bluuebunny/crossref_metadata_2025_split huggingface dataset:
Tomato pith necrosis caused by Pseudomonas corrugata n. sp.
Authors: SCARLETT CAROLINE M. , FLETCHER J. T. , ROBERTS PAULINE , LELLIOTT R. A. 
Published: February 2008

SUMMARYA disease of mature tomato plants is described, the symptoms of which include brown discoloration and/or necrosis and collapse of the pith. These are sometimes accompanied by vascular browning, external dark brown to black stem lesions, bacterial flux from stem wounds and adventitious root formation. The disease, which appears to be favoured by high humidity and/or free water on the plant surfaces and by high N fertiliser, has been widespread on many glasshouse holdings in England since 1971 but has caused severe loss on only a few. It is thought to be caused by a new species of the genus Pseudomonas for which the name P. corrugata Roberts and Scarlett is proposed.
Early warning of egg hatching in pea moth (Cydia nigricana)
Authors: LEWIS T. , STURGEON DOLORES M. 
Published: February 2008

SUMMARYFemale pea moths (Cydia nigricana) kept at 23 oC began to lay eggs 2–3 days after emergence, lived for 16–21 days and laid on average 71 eggs. Individuals kept in field cages lived for slightly longer and laid on average 91 eggs. About 85% of eggs were laid during the first 11 days of the oviposition period, usually in the late afternoon and early evening.The relationship between the rate of egg development and temperature was defined. The estimated developmental zero was 9‐4 oC at constant temperatures and 8‐5 oC at fluctuating temperatures. Above 28 oC mortality increased and above 31 oC development was apparently retarded. Development at constant temperatures took 6–16% longer than at fluctuating temperatures with the same mean.Estimates of hatching dates in the field made from temperature data recorded at several sites in and near a pea crop, and 8 km distant, were usually within a day of the observed date. In warm weather, estimated and observed dates usually coincided; in cooler weather hatching was 2–3 days later than expected. Hatching dates predicted from temperature data after only 80% of development had occurred were correct on 28 out of 36 occasions.An example is given to show how the method could be used eventually with a sex attractant trapping system to provide early warning of first hatching and spraying dates.
Occurrence of Phialophora radicicola var. graminicola and Gaeumannomyces graminis var. tritici on roots of wheat in field crops
Authors: SLOPE D. B. , SALT G. A. , BROOM E. W. , GUTTERIDGE R. J. 
Published: February 2008

SUMMARYAssessments of Phialophora radicicola var. graminicola (PRG) and Gaeumannomyces graminis var. tritici (GGT) were made by culturing and by direct microscopic examination of pieces of seminal roots from 16 winter wheat crops grown in different cropping sequences and with different phosphate manuring. PRG occurred on all wheat crops, but was abundant only on wheat after grass, where it seemed to delay the onset of damaging take‐all by 1 yr. Delayed occurrence of take‐all by phosphate fertiliser was not related to differences in populations of PRG. Wheat grown in ‘take‐all decline’ soils had only small amounts of PRG, indicating that the development and the decline of take‐all epidemics may be influenced by different biological control mechanisms; breaking sequences of wheat crops by 1 yr grass leys might harness the advantages of both mechanisms.
Thermal inactivation of cherry leaf roll virus in tissue cultures of Nicotiana rustica raised from seeds and meristem‐tips
Authors: COOPER VALERIE C. , WALKEY D. G. A. 
Published: February 2008

SUMMARY Nicotiana rustica tissue cultures derived from seeds or embryos infected with cherry leaf roll virus (CLRV), remained infected after culture at 22 oC. No infectivity was found in cultures held at 32 oC for 5 days but it was readily detected after such cultures were transferred to 25 oC for 8 days. Virus was permanently eradicated from most plants after 20 days incubation at 32 oC and from all plants after 7 days incubation at 40 oC.Partially purified preparations of CLRV lost infectivity after 9–12 days at 22oC, 5 days at 32oC and 3 days at 40oC.
Frequency and geographical distribution of specific virulence factors in Bremia lactucae populations in England from 1973 to 1975
Authors: DIXON G. R. , WRIGHT I. R. 
Published: February 2008

