bluuebunny/crossref_metadata_2025_split huggingface dataset:
Distribution of trichodorid nematodes in Great Britain
Authors: ALPHEY T. J. W. , BOAG B. 
Published: February 2008

SUMMARYThis survey describes the distribution of trichodorid nematodes in Great Britain. Twelve species were recorded, including the newly described species Trichodorus hooperi Loof, 1973 and the first British record of T. sparsus Szczygiel, 1968. In the survey 3614 samples and records were analysed using the Statistical Package for Social Sciences computer programme. Seven hundred and ninety‐two positive sites, containing 971 trichodorid populations, were located. Outline maps show the geographical distribution of each species. T. primitivus de Man, 1880 was the most commonly found species and had a cosmopolitan distribution. Paratrichodorus pachy‐dermus Seinhorst, 1954 was the next most prevalent and occurred mostly in eastern England and Scotland. Populations of the other ten species were more restricted in both number and distribution. The distribution of trichodorid spp. with respect to altitude, soil type, pH and primary vegetation was tested using chi‐squared contingency tests. A significant relationship between nematodes and environmental factors was found in all cases examined. However, interactions were found between several environmental factors and further tests were applied to study the independence of the species distributions with respect to these interactions.
Synchronization of germination of celery seeds
Authors: SALTER P. J. , DARBY R. J. 
Published: February 2008

SUMMARYThe effects of osmotic pre‐treatments on the germination response of celery seeds were studied in a series of experiments designed to optimize that treatment. The experimental variables were different osmotica (polyethylene glycol (PEG) or a mixture of potassium nitrate and tri‐potassium orthophosphate), levels of osmotic potential, temperature and duration of treatment. The rate and synchronization of germination were very significantly improved by many of these pre‐treatments but the maximum effects on cv. Lathom Blanching were obtained by treating the seeds with a solution of the salt mixture of c.–10 bars potential at 15 °C for 21 days. This treatment resulted in 50 % germination of the viable seeds within 1–4 days at a temperature of 20 °C compared with 13‐7 days from the untreated seeds. There were indications that the optimum pre‐treatment may vary somewhat between varieties and seed stocks. The results showed that the effects of the two osmotica on germination response were similar, thus enabling a technique to be developed for treating, with the salt solution, larger quantities of seed and germinating them prior to fluid drilling in the field.
Selection of perennial and Italian ryegrass plants resistant to ryegrass mosaic virus
Authors: GIBSON R. W. , HEARD A. J. 
Published: February 2008

SUMMARYPerennial ryegrass plants collected from fields and Italian ryegrass plants grown from seed were selected for resistance to infection by ryegrass mosaic virus (RMV) by repeated manual inoculation. Two of 108 perennial ryegrass plants and one of 150 Italian ryegrass plants were symptomless after seven and nine inoculations respectively. These three plants were propagated vegetatively. Plants of the two perennial ryegrass clones showed no symptoms after further manual inoculations with the initial isolate of RMV, or with an inoculum from infected plants collected from several fields, or after inoculation by viruliferous mites. Electron microscopy and back tests indicated that the plants were virus free.Some plants of the selected Italian ryegrass clone became infected after a further inoculation with mites or sap, but fewer than similarly inoculated unselected plants.
Cultivated and wild host plants supporting populations of the cabbage root fly
Authors: FINCH S. , ACKLEY CHRISTINE M. 
Published: February 2008

