bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of aeration during cold storage of germinated vegetable seeds prior to fluid drilling on seedling viability
Authors: BROCKLEHURST P. A. , DEARMAN JANE , FINCH‐SAVAGE W. 
Published: February 2008

SUMMARYGerminated seeds of cabbage, carrot, lettuce and onion were stored for 15 days at 1 °C either in water or humid air before being fluid drilled. In aerated water and humid air, seedling viability was maintained for cabbage, carrot and lettuce, and only slightly reduced for onion. Storage in unaerated water reduced seedling viability by 48%‐100%. Seeds continued to germinate in aerated storage, but radicle elongation occurred only with cabbage and lettuce.
Controlled atmosphere storage of winter white cabbage
Authors: GEESON J. D. , BROWNE K. M. 
Published: February 2008

SUMMARYIn four laboratory experiments and five commercial scale trials carried out between 1977 and 1979, five cvs of winter white cabbage were stored at 0–2 °C for 29–43 wk in controlled atmospheres (C A) consisting of c. 5–6% CO2, 3% O2 and the remainder N., or in air. The incidence of rots caused by Botrytis cinerea was reduced and the incidence of ‘pepper‐spotting’ (a non‐microbial leaf necrosis disorder) was reduced or eliminated by storage in CA. Storage and trimming weight losses were lower and the recoveries of trimmed cabbage suitable for marketing or processing up to 22% higher in cabbage stored in CA than in those stored in air. Sensory assessments of four cvs tested indicated that CA‐stored cabbages retained their green colour, crisp texture and fresh flavour better than the corresponding air‐stored samples.
Effect of temperature on growth of some avirulent fungi and cross‐protection against the wheat take‐all fungus
Authors: WONG P. T. W. 
Published: February 2008

SUMMARYThe linear growth rates of Gaeumannomyces graminis var. graminis, G. graminis var. tritici, Phialophora radicicola var. graminicola and a lobed hyphopodiate Phialophora sp. were studied on agar at various temperatures between 5 and 30 °C and on wheat roots at two temperature regimes (12 h at 7°/12 h at 13 °C and 12 h at 17°/12 h at 23 °C). On agar at 30 °C, the isolates of G. graminis graminis grew faster than those of G. graminis tritici and Phialophora sp. but three isolates of G. g. graminis grew more slowly than the other two fungi at 5 and 10 °C. Two other isolates of G. g. graminis were cold‐tolerant and had growth rates comparable to those of G. g. tritici and Phialophora sp. at 10 °C. The growth rates of Australian isolates of P. radicicola graminicolu were similar to that of a British isolate and were about a third to a half those of the other three fungi at most temperatures. The growth rates of the fungi on wheat roots at the low and high temperature regimes were correlated with the growth rates on agar at 10 and 20 °C respectively. The correlation was better at low temperatures r= 0.81) than at high temperatures (r = 0.62).Cross‐protection experiments using two G. g. graminis isolates which grow poorly at temperatures below 15 °C and a cold‐tolerant isolate each of G. g. graminis and Phialophora sp. showed that, while all four fungi protected wheat against take‐all at high temperatures (17/23 °C) as evidenced by less severe disease and significantly greater dry weights, only the cold‐tolerant fungi were effective at low temperatures (7/13 °C). The use of cold‐tolerant isolates of avirulent fungi in field experiments may result in better protection in the early stages of wheat growth when Australian soil temperatures are mostly below 15 °C.
The effect of iprodione on sclerotium germination, root infection and mycelial spread of Sclerotium cepivorum in salad onions
Authors: ENTWISTLE A. R. , MUNASINGHE H. L. 
Published: February 2008

SUMMARYIprodione seed treatment at 125 g a.i./kg seed and stem base sprays at 0–3 and 0.125 g a.i./m row delayed the appearance and reduced the incidence of stem base symptoms and root infection with Sclerotium cepivorum in autumn‐ and spring‐sown salad onions. Viability of sclerotia was unaffected by the treatments but their germination was delayed. The spread of mycelium between plants was suppressed but growth of hyphae within infected roots was much less affected.
Glycine mosaic virus: a comovirus from Australian native Glycine species
Authors: BOWYER J. W. , DALE J. L. , BEHNCKEN G. M. 
Published: February 2008

