in the insect decreased from 27 days to 8 days and the final proportion of transmitting insects increased from 5% to 100%. After 7 days access the median incubation period (IPsO) was 14.3 days (IP50 females = 12.9 days: IP50 males =16.8 days), while the proportion of transmitting insects increased from 4. 3% (9 days after the start of acquisition access) to a maximum of 93% (after 22 days), before decreasing. Females started transmitting significantly earlier and a greater proportion transmitted each day than males, until day 22 when both sexes transmitted equally.Of the insects which transmitted CSS, 29% did so continuously until death; 66% failed to transmit during the last 1–3 days, and 5% transmitted intermittently towards the end of their life. During daily transfer, females were more likely to infect plants consecutively (up to 25) than males, and females infected the higher proportion of test plants.As the transmission access period was increased from 1 h to 72 h, the proportion of transmitting insects increased from 22.5% to 97.3% and the incubation period in maize decreased.
Host specificity of the rust Phragmidium violaceurn, a potential biological control agent of European blackberry
Authors: BRUZZESE E. , HASAN S. 
Published: February 2008

SUMMARYThe host specificity of the rust fungus Phragmidium violaceum, a potential biological control agent of European blackberry (Rubus fruticosus) was studied by inoculating a mixture of 15 isolates of the rust on 108 plants of importance to the Australasian region. A scale of infection types was developed based on the results of microscopic and macroscopic observations of the reaction of host and non‐host plants to the rust. The results showed that P. violaceum has a limited host range in the genus Rubus. The rust was able to reproduce on 17 taxa of Rubus previously unrecorded as hosts, including Australasian species of Rubus subgenera Dalibarda and Lampobatus. All other taxa attacked were species of Rubus subgenus Eubatus and the majority were hybrid cultivars containing European blackberry species.
The effects of ethylene concentration in controlled atmosphere storage of tomatoes
Authors: GEESON J. D. , BROWNE K. M. , GUARALDI FRANCESCA 
Published: February 2008

SUMMARYPrevious studies have demonstrated that mature green tomatoes can be stored for up to 10 wk at 12. 5°C, 93–95% r.h. in a controlled atmosphere (CA) containing 5% CO2, 5% O2 and 90% N2, and will then ripen satisfactorily in air at 20°C. The effects of different concentrations of ethylene between <0.1 and 30 μl/litre in this storage atmosphere on ripening changes and fruit quality after 5 wk CA storage and a further 8 or 9 days ripening in air were investigated using cv. Sonatine glasshouse tomatoes.Maintaining ethylene concentrations in the storage atmosphere to.1 plllitre resulted in poor and uneven ripening of the tomatoes after storage, and increased their susceptibility to infection by Botrytis cinerea and Penicillium spp. Fruit previously stored in atmospheres containing 5 to 30 μl/litre ethylene were significantly softer after ripening than tomatoes stored in lower ethylene concentrations. Overall, the best results in terms of fruit quality (colour, firmness) and a low incidence of fungal infection were achieved with 1–3 μl/litre ethylene. The practical problems in achieving and maintaining optimum conditions, including the correct ethylene level, in CA storage of tomatoes are also discussed.
Temperature response and flowering of white clover (Trifolium repens) varieties in controlled environments and the field
Authors: NORRIS I. B. 
Published: February 2008

SUMMARYFloral initiation of 10 white clover varieties growing in three controlled day/night temperature regimes, 22“/10°C, 20°/10°C, 17°/10°C, was recorded. Effects of artificial soil heating on floral initiation of the same plants subsequently transferred to the field were also examined.In the controlled environments only a slight increase in day temperature (2–5°C) was necessary to significantly increase flowering. Defoliation at the three temperatures had contrasting effects on subsequent flower production.Results from the soil heating experiment suggested that increased temperature might compensate for short daylengths, by bringing forward reproductive bud initiation by 1 month.Soil heating increased the total number of inflorescences produced.
Russeting of apples caused by apple rust mite Aculus schlechtendali (Acarina: Eriophyidae)
Authors: EASTERBROOK M. A. , FULLER MORWENNA M. 
Published: February 2008