SUMMARYTo determine the relative importance of different potential host plants for supporting populations of the cabbage root fly, wild and cultivated crucifers were sampled for pupae at four locations during 1971‐3. In addition, eighty‐three species of Cruciferae native to or naturalized in the British Isles were inoculated with cabbage root fly eggs in a glasshouse to determine which species could support the larvae.In the field, most pupae (28‐7/plant) were collected from untreated cauliflowers. Fewer pupae (i‐7–8‐6/plant) were obtained from untreated crops of Brussels sprout, cabbage and swede. Applications of chlorfenvinphos reduced populations to two or less pupae per plant on all crops. Of five common weed species sampled, only Raphanus raphanistrum produced as many pupae as certain of the untreated brassica crops. Pupae did not occur in samples from Capsella bursa‐pastoris but Sisymbrium officinale, Thlaspi arvense and Sinapis arvensis usually supported low numbers.In the glasshouse, only forty‐four of the eighty‐three cruciferous species tested supported larval development. Most pupae were obtained from 12‐wk‐old plants of Barbarea intermedia. B. stricta, Brassica napus, Cochlearia officinalis and R. raphanistrum and from 24‐wk‐old plants of Brassica rapa, Erysimum aureum, Cochlearia anglica and C. officinalis. Plant age considerably affected pupal production. Plants within a genus often gave similar results, pupae not being recovered from any of the Diplotaxis or Arabis species tested, or from young plants of Erysimum spp. In other families, Reseda lutea and R. luteola supported larval development, but the widely‐separated Plantago major did not.Arguments for and against the removal of cruciferous weeds from the vicinity of cruciferous crops are discussed.
Glitoria yellow vein virus, a tymovirus from Kenya
Authors: BOCK K. R. , GUTHRIE E. J. , MEREDITH GINA 
Published: February 2008

SUMMARYClitoria yellow vein virus (CYW) was found in Clitoria ternatea and Abrus precatorius in coastal districts of Kenya, but was not detected in food legume crops. When transmitted by inoculation of sap, CYW infected many species in the Papilionaceae, commonly causing yellowing of secondary and smaller leaf veins. All the economically important food legumes grown in the area of occurrence were very susceptible, so that CYW is potentially very important. The virus also infected okra (Hibiscus esculentus) and species in the Solanaceae, but none of many species of Cucurbitaceae.CYW is serologically closely related to cocoa yellow mosaic and kennedya yellow mottle viruses, and more distantly to okra mosaic and desmodium yellow mottle viruses. Other properties of CYW^ typical of the tymoviruses include particle morphology (particle diameter c. 28 nm; two components) with sedimentation coefficients of 50S (top) and 109S (bottom); molecular weight of protein sub‐units c. 20000; thermal inactivation point c. 72 oC; and longevity in vitro c. 3 wk.
Chemical control of onion fly, Delia antiqua
Authors: SAYNOR M. , HILL D. S. 
Published: February 2008

SUMMARYIn nine trials done in 1972‐4 seed treatments reduced attacks of onion fly larvae very effectively and most of the organophosphorus formulations gave protection up to harvest, 12–17 wk after sowing. Pirimiphos‐ethyl and isofen‐phos each at 10 or 20 g a.i./kg seed controlled onion fly larvae well and they were not seriously phytotoxic in any of the trials. Chlorpyrifos, trichloronate, ethion, iodofenphos, chlorfenvinphos wettable powder or triazophos all at iog a.i./kg seed were also effective, but they were tested in fewer trials. Diazinon at 10 or 20 g a.i./kg seed, carbophenothion and chlorfenvinphos liquid seed dressing at 10 g a.i./kg seed controlled onion fly well, but in some trials they were phytotoxic; methiocarb, mecarphon and oxamyl were much less effective.At 1–12 kg a.i./ha chlorfenvinphos granules applied over the rows shortly before the attack was expected was the best granular formulation, but it was not as effective as the better seed treatments.
Root and shoot development in peas
Authors: ALI‐KHAN S. T. , SNOAD B. 
Published: February 2008

SUMMARYSeven root and shoot characters of young pea (Pisum sativum and Pisum fulvum) seedlings were analysed to study genetic variability and to obtain measures of heritability in the broad sense. Considerable genetic variation was noted in all characters studied in the thirty genotypes with the length of the main root showing the greatest variability. Estimates of heritability exceeding 50 % were noted for the number of laterals, length of shoot, weight of root and weight of shoot. Seed weight was significantly correlated only with length of longest lateral and weight of root. The length of the longest lateral and the length to the last lateral were correlated with most other characters.
Performance of carbendazim formulations injected for the control of Dutch elm disease
Authors: CLIFFORD D. R. , COOKE L. R. , GENDLE P. , HOLGATE M. E. 
Published: February 2008

SUMMARYFormulations of carbendazim, containing varying mineral acid concentrations, injected into elm trees were evaluated for their protectant and eradicant activities against Dutch elm disease. Those with high acid contents were the best protectants but none was entirely successful as an eradicant.The distribution of carbendazim within elm trees was erratic and there was a large fall‐off in available fungitoxicant within the twigs 55–97 days after injection.
Bioassay of residues on Cox's Orange Pippin apples following summer sprays of benomyl
Authors: MURRAY R. A. 
Published: February 2008