SUMMARYTwo strains of a virus designated Glycine mosaic virus (GMV) were found in Glycine clandestina and G. tabacina, legumes indigenous to Australia and the western Pacific region. When transmitted by sap inoculation, GMV infected mostly leguminous species, and caused mosaic and mottling symptoms. The virus was not found naturally in soybean G. max, but it infected all of the 21 cultivars tested.GMV has isometric particles of c. 28 nm diameter, and produces three components with sedimentation coefficients of 60 S (top), 103 S (middle), and 130 S (bottom). Both middle and bottom components are required for infectivity. The virions contain two major proteins with molecular weights of c. 21 500 and 42 000. GMV produces large aggregates of particles in the cytoplasm of the mesophyll cells of pea Pisum sativum, and also induces amorphous membrane‐bound bodies and cytoplasmic vesicles. The type strain (from New South Wales) reacts with antisera to Echtes Ackerbohnenmosaik, broad bean stain, and a Californian isolate of squash mosaic virus. The GW strain (from Queensland) reacts with all of the latter antisera, as well as with antisera to cowpea mosaic virus (Sb and Ark strains), bean pod mottle, and red clover mottle viruses, and is serologically related to, but not identical with, the type strain. These properties clearly establish GMV as a new member of the comovirus group.
Effect of plant density and nitrogen on wheat F1 hybrids and their parents
Authors: DONE A. A. , WHITTINGTON W. J. 
Published: February 2008

SUMMARYIn two field experiments (1973, 1974) the effects of increasing plant density (17.25, 34.5, 69.0, 138.0, 276.0 kg seed ha‐1 in Expt 1 and 23.5, 47.0, 94.0, 141.0 188.0, 282.0 kg seed ha‐ in Expt 2) and nitrogen levels (0. 39, 78, 117, 156 kg N ha‐ and 45, 67, 89 kg N ha‐1) were studied. Increased grain yields in both experiments only occurred from the lowest to the second lowest seed rate. Increased seed rate increased tiller density but decreased the number of grains per spikelet and spikelets per ear. In the first experiment yield and thousand‐grain weight were reduced by increased nitrogen whilst in the second experiment these characters were increased. Mildew was prevalent in the first experiment especially at the higher nitrogen levels. In both experiments the inbred and F1 hybrid genotypes tended to behave similarly and the grain yields of the hybrids did not exceed either those of their parents or the highest inbred at any plant density or nitrogen level. The F1 hybrids had greater mean grain weights than the inbreds, probably as compensation for a reduced number of grains per ear or decreased tiller density.
Studies on the taro leaf blight fungus Phytophthora colocasiae in Solomon Islands: control by fungicides and spacing
Authors: JACKSON G. V. H. , GOLLIFER D. E. , NEWHOOK F. J. 
Published: February 2008

SUMMARYWith mist blower application, copper oxychloride at 2.25 kg/ha was effective in controlling PHYTOPHTHORA colocasiae but mancozeb at 3.6 kg/ha was not. Phytotoxicity from captafol at 1.8 and 3.6 kg/ha nullified any potential gain in yield from control of blight. Leaf removal from healthy plants to maintain four leaves per plant for 90 days, to simulate roguing of leaves for disease control, was shown to cause no loss in yield. However, regular roguing of diseased leaves over the same period in plots affected by a severe epiphytotic did not eradicate the pathogen. When roguing ceased at 90 days disease increased rapidly to epidemic proportions that seriously affected final corm yield.An attempt to reduce the effect of blight by wider than traditional spacing was unsuccessful. Under continuous epiphytotic conditions disease had the maximum possible impact regardless of spacing. Whereas plants free from competition normally bear six to seven leaves, this number was reduced by severe disease to three or four, the same number as was borne by plants under the competitive conditions of closer‐than‐traditional spacing. Instead of the traditional 20–30 000 plantdha, it was shown that density can be doubled under conditions of high leaf blight hazard and increased yields still be obtained.
Scab disease of cowpea (Vigna unguiculata) caused by Sphaceloma a species of the fungus
Authors: EMECHEBE A. M. 
Published: February 2008

