bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemical aids to drying seeds of beans (Phaseolus vulgaris) before harvest
Authors: HOLE C. C. , HARDWICK R. C. 
Published: February 2008

SUMMARYThe effects on seed moisture content of seven different chemical formulations applied to bean (Phaseolus vulgaris) crops in two successive years were observed. Those containing bipyridyl herbicides caused the biggest effects. In 1974, diquat (0–59 kg a.i. ha‐1), applied to a French bean crop cv. Processor 26 days before harvest, decreased seed moisture content by 98 mg g_1 dry weight below a control value of 438 mg g_1. In 1975, diquat applied at the same rate to a navy bean crop cv. Seafarer 16 days before harvest, decreased seed moisture content by 123 mg g_1 below a control value of 364 mg g_1. Diquat applied at a lower rate (0–3 kg a.i. ha‐J) caused a decrease of 79 mg g_1 and paraquat decreased seed moisture by 147 mg g_1. In both years smaller effects were observed for dimexan (15 kg a.i. ha‐1) which decreased seed moisture content by 32 mg g‐1 in 1974 and 72 mg g_1 in 1975 and for ethephon (1‐0 kg a.i. ha‐1) which caused decreases of 78 mg g_1 in 1974 and 31 mg g_1 in 1975. In 1975, metham‐sodium (70 kg a.i. ha‐1) a soil sterilant, proved almost as effective as the bipyridyls, decreasing moisture content by 105 mg g_1. Trimming the roots mechanically reduced seed moisture by 67 mg g_1. Other chemical treatments, tried in 1975 only, were less effective and decreased seed moisture content by 31–60 mg g_1. These were Wiltz‐65 (pentanoic and hexanoic acids, 14‐6 kg a.i. ha‐1), N252 (dihydro‐dimethyl‐dithiin tetroxide, 0–56 kg a.i. ha‐1) and an application of diquat (0–3 kg a.i. ha‐1) to plants treated 10 days before with ethephon (1‐0 kg a.i. ha‐1)‐ In addition to the effects on seed moisture content, all treatments decreased seed yield. The largest decreases were caused by diquat and were attributable mainly to effects on mean seed weight. The paper concludes with an economic analysis which shows that at present prices chemical drying of beans in the field is not worthwhile because the yield loss nullifies any savings in drying costs.
Studies on plant growth‐regulating substances. L. The cytokinin activity of some substituted benzyloxypurines
Authors: WILCOX E. J. , SELBY C. , WAIN R. L. 
Published: February 2008

SUMMARYThe series of 6‐mono and di‐methyl and mono‐ and di‐methoxy benzyloxypurines have been prepared and tested for cytokinin activity in a number of biological tests. The 2‐methyl and 3‐methoxy derivatives were more active than the unsubstituted compound but substitution into any other position led to a decrease in activity. Di‐substitution also caused a lowering of activity particularly with the di‐methoxy compounds.
Fixation and transfer of nitrogen in a white clover‐grass sward under hill conditions
Authors: HAYSTEAD A. , MARRIOTT CAROL 
Published: February 2008

SUMMARYExperiments are described to illustrate the different effect of defoliation and diurnal changes in light intensity and temperature on grazed white clover (Trifolium repens) ecotypes and pot grown clover. Removing all the fully expanded leaves from grazed clover has no effect on nodule numbers or on nitrogen fixing activity during the phase of early season rapid growth. No diurnal rhythm in nitrogen fixing activity is apparent in grazed clover swards. Isotope dilution experiments demonstrate that in the first half of the growing season underground transfer of nitrogen is low in cut plots in a previously grazed hill situation. The results are briefly described in the context of improved hill pasture utilisation.
A reappraisal of flight regulation in the green spruce aphid, Elatobium abietinum
Authors: PARRY W. H. 
Published: February 2008

SUMMARYAlate formation and its importance in the population dynamics of Elatobium abietinum is examined. It is concluded that alate formation is related to high soluble nitrogen levels in Sitka spruce needles. In N.E. Scotland the proportion of the population developing as alatae was related to aphid density. The apparently differing status of alatae in S. England may be related to differences in the physiology of the host caused by heat input. In Scotland alate formation may cause a decline in spruce aphid populations when densities are very high but, at the densities normally encountered in Scotland and Germany only small proportions of the populations become alate. In these areas the population collapses in late June or early July occur in response to low soluble nitrogen levels in the spruce needles. The role of alate adults in the formation of new colonies following migration to uncolonised hosts is discussed.
Experiments with foliar sprays of thiabendazole and captafol for control of potato gangrene
Authors: LOGAN C. , COPELAND R. B. , LITTLE G. 
Published: February 2008