SUMMARYBioassay of residues of benomyl applied as orchard sprays has demonstrated the persistence of fungicide on apple fruits. Surface concentrations of fungicide from June applications were 60 % of those from July and August applications; this difference may be related to the relative sizes of fruits and leaves. The harvest residues were low and even after post‐harvest dipping, were well within acceptable levels.
The control of Gloeosporium storage rot of apple by reduced spray programmes
Authors: EDNEY K. L. , BURCHILL R. T. , CHAMBERS D. A. 
Published: February 2008

SUMMARYSingle sprays of benomyl (0.025 % a.i.) applied to Cox's Orange Pippin apple in either June, July or August, controlled rotting in store by Gloeosporium spp. Post‐harvest dips of either benomyl (0.05 % a.i.) or thiabendazole (0.025 % a.i.) effectively controlled any infection surviving orchard treatment.
Effects of organomercury treatment of wheat seed on Fusarium seedling disease in inoculated soil
Authors: BATEMAN G. L. 
Published: February 2008

SUMMARYIn growth room experiments, treatment of wheat seed with phenyl mercuric acetate significantly reduced seedling disease caused by soil‐borne Fusarium culmorum, F. nivale and F. avenaceum in inoculated soil. Seed treatment improved the low germination caused by F. culmorum, but did not affect the reduced seedling vigour caused by F. nivale. Seed treatment was normally as effective in conditions favouring disease as it was in less favourable conditions. Conditions favouring disease in soil inoculated with F. culmorum were high inoculum level, deep sowing and dry soil.
Seed treatment for the control of halo‐blight of beans (Pseudomonas phaseolicola)
Authors: TAYLOR J. D. , DUDLEY C. L. 
Published: February 2008

SUMMARYStreptomycin and kasugamycin were applied as soaks, slurries or dusts to dwarf bean seeds either naturally (internally) infected or externally contaminated with Pseudomonas phaseolicola. Slurries of streptomycin (2–5 g a. i./kg seed) or kasugamycin (0–25 g a.i./kg seed) were the most effective treatments against both types of infection and were generally non‐phytotoxic at these rates. Combined analysis of eight field experiments made over a 3 yr period showed that on average both compounds applied in slurries reduced primary infection from infected seeds by 98 %. The method thus shows considerable promise as a commercial control treatment.
The effects of rootstock and scion on tobacco mosaic virus infection in susceptible, tolerant and immune cultivars of tomato
Authors: ARROYO A. , SELMAN I. W. 
Published: February 2008

SUMMARYReciprocal grafts were made between tomato cultivars Potentate, susceptible, and Virocross, tolerant (heterozygous for resistance gene Tm‐i) to tobacco mosaic virus (TMV) isolates of Pelham type o and between isogenic lines of cv. Craigella, susceptible and homozygous for gene Tm‐i. The grafted plants were inoculated with a type o isolate; both scion and stock inoculation were studied in the former, scion inoculation only, in the latter. With scion inoculation the virus content of a tolerant scion was greater on a susceptible stock than on a tolerant one, but that of a susceptible scion was unaffected by the type of stock: in contrast, the virus content of a tolerant stock was unaffected by the type of scion but that of a susceptible stock was less with a tolerant than with a susceptible scion. With root inoculation the virus contents of both tolerant and susceptible scions were greater on a susceptible than on a tolerant stock.With cv. Craigella the genotype Tm‐1/Tm‐1 was found to be immune to the type o isolate used, but in grafts the leaves of Tm‐1/Tm‐1 scions became tolerant to leaf inoculation when on susceptible stocks and the virus entered the stock. Tm‐1/Tm‐1 stocks became infected when attached to infected, susceptible scions and did not affect the virus content of those scions.The results indicate that a susceptible healthy stock may change the reaction of a tolerant or immune scion to infection by a strain of TMV.
Some pathological aspects of narcissus basal rot, caused by Fusarium oxysporum f. sp. narcissi
Authors: PRICE D. 
Published: February 2008