SUMMARYScab disease of cowpea (Vigna unguiculuta) was shown to be caused by Sphaceloma sp. It affects all above ground parts of the plant. The first symptom of the disease, appearing within 3 to 6 days of inoculation, is puckering of the lamina. Spots on mature leaves are white with or without brown margins. Typical scab lesions on petiole, stem, peduncle and pod are white turning dark brown when chlamydospores are formed and are oblong‐elongate except for pod lesions that are ovoid. The most destructive phase is scab of the flowering axis which causes flower and, or, pod abortion or completely prevents flower formation.Inoculation of asparagus pea (V. sesquipedalis) with a cowpea isolate of Sphaceloma sp. produced symptoms similar to those on cowpea. Inoculated hyacinth bean (Lablab niger) produced atypical mild lesions. The following legumes were not affected when artificially inoculated with the fungus: black gram (Phaseolus mungo), green gram (P, aureus), French bean (P. vulgaris), Lima bean (P. lunatus), groundnut (Arachis hypogaea), and soyabean (Glycine max). The characteristics of the fungus on potato dextrose agar are described.
The role of seed‐tuber and stem inoculum in the development of gangrene in potatoes
Authors: ADAMS M. J. 
Published: February 2008

SUMMARYTo determine the relative importance of seed tubers and stems as sources of inoculum for potato gangrene in progeny tubers, different levels of inoculum of Phoma exigua var. foveata were established in field experiments by planting rotting or contaminated seed tubers and by inoculating stems shortly before haulm desiccation.The pathogen was only occasionally detected by isolation from inside green stems in June and July on plants growing from contaminated but unrotted seed. The incidence of pycnidia on desiccated stems increased with increasing concentration of inoculum contaminating seed tubers and with increasing time interval between desiccation and harvest. Stem infection was probably derived from inoculum on seed tubers spreading via the soil to the stem bases. Stem inoculation of plants growing from uninoculated or uncontaminated seed greatly increased both the gangrene potential of progeny tubers (defined as % wounds with gangrene after uniformly damaging tubers and storing them at 5°C for 12 wk), and tuber contamination (defined as % wounds with gangrene after spreading tuber‐borne soil onto test tuber slices and storing them at 5°C for 8 wk). However, when stems of plants growing from rotting or contaminated seed were cut at ground level and removed before desiccation, gangrene potential of progeny tubers was only slightly less than that of tubers from untreated plots. There was no evidence that soil inoculum or aerial spread played a significant role in disease development.Gangrene potential and contamination of progeny tubers were related to Contamination levels on seed tubers. Some transmission also occurred from rotted seed tubers to progeny. Inoculum levels around progeny tubers increased rapidly after desiccation even in plots where stems had previously been cut at soil level and removed to eliminate pycnidial development above ground as a source of inoculum. Both gangrene potential and contamination of progeny tubers were greater on cv. Ulster Sceptre than on cv. Pentland Crown. The results showed that the inoculum on seed tubers, whether from rots or surface contamination, contributed more to the contamination of progeny tubers at harvest than did the inoculum from pycnidia on stems following desiccation of the haulm.
Effect of inoculum density, stage of plant growth and dew period on the incidence of black point caused by Alternaria alternata in durum wheat
Authors: SOUTHWELL R. J. , BROWN J. F. , WONG P. T. W. 
Published: February 2008

SUMMARYGlasshouse studies showed that the incidence of black point caused by Alternaria alternata in durum wheat was positively correlated with both the density of the inoculum and the growth stage of the wheat plants at the time of inoculation. A curvilinear relationship of the form Y=a + log X was found between inoculum density and disease incidence. The incidence of black point was linearly related to the stage of plant growth, between anthesis and the late milk stages of development, at the time of inoculation. A better relationship between growth stage and disease incidence was found when plant growth was expressed as days after anthesis than when the Romig scale was used (R2= 0.30 and 0.24 respectively). A threshold dew period of 3–6 h was required for black point symptoms to develop. The incidence of black point increased with increasing duration of the dew period until maximum disease incidence occurred after exposure to a dew period of 48 h.
Crimson clover latent virus ‐ a newly recognised seed‐borne virus infecting crimson clover (Trigolium incarnatum)
Authors: KENTEN R. H. , COCKBAIN A. J. , WOODS R. D. 
Published: February 2008

