bluuebunny/crossref_metadata_2025_split huggingface dataset:
Assessing the age of field female wheat bulb flies (Leptohylemyia coarctata)
Authors: JONES MARGARET G. , BARDNER R. , FLETCHER K. E. 
Published: February 2008

SUMMARYFrom 1967 to 1971, wheat bulb fly females caught by sweeping from a number of localities contained mature eggs from the third week of July to the end of August.In 1971 when female wheat bulb flies were caught by sweeping, by white water traps, by suction traps as well as by light traps, the first flies containing mature eggs were caught 29 days after the first detected emergence while the first batch was laid 29–58 days after first emergence. The peak period of egg laying occurred in the fourth week of July, 24–38 days after the peak emergence. The second batch of eggs was laid when the flies were 8 weeks old, 29 days after the first; the peak for this batch was 35 days after the first. A few females laid a third batch of eggs 28 days after the first record of the laying of the second batch. A female that lives sufficiently long to lay the third batch of eggs is at least 12 weeks old. In 1970, when emergence started earlier in June, ripening and laying of eggs of the three batches was also earlier.After the harvest of cereal crops more females were caught by white water traps placed on the fallow than by other methods.The most important pathogen affecting adult wheat bulb flies was a fungus, probably Entomophthora muscae. When infection occurred early in July, fewer eggs from the first batch were laid than when infection developed later. Fewer flies were infected in 1971 than in 1970.To be effective against wheat bulb fly in the early spring, control measures‐should be applied against adults before their eggs mature in early July of the preceding year.
Induction of sporulation of fungi isolated from Dactylis glomerata seed by exposure to near‐ultraviolet radiation*
Authors: LEACH C. M. , TULLOCH MARGARET 
Published: February 2008

SUMMARYPure cultures of fifty‐two species of plant pathogenic and saprophytic fungi isolated from orchard (cock's‐foot) grass seed (Dactylis glomerata L.) were incubated either in total darkness or exposed to a diurnal cycle of near‐ultraviolet (NUV) radiation (12 h NUV/12 h darkness). Twenty‐four species sporulated only after exposure to NUV including seven species of Drechslera, five species of Fusarium, as well as species olAscochyta, Photna, Septoria, Pyrenochaeta, Rhynchophoma and Stagonospora; six species sporulated moderately in darkness but more profusely following exposure to NUV; twenty species sporulated whether they were irradiated or not; and only two species failed to sporulate. To assess the pathogenic fungal microflora of orchard grass seed accurately, seeds should be incubated under a daily regime that includes NUV to induce sporulation.
Effect of Ophiobolus graminis infection on the assimilation and distribution of 14C in wheat
Authors: ASHER M. J. C. 
Published: February 2008

SUMMARYThe uptake of 14C and movement of 14C‐labelled assimilates in wheat plants inoculated with Ophiobolus graminis was examined following exposure of the second youngest leaf to 14CO2. Autoradiographs of plants with infected seminal roots showed that assimilates were not translocated past the sites of root infection but accumulated in the undamaged portions of infected root systems, in particular the developing crown roots. There was no evidence that assimilates accumulated in the vicinity of O. graminis lesions.The net assimilation of 14CO2 by wheat plants over a 5 h feeding period was not significantly affected by O. graminis infection. However, infection reduced the amount of 14C lost through respiration. Infection delayed the transfer of labelled assimilates from the fed leaf to the remainder of the plant but increased the proportion translocated to the roots. The latter effect was not apparent when infected plants were continuously irrigated during, and for 20 h following, the feeding period.
Relationships between a parsley virus, nasturtium ringspot virus and broad bean wilt virus*
Authors: FROWD J. A. , TOMLINSON J. A. 
Published: February 2008

SUMMARYA non‐persistent, aphid‐transmitted virus (PV3) found in parsley in Britain was cultured in Chenopodium quinoa. It was mechanically transmissible, relatively stable in vitro and had polyhedral particles approximately 30 nm in diameter.Virus particles occurred within the cells as crystals, scrolls and tubular structures. In purified preparations, virus particles were mostly aggregated, especially in the presence of salts.PV3, nasturtium ringspot virus and broad bean wilt virus were found to be closely related serologically.
The translocation of herbicide from bean (Viciafaba) to broomrape (Orobanche crenata)
Authors: WHITNEY P. J. 
Published: February 2008