SUMMARYSamples of lettuces infected with Bremia lactucae were collected from seven areas of England during 1973‐5. These were tested under controlled environmental conditions on a range of differentially resistant cultivars to determine the frequency of virulence (V) factors in the pathogen population. In most cases the results could be accommodated by the relationship advanced by Crate & Johnson (1976). A virulence phenotype was determined for each isolate and individual virulences within isolates were identified as present at high or low frequencies. The most common V factors were V3, V4, V6 and V8 which reflected the resistance (R) factor complement of lettuce cultivars currently in commercial production. There were few gross differences in the geographical distribution of virulence factors between the seven areas. In the West Central region, however, which encompasses the Evesham and Lancashire production areas, results indicated that the use of cultivars containing resistance (R) factors 2 and 8 respectively would have provided protection from the disease during 1974. There were differences in virulence combinations at the holding or locality level within each large area, which could be exploited by growers providing testing was done in their particular locality.Universally susceptible cultivars and those with only limited resistance factors were often found to be infected with B. lactucae populations which contained large numbers of V‐factors. It might have been expected that these pathogen populations would have been restricted to cultivars with large numbers of R‐factors. This finding conflicts with the suggestion that pathogen populations with complex virulence patterns are ‘unfit’ as compared with those with more simple virulence components.
The effect of sowing density and application of gibberellic acid on male sterility and ear emergence in ethephon‐treated field‐grown wheat
Authors: HUGHES W. G. , BODDEN J. J. , GALANOPOULOU STELLA 
Published: February 2008

SUMMARYThe induction of male sterility with ethephon and improvement in ear emergence with GA3 (1‐1 kg a.i./ha) applied 3 days later, was investigated in the winter wheat cv. Maris Nimrod sown in the field at72, 138 and 276 spaced plants/m2. Increased sowing density resulted in fewer surviving tillers per plant, a larger number of tillers per unit area and consequently a narrower range of stage of tiller development. This permitted a more accurate assessment of the correct time for ethephon application and resulted in a larger proportion of tillers responding to GA3 by having fully emerged ears. The most effective treatments for the production of emerged male sterile ears were 6‐4 and 12‐8 kg ethephon/ha applied to crops sown at the highest density.
The creation and management of wildfowl refuges as a means of lessening the conflict between farmers and geese
Authors: Owen Myrfyn 
Published: February 2008

ABSTRACTWith increases in goose numbers and incidences of problems with other than traditionally damaging species on new crops conflict has greatly increased recently.This paper suggested that the creation of managed goose refuges in problem areas provided the best long‐term solution. Examples of the success of refuges were given based on experience at two Wildfowl Trust goose refuges. Goose use of land surrounding these refuges had decreased following their creation and the goose carrying capacity of refuge land had been increased by up to 150% by controlling winter disturbance, cropping and stock grazing. This had been achieved without drastically changing the agricultural regime, which in both areas was in line with local practices.Because of great annual fluctuations in goose numbers following variations in breeding success and of the difficulty of predicting goose carrying capacity, assessments of the area of land required to accommodate geese in conflict with agriculture in Britain can only be very approximate. Based on goose counts in 1975‐6, some 150000 geese (of four species) were potentially involved and the land area required as refuges to accommodate all of them (giving a maximum figure) in the region of 20 000 acres (7800 ha).
Red deer farming
Authors: Sharman G. A. M. 
Published: February 2008

SUMMARYAn experimental deer farm has been in operation on heather dominant upland in Kincardineshire since 1970 where the Rowett Research Institute and the Hill Farming Research Organisation have been exploring the possibility of intensifying venison production from such land. Six years' experience indicates that a tame foundation stock of red deer is a feasible basis for making good use of such land for the production of lean deer meat.
A method of inoculating young cocoa plants with basidiospores of Oncobasidium theobromae
Authors: PRIOR C. 
Published: February 2008

SUMMARYA method is described for collecting basidiospores of Oncobasidium theobromae onto agar containing 35% w/v sucrose and preparing infective spore suspensions. When cocoa seedlings and clonal cuttings were inoculated, large differences in percentage infection were demonstrated between seedling progenies of resistant and susceptible trees. Resistant clonal cuttings were generally difficult to infect. The value of the technique for resistance screening is discussed.
Control of potato cyst nematode (Globodera rostochiensis) by nematicides and a resistant potato cultivar at four sites in Scotland
Authors: TRUDGILL D. L. , MACKINTOSH G. M. , OSBORNE P. , STEWART R. M. 
Published: February 2008

