bluuebunny/crossref_metadata_2025_split huggingface dataset:
Carbon dioxide evolution as a measure of attack of wood by fungi and its application to testing wood preservatives and sap stain preventives
Authors: SMITH R. S. 
Published: February 2008

SUMMARYA method of assessing fungal attack on wood, using a conductivity respirometer to measure the CO2 evolution of the attacking fungus, is described and its application to the testing of wood preservatives and sapstain preventives is explored.Tests made by this method established in 9–13 days that the minimum fungitoxic concentration of Timbor (disodium octaborate decahydrate) was between 0·05 and 0·1%—a value agreeing with that given by the standard wood‐block test lasting 12 weeks.The use of the CO2‐measurement method for fungitoxicity determinations on a copper‐chrome‐arsenate wood preservative and on the sapstain preventive, Santobrite (a sodium pentachlorophenate preparation), gave unsatisfactory results.
Studies on the transmission of groundnut rosette virus by Aphis craccivora Koch
Authors: WATSON MARION A. , OKUSANYA BOLAJOKO A. M. 
Published: February 2008

SUMMARYFour strains of groundnut rosette virus were transmitted by a race of Aphis craccivora (Koch) from groundnut in Nigeria. Two of these strains, both from East Africa, were transmitted only by A. craccivora from Kenya. A fifth isolate, from Nigeria, was not transmissible by either race. The two races of aphids have been shown elsewhere to be distinct biotypes.Most A. craccivora needed longer than 24 h feeding on infected groundnuts to acquire virus, and many needed 2–3 days of feeding on healthy plants to cause infection, even after several days on infected plants. The delays partly reflect the slow uptake of virus and possibly a period needed for virus multiplication in aphid tissue but some is lost through resistance of the test plants to infection.In consecutive feeding experiments Natal Common variety could be infected soon after aphids had left the source of virus, but a more resistant Nigerian variety sometimes needed several more days. The frequency of inoculation by aphids, or the concentration of virus in the inocula or both, increased with time, but the times at which aphids were able to infect plants was also dependent on variety.
The use of steam/air mixtures for partially sterilizing soils infested with cucumber root rot pathogens
Authors: DAWSON J. R. , KILBY A. A. T. , EBBEN MARION H. , LAST F. T. 
Published: February 2008

SUMMARYAn apparatus for experimentally heating glasshouse soils in situ with steam/ air mixtures is described. Covering soil with a rigid hood enabled mixtures to be introduced at ground level at pressures sufficient to give reasonable rates of heat penetration.Heat‐treating soils (66–100° C), in which cucumbers had previously grown poorly, increased yields of subsequent crops from (1) 33 to 39/43 kg/plot of four plants and (2) 95 to 178/191 kg/plot. These increases were associated with the eradication of a dark sclerotial pathogenic fungus causing tap root rot.Increasing partial sterilization temperatures increased concentrations of soluble and exchangeable soil Mn from 4 p.p.m. in unheated soil to 9, 43, 87 and 108 p.p.m. at 66, 77, 88 and 100° C respectively, these differences being paralleled by concentrations of Mn in leaf laminae. Cucumbers grown in soils sterilized at 88° C yielded 8 % more than those in soils treated at 100° C.
The effects of length of the growth period and of nutrition upon potato‐tuber susceptibility to dry rot (Fusarium caeruleum)
Authors: BOYD A. E. W. 
Published: February 2008

SUMMARYStandardized inoculations of the potato varieties Catriona and Doon Star over 6 years have shown that shortening the growth period, either by deferring planting or by removing the haulm prematurely, may considerably reduce susceptibility of the tubers to dry rot (Fusarium caeruleum). Although these treatments reduce dry‐matter content of the tubers, no direct relationship between this factor and susceptibility was established.High pre‐maturity susceptibility was confirmed at the time of flowering; as the haulm matured susceptibility decreased: when the haulm was dead tubers were resistant. Within a fortnight after any time of premature haulm removal, tubers became completely resistant and showed a decrease in sucrose content but not in content of reducing sugars. It is suggested that susceptibility in the immature tuber is closely related to the content of sucrose, which accumulates because of rapid translocation from the vigorously growing haulm.After harvest, tuber susceptibility slowly increased during storage, with an increase mainly in reducing sugars, but these two factors were not directly related.An application of 6 cwt/acre (753 kg/ha) of 12:12:18 NPK fertilizer to Catriona significantly reduced liability to infection. Additional nitrogen (6 cwt/acre ammonium sulphate) raised tuber susceptibility to that in a non‐fertilized plot: when sulphate of ammonia was the only treatment given, the tubers were significantly more susceptible than those receiving complete fertilizer.
Vapour action of fungicides against powdery mildews
Authors: BENT K. J. 
Published: February 2008