SUMMARYSignificant correlations were found between the numbers of apple rust mites Aculus schlechtendali feeding on fruitlets shortly after the blossom period and the amounts of russet on the calyx‐end and cheek of apples at harvest. Stalk‐end russet was not usually affected. Fruits from clusters or trees on which rust mite numbers had been reduced with an acaricide pre‐blossom had less calyx‐end and cheek russet than apples from untreated comparisons. Histological studies showed that feeding by mites on flower receptacles/fruitlets in May and June damaged epidermal cells, resulting in russet formation.
Allozymatic diagnosis of four economically important Liriomyza species (Diptera, Agromyzidae)
Authors: MENKEN STEPH B. J. , ULENBER SANDRINE A. 
Published: February 2008

SUMMARY Liriomyza bryoniae, L. huidobrensis, L. sativae and L. trifolii are leafminers of great economic importance; morphologically they are difficult to separate, many being inseparable at the pre‐adult stages. Horizontal starch gel electrophoresis of larvae, pupae and adults was carried out in order to search for diagnostic allozymic characters. Analysis of the variation patterns at 15 genetic loci reveals that each species can be identified at all three stages of the life cycle. A biochemical key is presented.
The fate, distribution and biological performance of insecticide residues in vegetable crops following seedling treatment
Authors: SUETT D. L. , WHITFIELD C. E. 
Published: February 2008

SUMMARYCarrot, cauliflower and radish seedlings raised in sand culture and treated with aqueous suspensions containing chlorfenvinphos, diazinon, iodofenphos or triazophos were planted into the field in 1982 and 1983 to compare the performance against cabbage root fly and carrot fly of these treatments with that of bow‐wave applications of granular formulations at sowing.Initial residue concentrations were up to 4100 mg kg‐1 in the seedlings at planting. Thereafter the amounts of insecticides per root system declined. Residue concentrations in mature carrot and radish roots were smaller when plants had been treated as seedlings rather than by bow‐wave application. Chlorfenvinphos was the most effective insecticide against both pests. Amounts of insecticide applied in transplanted seedlings were < 5% of the amounts applied by the bow‐wave method but short‐term control of cabbage root fly on radish was similar. Carrot fly damage was reduced by 60% by some of the seedling treatments after 16 wk in 1982 but in 1983 they were less effective.Pot experiments with chlorfenvinphos showed that most of the insecticide in the seedlings was transferred rapidly into the surrounding soil and it was concluded that the bioactivity resulted mainly from uniform distribution of the released insecticide between and around individual plants.
Failure of in vitro growth inhibition by cysteine to differentiate between Australian Gaeumannomyces graminis isolates pathogenic and non‐pathogenic to oats
Authors: YEATES J. S. 
Published: February 2008

SUMMARYRadial growth of oat and non oat‐attacking Australian isolates of Gaeumannomyces graminis was greatly inhibited by increasing concentration of DL‐cysteine in basal medium agar, and growth was completely inhibited by cysteine concentrations of 3 μM. As a group, isolates of G. graminis var. tritici (both oat and non oat‐attacking forms) were more inhibited than isolates of G.graminis var.avenae at 1 μM cysteine, but differences did not occur at other concentrations. Isolates of a lobed‐hyphodiate fungus similar to G. graminis var. graminis were more tolerant of cysteine than other isolates.The findings indicate that in vitro inhibition of Australian G. graminis isolates by cysteine is not useful for differentiation between oat and non oat‐attacking types, and is unlikely to be fundamentally related to the ability of isolates to attack oats.
Cross pathogenicity studies with isolates of Fusarium oxysporum from either cucumber or watermelon pathogenic to both crop species*
Authors: MCMILLAN R. T. 
Published: February 2008

SUMMARYIsolates of Fusarium oxysporum from Abaco, the Bahamas, whether obtained from wilted plants of cucumber (Cucumis sativus) or watermelon (Citrullus lanatus), were pathogenic to cucumber, watermelon, and cantaloupe (Cucumis melo var. reticulatus). The West Indian gherkin (Cucumis anguria), pumpkin (Cucurbita pepo), and three cultivars of summer squash (C. pepo var. melopepo) were not susceptible. Strains of F. oxysporum from wilted cucumber or watermelon plants from Florida were highly pathogenic only to their original host species and are regarded as different formae speciales.
Further evidence that dioscorea latent virus is a potexvirus
Authors: PHILLIPS SUE , PIGGOTT J. D'A. , BRUNT A. A. 
Published: February 2008