SUMMARYCrimson clover latent virus (CCLV) was detected in five seed lots of crimson clover (Trifolium incarnatum) from Europe and in one from the United States of America. Ninety‐seven per cent of all crimson clover plants examined were found to be infected but were without symptoms. Keeping crimson clover plants at 32–38°C for 34 days failed to free them from CCLV. The virus was not transmitted by Myzus persicae, but was transmitted by inoculation of sap to Chenopodium album, C. amaranticolor and C. quinoa. Twenty‐four other plant species from seven families were not infected. CCLV was best propagated in C. quinoa in which it caused stunting and systemic chlorosis. Sap from infected C. quinoa was infective after dilution to 10‐2 but not 10‐3, after 10 min at 60°C but not 65°C, and after 20 days at 20°C.In neutral phosphotungstate, CCLV had isometric particles c. 26 nm in diameter with a hexagonal profile. About 20 to 80 A1cm,260 units of purified virus were obtained from 1 kg of infected C. quinoa or C. amaranticolor leaves by extraction in 0.5 M phosphate buffer, pH 7.5, containing 0.01 M ethylene diamine tetra‐acetate and 0.4% 2–mercaptoethanol and clarification with chloroform‐butanol followed by two precipitations with polyethylene glycol (mol. wt 6000) and several cycles of differential centrifugation. Purified virus sedimented as three components with sedimentation coefficients (s°20, w) of 52S, 101S and 122S. The 101S and 122S components had buoyant densities in CsCl of 1.438 and 1.495 g/cm3 respectively. From these values the nucleic acid content of the 101S and 122S components was estimated to be 32–35% and 40–41% respectively. The virus contained a single protein with an estimated mol. wt of 52 000 and two single‐stranded RNA species of estimated mol. wt 1.6 × 106 and 2.2 × 106. CCLV was serologically unrelated to 31 other morphologically similar viruses. Although its vector is unknown, CCLV seems to have affinities with nepoviruses.The cryptogram of CCLV is R/1:2.2/40–41 + 1.6132–35:S/S:S/*.
Treatment of seed and ware potato tubers with thiabendazole for control of storage diseases
Authors: HIDE G. A. , CAYLEY G. R. , READ P. J. , FRASER J. H. 
Published: February 2008

SUMMARYIn March 1977 and 1978 King Edward seed potatoes from three commercial stocks and one stock derived from stem cuttings (healthier seed) were treated with thiabendazole at 320 g a.i./t and 46% of the material applied was deposited on tubers. Seed was stored on trays to sprout and in April samples were planted in replicated plots on two farms in Lincolnshire. Treatment did not consistently affect numbers of stemslplant or total yields but decreased infection of underground stems by Polyscytalum pustulans and Rhizoctonia solani and of tubers at harvest by P. pustulans, R. solani and Helminthosporium solani. In samples stored for 20 wk at Sutton Bridge Experimental Station seed treatment decreased the incidence of skin spot from 25 to 4%, of black scurf from 36 to 20% but had less effect on silver scurf (untreated 52% tubers, treated 47%) and did not affect the incidence of black dot (Colletotrichum coccodes) on stored tubers.In another series of experiments 1 t samples of seed from six King Edward stocks (1977) and four King Edward and one Maris Piper stocks (1978), collected from different farms in Lincolnshire in March, were treated with thiabendazole at 40 g a.i./t. Tubers retained 48% of the material applied. The treated seed was planted on the respective farms in a single large plot adjacent to untreated seed similarly stored and sprouted. Seed treatment significantly decreased the incidence of skin spot, black scurf, silver scurf and gangrene in tubers stored at Sutton Bridge in 1977–78. After lifting the experiment in 1978 samples from treated and untreated seed were treated with thiabendazole (40 g a.i./t) before storage (ware treatment). Skin spot was decreased more by seed treatment than ware treatment whereas silver scurf was controlled best by ware treatment. Incidence of black dot was not consistently affected by seed or ware treatment.
Beet curly top virus from phloem exudate of Amsinckia douglasiana
Authors: MAGYAROSY A. C. 
Published: February 2008

