bluuebunny/crossref_metadata_2025_split huggingface dataset:
Benomyl tolerance in Verticillium dahliae
Authors: TALBOYS P. W. , DAVIES MOIRA K. 
Published: February 2008

SUMMARYIn Verticillium dahliae isolates (‘wild type’) obtained prior to the advent of benzimidazole fungicides, growth of germ tubes and extension of mycelium were typically inhibited by benomyl at 0–3 ppm and 0.5‐1.0 ppm respectively. Culture of such isolates in the presence of increasing concentrations of benomyl resulted in the selection of variants able to grow at 12.0 ppm.Conidia, and mycelium grown for 24 b, were each more sensitive to inhibition by benomyl than mycelium grown for 48 h. Mycelium of both wild‐type and selected variants was still viable after treatment with 20 ppm benomyl in a nutrient medium for 112 days. Long‐term treatments at 20 ppm caused the enlargement of mycelial cells and conidia, thickening of the cell walls and formation of large spherical inclusions apparently comprising or containing lipids.
The transmission and effect on yield of ryegrass mosaic virus in a filtered air environment
Authors: GIBSON R. W. , PLUMB R. T. 
Published: February 2008

SUMMARYThe eriophyid mite vectors of ryegrass mosaic virus (RMV) were excluded from ryegrass by covering plots with a polyethylene film house ventilated by filtered air. Initially plots were manually inoculated to give different levels of RMV. During two seasons no mites were found within the house so that all transmission of virus was by sap. Rolling and frequent cutting of uninfected plots decreased yields, but surprisingly, increasing virus infection did not decrease yields significantly. Cutting transmitted virus within infected plots but not from infected to healthy plots, whereas combined rolling and cutting did transfer virus to healthy plots.
Occurrence of plantago mottle virus in pea, Pisum sativum, in New York State
Authors: PROWIDENTI R. , GRANETT A. L. 
Published: February 2008

SUMMARYPlantago mottle virus (RMV), a member of the tymovirus group, was identified as the causal agent of a disease of pea (Pisum sativum) in New York State. The pea virus isolates were identical in host range and serology to the type strain from Plantago major. In susceptible pea genotypes symptoms were strongly influenced by ambient temperature; high temperature (35°C) reduced infectivity and suppressed symptoms, whereas low temperature (15 and 25°C) prolonged the incubation period but favoured the development of conspicuous leaf veinal chlorosis, mottle and necrosis.Resistance to P1MV was found in seventeen of twenty‐five domestic pea cultivars and in two of twelve foreign introductions. Many of the P1MV‐resistant lines were resistant also to bean yellow mosaic virus. The use of resistant cultivars and the apparent limited conditions for efficient transmission of this virus have minimized its importance to pea crops in New York State.
Fumigation with D‐D or Telone on soils prone to Docking disorder
Authors: COOKE D. A. , WINFIELD A. L. , ATKINSON KAY M. , JOHN MARGARET E. , WILSON W. R. 
Published: February 2008

SUMMARYField trials in 1970‐2 tested the effect on nematode numbers of pre‐sowing fumigation with c. 641 D‐D/ha or c. 43 1 Telone/ha injected behind coulters at the same spacing as the rows of beet (‘band treatment’), the same amounts of fumigant injected both beneath and between the rows, i.e. at half‐row spacing (‘overall‐low’, totalling c. 1281/ha or 851/ha respectively) and a double dose of these fumigants at half‐row spacing (‘overall‐high’, totalling c. 256 1/ha or 170 1/ha respectively). Numbers of Trichodorus and Longidorus in the sugar‐beet rows were decreased by 68 and 86% respectively by band treatment; by 83 and 94% by overall‐low and 92 and 97% by overall‐high treatments. Populations of Longidorus recovered slowly, especially following overall treatment; populations of Trichodorus recovered more quickly, but 16 months after overall treatment they were still fewer than in the unfumigated plots. There was no correlation between nematode numbers recorded before sowing sugar beet and either the response of the crop to fumigation or the final yield of sugar beet.
Respiration of maleic hydrazide treated and untreated onion bulbs during storage
Authors: WARD C. M. , TUCKER W. G. 
Published: February 2008