SUMMARYCertain fungicides prevented the growth of powdery mildews at distances extending several millimetres beyond the edge of localized deposits on leaves. Most of the materials also acted at a distance when separated from the leaf by glass cover‐slips, indicating that the effect was due to the emission of vapour. In addition to sulphur and lime‐sulphur, whose vapour action is already known, fungicides based on drazoxolon, oxythioquinox, binap‐acryl, dinitro‐octyl phenyl crotonates and a phthalimido‐phosphonothionate were found to act in this way. Two systemic fungicides, griseofulvin and triamiphos, did not give a detectable vapour action. Tests were conducted mostly on open glasshouse benches. A draught from a fan shifted the zones of inhibition to one side of the deposits, but did not reduce their areas. Vapour effects were similar in extent on plants maintained at 18–25° C and at 27–32° C. Variation in the areas protected was studied in relation to the size and fungicide content of the deposits, to different powdery mildews, to time of incubation and to different types of formulation. Deposits applied to leaves by high‐ or low‐volume sprays at concentrations used in the field gave significant protection at a distance.Vapour effects were demonstrated also on mildew conidia incubated on glass slides bearing a spot of fungicide, and on infected plants placed in beakers coated on the bottom with fungicide.Movement of fungicides in the gaseous state is discussed in relation to the control of foliage diseases in the field.
Some observations on the economic importance of sugar‐beet downy mildew in England
Authors: BYFORD W. J. , HULL R. 
Published: February 2008

SUMMARYSugar‐beet downy mildew is most prevalent in England in the sugar‐beet and mangold seed‐growing area of South Lincolnshire and West Norfolk. The most widespread and severe recent outbreaks were in 1957, and in 1965 when 6412 acres were reported with more than 10% infected plants. The fungus usually overwinters in sugar‐beet and mangold seed crops, and in England other ways of overwintering are seldom important. Steckling beds are infected in the autumn, and the disease may increase rapidly in the seed crop in early spring. Summer‐sown stecklings get more downy mildew than stecklings sown in spring under a cereal cover crop, and direct‐drilled seed crops get more downy mildew than transplanted crops.
Resistance in maize to a third East African race of Puccinia polysora Underw
Authors: STOREY H. H. , HOWLAND AUDRIE K. 
Published: February 2008

SUMMARYIn 1961 a third race, EA. 3, of Puccinia polysora was recognized in Kenya. This was virulent to maize carrying either of the genes Rpp1 or Rpp2, previously isolated. Resistance to EA. 3 was found in many Central American maizes; in two, Andaqui (Colombia) and Zapalote Chico (Mexico), genes Rpp10 and Rpp11 were recognized. Rpp10 was fully dominant and its genotypes highly resistant to both EA. 1 and EA. 3. Rpp11 was incompletely dominant, but determined effective resistance to both races when homozygous.Experimental crosses gave no evidence of linkage between the genes Rpp1, Rpp10 and Rpp11.
Studies on plant growth‐regulating substances XXIV. Factors influencing kinetin‐induced phosphorus mobilization in detached radish cotyledonary leaves
Authors: ATKIN R. K. , WAIN R. L. 
Published: February 2008

SUMMARYKinetin treatment of localized areas of detached radish cotyledonary leaves was shown: (a) to defer the dry weight and chlorophyll declines that usually occur after leaf detachment; and (b) to promote the re‐distribution of phosphorus towards treated regions. These responses, which were most pronounced in leaves taken from 12‐day‐old plants, were much reduced in the light and were not found under anaerobic conditions. Kinetin‐induced responses were also inhibited in leaves pretreated with actinomycin D and ribonuclease.
Effects of growth regulators, CCC and B9, on some potato varieties
Authors: HUMPHRIES E. C. , DYSON P. W. 
Published: February 2008

