bluuebunny/crossref_metadata_2025_split huggingface dataset:
The effect of disinfecting and bruising seed potatoes on the incidence of dry rot (Fusarium caeruleum (Lib.) Sacc.)
Authors: Small T. 
Published: February 2008

The effect of bruising and of disinfecting (‘dipping’) seed potatoes with a proprietary organo‐mercury preparation on the incidence of dry rot in them was tested in field trials during three seasons. The tubers used were of the susceptible variety Ninetyfold, taken from crops grown in contaminated soil, harvested immature in July to early August each year under farm conditions, and stored in boxes.Seed tubers not deliberately bruised, whether dipped or not at lifting time, remained practically sound until planting time in the fallowing season, if left undisturbed in their boxes.Tubers deliberately bruised, either at digging time or 1‐2 weeks later, but not dipped, developed severe dry rot with few exceptions. The disease had run its course by mid‐October. When undipped, sound tubers were bruised in October, they contracted severe dry rot, but dipping such tubers immediately before bruising reduced the loss satisfactorily in five out of six trials.Tubers bruised at digging time and immediately dipped suffered little from dry rot in almost all cases. Delayed dipping of bruised tubers checked the disease in some trials but not in others. Seed tubers severely bruised 1‐2 weeks after being dipped remained practically sound except in one instance, whereas tubers severely bruised approximately 3 months after being dipped, subsequently developed severe dry rot in four out of six tests, unless they had been redipped immediately before they were bruised.Inoculation of healthy tubers with soil samples showed that the fungus is widely distributed in potato fields in Cheshire. Dipping killed all, or almost all, of the fungus in the soil adhering to the seed tubers.The results are discussed and suggestions are made for further investigations and for practical control measures.
Water plants in the Gezira canals: A study of aquatic plants and their control in the canals of the Gezira cotton area (Anglo‐Egyptian Sudan)
Authors: Andrews F. W. 
Published: February 2008

The geographical position and climatic conditions of the Gezira cotton area are briefly described. A description is given of the Blue Nile river, and Sennar Reservoir. The common water plants of die latter are listed. It is shown in the case of five of these plants that they tend to be divided in those that occur in shallow water and those that prefer deeper water. Details of the annual rise and fall of the water of the Reservoir are also given.The system of canalization in the Gezira is described and details given of the method of irrigation. A list is given of the common water plants in the Gezira canals, and their distribution over the canalized area is discussed. A comparison is made of the water flora of the canals of Egypt with those of the Gezira.A system of small experimental canals was used to study the life history of the more important water plants in the Gezira canals. Details are given of the extent of the spread of the plants in these canals during a period of 14 months. It was found that abundant growth and seed formation occurred when clear water was entering the canals, but that the bulk of the vegetative part of the plants tended to die when turbid flood water arrived. Abundant seed germination occurred during the turbid water period. Drying the canal bed for 3 1/2 months had little effect on the final quantity of weed developed in the canals when they were refilled. Seed remained viable after 3 1/2 months' dry exposure. Removal of the surface soil from the dry canal bed produced no significant control of the water plants when water again entered the canals. A short flush of water was allowed to flow down the dry canal bed. It was hoped that the seed would germinate and the seedlings be killed by exposure after the flush had ceased. The effect of this treatment on the subsequent plant growth was negligible.Laboratory experiments on the more important water plants showed that the vegetative part of the plants was killed after 8 days' dry exposure to the sun and that mercuric chloride, mercuric chloride‐iodide, and sodium arsenite in a concentration of 1/10,000 killed all plants after immersion in the poison solution for 5 days. At a concentration of 1/100,000 and immersion for 7 days none of these poisons was able to kill Potamogeton nodosus Poir. Work on poisons was discontinued for reasons stated in the text.A short account is given of plants that invade the canals from the banks.The problem of water plant control is discussed, and it is shown that the most hopeful method of control would be a system whereby all infested canals are cleared at regular intervals designed to prevent seeding during the clear‐water period and to remove seedlings during the flood‐water period. The application of this method in the Hag Abdulla Subdivision is described. The successful control that resulted reduced the weeding costs by half.
The suppression of one plant virus by another
Authors: Bawden F. C. , Kassanis B. 
Published: February 2008