SUMMARYApplication of 14C‐labelled 2,4‐D to bean plants parasitized by broomrape led to a concentration of the herbicide in the immature parasite that was up to fourteen times that in the bean root. Not all substances are translocated in this way. 22Na in sodium chloride was not moved in significant amounts away from the site of application, but sucrose was found to be translocated to the parasite.Application of 2,4‐D,2,4,5‐T, N.A.A. and D.N.P. to mature Orobanche under field conditions had little effect.2,4‐D is not considered a suitable herbicide for the control of Orobanche in bean crops because of the high sensitivity of the host of this compound. It is thought, however, that the application to the host of a systemic herbicide which becomes concentrated in the parasite to a toxic level could well be an efficient way of controlling this type of parasite.
An assessment of some new treatments for the control of rotting of stored apples
Authors: BURCHILL R. T. , EDNEY K. L. 
Published: February 2008

SUMMARYBenomyl (0.025% a.i.) and thiabendazole (0.05 % a.i.) applied in July, August and September to apple trees cvs. Sunset and Cox's Orange Pippin gave slightly better control of Gloeosporium spp. rots in stored fruit than captan (0.1% a.i.) applied at similar intervals. On Cox's Orange Pippin, treatment with captan at 0.1 % a.i. in July and at 0.2% a.i. in August was as effective as three sprays at 0.1 % a.i. in July, August and September in controlling both Gloeosporium spp. and Nectria galligena rots. Benomyl applied in the spring and early summer to control apple scab on orchard trees reduced the incidence of Gloeosporium spp. and Monilia fructigena in stored fruit. Pre‐harvest sprays of benomyl and captan gave good control of rotting caused by N. galligena but thiabendazole was ineffective. Post‐harvest dips of thiabendazole controlled rotting by Gloeosporium spp. butnot byN. galligena.
Specificity and host specialization of Puccinia chondrillina
Authors: HASAN S. 
Published: February 2008

SUMMARYVarious strains of Puccinia chondrillina, the Chondrilla rust, were collected during surveys in the Mediterranean, undertaken to discover biological control agents suitable for use in Australia against skeleton weed, Chondrilla juncea. Only the strain collected at Vieste (S.E. Italy) was highly virulent against the common Australian form of C. juncea. The specificity of this strain of the rust was tested by inoculation of many unrelated cultivated plants, related cultivated plants and closely related wild plants; all were immune to the rust. These tests satisfied the Australian plant quarantine authorities and this strain of the rust has now been introduced into Australia as a biological control agent for C. juncea.
Resistance to Rhynchosporium secalis in the winter barley cultivar Vulcan
Authors: HABGOOD R. M. 
Published: February 2008

SUMMARYThe six‐rowed winter barley cultivar Vulcan was found to be highly resistant to Rhynchosporium secalis in the field, although this resistance was not apparent in routine screening tests of barley genotypes carried out at the seedling stage. More precise seedling tests, using graded inoculum levels to derive dose‐response curves, showed that cv. Vulcan had an ED50 which was 4.8 times that of the susceptible, two‐rowed cv. Maris Otter, and 4.1 times that of cv. Maris Puma.The inheritance of resistance was investigated at the adult plant stage in a cross with cv. Maris Otter. Although a clear‐cut segregation of the F3 progeny into resistant, segregating and susceptible phenotypes was not observed, the genetic variance of the F3 family means was compatible with the hypothesis of monogenic control of resistance. Resistance was inherited independently of the factor for six‐rowed head type.
Secondary leaf fall of Hevea brasiliensis: meteorological and other factors affecting infection by Colletotrichum gloeosporioides
Authors: WASTIE R. L. 
Published: February 2008

