bluuebunny/crossref_metadata_2025_split huggingface dataset:
THE GROWTH OF BOTRYTIS CINEREA PERS., FUSARIUM CAERULEUM (LIB.) SACC., AND PHOMA FOVEATA FOISTER IN THE PRESENCE OF TETRACHLORONITROBENZENE ISOMERS
Authors: BROOK M. , CHESTERS C. G. C. 
Published: February 2008

The linear growth of Botrytis cinerea, Fusarium caeruleum and Phoma foveata in culture was reduced in the presence of vapour from any of the three isomers of tetrachloronitrobenzene. The isomers were fungistatic but not fungicidal.Differences in activity were observed amongst the isomers. The 2:3:4:6 isomer was the most active against all three test fungi. 2:3:5:6‐TCNB (tecnazene) was more active than 2:3:4:5‐TCNB against Botrytis cinerea, but less active against Fusarium caeruleum and Phoma foveata. Two strains of Fusarium caeruleum resistant to the 2:3:5:6 isomer were not resistant to the other two isomers, although they were more resistant than their 2:3:5:6‐TCNB sensitive parent strains.Sporulation and sclerotial production by Botrytis cinerea were completely suppressed by 2:3:5:6‐TCNB and 2:3:4:6‐TCNB but not by the 2:3:4:5: isomer.
SOME CONTROL MEASURES FOR ANTHRACNOSE DISEASE OF TOBACCO*
Authors: COLE J. S. 
Published: February 2008

Laboratory, greenhouse and seed‐bed trials of copper and organic fungicides for the control of Colletotrichum tabacum on tobacco were made in Southern Rhodesia. In the seed‐bed trials the best control was obtained by sprays of maneb, thiram, zineb and captan. During the hot, dry weather in the early part of the season little damage was caused by the disease and it was easier to control than later, when rain and overcast weather were more frequent. Mixtures of zineb and copper compounds gave better control than either component alone.When seed‐beds were covered with light cloth for shade, they suffered greater damage from the disease than when a thin grass mulch was used.
THE REACTION OF WHEAT VARIETIES TO LOOSE SMUT AS DETERMINED BY EMBRYO, SEEDLING, AND ADULT PLANT TESTS
Authors: BATTS C. C. V. , JEATER ANN 
Published: February 2008

The possibility of using an embryo test as a means of determining the reaction of wheat varieties to loose smut (Ustilago tritici (Pers.) Rostr.) has been investigated. Fifty‐seven varieties were inoculated with two physiologic races by the partial vacuum method and the embryos, seedlings, and adult plants were examined for infection. Most of the varieties were fully susceptible to one or both races, and only ten showed real resistance to any one race. Braun R and Molinel proved almost immune to infection. The resistance in other varieties which showed no infection in the field was expressed as embryo susceptibility, i.e. the embryo became infected in much the same way as in field‐susceptible varieties.In the latter varieties infection passes from the embryo into the growing point of the young seedling. In the embryo‐susceptible field‐resistant varieties, infection does not pass from the scutellum and the growing point is therefore uninfected.The reaction of most of the varieties tested was straightforward resistance or susceptibility, but in a few varieties a small proportion of the grains reacted differently from the majority. These reactions are discussed.
AN APPARATUS FOR SCREENING COMPOUNDS FOR REPELLENCY TO FLIES AND MOSQUITOES
Authors: BOVINGDON H. H. S. 
Published: February 2008

An apparatus for determining the repellency of a chemical compound is described. Its action depends upon the insects' coming into contact with the compound deposited on a glass surface. The numbers of insects settling on treated and untreated glass plates at intervals over a period of 40 min. and under conditions that minimize varying disturbing factors are counted. The quotient obtained by dividing the total numbers on the untreated plates by the total numbers on the treated plates is called the ‘repellence quotient’, and must reach certain given values before significance is assumed and a compound is regarded as repellent.Typical results obtained with the apparatus are given and include the detailed determination of the repellency of butoxypolypropylene glycol (MW 800).
STUDIES ON PLANT CUTICLE
Authors: MARTIN J. T. , BATT R. F. 
Published: February 2008