Severe etch virus prevents die multiplication of potato virus Y and Hyoscyamus virus 3 and replaces them even in plants in which they are established. Mild etch virus reduces the concentration of potato virus Y but does not suppress it completely. Cucumber virus 1 multiplies normally in mixed infections with any of the three other insect‐transmitted viruses. Possible implications of these results on the mechanism of virus multiplication are discussed; it is suggested that these viruses inactivate in cell sap at approximately the same rate as they denature in vitro.No differences were found between the stability of antibodies to viruses with different properties.
Observations on the biology and experiments on control of the mangold fly (Pegomyta betae Curtis) on sugar beet
Authors: Roebuck A. , Baker F. T. , White J. H. 
Published: February 2008

The fly (Pegomyia betae Curtis) was studied in its ecological and phenological aspects in central Nottinghamshire, and experiments on the lines of Continental workers, using sodium fluoride and molasses spray, were carried out.It is shown that some pupae from the second generation‐ fail to emerge in the late summer but emerge in the spring of the following year, rather earlier than the pupae resulting from the third generation. The flies resulting from this early emergence are less fertile than those appearing later.Methods of control discussed include cultural, biological and chemical means. Delayed drilling (not before mid‐May) helps to avoid the attack of the first generation. A rapid increase in number of parasites was observed and resulted in the annihilation of a large population of the fly. Treatment with molasses/sodium fluoride bait spray gave promise of control.
The nature and distribution of various forms of nitrogen in the potato
Authors: Street H. E. , Kenyon A. E. , Watson G. M. 
Published: February 2008

The distribution of nitrogen fractions in the organs of King Edward potato plants harvested at intervals during the growing season has been determined. A general picture of the nitrogen distribution is presented and certain problems suggested by the data are discussed.Each organ of the plant shows a uniformity in its nitrogenous composition during the whole season of active growth. The seed tubers are characterized by their high content of non‐protein nitrogen. This fraction yields the greater part of the nitrogen withdrawn from the seed tubers; the amide, amino and ‘other nitrogen’ fractions all being markedly depleted. The severely depleted tubers retain some 20% of their initial nitrogen content.The roots are rich in non‐protein nitrogen, in which nitrate nitrogen is an important fraction. The roots from ammonium sulphate‐treated plots had a higher total nitrogen content than those from untreated plots, due to accumulation of ammonia nitrogen.The ‘tops’ have a higher nitrogen content and a higher proportion of protein than the roots. There is an increase in protein content and a decrease in non‐protein nitrogen in passing from stems, to petioles, to leaf laminae. The depleted tubers and roots and stems have a uniform low‐protein content of the order 0.4‐0.6 mg. protein nitrogen per g. fresh weight.Asparagine and glutamine occur in approximately equal amounts in the seed tubers and roots. Glutamine is more completely withdrawn than asparagine from the tubers, and in the ‘tops’ it constantly exceeds asparagine in amount.A study of the concentration gradients, from leaves to petioles, to stems, to stem bases and new tubers, of the fractions of the non‐protein nitrogen focuses attention upon the ‘other nitrogen’ as containing the organic nitrogen most actively involved in translocation.The concentration and total content of the glycoside solanine in the different organs has been determined at each sampling.
Varietal differences in susceptibility to potato virus Y
Authors: Bawden F. C. , Kassanis B. 
Published: February 2008