SUMMARYThe effects of CCC and B 9 on the growth habit of potato differed between varieties. CCC diminished stem lengths and dry weight more than Bo because CCC was applied early when shoots emerged from the soil, but B 9 was applied about 3 weeks later when several leaves had formed.In some varieties lateral stem growth was increased by treatment and in others decreased. There was an inverse relation between main stem and lateral stem growth so that varieties with vigorous main stem growth had poor lateral growth and vice‐versa. Treatment with the growth‐regulators diminished leaf dry weight of main stem leaves less than leaf area, but the degree of magnitudes of the changes depended on the variety. Both regulators lessened net assimilation rate. Net assimilation rate and dry matter per unit area of leaf were inversely related, possibly because accumulation of substances in leaves decreases photosynthesis.Stolon dry weight was positively correlated with main stem leaf area. There was a direct relation between stem length and tuber dry weight, suggesting that tuber initiation occurs at different stem lengths in different varieties. Tubering was earliest in Epicure and latest in King Edward. Epicure had the greatest tuber weight and smallest stem length.
Effects of changes in environmental schedules on the penetration of leaves and epidermal strips of wheat seedlings by Puccinia graminis tritici
Authors: SHIPTON W. A. , BROWN J. F. , WHITE N. H. 
Published: February 2008

SUMMARYThe frequency with which intact leaves and epidermal leaf strips of wheat seedlings were penetrated by Puccinia graminis tritici, strain 21 Anz 2, was observed following exposure of inoculated material to various regimes of illumination/darkness and temperature.Epidermal strips, at 24°C, were penetrated most frequently when continuous light (540 ft‐c) was commenced at either 4 or 8,20 or 24, or 36 or 40 h after inoculation or when a 4 h period of light was applied at these times. With both treatments, the curve obtained when the length of the dark period preceding illumination was plotted against the frequency of penetration showed a series of alternate peaks and troughs and the periodicity of the curves was significant at the 1 % probability level. In the former curve the best form of regression was linear modified by a cosine function, while in the latter the linear term proved to be non‐significant. When dark periods of different lengths were applied, penetration was more variable on intact leaves than on epidermal strips. Penetration of intact leaves was influenced by the light intensity to which the seedlings were exposed after the dark treatment.The time of day when intact leaves were inoculated influenced penetration when they were grown under controlled conditions. Greatest penetration of the variety Little Club occurred when leaves were inoculated at 1.30 a.m. The time of day when epidermal strips were inoculated did not influence penetration.The inhibitory effect of continuous light on penetration of epidermal strips was overcome by changing the temperature from 18·5 to 24°C. Greatest penetration was obtained when the change was made 24 or 28 h after inoculation.
On cyst colour changes, bionomics and distribution of potato cyst‐eelworm (Heterodera rostochiensis Woll.) pathotypes in the East Midlands
Authors: GUILE C. T. 
Published: February 2008

SUMMARYPot tests and field trials in 1966 confirmed earlier observations that pathotype A potato cyst‐eelworm (Heterodera rostochiensis Woll.) showed marked colour differences from pathotypes B and C during development on the roots of susceptible potatoes. In hatching tests started in July, newly formed brown cysts of pathotype A released four times as many larvae as those of pathotypes B and C, without entering an immediate diapause; the latter produced larvae after a rest period of 18–21 days. Subsequent second‐generation cyst production in glass‐tube culture was greater from pathotype A. Field observations suggested that all pathotypes mature at about the same time and give rise to only one flush of cysts on both early and maincrop potatoes in the growing season.Cyst colour surveys in commercial crops, and pot and field trials using resistant potato selections, confirmed that pathotypes B and C are both dominant and widespread in the East Midlands.
The effect of resistant solanaceous plants on the sex ratio of Heterodera rostochiensis and the use of the sex ratio to assess the frequency and genetic constitution of pathotypes
Authors: TRUDGILL D. L. , WEBSTER J. M. , PARROTT D. M. 
Published: February 2008