The waxy coverings of the leaves of different species of plant have been fractionated into wax, acidic, volatile and oil components. The levels of the waxy deposits on the leaves and the relative proportions of the principal components of the waxy coverings differed widely. Wax predominated in the waxy coverings of the leaves of cabbage and cauliflower and acidic materials in those of apple and pear.The role of ether‐soluble acidic constituents in a possible defensive mechanism of leaves against fungi, the contribution of water‐soluble acidic constituents to the toxic action of copper fungicides and the influence of the waxy covering on spray deposition, phytotoxicity and the behaviour of DDT deposits on leaves are discussed. Earlier work on the nature of leaf wax components is reviewed.
OBSERVATIONS ON THE CONTROL OF MITE INFESTATIONS IN STORED WHEAT BY CHEYLETUS SPP. (ACARINA, CHEYLETIDAE)
Authors: NORRIS J. D. 
Published: February 2008

An account is given of the control of the grain mite Acarus siro L. (=Tyroglyphus farinae L.) by the predatory mite Cheyletus sp. in imported wheat stored in bags or in bulk. After 12–18 months of storage Cheyletus sp. had developed in 75% of the parcels of wheat and in 67% of these it became dominant over other mites. This usually occurred in late summer for bagged wheat. Control of A. siro by Cheyletus sp. compared favourably with that achieved by fumigation with methyl bromide and on occasion was superior. Both development and dominance of Cheyletus sp. were adversely affected by earlier fumigation but there was some evidence that spraying wheat with γ‐BHC favoured the development of this species and, in some circumstances, its dominance. Dominance by Cheyletus sp. in bulk grain often occurred in the winter months when the surface moisture content of the wheat was at its highest.The development of Cheyletus eruditus Schr. is described in a bulk grain store where dense populations of A. siro and Glycyphagus destructor Schr. were eliminated by the predator. The numbers of C. eruditus in wheat tended to increase faster when the surface layers were disturbed than when the grain was undisturbed. Nevertheless, dominance over the other mites tended to occur first in undisturbed grain.
THE ADAPTATION OF FUNGI TO FUNGICIDES: ADAPTATION TO COPPER AND MERCURY SALTS
Authors: PARRY K. E. , WOOD R. K. S. 
Published: February 2008

The susceptibility of Botrytis cinerea to copper sulphate in liquid media increased when the volume, and therefore the depth, of the medium in culture bottles exceeded certain values; when the volume was 40 ml. the maximum concentration allowing growth was 300 p.p.m.By growing mycelium in media containing progressively higher concentrations of copper sulphate a strain was produced which grew at a concentration of 750 p.p.m.In high concentrations of copper sulphate growth always started at the edge of the liquid, and inocula grew only if they were placed in this position.In germination tests spores from the resistant strain were more resistant to copper sulphate than were spores of the parent strain.The resistance of mycelium, and to a lesser extent of spores, was retained after growth of the resistant strain for six months in fungicide‐free media.Spore and mycelial inocula grew in much higher concentrations of copper sulphate when nutrient media were solidified with agar.The strain resistant in liquid media was no more resistant than the parent strain on agar media.The resistance of the fungus was not increased after growth for long periods on agar containing high concentrations of copper sulphate. The resistance of the strain resistant in liquid media was not lost after growth on agar media for 3 months.Attempts to produce strains more resistant than the parent to mercuric chloride were unsuccessful.The results obtained with phenyl‐mercuric acetate were essentially similar to those obtained with copper sulphate, but relatively much more resistant strains were produced.
THE EFFECT OF LARVAE OF CHIRONOMUS RIPARIUS MEIGEN ON THE REDOX POTENTIALS OF SETTLED ACTIVATED SLUDGE
Authors: EDWARDS R. W. 
Published: February 2008

The introduction of Chironomus riparius larvae to give densities of 12,500 and 50,000/m2in activated sludge, previously settled and consolidated for 6 months, had the following effects:(a)a rise in pH initially at the sludge surface but later extending to all depths,(b)an increase in the depth of the surface layer of sludge where the redox potential is high,(c)increases in the pH value and concentration of ammonia and a decrease in the concentration of oxidized nitrogen in the overlying water.
THE DEVELOPMENT OF A COMPARATIVE METHOD FOR THE EVALUATION OF THE MOTH‐PROOFNESS OF WOOL SERGE
Authors: HUECK H. J. 
Published: February 2008