SUMMARYThe lower leaf surface of Hevea brasiliensis was more susceptible to infection by Colletotrichum gloeosporioides than the upper. Few lesions were produced if spore drops on susceptible leaves were allowed to dry. Lesion development after 72 h was quickest at 21 oC, slower at 26.5 oC and was stopped at 32 oC, probably because of bacteria in the inoculation drop. On leaflets aged 7 days from bud‐burst, the effective spore dose for 50% of leaflets infected (ED50) after 16 h incubation, was 260 spores and after 46 h, 120 spores/infection droplet; the minimum ED50 for the upper leaf surface was about 4 spores/mm2. Leaflets 15 days old, which are normally resistant, were rendered susceptible by abrading the surface with carborundum powder.Spores caught in a Hirst spore trap reached a daily maximum at 23 h, at rates of up to 440 spores/m3 air/h, but fell to low concentrations as the humidity dropped during the daytime, and also during rain. There was some correlation between disease severity and duration of 97–100% relative humidity, and moderate to severe defoliation of clone PB 86 occurred when this reached 13.5 h/day. Rainfall increases infection by prolonging the period of atmospheric saturation and leaf wetness.
The effect of pH and composition of test solutions on the inhibitory activity of wyerone acid towards germination of fungal spores
Authors: DEVERALL B. J. , ROGERS PAMELA M. 
Published: February 2008

SUMMARYWyerone acid at 100μg/ml prevented germination of conidia of Botrytis cinerea Fr. in aqueous extracts of leaves of Vicia faba L., but it was inactive in water and some synthetic nutrient solutions though antifungal activity appeared when the pH of these media was adjusted to 4.0 or 4.5. In pollen diffusates (V.faba or Nicotiana glutinosd) wyerone acid had little activity even at pH 4.0. In malt extract at pH 4.5 wyerone acid was active against several other plant pathogenic fungi but not against B. cinerea. It was concluded that both pH and unknown components of natural media affected the fungitoxicity of wyerone acid.
Control of potato cyst‐nematode, Heterodera rostochiensis, in peaty loam soil by D‐D, aldicarb and a resistant variety of potato
Authors: WHITEHEAD A. G. , TITE D. J. , FRASER JANET E. , FRENCH EILEEN M. 
Published: February 2008

SUMMARYIn peaty loam soil in Cambridgeshire, 5.2 or 10.3 kg aldicarb/ha incorporated in the top‐soil before potatoes were planted controlled potato cystnematode (Heterodera rostochiensis Woll.) better than 384, 769 or 1153 kg D‐D/ha injected 15 cm deep into the top‐soil in the preceding autumn. 10.3 kg aldicarb/ha applied in 1968 and 1969 permitted King Edward potatoes (susceptible to H. rostochiensis) to grow well in infested soil and prevented multiplication of pathotypes of H. rostochiensis on Maris Piper potatoes (resistant to H. rostochiensis pathotype A). Although large amounts of D‐D applied in 1968 and 1969 increased the yield of King Edward potatoes in both years they did not control potato cyst‐nematode in the second year.
Changes in growth‐substance contents during growth of wheat grains
Authors: WHEELER A. W. 
Published: February 2008

SUMMARYSamples of developing wheat grains were extracted at weekly intervals from ear emergence until maturity and the growth substances estimated by bioassay. Immature grains contained two cytokinins; one was similar to zeatin and another, with more cytokinin activity, had different properties. Ovules contained only small amounts of growth substances but at the end of anthesis the grains had a maximum content of cytokinin. The gibberellin content increased until 3 wk after anthesis then decreased; their auxin content increased until 4 wk after anthesis but decreased as the grains ripened and lost fresh weight. The husks contained smaller amounts of growth substances than the grains they surrounded. Exudates from young stems contained cytokinins and these may originate in the roots and move to the ears through the stems. The auxin in the grains was identified as indole‐3yl‐acetic acid and may be derived from the phenols present reacting with tryptophan.
Some effects of crowding on the biology of Megoura viciae
Authors: BONNER A. B. , FORD J. B. 
Published: February 2008