SUMMARYDioscorea latent virus (DLV) was isolated from Dioscoreafloribunda but was not detected in any of 37 cvs of D. alata, D. bulbifera, D. esculenta or D. rotundata from eight countries. It was readily sap‐transmitted to 13 of 34 species from five of 12 families; it induced symptomless systemic infection in Nicotiana benthamiana and N. megalosiphon, but only symptomless local infection in other hosts. DLV was stable in vitro: sap from infected N. megalosiphon was still infective after 10 min at 75–80 oC but not 85 oC, after dilution to 10‐6 but not 10‐7, and after at least 12 months at 23 oC. DLV was not transmitted through seed, by contact or by the aphids Aphis gossypii and Myzus persicae.DLV had filamentous particles most of which measured c. 350–900 nm in purified preparations, with two modal lengths of 445 and 875 nm; the particles sedimented as two components with sedimentation coefficients of 111 S and 131 S and had a buoyant density in caesium chloride of 1–33 g cm‐3. The virus had a single nucleic acid species with a mol. wt of 2–3 ± 04 × 106 and usually produced two protein bands (mol. wts 24 900 and 23 100) in SDS‐PAGE, although virus preparations made in the presence of chloroform yielded only the larger polypeptide. DLV was serologically distantly related to commelina X and lily X viruses, but not to 11 other established or possible members of the potexvirus group.These results provide further evidence that DLV is a distinct but definitive potexvirus.
Beet necrotic yellow vein virus: different isolates are serologically similar but differ in RNA composition
Authors: KUSZALA MARIA , ZIEGLER VÉRONIQUE , BOUZOUBAA S. , RICHARDS K. , PUTZ C. , GUILLEY H. , JONARD G. 
Published: February 2008

SUMMARYTwelve isolates of beet necrotic yellow vein virus, agent of rhizomania in sugar beet, have been obtained from five European countries and the USA. The isolates were cloned and multiplied in the local lesion host Chenopodium quinoa. By ELISA, a close serological relationship was observed among all the isolates. The isolates differed, however, in the number of viral RNA species present (2, 3 or 4) and in the lengths of RNAs 3 and 4, the two smallest RNAs. A comparison of the symptoms induced by the different isolates in C. quinoa revealed a correlation between the presence of a full‐length RNA 3 (about 1850 nucleotides) and the appearance of severe chlorotic local lesions.
Stable resistance to bacterial blight disease in rice
Authors: NAYAK P. , CHAKRABARTI N. K. 
Published: February 2008

SUMMARYTen rice cultivars were evaluated for stable resistance to 18 isolates of Xanthomonas campestris pv. oryzae. Stable performance of the host cultivar was evaluated by regressing the cultivar means on the mean level of pathogenicity of the isolates averaged over all cultivars. A cultivar with low disease incidence, a regression coefficient near or equal to zero (b= 0) and the deviation from regression as small as possible (S2d= 0) was considered highly stable while that with low disease incidence, b= 1 ‐0 and S2d= 0 was considered to possess average stability. Accordingly, cvs TKM‐6, CB II, DV 85 and Ramakrishna were considered to possess average stability while IR 20 and Indira were the most stable. Cvs Cemposelak, IR 1545, BJ 1 and IR 8 showed high response to disease incidence with relatively small changes in level of pathogenicity of the isolates and hence were considered most unstable. The regression technique was considered as a valuable tool for identification of stable resistance to bacterial blight disease of rice.
Effects of hydroxamic acids on the resistance of wheat to the aphid Sitobion avenae
Authors: BOHIDAR K. , WRATTEN S. D. , NIEMEYER H. M. 
Published: February 2008

SUMMARYResistance to the aphid Sitobion avenae F. was assessed on six wheat cultivars of known concentrations of total hydroxamic acids. A range of values for intrinsic rate of increase (rm) were obtained, 96% of the variation in which was explained by acid concentrations. Of the components of rm, age‐specific fecundity was the most significant factor contributing to resistance.
Genetic analysis of resistance in Brussels sprout to cauliflower mosaic and turnip mosaic viruses
Authors: PINK D. A. C. , SUTHERLAND R. A. , WALKEY D. G. A. 
Published: February 2008