SUMMARY Amsinckia douglasiana when infected with beet curly top virus (BCTV) produces more exudate, which is highly infective, than any other known host. Attempts were made to purify BCTV from the phloem exudate of infected Amsinckia douglasiana by differential centrifugation and sucrose density gradient fractionation. A260/280 ratio of virus preparations was 1.58; S values were 74 and 147. Infectivity was distributed among several fractions during density gradient purification. Electron microscopy revealed the presence of pentagonal and hexagonal particles of 14–23 nm, some of which were paired. The virus was insensitive to DNAse, RNAse, and trypsin when these enzymes were tested individually but infectivity was substantially decreased when the virus was subjected to trypsin treatment followed by DNAse, suggesting that DNA is associated with the beet curly top virus.
Beet curly top virus transmission by artificially fed and injected beet leafhoppers (Circulfer tenellus)
Authors: MAGYAROSY A. C. 
Published: February 2008

SUMMARYThe transmission of beet curly top virus (BCTV) by leafhoppers, Circulifer tenellus, fed virus through Parafilm® membranes was compared with their transmission when injected with virus from phloem exudates of Amsinckia douglasiana. Virus uptake from 32P‐labelled test solutions and the resulting virus transmission, as measured by an infectivity index, varied widely. By contrast, insects injected with virus transmitted with similar efficiencies. If insects were fasted for 3, 5, or 7 h before a 6 h acquisition access period on test solutions, their 32P, and presumably virus uptake, was greater than that of nonfasted insects and their variability in virus transmission decreased. The proportion of insects transmitting curly top virus, after fasting and given a 6 h acquisition access period, was similar to that of insects injected with virus. Maximum liquid uptake by the beet leafhopper occurred with a 12% sucrose solution.
Effects of infection with the cabbage black ringspot strain of turnip mosaic virus on turnip as a host to Myzus persicae and Brevicoryne brassicae
Authors: HODGSON C. J. 
Published: February 2008

SUMMARYWhen turnip plants with 3–7 leaves were inoculated with cabbage black ringspot virus (CBRSV) on the 3rd rough‐leaf, symptoms only appeared on leaves that had been less than 15 mm long at the time of inoculation, although infection decreased the area and both fresh and dry weight of all leaves. Leaves were ‘aged’ by their appearance and placed in Leaf Age Categories (LACs). Leaves with symptoms senesced (‘aged’) prematurely.CBRSV‐infection of cv. Green Top White did not change the distribution of populations of Myzus persicae between LACs, but increased the proportion of the plant suitable for colonisation. All suitable LACs were quickly colonised by adult apterae and nymphs. On CBRSV‐infected plants the nymphal period was shorter, F1 adults deposited larvae more frequently and the live body weight and tibial length of the F2 generation was greater, than on healthy plants.The distribution of Brevicoryne brassicae populations on cv. Green Top White differed from that of M. persicae but was also unchanged by CBRSV‐infection. On healthy plants the largest colonies were on mature leaves, so that on virus‐infected plants premature senescence shortened the life of the colony. On CBRSV‐infected plants the nymphal period was prolonged and the live weight of F1 and F2 adult apterae was less than on healthy plants. The differences between the biology of M. persicae and B. brassicae on CBRSV‐infected cv. Green Top White were associated with the accelerated senescence of CBRSV‐infected leaves.The possibility that CBRSV‐infection might reduce the resistance of turnips to aphid infestation was tested. M. persicae and B. brassicae were cultured on two favourable and two less favourable cultivars. No improvement in population growth rate was found when the less favourable host cultivars were infected with CBRSV, but both aphid species weighed less and/or had smaller nymphal populations on cultivars showing the severest symptoms. These results are discussed in relation to the evolution of non‐persistent virus transmission by aphids.
Effect of soybean canopy closure on landing rates of aphids with implications for restricting spread of soybean mosaic virus
Authors: HALBERT SUSAN E. , IRWIN M. E. 
Published: February 2008

SUMMARYAlate Aphis citricola and Myzocallis punctatus were caught more abundantly on horizontal ermine‐lime canopy‐level sticky traps in a closed soybean canopy than on similar traps in an open canopy. This is the first reported case in which more alate aphids were collected on traps in fields with relatively more ground cover. Capitophorus elaeagni were caught more abundantly on traps in relatively more open canopy, and Lipaphis erysimi, Rhopalosiphum maidis and Schizaphis graminum were collected in statistically similar numbers in open and closed canopies. Our trapping technique was designed in an attempt to collect only those aphids which would otherwise have landed on the soybean canopy. Landing rates differed among species; therefore, the efficacy of using ground cover manipulation to reduce spread of soybean mosaic virus would depend upon seasonal occurrence of the important local vector species.