SUMMARYCrowdingMegour a viciae(Buckton) on bean plants affects both the nymphs and adults. Crowded nymphs show a low mortality, develop more rapidly to produce light adults after a series of synchronized moults: isolated nymphs show a high initial mortality, develop more slowly to heavier adults, the duration of nymphal stages being extremely variable, with no synchronization of moulting. Development is discussed in terms of both weight gain and linear growth rate.Crowding does not affect adult mortality but it does reduce the rate at which nymphs are produced. The significance of these findings in relation to the formation and maintenance of the aphid colony is considered, and possible controlling factors are discussed.
The extent and survival of contamination of potato stocks in Scotland by Erwinia carotovora var. carotovora and E. carotovora var.atroseptica*
Authors: PÉROMBELON M. C. M. 
Published: February 2008

SUMMARYThe following results were obtained when fifty‐seven bulk and crate‐stored commercial seed potato stocks from the East of Scotland were examined in 1966‐8 for contamination by pectolytic Erwinia spp. (1) Most tubers of all the cultivars and stocks examined, irrespective of whether they were obtained from blackleg‐infected or blackleg‐free crops, were contaminated with E. carotovora; (2) some 80% of the Erwinia isolates obtained were identified as var. atroseptica, the rest being var. carotovora; (3) the organisms survived in and on tubers for 6–7 months of bulk storage over the winter and up to planting time the following spring; (4) contrary to what is generally thought, the high incidence of contamination of all stocks, while suggesting that the seed itself is the major source of E. carotovora for the growing crop, emphasizes that other factors affect manifestation of blackleg in the field and soft rot in store.
Studies on broccoli necrotic yellows virus
Authors: TOMLINSON J. A. , WEBB M. J. W. , FAITHFULL ELIZABETH M. 
Published: February 2008

SUMMARYElectron microscopy of infected D. stramonium cells showed that the virus particles occurred in the cytoplasm. Particles were mostly bacilliform and measured 297 ± 18 times 64 ± 4 nm. In negatively stained leaf homogenates, particles were mostly disrupted; intact particles measured 267 ± 20 times 69 ± 6 nm. In brussels‐sprout cells containing BNYV and CIMV, BNYV particles were rarely found compared with those of CIMV, and they occurred within and near CIMV inclusion bodies. BNYV particles were also found in extracts of virus‐carrying Brevicoryne brassicae.Broccoli necrotic yellows (BNYV) and cauliflower mosaic (CIMV) viruses occurred together in naturally infected Brussels sprout plants, which showed conspicuous symptoms, and in cauliflower. BNYV was transmitted to and maintained in Datura stramonium and Hyoscyamus niger. It was partially purified from D. stramonium. Using these preparations, from which inhibitor had been removed, BNYV was manually transmitted to cauliflower, causing mild symptoms, and to Brussels sprout, causing a symptomless infection. BNYV also infected Sinapis alba but not cabbage, lettuce, Sonchus oleraceus or Plantago major. BNYV was transmitted by Brevicoryne brassicae but not by Myzus persicae, Hyperomyzus lactucae or Aleyrodes proletella.
Deposition of spores and other particles on vegetation and soil
Authors: CHAMBERLAIN A. C. , CHADWICK R. C. 
Published: February 2008

SUMMARYThe rate of deposition of 20–30 μm diameter particles, including spores and pollen grains, on plant and other surfaces, is determined, first, by the frequency at which particles strike the surfaces and, secondly, by the proportion retained on the surface rather than rebounding into the airstream.Spores and pollen grains tagged with a radioactive marker were used to show that the impaction efficiency on leaves and stems depends very much on whether or not the surfaces are sticky or moist. If they are, the rate of deposition may approach that predicted aerodynamically. If the plant surfaces are dry, there is saltation of some spores and the effective rate of deposition is greatly reduced.
The effect of Tarsonemus fragariae Zimmermann (Acarina: Tarsonemidae) on strawberry yields
Authors: ALFORD D. V. 
Published: February 2008

SUMMARYExperimental plots, arranged within commercial strawberry fields, were used to study the effect of Tarsonemus fragariae infestations on strawberry yields. Yields and the mean weight of individual fruits were inversely related to mite infestation levels. Yield reductions of over 50% were attributable to this pest.
Some effects of darkness and partial defoliation on the resistance of sugar beet to downy mildew
Authors: RUSSELL G. E. , EVANS GWENLLIAN M. 
Published: February 2008