SUMMARYRespiration rates were determined at a range of temperatures on onion bulbs cv. Rijnsburger sampled from a cool‐stored bulk over a period of 8 months. In the first 5 months of storage, respiration rates were low and showed a small increase with temperature. During this period there was little or no difference between untreated bulbs and those treated with maleic hydrazide (MH) prior to harvest. Subsequently there was a rise in respiration rates, which preceded sprouting, but this was not evident in MH‐treated bulbs. A relationship between respiration and dormancy was suggested by the correlation between respiration rate in January and sprouting in June for four cultivars.
Glandular hairs are a possible means of limiting aphid damage to the potato crop
Authors: GIBSON R. W. 
Published: February 2008

SUMMARYGlandular hairs on leaves and stems stuck naturally‐occurring aphids to field grown plants of Solamim polyadenium, S. berthaultii, and first and second generation hybrid S. tuberosum cv. Pentland Crown ×berthaultii, but none became stuck on Pentland Crown. S. polyadenium had most glandular hairs, stuck most aphids and had fewest free aphids. In the glasshouse, the percentage of stuck aphids was positively correlated with the abundance of glandular hairs, especially on the leaves, so counting the hairs may be a simple preliminary method of screening for aphid‐trapping ability.
Prevention of potato top‐roll by aphicide and its effect on leaf area and photosynthesis
Authors: GIBSON R. W. , WHITEHEAD D. , AUSTIN D. J. , SIMKINS JANE 
Published: February 2008

SUMMARYIn a field of potatoes, top‐roll, which is induced by the aphid Macrosiphum euphorbiae feeding on the leaves, was restricted to two rows of plants which accidentally received no phorate aphicide granules at planting. The photo‐synthetic rate per unit leaf area and the ground cover of top‐rolled leaves were respectively 50% and 20% less than those of normal plants which may account for the smaller yields of affected plants observed in previous experiments.
Simple extraction and bioassay of the female sex pheromone of the citrus mealybug, Planococcus citri
Authors: ROTUNDO G. , TREMBLAY E. 
Published: February 2008

SUMMARYThe sex pheromone released by the females of the citrus mealybug was extracted from virgin females by ethanol, diethyl ether or petroleum ether but not by toluene, w‐hexane or w‐pentane. Extracts in ethanol, diethyl ether or petroleum ether placed on filter paper and hydrophilized polymethylmethacrylate disks elicited high attraction and copulation responses in the male mealybugs.
Influence of crop background on aphids and other phytophagous insects on Brussels sprouts
Authors: SMITH JUDITH G. 
Published: February 2008

SUMMARYMore Brevicoryne brassicae and other alate aphids were caught in yellow water‐traps in a weed‐free crop of Brussels sprouts than in a crop with a weedy background. More B. brassicae colonized Brussels sprout plants in bare soil than in weeds; very few alatae were attracted to cruciferous weeds in the crop. Results in 1 yr suggest that initially larger populations on the weed‐free sprouts became smaller than populations on the weedy sprouts because the larger aphid population attracted more natural enemies. Aleyrodes brassicae and certain Lepidoptera were also more abundant on sprout plants in bare soil than on sprouts surrounded by weeds; more adult A. brassicae were caught in water traps over the bare soil.More A. brassicae were present on sprout plants surrounded by a green than by a brown cloth background but the differences were not significant (P < 0–05). Numbers of B. brassicae on sprout plants with green and brown backgrounds varied greatly and did not differ significantly.In field cages, B. brassicae alatae were more attracted to potted sprout plants surrounded by bare soil than to ones surrounded by rings of living or cut grass or by artificial green rings. This effect was greater with small than with large sprout plants surrounded by grass rings.The maintenance of a limited weed cover is considered potentially useful in integrated control of some brassica pests.
The effects of Cercospora leaf disease on the growth of groundnuts (Arachis hypogaea) in Nigeria
Authors: ELSTON J. , HARKNESS C. , McDONALD D. 
Published: February 2008

SUMMARYThree experiments with five alternately‐branched and one sequentially‐branched cultivar of groundnuts are described. Spraying to control Cercospora leaf spot disease doubled the leaf area duration and increased the total weight of a plant by about 65 %. Spraying increased the weight of kernels per plant but in the alternately‐branched cultivars also increased the weight of stem and leaves. The proportion of the total dry weight in the kernels in the alternate cultivars was hardly changed by spraying. The sequentially‐branched cultivar gave the same increase in total dry weight when sprayed but spraying resulted in a larger increase in the dry weight of kernels. The sequentially‐branched cultivar, with few initials for vegetative growth, did not give the same increase in leaf growth.
Fungitoxicity of mineral oils against Rhizoctonia solani causing damping‐off of mung bean (Phaseolus aureus)
Authors: KATARIA H. R. , GROVER R. K. 
Published: February 2008