SUMMARYExcavations of ridge‐grown narcissus showed that most roots were beneath the bulbs and that few extended sideways to the next ridge. Root senescence preceded leaf senescence and moribund roots were available for colonization by Fusarium oxysporum f. 8p. narcissi when soil temperatures became favourable for the pathogen. Inoculation experiments with 1 and 2 yr crops showed that some inoculum is redistributed during the first season to allow increased disease incidence in the second. In 2yr crops, some bulbs rot without trace so that true disease incidence in a stock is greater than is indicated by examination of lifted bulbs.
The development of silver scurf (Helminthosporium solani) disease of potato
Authors: JELLIS G. J. , TAYLOR G. S. 
Published: February 2008

SUMMARYThe main source of inoculum of Helminthosporium solani was the seed tuber; the fungus was not detected in soils in which infected potatoes had been grown the previous year. Lesions spread rapidly on seed tubers after planting, so that within a few weeks the entire surface was covered. As lesions aged they lost the capacity to sporulate, so most inoculum was produced in the first few weeks after planting. Infection of progeny tubers was first detected at the heel (stolon attachment) end soon after their initiation. Once established, lesions spread slowly on the surface of progeny tubers when in the soil; more rapid spread took place during storage. Potatoes which seemed unaffected at lifting became diseased during storage.
Race non‐specific resistance of oats to primary infection by mildew
Authors: CARVER T. L. W. , CARR A. J. H. 
Published: February 2008

SUMMARYA range of oat species, species hybrids and derived addition lines, varied in their level of race non‐specific resistance to mildew. This resistance prevented attempted primary penetration by a proportion of spores. It was generally expressed more strongly in fifth than in first formed leaves and thus appeared to be a component of adult plant resistance. Penetration was most frequently arrested at the infection peg stage, implicating the papilla formed by the host as a defence mechanism. Epidermal cells close to stomata were more commonly invaded than others, but only in two of ten lines examined was preferential stomatal subsidiary cell infection observed. Where penetration was successful, host resistance could operate by arresting infections prior to the establishment of functional host/pathogen relations. In hybrids between resistant wild species and a susceptible cultivated oat, the level of both forms of resistance was reduced, indicating a similar effect of the susceptible host genome on genes conditioning both resistances.
Control of silver scurf (Helminthosporium solani) disease of potato with benomyl and thiabendazole
Authors: JELLIS G. J. , TAYLOR G. S. 
Published: February 2008

SUMMARYBenomyl and thiabendazole, applied as dusts to seed potatoes before chitting (sprouting), reduced the incidence of silver scurf disease on the progeny at lifting and during subsequent storage. Treatment of seed tubers 4 months prior to planting almost completely suppressed sporulation during storage, even under conditions very favourable for the growth of the fungus.The fungicides appeared not to act systemically because developing tubers grown from treated seed were just as susceptible to infection after inoculation as those from untreated. Control was due to effective inhibition of sporulation on the surface of diseased seed tubers after planting.There was no reduction in the amount of disease in subsequent generations of potato crops without further fungicidal treatment. Seed virtually free from silver scurf, produced from seed treated with fungicide in the previous year, yielded progeny with as much disease as progeny from untreated seed stocks.
Accumulation and metabolism of aldicarb by the free‐living nematodes Aphelenchus avenae and Panagrellus redivivus
Authors: BATTERBY S. , LE PATOUREL G. N. J. , WRIGHT D. J. 
Published: February 2008

SUMMARYThe accumulation and metabolism of aldicarb has been compared in two species of free‐living soil nematodes, Aphelenchus avenae and Panagrellus redivivus, which differ considerably in their sensitivity to this and other pesticides. Similar levels of aldicarb were found to accumulate in the two species. The results showed that although the rate of uptake of aldicarb was greater in P. redivivus, so also was the rate of metabolism and elimination. Levels of toxic metabolites of aldicarb were two to three times higher in the more susceptible species A. avenae after 24 h incubation than in the less susceptible P. redivivus. The toxicological significance of these findings is discussed in relation to previous work with the organophosphorus pesticide phorate and its effects on the same two nematode species.
Effects of Poa trivialis, Stellaria media and Rumex obtusifolius on the growth of Lolium perenne in the glasshouse
Authors: GIBSON D. I. , COURTNEY A. D. 
Published: February 2008