SUMMARYA total of 28 inbred lines of Brussels sprout were assessed in the glasshouse for their reaction to inoculation with cauliflower mosaic (CaMV) or turnip mosaic (TuMV) virus. There was significant variation for resistance to both viruses. From the 28 inbred lines parents were chosen for two 9 × 9 diallel crossing programmes. The parents and their F1 progeny were assessed for their reaction to CaMV or TuMV in the field.There was significant additive and non‐additive (dominance) variation but no maternal effects. Resistance to both viruses was generally dominant but with some evidence of a recessive gene for resistance to CaMV. Resistance to TuMV and CaMV was apparently controlled by at least four genes and two genes respectively. The heritability of resistance to each virus was high.The implications for breeding F1 hybrid Brussels sprout cultivars are discussed.
Comparative transmission of soybean dwarf virus by three geographically diverse populations of Aulacorthum (= Acyrthosiphon) solani
Authors: DAMSTEEGT V. D. , HEWINGS A. D. 
Published: February 2008

SUMMARYThree populations of Aulacorthum (=Acyrthosiphon) solani were compared as vectors of the two strains of soybean dwarf virus (SDV). United States (CA = California) and New Zealand (NZ) populations transmitted both SDV strains less efficiently than did the Japanese population. The CA and NZ populations most readily colonised leaflettuce, curled dock, or wild geranium and the Japanese aphids readily colonised soybeans and curled dock. CA and NZ aphids were smaller, more pigmented, and less prolific on the hosts tested than were Japanese aphids. Nymphs were more efficient vectors than adults. Alatae and apterae transmitted the virus with equal efficiency. All aphids transmitted the dwarfing strain more efficiently than the yellowing strain.
Infection of strawberry flowers by Botrytis cinerea and its relevance to grey mould development
Authors: BRISTOW P. R. , McNICOL R. J. , WILLIAMSON B. 
Published: February 2008

SUMMARYNewly‐opened strawberry flowers of several cultivars were inoculated in the glasshouse, growth chamber and field with conidia of Botrytis cinerea from cultures of seven isolates. Infection in pistils, stamens, petals, sepals and receptacles was detected by u.v. microscopy after softening fixed tissues in 1 N sodium hydroxide and staining in 0–1% aniline blue. For all isolates, cultivars and environments, conidia germinated on the stigmas and their hyphae grew into the transmitting tissue of the styles, but so slowly that they sometimes took 4–6 wk to reach the style bases. Cv. Troubadour was the only cultivar in which hyphae grew from the style into the carpel, but growth there was limited and did not progress into the receptacle. The fungus produced conidiophores and conidia on the stigmas of 15 of the 23 cultivars tested in the field but did not do so in the growth chamber or glasshouse tests. It readily colonised the anthers and connective between the anther lobes and sporulated on anthers in the field; in some cultivars it grew to the base of a few stamen filaments and into the receptacle. In the glasshouse, conidia remained ungerminated on the petals and sepals for at least 6 days, but in a moist chamber they germinated and hyphae rapidly penetrated the epidermis and colonised internal tissues of these flower parts. Results indicated that stamens may be more important than styles as a source of latent infection.
The susceptibility of stems of different potato cultivars to blackleg caused by Erwinia carotovora subsp. atroseptica
Authors: LAPWOOD D. H. , READ P. J. 
Published: February 2008

SUMMARYThe susceptibility of stems of six potato cultivars to Erwinia carotovora subsp. atroseptica was assessed in two years (1981 and 1982) either by direct inoculation in the field or by inoculation of detached stems in the laboratory. These six and a further 22 cultivars were also assessed in three years (1982‐84) by inoculating stems of glasshouse‐grown plants.Different methods of inoculation and types of inocula were tested. In the field, wooden toothpicks rubbed in bacterial slime were more successful in establishing infection than when dipped in a bacterial suspension, but injection of bacterial suspension with a hypodermic needle was reliable in establishing infection over a range of concentrations. Detached stems were more readily infected and gave more consistent results compared with inoculation in the field.The range of reaction of the six cultivars was similar in both detached stem and glasshouse tests. The early cultivars Pentland Javelin and Ulster Sceptre were most susceptible and of the maincrop cultivars, Maris Piper was intermediate and Desiree and King Edward least susceptible whereas Pentland Crown showed greater resistance in the glasshouse than in the field. Glasshouse tests using hypodermic inoculation indicated a range of susceptibilities; the early cultivars Manna, Maris Bard and Estima were most susceptible and the maincrop Pentland cultivars Crown, Dell, Hawk, Ivory and Squire least susceptible.
Synergistic action between ioxynil, bromoxynil acids and aminotriazole
Authors: BALAYANNIS P. G. 
Published: February 2008