In addition to giving different kinds of symptoms when infected with potato virus Y, individual potato varieties also differ in their susceptibility to infection, in the concentration of virus attained in their sap, and in their efficiency as sources of virus for aphides. Their relative susceptibility in the open when exposed to equal chances of infection is correlated with the ease with which they become infected when colonized with infective aphides, and can be assessed from tests made under glass. Methods for making such tests are described; these need few tubers and give reproducible results. It is considered that they could be applied in studying the inheritance of this type of resistance and to test the behaviour of new seedlings. The American variety Katahdin was the most resistant of those tested, but there were significant differences between commercial British varieties.In the open, all varieties were equally colonized by aphides and resistance to infection with virus Y was not correlated with resistance to leaf roll.
Resolution of strawberry virus complexes by means of the aphis vector Capitophorus fragariae Theob
Authors: Prentice I. W. , Harris R. V. 
Published: February 2008

Aphides (Capitophorus fragariae) were fed for periods of up to 24 hr. on strawberry plants infected with mild crinkle, severe crinkle or yellow‐edge and then transferred to plants of the wild strawberry, Fragaria vesca, or of the cultivated strawberry, variety Royal Sovereign. On F. vesca the symptoms produced were chlorotic speckling, distortion and dwarfing of the leaves, varying in intensity', and on Royal Sovereign scattered, inconspicuous, diffuse, chlorotic spots.The symptoms from all three sources of infection were similar and were indistinguishable from those of mild crinkle of Harris & King. The virus thus selectively transmitted is tentatively concluded to be the mild crinkle virus.The virus was transmitted after feeding periods of 1 hr. or more and did not generally persist in the vector for more than 3 hr.
Field trials of copper fungicides for the control of potato blight II. Spray retention
Authors: . E. C. Large , Beer W. J. , Patterson J.B.E. 
Published: February 2008

Spray‐retention estimations were made during four seasons at Dartington in south Devon, on maincrop potatoes, twice‐sprayed, as in farm practice, with about 120 gal./acre for the first application and 160 gal. for the second.Evidence is given concerning the limits of reliability of the disk method of leaf sampling; and an alternative method, batten.' washing, is described.With from 2,1/2 to 3,1/2 in. of rain over test periods of 3‐4 weeks, 1% Bordeaux mixture showed about 40 % spray retention. Cuprous oxide and copper oxychloride sprays at the same copper dosage but compounded with sulphite lye or other water‐soluble dispersing agent showed less than 20% retention. Compounding of these materials with an insoluble sticker (bentonite) improved the adhesion.The percentage retention of 1/2% Bordeaux mixture was found to be less than that of the usual 1 % mixture, but adequate spray deposits could be maintained with this and other low‐copper fungicides by more frequent applications.A rapid method for determining total expanse of foliage in the field is described, and the importance of such determinations in connexion with spray‐retention trials, and practical spray timing, is stressed.Experiments were made to determine whether any copper is absorbed by potato leaves from the spray deposits. Absorption, or acid‐resistant adsorption, of the order of 0.02 mg. Cu/120 sq.cm. of leaf area was indicated.
The analysis of a factorial series of insecticide tests
Authors: Finney D. J. 
Published: February 2008

When a set of insecticidal toxicity tests yields parallel regression lines for the relationship between mortality probit and log dose, the potencies of the materials or conditions under test may be compared purely in terms of log L.D. 50's. The purpose of this paper is to suggest that, when tests have been made with all combinations of several different factors, standard methods for the statistical analysis of factorial experiments may be adapted to the examination of the relative potencies.Data obtained by Potter & Gillham (1046), in a 2′ factorial experiment on alternative storage conditions for insects before and after spraying and the adjuvant action of terpineol in a pyrethrins spray, are used in an example of the computations. Details are given of the test of parallelism of the regression lines, the factorial analysis of the log L.D. ′50s, the estimation of the mean effects and interactions and their standard errors, the significance tests, and the preparation of summary tables.
Diseases of the gladiolus IV. Note on the incidence and control of scab disease {Bacterium marginatum McCull.)
Authors: Hawker Lilian E. 
Published: February 2008