Existing test methods for the moth‐proofness of wool were compared in inter‐laboratory experiments and found to be lacking in accuracy and agreement between laboratories.Several factors influencing the usefulness of such a test method were investigated, and it was found that a considerable gain in accuracy could be reached if weight loss due to larval attack on test samples was referred to weight loss obtained with a standard wool serge impregnated with a standard moth‐proofing substance. Apart from this principle, improvements in the general testing procedure, including the number of test samples and test animals used, the definition of weight loss and the introduction of strict randomization procedures proved to be valuable.As a provisional reference standard, wool serge impregnated with dinitro‐α‐naphthol was adopted. A tolerance level for the moth‐proofness of wool serge was laid down.
FURTHER STUDIES ON RASPBERRY RINGSPOT AND TOMATO BLACK RING, SOIL‐BORNE VIRUSES THAT AFFECT RASPBERRY
Authors: HARRISON B. D. 
Published: February 2008

Raspberry ringspot virus (RRSV) was found in eastern Scotland and Wiltshire infecting several varieties of raspberry, several weed species and sugar beet. Serological tests, and protection tests in Petunia hybrida, showed that isolates from different host species found at several localities in eastern Scotland were more closely related to one another than to the isolate from Wiltshire. RRSV was readily transmitted to Chenopodium amaranticolor by mechanical inoculation of sap from diseased raspberry but less readily to other species. Both the symptoms shown by C. amaranticolor, French bean, tobacco and Petunia hybrida, and its behaviour in serological and plant‐protection tests, distinguished RRSV from tomato black ring, raspberry yellow dwarf, tobacco ringspot and cucumber mosaic viruses. Preparations of RRSV lost infectivity when diluted 10‐4, kept for 3 weeks at 18° C., or when heated for 10 min. at 70° C. but not at 66° C. RRSV was precipitated without being inactivated by ammonium sulphate, ethanol or acetone. It was inactivated at pH 3.The beet ringspot strain of tomato black ring virus was isolated from the raspberry varieties Malling Seedling V and Malling Exploit by mechanical inoculation of sap to Chenopodium amaranticolor, but not from other varieites growing in virus‐infested soil.RRSV and the beet ringspot strain of tomato black ring virus are soil‐borne. They infected plants grown under glass in soil collected from several different fields: the incidence of infection differed in different soils, but infection by each virus was favoured by the same samples of soil. Infection with tomato black ring virus occurred equally in soil collected at different times of the year. Treatment with formaldehyde or parathion made soil non‐infective. Attempts to detect virus in extracts of virus‐containing soils, and to make autoclaved soils infective by watering them with virus suspensions or by growing artificially infected plants, failed, suggesting that infection depends on some factor other than free virus, possibly the presence of an organism.
EXPERIMENTS IN THE SUDAN GEZIRA ON CONTROL OF WILT OF DOLICHOS BEAN (DOLICHOS LABLAB) ASSOCIATED WITH ATTACK BY COCKCHAFER GRUBS (SCHIZONYCHA SP.)
Authors: TARR S. A. J. 
Published: February 2008

Wilt of dolichos bean (Dolichos lablab) in the Sudan Gezira appeared to be due primarily to cockchafer grubs (Schizonycha sp.) in the soil attacking the hypocotyls or roots of plants up to about 6 weeks after sowing. Many wilted plants also showed symptoms of ashy stem blight (Macrophomina phaseoli), but in these the fungus was probably a secondary invader rotting roots weakened or damaged by unfavourable soil conditions or insects. Wilt was often severe in dolichos sown on land cropped to sorghum (Sorghum vulgare) in the preceding season, sorghum roots in the soil harbouring the grubs. Under moderate grub attack seed dressings containing organomercurial and γ‐benzene hexachloride (BHC) gave satisfactory‐protection at 0.089%γ‐BHC/seed but were inadequate when wilt was severe. Dieldrin and aldrin at 0.044 or 0.089%/seed gave excellent protection in all experiments, but their performance under exceptionally severe wilt conditions has yet to be tested, as also the relative efficiencies of seed treatment and soil treatment under such conditions. Fungicide‐insecticide seed treatment also reduced preemergence rotting of germinating seeds due to grub attack.Wilt rarely occurred in dolichos planted on land fallow in the preceding season, but, even in the apparent absence of wilt, seed treatment often appreciably improved emergence, plant populations, growth and yields. These effects possibly resulted from control of root damage by soil insects, such damage reducing growth and yields but not sufficiently severely to cause wilting. Pending further investigation a powder seed dressing containing organomercurial plus 20% dieldrin, and applied at 1:450 by weight to seed (about 5–6 g./acre of dieldrin), is recommended for dolichos bean in the Gezira.
SOME EFFECTS OF CHANGING TEMPERATURE AND OF VIRUS INHIBITORS ON INFECTION BY CUCUMBER MOSAIC VIRUS
Authors: BADAMI R. S. 
Published: February 2008