SUMMARYIn an experiment designed to measure the effect of foliar sprays of fungicides on gangrene in stored tubers thiabendazole but not captafol reduced yield by 30%. Although both fungicides reduced disease incidence in stems and tubers the extent of the reduction was so small that foliar sprays were considered unimportant as a method of control. Sprays of thiabendazole and captafol applied to the haulm 1 wk or 1 wk and 2 wk after desiccation did not reduce the incidence of gangrene in storage.
The reactions of swede (Brassica napus) to infection by turnip mosaic virus
Authors: TOMLINSON J. A. , WARD C. M. 
Published: February 2008

SUMMARYTurnip mosiac virus (TuMV) and cucumber mosaic virus (CMV) were the only viruses commonly isolated from naturally diseased swedes (Brassica napus) showing leaf mosaic and leaf and root necrosis. Only TuMV caused these symptoms when re‐inoculated to swede. TuMV‐infected plants showed a severe loss in leaf (55%) and root (63%) fresh weight after 140 days.Systemic leaf symptoms in infected swede plants varied greatly, but were predominantly necrotic (N) or mosaic (M). Plants were classified into one of seven reaction classes ranging from slight or severe necrosis, and mosaics with and without slight veinal necrosis. Swede cultivars differed markedly in their reaction to TuMV and contained different proportions of N‐ or M‐reacting plants. The reactions of progeny of four resistant cv. Bangholm plants were separately inherited; progeny of two plants reacting either symptomlessly or necrotically and those of the other two plants developing mosaic symptoms only.Five isolates of TuMV from swede crops in different regions caused similar reactions but differed in virulence in the progeny of a self‐pollinated resistant swede plant.
Physiological studies of a hybrid between populations of Dactylis glomerata from contrasting climatic regions. II. Intra population variation
Authors: EAGLES C. F. , Othman OMAR B. 
Published: February 2008

SUMMARYConsiderable intra‐population variation was found for leaf expansion characteristics of three populations of Dactylis glomerata grown in a cool glasshouse during winter. The rates of leaf area expansion of a winter‐dormant population of North European origin were very low, while a colchicine‐induced autotetraploid of a winter‐growing Portuguese population had high rates. The progeny of a cross between these two populations had intermediate rates with a population mean significantly different from the mean rates of its parents. Some of the individual hybrid plants had rates greater than the mean rate of the Portuguese parent and selections were made based on these plants with the aim of improving the rate of leaf area expansion of the hybrid under winter conditions. Some of the F1 polycross progenies from the first cycle of selection showed a marked improvement with mean rates of leaf area expansion for certain maternal lines approaching the mean rate of the Portuguese parent.
Electrophoretic detection of the internal parasite, Aphidius matricariae in Myzus persicae
Authors: WOOL DAVID , EMDEN H. F. VAN , BUNTING S. W. 
Published: February 2008

SUMMARYThe presence of the internal parasite (Aphidius matricariae) of the aphid Myzus persicae can be identified by electrophoresis, and staining of several enzyme systems, of which malate dehydrogenase is recommended as the most reliable. It is suggested that the technique could be extended to other small insects, and that pest populations can be screened for percentage parasitism as an adjunct to insecticide and integrated control field trials.
Supercooling of Myzus persicae in relation to gut content
Authors: PARRY W. H. 
Published: February 2008

SUMMARYThe supercooling distribution curves of Myzus persicae varied in response to feeding position, diet and age. Unfed instar I aphids supercooled to temperatures lower than –20 °C. Feeding aphids supercooled to higher temperatures, the earlier instars on subsidiary veins supercooling to lower temperatures than the late instars and adults on the main veins. Starvation decreased supercooling ability in some adult aphids. The supercooling ability of aphids feeding on sucrose solutions through a Parafilm membrane decreased in response to an increasing concentration, the position being reversed on 25% sucrose. Varying the amino acid concentration had no effect. The possible effects of this variable supercooling ability on the winter survival of the aphid are discussed.
Relationships between the severity of leaf blotch (Rhynchosporium secalis) and the water‐soluble carbohydrate and nitrogen contents of barley plants
Authors: JENKYN J. F. , GRIFFITHS ELLIS 
Published: February 2008