Stocks of imported gladioli which originally contained a proportion of scabbed corms showed very little carry‐over of the disease during the eight growing seasons 1938‐45. Carry‐over was greatest on ground where gladioli had been planted for several successive years.The incidence of the disease was greatest in the hot summer of 1940.Treatment with mercurial fungicides just before planting time gave good control. Two non‐mercurial fungicidal dusts were less effective.
Dry rot of potato (Fusarium caeruleum (Lib.) Sacc.) Effect of planting infected and contaminated sets on plant establishment
Authors: Small T. 
Published: February 2008

The effect on plant establishment of planting infected and contaminated sets of susceptible varieties has been studied in field trials from 1942 to 1945.Healthy whole sets, and whole sets inoculated internally 3 days before planting, yielded good stands, whilst whole sets with obvious dry‐rot lesions present at planting time produced gappy crops.Healthy cut sets gave satisfactory stands except in one test with Doon Star, whilst sets cut with a contaminated knife at planting time yielded only a few misses in 1943 but many in the unfavourable 1944 season and in 1945.
The provision of supplementary food to hive bees
Authors: Butler C. G. 
Published: February 2008

Sucrose syrup is less satisfactory than honey as a winter and spring food for bees: a mixture of approximately equal parts of honey and syrup is of almost the same value as honey alone.Feeding confined to early autumn induced the strongest spring development of colonies; syrup feeding in the spring may retard colony development, and food supplied at this time is apparently wasted. Feeding with syrup and pollen is advantageous only when a colony is lacking in stores of carbohydrate and protein.A total of four British Standard brood combs full of pollen provides sufficient protein for a colony on B.S. equipment from autumn until April: the best results were obtained by providing colonies on eleven B.S. combs, in early autumn, with 35‐40 lb. of honey, or honey and concentrated sucrose syrup, and four brood combs full of pollen.
Studies on Oscinella frit Linn: Notes on the resistance of cereals to infestation
Authors: Cunliffe Norman , Hodges D. J. 
Published: February 2008

Resistance of the oat plant to infestation by the frit fly is not correlated with either carbohydrate or silica content. By increasing the number of eggs placed on an oat variety, proved to be resistant in the field, its resistance can be reduced below that of the most susceptible type, the inference being that resistance is indirect and due to some form of plant attractiveness which determines extent of oviposi‐tion. Oviposition studies in the held show that oviposition on susceptible varieties of oats, such as Victory and Star, is three times as great as on resistant types, such as Summer and Spet; selections from crosses between susceptible and resistant types, intermediate in resistance, receive a proportionate number of eggs, resistance being inherited. Some oviposition data for wheat and barley are included. Fly orientation is not controlled by either chemotaxis or hydrotaxis, but is influenced by stereotaxis; negative results have so far been obtained from phototaxis studies. Trie resistance to infestation in the field of twenty‐two named varieties of oats is compared with that of a standard variety; none is so resistant as Summer, while Richland Iowa 411 and Eagle approach Sandford in possessing moderate resistance. The marked difference between Victory and Summer in regard to stem infestation in spring is not extended to the grain infestation, no marked difference being observed. Susceptibility to sterility of grain shows significant differences, and there is an indication that segregation may be transgressive. Late nitrogenous dressings have no effect on extent of either grain infestation or sterility. The recovery capacity of Sandford almost equals that of Gris de Houdan, a good tillering variety. Maize exhibits varietal differences in extent of resistance to attack. The protective effect of D.D.T. is considerable, but not complete.The essential statistical analyses have been lodged with the Librarian of the British Museum. A statement of significance of result means significance at the 1 % point of distribution.
The assimilation of ammonium and nitrate nitrogen by detached potato sprouts
Authors: Street H. E. , Kenyon A. E. , Watson G. M. 
Published: February 2008