SUMMARYThree mineral oils, BSO, EWOS and E9267 and one vegetable oil (mustard oil), did not appreciably inhibit the mycelial growth of Rhizoctonia solani. However, treatment of 100 g seeds of mung bean with 2 ml EWOS and E9267 oils controlled more than 90% of the pre‐ and post‐emergence damping‐off and protected seedlings in soil inoculated with R. solani 5 days after sowing. Soaking seeds in solutions of these oils or drenching the soil did not control damping‐off.Mustard oil controlled only pre‐emergence damping‐off.
Effect of photoperiod on development and number of spikelets of a temperate and some low‐latitude wheats
Authors: ALLISON J. C. S. , DAYNARD T. B. 
Published: February 2008

SUMMARYFour low‐latitude cultivars (two Mexican and two Rhodesian) and a Canadian cultivar were grown in controlled environments in four photo‐periods, 16, 13, 10 and 7 h, respectively. Plants of two of the low‐latitude cultivars were also transferred between long and short photoperiods during ear differentiation.The intervals from sowing to successive stages of ear development up to the formation of the terminal spikelet, and to ear emergence, and the number of leaves, all increased as photoperiod decreased. The Canadian cultivar responded most and one of the Rhodesian cultivars least to changes of photoperiod in these respects. However, with all the low‐latitude cultivars, the interval between formation of the terminal spikelet and emergence of the ear responded similarly and relatively little to decreasing photoperiod except when photoperiod was reduced from 10 to 7 h. The mean rate of spikelet production decreased as the duration of the period of spikelet production (DSP) increased, i.e. as ear development slowed down with decrease in photoperiod. Accordingly number of spikelets per ear increased curvilinearly as DSP increased, suggesting a maximal number of spikelets of about thirty. Rate of spikelet production apparently differed between cultivars.Development of the ear slowed down when plants were moved to a shorter photoperiod and accelerated when they were moved to a longer photoperiod, both at the time at which the shoot apex began to elongate and at the double ridge stage. Final number of spikelets per ear increased when ear development was slowed down and decreased when it was accelerated.
The loss of electrolytes from leaves treated with hydrocarbons and their derivatives
Authors: BOYLES D. T. 
Published: February 2008

SUMMARYIndices of the effects on the leaves of a number of plant species of members of homologous series of hydrocarbons and certain of their oil‐soluble derivatives were based on changes in conductance of aqueous systems when hydrocarbon‐treated leaves were added. The results were compared with previous phytotoxicity studies where hydrocarbons were applied to plants in vapour and in aqueous treatments. A relationship between the conductance changes and the physical properties of the applied hydrocarbons is suggested. The presumed effects on cell membrane permeability indicated by the conductance changes agreed with known susceptibility of different plant species towards hydrocarbons of different homologous series applied in the liquid state.
Studies on plant growth‐regulating substances
Authors: PRICE D. N. , WAIN R. L. 
Published: February 2008

SUMMARYNitrophenols structurally similar to 4‐hydroxy‐3‐nitrobenzoic acid and 4‐hydroxy‐3‐nitrobenzaldehyde have been examined for their ability to inhibit chloroplast development in linseed and oat seedlings, and their activity has been estimated quantitatively in specifically designed clover and Lemna bioassays. Twelve compounds were found to be active and activity is considered in relation to chemical structure. A nitro group in the 3‐position and a hydroxyl group or ether linkage in the 4‐position were found to be essential for activity whereas the nature of the functional group in the 1‐position could vary considerably.Possibilities in which activity might arise from metabolism of the applied compound were investigated using excised wheat and pea tissue, and compounds with various groupings in the 1‐position were shown to be converted to the corresponding active benzoic acid derivative.
The genetic relationship between races of Bremiae lactucae and cultivars of Lactuca sativa
Authors: CRUTE I. R. , JOHNSON A. G. 
Published: February 2008

SUMMARYThe reactions of lettuce cultivars to physiologic races of Bremia lactucae are interpreted in terms of a gene‐for‐gene relationship between pathogen and host. The hypothesis takes into account the parentage of cultivars and the origins of their resistance, the characteristics of the resistance reactions and data available from detailed genetical analysis of various race/cultivar combinations. Cultivars are classified with respect to ten postulated resistance genes and B. lactucae races are defined by the virulence genes present. The practical significance of these studies is discussed in relation to both future lettuce breeding programmes and to the choice of cultivars available to counteract any given local race situation.
Breeding for reduced seed coat fuzz in Upland cotton (Gossypium hirsutum)
Authors: INNES N. L. , WIMBLE R. H. 
Published: February 2008