SUMMARYThe control of potato cyst nematode (Globodera rostochiensis) by the oxime‐carbamates aldicarb and oxamyl was tested in four fields in Scotland. Dazomet was tested in three of these fields and carbofuran in one. In untreated plots in the three most heavily infested fields Maris Piper (resistant) yielded better than Pentland Crown (non‐resistant). All nematicides increased the yields of both potato cultivars but had a greater effect on the yield of Pentland Crown. Dazomet increased yields of tubers most. Heavy nematode infestation reduced yield of tubers more in a sandy soil than in two sandy loams. In a field with few potato cyst nematodes nematicides did not significantly affect tuber yields.Although the nematicides greatly increased yields, they were not completely effective in controlling potato cyst nematodes. In treated plots in the lightly infested field, there were more nematode eggs following a crop of Pentland Crown than before. In contrast, Maris Piper markedly decreased post‐cropping populations and except at one site, where dazomet further decreased nematode numbers, combining nematicides with the resistant cultivar failed to decrease nematode numbers further. Nematicides decreased the numbers of larvae invading potato roots by up to 95%, oxamyl at 5–6 kg/ha being consistently the best treatment.
Genetically determined variation in seed germination and field emergence of Brassica oleracea
Authors: HODGKIN T. , HEGARTY T. W. 
Published: February 2008

SUMMARYThe germination and field emergence levels and germination rates were measured of Brassica oleracea seed lots obtained by outcrossing the progenies of two half diallels to a single pollen parent. Analysis of variation of the seed lots classified according to their maternal grandparents showed that both general and specific combining abilities were important in accounting for the observed differences; the observed performance of many of the seed lots was satisfactorily accounted for by their grandmaternal parentage. The capacity to give high levels of germination was not necessarily related to the capacity to give high relative field emergence levels, maternal grandparents apparently differing in their ability to contribute to these two characters.
Distribution of photosynthate produced before and after anthesis in tall and semi‐dwarf winter wheat, as affected by nitrogen fertiliser
Authors: MAKUNGA O. H. D. , PEARMAN I. , THOMAS S. M. , THORNE G. N. 
Published: February 2008

SUMMARYIn 2 years the distribution of radioactivity recovered in entire shoots of field‐grown winter wheat was determined at various times after exposing the top two leaves (flag leaf or second leaf) to 14CO2 for 30 s. In 1976 when 14C was supplied to either leaf 14 days before anthesis, 30% was in the ear at anthesis. Less than 5% was in the leaf exposed to I4CO2. The remainder was equally divided between the stem above and below the flag‐leaf node when the flag leaf had been exposed, and was mainly in the lower part of the stem when the second leaf had been exposed. By maturity the proportion in the stem had decreased; 20% of the total activity was in the grain and 30% was still in the ear structures.When 14C was supplied 10 days after anthesis, the proportion in the ear 24 h later ranged from 42 to 69% of that in the whole shoot when the flag leaf was exposed, and from 6 to 28% when the second leaf was exposed. At maturity these proportions increased to 92 and 85% when the 14C had been supplied to flag leaves and second leaves respectively. When 14C was supplied 25 days after anthesis to either flag leaves or second leaves, more than 90% of the activity was in the mature ears. Less than 5% of the 14C remaining at maturity from any treatment was still in the leaf exposed to 14CO2. Between 2 and 6% of 14C supplied after anthesis was in the non‐grain parts of the ear.The proportion of the 14C in the ear was greatest for the semi‐dwarf varieties Maris Fundin and Hobbit, less for Maris Huntsman, and least for Cappelle‐Desprez. These varietal differences were large 24 h after exposure to 14CO2, especially in 1976. They were small and rarely significant at maturity.Nitrogen fertiliser up to 210 kg N ha‐1 had negligible effects on the distribution of 14C, although it greatly increased growth and yield, especially in 1975.
Studies of Rhizobium meliloti isolated from salt‐affected soils
Authors: DOUKA CATHERINE E. , APOSTOLAKIS C. G. , SKARLOY V. D. 
Published: February 2008