SUMMARYThe sex ratios of two Heterodera rostochiensis populations were compared on fifteen solanaceous plants. Larvae did not mature in the roots of Atropa belladona, Datura stramonium or Nicotiana tabacum but adults were produced on the other plants, on some only males and on others, males and females. With two other populations, but not with a third, the percentage of larvae that became female on a potato hybrid with a dominant gene for resistance derived from Solanum tuberosum ssp. andigena increased during successive generations on the hybrid in accordance with the hypothesis that such larvae are double recessives (aa). Fewer larvae became adult in plants with two dominant genes for resistance than in plants with one, and such plants probably exerted selection of both males and females. A population from St Brelades (Jersey) produced fewer females and more males on the susceptible variety Arran Banner than did either the Thorney (Cambs.) or Aberystwyth populations. A much greater percentage of larvae from the St Brelades population became female on an ex andigena hybrid derived from CPC 1690 than on one derived from CPC 1685.
Extraction of Xiphinema and Longidorus species from soil by a modification of Cobb's decanting and sieving technique*
Authors: FLEGG J. J. M. 
Published: February 2008

SUMMARYA modification of Cobb's decanting and sieving technique is described which was found to combine speed of operation with efficiency when extracting Xiphinema and Longidorus species from a variety of soils. Standard times were set for sedimentation and the nematodes were collected on a bank of sieves each of 150 μ aperture (rather than of a range of apertures) before final separation from inert debris on a Baermann funnel.Preliminary tests showed that both time and temperature could have considerable effect on yield during the final separation stage. X. diversicaudaturn and X. vuittenezi showed different temperature optima at which the yield was up to twice that at other temperatures. Yields increased markedly with time over the first 20 h, but much less thereafter.
Morphology of the male reproductive system and spermatophore of the red bollworm, Diparopsis castanea (Hmps.) and the possible effect of the chemosterilant tepa on the gross structure
Authors: OUTRAM I. , CAMPION D. G. 
Published: February 2008

SUMMARYThe structure of the male reproductive system of the red bollworm, Diparopsis castanea (Hmps.), is described: it is typical for a Noctuid.After day‐old male moths had been injected with dosages of the chemosterilant tepa ranging from 10 to 50 μg, no impairment of the gross function of their accessory gland apparatus resulted, and spermatophores of normal size were transmitted during copulation. Microscopic examination of testicular preparations demonstrated no gross damage following treatment, and the sperm was motile. The injected males were nevertheless completely sterile.
Effects of Aphis fabae Scop, and of its attendant ants and insect predators on yields of field beans (Vicia faba L.)
Authors: BANKS C. J. , MACAULAY E. D. M. 
Published: February 2008

SUMMARYPredators (mainly coccinellid adults and larvae and syrphid larvae), although few, were important in decreasing numbers of Aphis fabae on a small plot of field beans during the early stages of infestation in a year favourable to the aphid. At the same time, ants (Lasius niger L.), attending aphids on other plants on the same plot, effectively protected the aphids from predators for about 2 weeks, enabling the attended aphids to multiply faster than the unattended. When all aphid populations started to decline, predators became more numerous and accelerated the decline on both sets of plants.Bean plants without aphids yielded fifty‐six seeds per plant; those with aphids but free from ants gave seventeen; and those with ant‐attended aphids, eight seeds per plant. The damage and loss of yield was caused by the large aphid populations that developed when the pods were maturing, and not by the fewer aphids present when the plants were in flower. It appears that small, temporary infestations during flowering might increase the yield of field beans.
The horizontal and vertical distribution of flying insects near artificial windbreaks
Authors: LEWIS T. 
Published: February 2008