SUMMARYThe inheritance of seed coat fuzz was studied in two half diallel sets of crosses of Upland cotton. One with F4 selections from an inter‐varietal cross showed a significant level of non‐additive variance attributable to dominance and non‐allelic interaction. In the other, using inbred varieties of diverse origin, the genetic control of seed fuzz was adequately accounted for by an additive‐dominance model with no interaction.Genotypic correlations between seed coat fuzz, yield and lint quality characters, calculated for both diallel sets and for two other groups of breeding material, showed good agreement within each experiment between parents and hybrids or between parents and progenies but no consistent pattern between experiments. The results serve to emphasize the risks in extrapolating correlations from one group of breeding material to another.A useful level of reduced fuzz has been obtained in selections from the AH breeding programme and the genetical investigations indicate that a further reduction may be possible, thereby leading to easier handling of seed, speedier and cheaper ginning, low levels of seed coat nep and better seed germination.
Post‐harvest chemical treatments for the control of storage disorders of apples
Authors: SHARPLES R. O. , JOHNSON D. S. 
Published: February 2008

SUMMARYImmersion of apples of the varieties Cox's Orange Pippin and James Grieve for 1 min in solutions of calcium chloride or nitrate reduced the incidence of bitter pit and senescent breakdown that developed during air storage at 3 °C. Calcium nitrate treatments decreased the severity of superficial scald in both Bramley's Seedling and Cox apples probably by slightly delaying the rate of senescence. Calcium chloride caused unacceptable levels of damage when applied to Cox and Grieve at concentrations above 0.125 M; this injury was enhanced in Cox when benomyl was added to this strength of solution. Bramley's Seedling apples were more sensitive to calcium injury than Cox, especially in the presence of benomyl and the scald inhibitor, ethoxyquin; diphenylamine did not increase calcium injury. Calcium nitrate caused more damage to Cox than equimolar concentrations of the chloride without improving the control of bitter pit. Virtually no damage occurred when Cox and Grieve apples were immersed for 10 min in 0.125 M calcium nitrate at 45 °C. The incorporation of calcium in warm water treatments to control rotting and scald may delay sensecent breakdown in heat‐treated apples.
Observations on the effect of black root rot (Phomopsis sclerotioides) on the susceptibility of cucumber to powdery mildew (Sphaerotheca fuliginea)
Authors: EBBEN MARION H. , SEARLE LINDA M. 
Published: February 2008

SUMMARYPowdery mildew (Sphaerotheca fuliginea) infection of cucumber leaves was earlier and increased more rapidly on plants with black root rot (Phomopsis sclerotioides) than on plants with healthy root systems in the same glasshouse.
Progress towards a biological control programme for glasshouse whitefly (Trialeurodes vaporariorum) on tomatoes
Authors: PARR By W. J. , GOULD H. J. , JESSOP N. H. , LUDLAM F. A. B. 
Published: February 2008

SUMMARYDuring 1969/74 different methods of using the parasite Encarsia formosa to control whitefly infestations on tomatoes in glasshouses have been evaluated commercially. The most effective control was achieved by the Glasshouse Crops Research Institute (GCRI) programme of timed parasite introductions at rates totalling 120000 parasites per ha (48000/acre) following the pre‐establishment of a low, evenly distributed infestation of the pest throughout the crop. Other methods, including the regular introduction of parasites after planting in anticipation of a whitefly infestation or starting when the first whiteflies appear on the plants, are also described. These multiple introduction (‘dribble’) methods, gave mostly satisfactory control but were less predictable.The efficiency of the parasite is greatly impaired during the short days and low light intensities of the late winter months and alternative methods of dealing with early whitefly infestations, including the use of chemicals, are discussed.
Strains of Colletotrichum coffeanum, the causal agent of coffee berry disease, tolerant to benzimidazole compounds in Kenya
Authors: COOK R. T. A. , PEREIRA J. L. 
Published: February 2008