SUMMARYTwo halogenated organic compounds, ioxynil acid and bromoxynil acid, were shown to inhibit the oxidation of aminotriazole in a free radical generating system. When hypotoxic concentrations of aminotriazole plus ioxynil acid or bromoxynil acid were applied as sprays to wheat plants synergistic action was observed; whereas the three chemicals applied separately caused no damage to wheat plants, the combined spray destroyed them. The statistical analysis of the results confirms that the above combinations act synergistically.
Common resistance in red raspberry to Botrytis cinerea and Didymella applanata, two pathogens occupying the same ecological niche
Authors: WILLIAMSON B. , JENNINGS D. L. 
Published: February 2008

SUMMARYComparisons were made between Botrytis cinerea and Didymella applanata, which occupy the same ecological niche on canes of red raspberry. Isolates of B. cinerea from diverse localities within the British Isles were pathogenic to the SCRI selection M30 when internodal wounds on young canes were inoculated. A single inoculation frequently caused the buds at several nodes to fail the following spring. Differences in the lengths of the stem lesions that formed indicated differences in isolate pathogenicity, but these were not related to isolate origin. Bud suppression and lateral shoot failure also occurred when petioles of cvs Mailing Orion, Mailing Jewel and Glen Clova were wound inoculated with B. cinerea up to late August.The relative resistance of seven cultivars to three isolates of each pathogen was determined. Principal components analysis of data from five estimates of resistance to each pathogen showed that 40% of the variation described a common resistance to the two diseases.Further analysis showed that cvs Chilcotin and Meeker had the strongest common resistance and that cvs Glen Prosen and Mailing Jewel had the weakest. The remaining variation described cultivar differences in relative bud length after petiole inoculation with either pathogen, and differences in the relative importance of spring and autumn symptoms. Only 7% of the variation indicated independent resistance to the two pathogens and this was not influenced by cultivar differences.
Effects of shading and plant density on leaf growth of Viciafaba
Authors: KASIM K. , DENNETT M. D. 
Published: February 2008

SUMMARYFaba beans (Viciafaba cv. Maris Bead) were grown in the field at densities of 20 and 60 plants m‐2 and under zero, 34 and 56% reduction in incoming solar radiation. Measurements of the area of individual leaves were made every two days. Rates of leaf appearance and the duration of expansion of a leaf were virtually unaffected by the experimental treatments. Leaves required approximately 200 oC days (above 1 oC) from appearance to full expansion. Shading consistently increased specific leaf area but decreased leaf weight only at the greater shading level. At low density leaves were largest under 34% shade and smallest under 56% shade, but at high density there were no significant differences in leaf size.
Alternatives for gold wire electrodes in electronic measurement systems for studying insect probing behaviour
Authors: KIMSEY R. B. , MARKHAM P. G. , KINSEY M. G. , ULLMAN D. E. , McLEAN D. L. 
Published: February 2008

SUMMARYSingle stranded materials including individual silk fibres and human hair were gold plated with a sputter coater and used in place of gold wire electrodes in electronic systems for monitoring insect feeding behaviour.
Short‐term forecasting of peak population density of the grain aphid (Sitobion avenae) on wheat
Authors: ENTWISTLE J. C. , DIXON A. F. G. 
Published: February 2008

SUMMARYThe trends in population density of Sitobion avenae in wheat fields were analysed for a total of 32 sites over the period 1975 to 1983 in eastern England and the Netherlands. The peak population density on each field was positively correlated with the population densities at the end of ear emergence, mid‐anthesis and the end of anthesis. It was also positively correlated with the observed rates of increase of the aphids on the crop immediately before these stages. Both parameters were incorporated in multiple regressions to forecast peak population density, and data from a further nine populations monitored in 1984 was used to validate the model.The accuracy of these forecasts, based on two counts on the crop, increased from ear emergence to the end of anthesis, the forecast at mid‐anthesis of peak density being much more accurate than any other published method.