Detached potato sprouts have been grown successfully in ammonium and nitrate culture solutions for 5 weeks. The pH and concentration of each solution were such that a similar rate of nitrogen absorption took place from both. The general appearance, increase in fresh and dry weight and the nitrogen distribution in the shoots and roots of sprouts removed at intervals for analysis have been compared. Sprouts, previously grown in nitrate or ammonium culture solutions, have been transferred and grown for 8 days on a minus‐nitrogen culture solution, and the changes in appearance, growth rate and nitrogen distribution followed in a similar manner.The importance of aerating the culture solution, of frequent solution renewal and of an adequate supply of soluble iron for successful solution culture of potato sprouts is stressed.The ammonium sprouts developed more evenly and ultimately more rapidly than the nitrate sprouts. The nitrate sprouts were a lighter green, showed a tendency for the lower leaves to yellow and dry up and, when transferred to the minus‐nitrogen solution, rapidly developed symptoms of nitrogen deficiency. Evidence is presented that, in young potato sprouts, the rate of nitrate reduction and assimilation are a serious limiting factor to the availability of nitrate nitrogen for protein synthesis.Ammonium assimilation takes place actively and mainly in the roots and stem bases. Nitrate assimilation takes place in both shoot and roots, but is more active in the shoot. Absorption of nitrate ions can take place even when a much higher concentration of nitrate ions is present in the root cells than in the external solution. The initial nitrate nitrogen present in the sprouts is not appreciably utilized during culture on ammonium solution.The ammonium shoots as compared with the nitrate shoots have a higher content of total nitrogen, protein nitrogen, non‐protein organic nitrogen, amide and amino‐acid nitrogen, but a lower content of inorganic nitrogen. The nitrate roots as compared with the ammonium roots have a higher content of total nitrogen, protein nitrogen and inorganic nitrogen, but a lower content of non‐protein organic nitrogen, amide and other nitrogen.The higher protein content of the nitrate roots is associated with a higher percentage dry weight and a lower content of ‘other’ nitrogen. The significance of this relationship is discussed.During ammonium culture both asparagine and glutamine accumulate, particularly in the shoot.Evidence is presented that asparagine is the amide primarily concerned in ammonia storage and also that it is formed during nitrate assimilation.Knowledge of the absorption and assimilation of ammonium and nitrate ions by plants is of fundamental importance for an understanding of fertilizer practice, and the present investigation, in which detached potato sprouts have been successfully grown in ammonium and nitrate culture solutions, forms part of a study of this problem.
A note on the efficiency of a pyrethrum spray in controlling Ephestia elutella Hb. moths in a granary
Authors: Owen R. W. 
Published: February 2008

A stowage in a London granary containing 500 tons of Manitoba wheat was sprayed with 0.8 % w/v pyrethrins in Shell oil P31, in an attempt to control an Ephestia elutella infestation. The mean deposit on the surface of the wheat was 1‐5 mg./sq.cm., of which one‐sixth was due to the settling of mist.All the moths in the stowage at the time of spraying, estimated at 68,900, were killed or fatally affected within 24 hr., and those which emerged later, estimated at 7500, were killed by the insecticidal film.The spray was not observed to have any marked effect on the size of the migrating larval population.
The use of toxic polynitro derivatives in pest control III. The stability of dinitro‐o‐cresol in compounded products
Authors: Bennett S. H. , Kearns H. G. H. , Martin H. , Wain R. L. 
Published: February 2008

Under certain conditions dinitro‐o‐cresol (D.N.C.) is easily decomposed to reduction products devoid of ovicidal properties to eggs of apple sucker, winter moth and fruit tree red spider.Because of this, corrosion of containers in which D.N.C. products are stored may be accompanied by a deterioration of the product.At the concentration normally used in winter washes (0.1%), D.N.C. is equally effective whether present as cresol or as the sodium cresylate against eggs of apple sucker and of winter modi, but against eggs of fruit tree red spider the cresol is more ovicidal than the cresylate.