SUMMARYThe detection of Colletotrichum coffeanum tolerant to methyl ester of benzimidazole 2‐carbamic acid (carbendazim) and a related benzimidazole compound, cypendazole, followed increases in levels of coffee berry disease observed on Coffea arabica in experimental plots sprayed for 2 yr with these compounds.Sporulation by the pathogen on naturally infected berries removed from carbendazim‐, cypendazole‐ or benomyl‐sprayed plots was not checked by a further application of 0–05 % (a.i.) of any of the compounds. Nearly all the isolates from these berries were capable of some growth on agar media containing 1000 ppm (a.i.) of either carbendazim or cypendazole. However, only a few could tolerate 1000 ppm of benomyl and the inability of this compound to reduce sporulation on berries infected with tolerant strains was presumably due to its rapid conversion to carbendazim within the host tissue.Less than 1 ppm of carbendazim, cypendazole or benomyl was needed to give 50% inhibition of conidia of the normal strain. Against the most tolerant strains, however, the LD 50 was > 100 ppm of carbendazim and about 30 ppm of benomyl.Whether isolated from unsprayed or benzimidazole‐sprayed plots, all isolates of Colletotrichum acutatum, a saprophytic cohabitant of lesions initiated on berries by C. coffeanum, showed the highest degree of tolerance to benzimidazole compounds.No tolerance of either fungus to the ‘conventional’ fungicide captafol was detected.
Overwintering of Sphaerotheca humuli, the cause of hop powdery mildew
Authors: LIYANAGE A. de S. , ROYLE D. J. 
Published: February 2008

SUMMARYThe ability of Sphaerotheca humuli to overwinter as cleistocarps in infected hop cones and leaves and in aerial buds on rootstocks was examined during the winters of 1970‐1, 1971‐2 and 1972‐3.Periodical examination of cleistocarps, collected in October and overwintered in Terylene bags on the soil of a hop garden, consistently revealed two periods of maturation ending in November and in March, when over 50% contained eight, well‐defined ascospores. In laboratory tests cleistocarps, kept either in the hop garden or dry at 4, 8 or 18oC during the winter, could not be encouraged to dehisce earlier than April when naturally dehisced cleistocarps were first detected in the field. More ascospores were discharged from cleistocarps, and germination of ascospores in laboratory tests was greater, at 18 than at 4, 8 or 24oC. Colonies of S. humuli arose on leaves of potted plants exposed to overwintered cleistocarps in the hop garden and were observed microscopically to originate from ascospores. However, a Burkard spore trap, operated amidst the cleistocarps in this garden in 1972 and 1973, failed to detect ascospores. Ascospores, discharged onto susceptible leaves in the laboratory, germinated but failed to produce colonies.It was demonstrated that S. humuli can perennate in aerial, dormant buds on hop rootstocks. Examination of buds in autumn revealed mycelium external to and between the bud scales. At budburst the mycelium was still present internally. Cleistocarps were occasionally associated with hibernating mycelium. Primarily infected shoots arose from plants bearing infected buds in conditions which precluded chance infection. Some evidence was obtained that conditions during the winter determine the success of survival in buds.The fungus appeared to be incapable of infecting a selection of weeds common to hop gardens and their vicinity.
Tolerance to ryegrass mosaic virus, its assessment and effect on yield
Authors: WILKINS P. W. , HIDES D. H. 
Published: February 2008

SUMMARYSymptom severity of eighteen populations of Italian ryegrass infected artificially in the glasshouse and naturally in the field with ryegrass mosaic virus (RMV) was strongly correlated. A smaller proportion of plants of the more tolerant populations showed symptoms in the field, but this was probably due to an association of tolerance with increasing incidence of symptomless infection rather than with resistance to infection.Under sward conditions, the yield of a sensitive genotype was reduced by 27% and that of two more tolerant ones by 15 and 13 %. The percentage dry matter yield loss of the most sensitive genotype was similar in all cuts, despite the appearance of extensive necrosis at the time of one cut. With the more tolerant genotype the yield loss varied from 7 to 25 % according to cut. Over the period of the experiment RMV infection did not increase plant mortality.
The involvement of ethylene in the coiled sprout disorder of potato
Authors: CATCHPOLE A. H. , HILLMAN J. R. 
Published: February 2008

SUMMARYApplication of low concentrations of ethylene gas to the sprouts of Arran Pilot elicited many of the morphological and anatomical symptoms of the coiled sprout disorder. Similar effects were observed using 2‐chloroethyl‐phosphonic acid (Ethrel).Obstruction of coil‐prone etiolated sprouts led to enhanced ethylene production for a period of two to three days but this pattern was not shown by non‐coil‐prone sprouts.