SUMMARYIn glasshouse experiments shoot dry weight, leaf area and tiller number of Lolium perenne, cv. S. 24, were compared when grown in monoculture and in competition with Poa trivialis, Stellaria media or Rumex obtusifolius at a range of densities and for different time intervals. The results showed that S. media and R. obtusifolius were more competitive than P. trivialis. Competition effects with S. media and R. obtusifolius appeared between the 4 and 6 wk stage, coinciding with the production of the first S. 24 tillers. Spraying with 2,4‐D (0·84 kg acid equivalent/ha) for control of R. obtusifolius did not decrease grass yield whereas mecoprop (2·80 kg a.e./ha) for control of S. media damaged young L. perenne. It appeared that the optimum time for mecoprop treatment was between 4 and 6 wk after sowing when tillering had commenced. At this stage weed competition was only beginning and crop tolerance to the herbicide was adequate.
Beetle, contact and potato true seed transmission of Andean potato latent virus
Authors: JONES R. A. C. , FRIBOURG C. E. 
Published: February 2008

SUMMARYA species of the flea beetle (Epitrix sp.) transmitted Andean potato latent virus (APLV) from Datura stramonium to D. stramonium, Nicandra physalodes and potato, and from N. physalodes to N. physalodes and D. stramonium. Although the acquisition and inoculation feeding times used were varied, this transmission always occurred at low efficiency. By contrast, APLV was very readily transmitted in tests in which infected plants of D. stramonium, N. physalodes, Nicotiana bigelovii and potato were brushed against healthy plants of one or more of these species. A low level of seed transmission of APLV occurred in potato.
Studies on the effect of gamma radiation (from Cobalt 60 source) on storage life of white yam (Dioscorea rotundata var. efon) infected with Scutellonema bradys
Authors: ADESIYAN S. O. 
Published: February 2008

SUMMARYStudies on the effect of gamma irradiation on yam tubers infected with Scutellonema bradys showed that dosages between 5 and 15 krad did not eliminate the nematodes completely, but suppressed sprouting and signs of deterioration in the tubers. Dosages between 20 and 30 krad eliminated 70–80 % of the nematode population in yam peels. The appearance and taste of yams treated with between 7·5 and 15 krad were generally acceptable to a panel of tasters.
The effect on grain yield of adult plant resistance to mildew in oats
Authors: JONES I. T. 
Published: February 2008

SUMMARYLines were selected from progeny of the crosses Maldwyn × Milford and Maldwyn × Sun II which consistently exhibited small and large amounts of mildew in similar situations. These are referred to as ‘low’ and ‘high’ mildew lines respectively. In small plot field trials conducted in 1971, 1972 and 1973 the low mildew lines produced substantially more grain each year compared with the high mildew lines in plots where mildew was allowed to develop normally. In plots which were kept comparatively free from infection by spraying with tridemorph, both low and high mildew lines gave similar yield.When the unsprayed plots were compared with the sprayed plots the low mildew lines invariably showed very small losses in grain yield and the high mildew lines usually very large losses. This same trend was evident also in the parent cultivars in 1972. Maldwyn, with only 7·9% mildew cover in the unsprayed plots due to its resistance, suffered a decrease of only 9·2% in grain yield compared with losses of 17·1 and 20·3% in the more susceptible cultivars Milford and Sun II.Certain lines and cultivars sustained heavy levels of mildew without corresponding loss of grain yield, i.e. showed low sensitivity to the disease. The importance of combining low sensitivity (or tolerance) with adult plant resistance to mildew is discussed.
Genetic analysis of several traits in potatoes by means of a diallel cross
Authors: KILLICK R. J. 
Published: February 2008

SUMMARYGenetic variation for nine traits of importance in potatoes was analysed in a half‐diallel set of crosses with six parents. General combining ability (GCA) effects were responsible for differences in maturity. For the other traits (yield, number of tubers, mean tuber weight, percentages of cracked and diseased tubers, texture and blackening following cooking and specific gravity) special combining ability (SCA) was important. The correlations between the traits were calculated. The implication for breeding is that trial crossing would be necessary to identify progenies with good potential. The analyses revealed associations between traits which are potentially useful to the breeder.