SUMMARY Rhizobium meliloti strains have been isolated from salt‐affected, non‐cultivated soils of Greece. The effectiveness of the isolates was investigated in test‐tubes using nitrogen‐free salts agar or soil. In the latter case a new simple and rapid technique was used during which plants of Medicago saliva were grown in large test‐tubes containing salt‐affected soil under controlled sterile conditions. Field trial measurements in salt‐affected soils indicate a good response to inoculation.
Effect of high soil temperatures on nodulation of cowpea, Vigna unguiculata
Authors: DAY J. M. , ROUGHLEY R. J. , EAGLESHAM A. R. J. , DYE M. , WHITE S. P. 
Published: February 2008

SUMMARYCowpeas, inoculated with one of five effective strains of Rhizobium isolated from African soils, were grown at root temperatures of 30 oC continuously or at 36, 38, 40, 42 and 44 oC for 5 h/day and returned to glasshouse ambient for the intermediate period. Growth was best at 30 and 36 oC; above 40 oC growth was poor and no nodules formed. At 40 oC two strains failed to nodulate. Symbiotic performance was not dependent only on nodule production as nodule efficiency varied inversely with temperature.The number of nodules formed by strain R5000 after exposure of inoculated seed or seedlings to 40,42 or 44 oC for 5 h/day on each of 3 or 6 days depended on the age of plant and the duration of exposure to stress. When exposed to 42 or 44 oC during the first 3 days after sowing nodulation was reduced from 18 to 1–3 nodules/plant even after a further 40 days growth at ambient (30 day, 20 oC night). Nodulation was unaffected when 10–15‐day‐old seedlings were exposed to the same conditions.Numbers of strain R5000 on seed declined rapidly following three daily exposures of 5 h at 39 and 42 oC; at 45 oC less than three bacteria survived on each seed. Other rhizobia of the cowpea group varied greatly in their toleration of high temperatures, some survived well at 45 oC whereas others behaved like R5000.
Observations on the morphs of Macrosiphum avenae and Metopolophium dirhodum on cereals during the summer and autumn
Authors: DEAN G. J. 
Published: February 2008

SUMMARYFrom June to early August 1970, populations of Macrosiphum avenae and Metopolophium dirhodum on marked tillers of field barley were compared with the numbers of alatae trapped at crop height and at 12.2 m. There were always more M. dirhodum than M. avenae on the tillers. Only apterae were produced until mid‐June when both alatae and apterae occurred; after mid‐July only alate M. avenae were found. Until mid‐June most of the flying alatae were caught at 12.2 m as they migrated from spring hosts to cereals. Thereafter, more alate M. avenae were trapped at 12.2 m than at crop level, whereas numbers of alate M. dirhodum were usually comparable at both heights. Although crop and flying populations occasionally showed temporal similarities, insufficient is known about their field distribution and the factors affecting their alate production and flight activity to interpret this relationship.In the autumn, two consecutive reproductive phases of M. dirhodum occurred on winter wheat grown in pots outdoors. Initially, apterous virginoparae and alatae, probably sexuparae, were produced, whereas only alate males appeared during the second phase. In contrast, M. avenae deposited mainly apterous virginoparae although some oviparae developed in October to lay scattered, probably infertile eggs on the tillers.
Factors influencing the prevalence of Pleospora bjoerlingii on sugar‐beet seed
Authors: BYFORD W. J. 
Published: February 2008

SUMMARYPleospora bjoerlingii was more prevalent on the seed of some sugar beet cultivars than others following both a dry seed harvest when infection was scarce and a wet harvest when superficial infection of seed was common. Methods of cultivation and harvesting that delayed ripening and increased the exposure of the seed to rainfall in a wet season increased the incidence of seed‐borne P. bjoerlingii but the incidence of the fungus on the seed of different cultivars was independent of the effect of cultivar on the time of ripening of the crop.
Interactions of Puccinia hordei and Erysiphe graminis on seedling barley
Authors: ROUND P. A. , WHEELER B. E. J. 
Published: February 2008