SUMMARYLath fences 3 ft and 8 ft high affected the horizontal distribution of flying insects similarly: most insects accumulated at a distance equal to 2–3 times the height of each fence to leeward, where catches, measured at 14 and 38 in. (≡ to 0·4 times the height of the fence above the ground) were 30–40 % greater than in exposed positions. Behind an 8 ft fence accumulations extended vertically to 12–16 ft (≡ to 1·5‐2·0 times the height of the fence). Vertical profiles of weak‐flying insects, in winds > 3 m.p.h. differed in sheltered and exposed positions; in shelter the boundary layer was deeper and insects were more abundant nearer the ground than elsewhere. For strong flyers, and insects which flew only in winds < 2 m.p.h., vertical profiles in sheltered and exposed positions were indistinguishable.
Darkness and the activity of diquat and paraquat on tomato, broad bean and sugar beet
Authors: BRIAN R. C. 
Published: February 2008

SUMMARYA period of darkness after treatment increased the activity of diquat and paraquat on tomato, broad bean and sugar beet. The extent of the increase was dependent on the time of day (and year) of treatment, on the light quality and intensity before spraying and on the duration of the darkness. Damage from morning treatments, unlike those in the afternoon, increased rhythmically with increasing darkness. The rhythm showed a maximum about every 24 hr and continued through several days of darkness.The results underline not only the complexity of diquat and paraquat action but also the importance of strictly controlling experimental procedure when studying their mode of action.
Antifungal phenolic acids in apple fruits after infection with Sclerotinia fructigena
Authors: FAWCETT C. H. , SPENCER D. M. 
Published: February 2008

SUMMARYSeveral compounds were separated from the antifungal materials produced in Edward VII apple fruits attacked by the brown rot organism Sclerotinia fructigena. Six phenolic compounds were isolated in the crude state by column chromatography and their fungicidal properties examined. Two of the phenolic acids present were purified and identified as 4‐hydroxybenzoic acid and 4‐hydroxy‐3‐methoxybenzoic acid. These phenolic compounds were shown to arise from the action of the pathogen on the juice of the fruit and not from the peel or the juice‐free pulp.
Competitive saprophytic colonization of wheat straw
Authors: BURGESS L. W. , GRIFFIN D. M. 
Published: February 2008

SUMMARYUsing the ‘Cambridge method’, the effect of temperature on the colonization of wheat straw by Fusarium culmorum, Gibberella zeae, Cochliobolus sativus and C. spicifer was studied. Within the range 10–30 °C, saprophytic colonization by the four fungi was favoured by lower temperatures. This could not be attributed to the effect of temperature on the growth of the fungi in pure culture, but was probably caused by increased antagonism at higher temperatures from the general soil microflora. Contrary to previous indications, C. sativus strongly colonized straw under suitable environmental conditions.
Observations on periodicity of hatching of eggs of the potato cyst nematode, Heterodera rostochiensis Woll.
Authors: SHEPHERD AUDREY M. , COX PATRICIA M. 
Published: February 2008

SUMMARYSoil containing new‐generation cysts of Heterodera rostochiensis was taken from the field at monthly intervals during late summer and autumn and kept in various conditions for up to a year. The number of eggs that hatched in the stored cysts was compared each month with the number that hatched in cysts taken directly from the field. Eggs did not hatch readily when stimulated during the late autumn and early winter, although more did so in cysts taken from the field before August than after. A few more eggs hatched in cysts stored in air‐dried soil than in cysts stored in moist soil. Some cysts were kept at 15 or 20 °C continuously and others at 5, 15 or 30 °C for 6 weeks followed by 20 °C continuously. Storage at 30 °C caused eggs to hatch sooner, but otherwise the temperature of storage had little effect on hatch at any time of the year. Warmth also increased the hatch of H. cruciferae sooner, and some synthetic hatching agents did so with both of these species. When freed from new cysts, more eggs of H. rostochiensis hatched than in intact cysts and hatch was further increased when the fragments of tanned cyst‐wall were left with the freed eggs. Puncturing the cyst‐wall of new brown cysts had little effect on the hatch in potato root diffusate. Like eggs in new cysts, those in 1‐year‐old cysts stored out of doors ceased to hatch during the autumn and winter. The term ‘dormancy’ is inadequate to describe the inability of eggs of H. rostochiensis and other Heterodera spp. to hatch in the appropriate stimulant and the term ‘facultative diapause’, as applied to insects, better fits the phenomenon.