Whereas the spinach strain of cucumber mosaic virus fails to multiply and cause symptoms in tobacco plants kept above 30° C., the yellow strain infects at 36° C. and causes more severe symptoms than at 20° C. Increasing the temperature up to 28° C. increases the initial rate at which the spinach strain multiplies, but the virus later reaches much higher concentrations in leaves at lower temperatures, presumably because it is rapidly inactivated at 28° C. Exposing inoculated plants to 36° C. for 6 hr. decreases the number of infections by the spinach strain when the exposure starts within 6 hr. of inoculation, but not afterwards.Pancreatic ribonuclease inhibits infections by strains of cucumber mosaic virus; inhibition is greatest when the enzyme is present in the inoculum, and when applied to inoculated leaves its effect decreases rapidly with increasing time after inoculation.Infection by and the multiplication of strains of cucumber mosaic virus in tobacco are only slightly affected by thiouracil and greatly by azaguanine, whereas strains of tobacco mosaic virus are inhibited much more by thiouracil than by azaguanine. Like tobacco mosaic virus, cucumber mosaic virus multiplies more when inoculated leaves are floated in nutrient solutions than in water, but unlike tobacco mosaic virus, its multiplication is not inhibited by thiouracil more in nutrient solutions than in water.
EFFECT OF NITROGENOUS FERTILIZER APPLIED AT DIFFERENT DATES ON TAKE‐ALL, EYESPOT AND YIELD OF WINTER WHEAT GROWN ON LIGHT SANDY LOAM
Authors: SALT G. A. 
Published: February 2008

In a replicated field experiment on light sandy loam at Woburn, where winter wheat is a very uncertain crop, Cappelle and Holdfast, grown after potatoes with dung, yielded 50 and 41 cwt./acre of grain, respectively, when given 6 cwt./acre of Nitro‐Chalk in April, compared with 19 and 20 cwt./acre when unfertilized. The same fertilized plots yielded 29 and 19 cwt., respectively, in the second, and 25 and 17 cwt./acre, respectively, in the third year on the same land, whereas unfertilized plots of both varieties yielded only 9 and 5 cwt./acre. The decrease in mean yield from 27 cwt. in the first, to 15 and 10 cwt./acre in the second and third crops was associated with a decrease in ear number from 16.7 to 14.6 and 12.2, respectively, and with a striking decrease in weight of grain per ear, caused partly by a large increase in the proportion of small grains. Eyespot (Cercosporella herpotrichoides Fron.) although present each year did not become prevalent; an increase in the percentage straws affected by take‐all (Ophiobolus graminis Sacc.) from 9 to 15 and 26%, respectively, and a severe increase in weed infestation (Agrostis gigantea) appeared to be the main factors reducing yield.Nitro‐Chalk applied in April yielded most grain every year, and wheat fertilized at this time had less eyespot and take‐all than that fertilized in March. Fertilizer applied in May increased weed growth, failed to decrease take‐all and yielded fewer ears, less grain, and a higher proportion of tailcorn than did earlier applications.
AN ANALYSIS OF THE GROWTH RESPONSE OF YOUNG TOMATO PLANTS TO INFECTION BY VERTICILLIUM ALBO‐ATRUM: II. THE PRODUCTION OF GROWTH SUBSTANCES
Authors: PEGG G. F. , SELMAN I. W. 
Published: February 2008