SUMMARYWater‐soluble carbohydrate (WSC) and total nitrogen (N) contents of leaves of field‐grown barley plants were measured in 1966 and 1967. Consistent differences were found between cultivars.The susceptibility of cultivars to leaf blotch was correlated negatively with WSC content and positively with N content at G.S. 10.4. Application of nitrogen fertiliser (which increased N and decreased WSC) also increased the severity of leaf blotch.The occurrence of primary lesions on seedlings does not seem to be affected by their WSC and N contents and the relation between WSC and N contents of leaves and severity of leaf blotch possibly depends on differences in growth and sporulation of the pathogen on substrates containing different amounts of carbohydrate and nitrogen.
Effect of some fungicides on the yield of grass swards
Authors: MALONE J. P. , McGIMPSEY H. C. , MCILWAINE R. S. , BINNIE R. C. 
Published: February 2008

SUMMARYWhen benomyl, drazoxolon, thiabendazole or zineb were applied as soil drenches to established grassland drazoxolon reduced the incidence of rhizoplane fungi. Benomyl and thiabendazole significantly increased yield at one harvest but only benomyl had a significant effect on total yield. When benomyl was applied at monthly intervals from March to July significant increases in total yield were obtained with the June applications which also significantly increased yield at the first harvest in the following year. Repeated applications from March to July also had a significant residual effect on total yield. Yield increases were not significantly affected by increasing the benomyl level from 2.5 to 5.0 g/m2.
Arracacha virus A, a newly recognised virus infecting arracacha (Arracacia xanthorrhiza; Umbelliferae) in the Peruvian Andes
Authors: JONES R. A. C. , KENTEN R. H. 
Published: February 2008

SUMMARYArracacha virus A (AVA), a previously undescribed virus, is common in arracacha (Arracacia xanthorrhiza; Umbelliferae) in the Huanuco region of the Peruvian Andes. AVA was not transmitted by Myzus persicae, but was transmitted by inoculation of sap to 38 species from 10 families out of 63 species from 12 families tested. AVA was best propagated and assayed in Chenopodium quinoa and Nicotiana clevelandii in which it caused severe diseases. Sap from infected C. quinoa was occasionally infective after dilution to 10‐4 but not 10‐5, after 10 min at 65 °C but not 70 °C, and after 15 days at 20 °C.In neutral phosphotungstate, AVA has isometric particles c. 26 nm in diameter with a hexagonal profile, some of which were either fully or partially penetrated by the negative stain. Up to 50–200 E2601cm units of purified virus was obtained from 1 kg of infected N. clevelandii leaf by extraction in 0.05 M phosphate buffer at pH 7.5 containing 0.05 M ethylene diaminetetra‐acetate, and clarification with chloroform, followed by differential precipitation with ammonium sulphate and three cycles of differential centrifugation. Purified virus sedimented as three components with sedimentation coefficients (S20w°) of 50 S, 92 S and 125 S and E260/E280 ratios of 0.65, 1.50 and 1.85 respectively. At equilibrium in CsCl gradients, buoyant densities of the 50, 92 and 125 S components were 1.32, 1.45 and 1.52 g/cm3 respectively. From the sedimentation coefficients and buoyant densities, the nucleic acid contents of the 92 S and 125 S components were estimated at 30–35% and 43–44% respectively. Only the 125 S component seemed to be infective but its infectivity was greater when mixed with the 92 S component. All three components contained a single protein with a molecular weight of 53 000. AVA was not serologically related to any of 33 other morphologically similar viruses. Although the vector is unknown, its properties suggest that it is a member of the nepovirus group.The cryptogram of AVA is */*: */43–44 +*/30–35: S/S:S/*.
The effect of herbicides on the root system of wheat plants
Authors: TOTTMAN D. R. , DAVIES E. LI. P. 
Published: February 2008