SUMMARYSeedlings of two susceptible sugar‐beet stocks were grown either in daylight or in darkness for 24 h before or after inoculation with Peronospora farinosa f.sp. betae. Post‐inoculation darkness did not significantly affect the percentage of inoculated plants that became infected but increased the percentage of plants on which the fungus sporulated in both stocks. The effects on sporulation of darkness before inoculation were more variable than those of post‐inoculation darkness.In the same stocks removal of all leaves, except those in the bud, before inoculation increased the percentage both of plants which became infected and of those on which P. farinosa sporulated. Infection and sporulation were not significantly affected by defoliation in a more resistant stock.Defoliation or darkness may have affected the concentration of certain sugars or amino acids in the bud leaves thereby changing the expression of polygenically‐controlled resistance to downy mildew.
Influence of organic soil amendments on Verticillium dahliae and on the microbial composition of the strawberry rhizosphere
Authors: JORDAN V. W. L. , SNEH B. , EDDY B. P. 
Published: February 2008

SUMMARYA technique was developed for assessing the saprophytic activity of Verticillium dahliae, using a strawberry root extract medium. The germination of conidia and microsclerotia, and mycelial growth in soil, was inhibited by the addition of chitin, laminarin, wheat straw and oven‐dried green clover as soil amendments. A significant decrease in the number of viable propagules of the pathogen counted from soil, and in disease severity, was obtained with chitin and laminarin. More bacteria and actinomycetes were recorded from the rhizosphere of plants grown in chitin‐amended soil than from those in natural soil.
Field studies on halo‐blight of beans (Pseudomonas phaseolicola) and its control by foliar sprays
Authors: TAYLOR J. D. 
Published: February 2008

SUMMARYIn 1968 when conditions were favourable for the spread of infection (rainfall 243 mm June‐August), halo‐blight of beans initiated from 0.38% primary infection produced 33.8% infected pods but in 1969 (rainfall 112 mm June ‐August+38 mm irrigation water), a similar level of primary infection resulted in only 3.2% infected pods. In both years plant and pod infection were reduced by approximately 90% by sprays of streptomycin sulphate or copper oxychloride (0.1% a.i. 60 gal/acre (675 l/ha)) applied every 10 days from seedling emergence to flowering time.
Effects of ammonium and nitrate nutrition or take‐all disease of wheat in pots
Authors: HORNBY D. , GORING C. A. I. 
Published: February 2008

SUMMARYPlant debris, naturaiiy infested with the take‐all fungus (Ophiobolus graminis), was washed from soil and added to a leached sandy loam, deficient in nitrate nitrogen (NO3‐N) and magnesium. Nutrient solutions containing potassium and phosphorus, with and without magnesium, were added to the amended soil unsupplemented, or with either NO3‐N, ammonium nitrogen (NH4+‐N), or both. Nitrification of NH4+‐N was inhibited by 2–chloro‐6–(trichloromethy1)‐pyridine (N‐Serve). After 38 days at 19°C, fewer plants had take‐all with N (75 or 100 mg/kg soil) than without and root systems were most discoloured and had most diseased axes when nutrients were not added. Plants given NH4+‐N developed less take‐all when magnesium was present. A comparison of forms of N in the presence of added magnesium showed that take‐all was least with a mixture of both forms of N, intermediate with NO3‐N alone and worst with NH4+‐N alone. The most extensive lesions on individual root axes occurred on plants given NH4+‐N. It is suggested that take‐all will be least when the amounts and ratio of NH4+‐N and NO3‐N are optimum for the growth of the host.
Similar effects of suspensions of copper oxychloride and kaolin on sprayed leaves*
Authors: EVELING D. W. 
Published: February 2008

SUMMARYWhen dried on leaves, aqueous suspensions of copper oxychloride and of kaolin damaged the leaves similarly. With both, the damage was correlated with the rate the leaves lost water, which increased as the size of the suspended particles of copper oxychloride decreased. The damage seemed to arise mainly from a physical effect of the particles and not from copper reacting chemically.