SUMMARYThe development of Puccinia hordei on the first leaf of barley seedlings previously inoculated with Erysiphe graminis was compared with that on uninoculated leaves of comparable age. On cv. Zephyr, more rust pustules developed when leaves were inoculated with both fungi within 24 h but fewer pustules if the period between the two inoculations was longer than 2 days. The reduction in numbers of rust pustules was especially marked where leaves were previously inoculated with many conidia of E. graminis. The size of rust pustules was reduced whatever the period between the two inoculations. Arresting mildew development by applying ethirimol as a soil drench to pots of seedlings inoculated with E. graminis 6 days previously, or floating segments of leaves inoculated with both fungi on 2% sucrose, in part counteracted these effects on rust pustule size. Similar effects were observed with cv. Mazurka where inoculations with E. graminis produced only small necrotic flecks but did induce premature loss of chlorophyll. On this cultivar (in contrast to Zephyr) the inoculation of one leaf surface affected the development of P. hordei on the other.In comparable experiments using Zephyr, E. graminis produced smaller colonies with fewer conidiophores on leaves previously inoculated with P. hordei. These effects could be alleviated by arresting rust development with a spray containing benodanil or by floating segments of leaves inoculated with both fungi on 2% sucrose. Germination of the conidia of E. graminis, formation of appressoria and initiation of colonies were not affected by the presence of P. hordei.
Alteration of spermosphere ecosystems affecting oviposition by the bean seed fly and attack by soilborne fungi on germinating seeds
Authors: HARMAN G. E. , ECKENRODE C. J. , WEBB D. R. 
Published: February 2008

SUMMARYIn laboratory studies, treating ‘Butternut’ squash (Cucurbita pepo) seeds with ascospores of Chaetomium globosum NRRL 6296 and 6297 reduced oviposition by the bean seed fly Hylemya platura (Meigen), and reduced seed rot caused by Pythium ultimum and P. aphanidermatum. Treatment of seeds with thiram or captan increased oviposition by the bean seed fly. In the field, treatment of snap bean seeds with C. globosum NRRL 6296, or a commercial seed treatment mixture containing captan, diazinon, and streptomycin sulphate, resulted in significantly less damage by bean seed fly larvae than a treatment with thiram.
Effects of feeding position of the aphids Sitobion avenae and Metopolophium dirhodum on wheat yield and quality
Authors: WRATTEN S. D. 
Published: February 2008

SUMMARYThe effects of feeding site of Sitobion avenae and Metopolophium dirhodum on grain weight, number and nitrogen content were investigated in the laboratory and in the field. When the latter species was confined to particular leaves in a growth room, grain weight reductions occurred only when the aphid fed on the flag leaf; reductions in percentage grain protein, but not grain weight, followed lower leaf feeding. Leaves which had borne aphids had a higher proportion of nitrogen at death than control leaves, but this explained little of the shortfall in grain nitrogen, which was mainly due to direct removal during aphid feeding.Multiple regressions of grain weight on aphid species/feeding site in the field confirmed the lack of grain weight effects when lower leaves were colonised; because grain size was greatly reduced by aphid feeding, percentage grain nitrogen increased with increasing aphid density in one cultivar and in others was unchanged. Successive comparison of control grain weights with those from tillers bearing an increasing range of aphid densities resulted in a significant reduction in weight with tillers bearing 21 to 25 aphid units on their ear and flag leaf combined, one unit comprising one adult or fourth‐instar aphid or three of earlier instars. These and other factors affecting the nature and extent of cereal aphid damage are discussed.
Sources and inheritance of resistance to halo‐blight of Phaseolus beans
Authors: TAYLOR J. D. , INNES N. L. , DUDLEY C. L. , GRIFFITHS W. A. 
Published: February 2008

SUMMARYForty‐three accessions of Phaseolus vulgaris and four of P. coccineus were classified on the basis of the reaction of their primary leaves and pods to inoculation with races 1 and 2 of the pathogen Pseudomonas phaseolicola. Four groups were recognised, (1) highly resistant to race 1 only, (2) resistant to both races, (3) slightly resistant to both races or (4) susceptible to both races. Race 1 resistance was present in a number of accessions (e.g. Red Mexican UI3, Rona, Cornell 42–242). Resistance to race 1 and 2 was present in PI 150414, GN Nebraska No. 1 sel. 27, OSU 10183 and other accessions with PI 150414 in their parentage.Studies on the inheritance of resistance in Red Mexican UI3 and PI 150414 were made in crosses with various susceptible bean cultivars. A single dominant factor was responsible for race 1 resistance in Red Mexican UI3. The resistance factor in PI 150414 to races 1 and 2 behaved as a recessive in crosses with Cascade and Seafarer but was partially dominant in crosses with Gallatin 50. These findings suggest that genetic background can influence the expression of the resistance factor from PI 150414 and largely reconcile the conflicting evidence of previous investigators.