Bioassays on ether‐soluble acid extracts from healthy and Verticillium‐infected tomato plants, showed the presence of substances inhibiting growth of wheat coleoptiles in both healthy and infected leaves and stems, but the amounts were greater in the infected.Assays of infected stems and leaves showed increases in growth‐promoting activity expressed as indole‐3‐acetic acid equivalents (IAAe), up to 200% of those for healthy controls.Similar assays of cultures of V. albo‐atrum showed growth‐promoting activity. No acid substance capable of inhibiting the growth of wheat tissue was detected in the culture filtrate. IAA was identified by colour test with Ehrlich's reagent on chromatograms from extracts of both infected stems and fungal culture filtrates.The vertical distribution of IAAe was determined in healthy and infected plants at the eight‐leaf stage by assaying individual leaves and four stem segments separately. In healthy plants the IAAe content was greatest in the young leaves (6–8) but no gradient was observed as between leaves 1–5. In infected leaves increases over the controls were found in leaves, 1, 3 and 6 and a decrease in leaf 8.In healthy stems IAAe was highest in the distal segment and infected stems showed higher values at all four levels, with the relative increase greatest in the distal region.It is suggested that the major part of the Verticillium syndrome including petiolar epinasty, tylosis, pith hyperplasia and the formation of adventitious roots is the result of an accumulation of growth substances in infected tissue.
THE INCIDENCE OF CERTAIN SEED‐BORNE DISEASES IN COMMERCIAL SEED SAMPLES: I. LOOSE SMUT OF BARLEY, USTILAGO NUDA (JENS.) ROSTR.
Authors: MARSHALL GILLIAN M. 
Published: February 2008

A simple whole‐embryo test for detecting the presence of loose smut, Ustilago nuda, in barley grains has been developed and is described. Embryos from 1000 grains can be examined within 24 hr. and the actual working time per sample is just over 1 hr.The results of embryo tests showed a high positive correlation with the incidence of the disease in field plots, (r= 0.83).Commercial samples of seed barley, submitted in 1954‐57 to the Official Seed Testing Station, have been examined by this embryo test for the presence of loose smut. The varieties received could be clearly divided into two groups: the Scandinavian‐bred varieties, e.g. Carlsberg and Herta, having 84% of the samples infected, with the level of infection up to 19%; and the English‐bred varieties, e.g. Proctor and Plumage‐Archer, where only 9.5% of the samples were infected, with the level of infection rarely more than 0.5%. In spite of differences in weather conditions during the period when infection occurred seasonal variations in the incidence of loose smut were not obvious from the results in the 3 years.
THE DETERMINATION OF THE SIZE OF PLOT SUITABLE FOR COTTON SPRAYING EXPERIMENTS IN THE SUDAN GEZIRA
Authors: JOYCE R. J. V. , ROBERTS P. 
Published: February 2008

An insecticidal experiment in the season 1955‐56 investigating interplot effect—defined as the interaction of one plot with the insect population on an adjacent plot—is described. This effect is considered to operate in three possible ways: (a) spray drift; (b) insect (pest) movement; (c) insect (parasite and predator) movement.In the experiment, care was taken to minimize (a). The plot sizes were 10‐ or 20‐feddan fields within areas of 90 and 180 feddans, respectively.There was strong evidence that yields of fields on the boundaries between sprayed and unsprayed fields were affected by the treatments on the other side of the boundary. That is, sprayed fields yielded less when adjacent to unsprayed fields and unsprayed fields yielded more when adjacent to sprayed.When cotton fields of 10 feddans in areas of about 90 feddans were unsprayed and separated by 150 or 450 m. of unsprayed cotton from sprayed fields, Empoasca libyca de Berg. and bollworm infestations were not measurably changed, but the Hercothrips spp. infestations were significantly reduced and the Bemisia tabaci Genn. infestation slightly increased compared with those found on 10‐feddan fields within 90 feddans of completely unsprayed cotton, the changes in infestation corresponding to the distance from the sprayed cotton. Yields from such fields tended to be higher than those from within completely unsprayed cotton, although these differences were not significant.When fields of 20 feddans in areas of 180 feddans were unsprayed and separated by 150 or 450 m. of unsprayed cotton from sprayed fields of similar size, there were no apparent differences when their insect infestations or yields were compared with those from 20‐feddan fields within 180 feddans of completely unsprayed cotton.These results are adduced as evidence that interplot effect might have affected infestations and yields in 10‐feddan fields of unsprayed cotton at distances of 150 or 450 m. from sprayed cotton. No such interplot effect was apparent when 20‐feddan fields were used. It is considered that spray drift was unlikely to have caused these results which must, therefore, have been due to insect (pest, parasite and predator) movement.It is concluded that in experiments in the Sudan Gezira, where treatments affect the insect complex on cotton, it is dangerous to assume that a 10‐feddan field in a 90‐feddan area is independent of differently treated fields in that area. On the other hand, independence can probably be assumed in 20‐feddan fields in 180‐feddan areas of cotton, provided that the field is separated from its differently treated neighbour by at least 150 m.