SUMMARYThree commercial herbicides, at the rates normally recommended for selective weed control in cereal crops, deformed the roots of spring wheat plants grown in sand culture. Affected roots produced large numbers of short swollen lateral branches which later grew on to form tassel‐like bundles of side roots. Only the mecoprop and MCPA components of the mixtures were responsible for the deformities; ioxynil and dicamba had no effect. Mecoprop applied to the rooting medium severely deformed the roots but foliar application also resulted in some abnormalities. The effects of the herbicides on root and shoot dry weights were not correlated with their deformative effects.
Studies on plant growth‐regulating substances LV. The Plant growth‐promoting properties of some β‐aryl‐propionic acids
Authors: CHAMBERLAIN K. , WAIN R. L. 
Published: February 2008

SUMMARYA series of 17 β‐arylpropionic acids were synthesised and examined for plant growth‐regulating activity in wheat and pea tests. The results are discussed in relation to chemical structure. The activity of β‐(2, 4‐dichlorophenyl)propionic acid was compared with those of the 2, 4‐dichloro‐derivatives of phenoxyacetic, phenyithioacetic and phenylimino acetic acids using the same tests. When wheat coleoptiles or pea stem tissues were incubated with solutions of β‐(2, 4‐dichlorophenyl)propionic acid no chromatographic evidence of β‐oxidation of the side chain or other type of degradation was obtained.
Production and distribution of dry matter in maize following changes in plant population after flowering
Authors: H.WILSON J. , ALLISON J. C. S. 
Published: February 2008

SUMMARYMaize plants were grown singly in pots in a population of 3.7 plants m‐2, and 98 days after sowing (shortly after flowering) were arranged into three populations, 1.27 (W), 3.70 (M), and 6.15 (C) plants m‐2, respectively. The plants were harvested 131 days after sowing, about 4 wk before the normal time of maturity, because some plants at the closest spacing began dying.Increment of dry weight between days 98 and 131 was 373, 243, and 108 g/plant and grain dry weight at harvest was 218, 220 and 195 g/plant in populations W, M and C, respectively. Thus, dry weight of parts of the plant other than grain increased in population W, remained about the same in population M, and decreased in population C between days 98 and 131. Number of kernels per plant was c. 540 in all three populations. On day 98, immediately after rearrangement, leaf area index (L) was 2.0, 5.8 and 9.7 in populations W, M and C, respectively. By day 131 L had decreased to 6.7 in population C, but had hardly changed in the other two populations. Crop growth rate between days 98 and 131 was 101, 191 and 141 g m‐2 wk‐1, and grain dry wt per unit of land on day 131 was 277, 816 and 1196 g m‐2, in populations W, M and C, respectively.
Effect of plant population on ear differentiation and growth in maize
Authors: WILSON J. H. , ALLISON J. C. S. 
Published: February 2008

SUMMARYMaize was grown at 2.47, 3.70 and 4.94 plants m‐2. Ears were apparently initiated about 2 days later in the densest than in the least dense population, but rate of formation and final number of female floret primordia per row of the ear were similar in the two populations. In the densest population fewer primordia produced fully developed florets than in the least dense population and of those that were produced fewer extruded silks before pollen shedding ceased. Relative growth rates of dry mass and of length of the ear before flowering were unaffected by density, but with the apparent later start of ear growth in the densest population ears were lighter and shorter than in the least dense population.Number of florets per row of the ear at the time of flowering decreased slightly with increase in population. Number of kernels per row decreased with time after flowering, especially in the densest population. At final harvest size and mass per kernel, number of kernels per ear, length and circumference of the rachis, and space per kernel on the rachis all decreased with increase in population.Thinning the intermediate population at various times from shortly before flowering until near final harvest increased mass of grain and shoot, and number of kernels of the remaining plants at final harvest. The extent of the increases decreased progressively the later the thinning. Mass and volume per kernel were increased by thinnings done up to the time of flowering, but were unaffected by thinning from c. 16 days after flowering.
Survival of mature larvae of codling moth (Cydia pomonella) on apple trees and ground
Authors: GLEN D. M. , MILSOM N. F. 
Published: February 2008

SUMMARYThe effects of predation by carabid and staphylinid beetles and birds (blue‐ and great‐tits) on mature larvae of the codling moth Cydia pomonella were investigated in a field experiment. The number of predatory beetles on the ground beneath eight of 16 apple trees was reduced by an insecticide spray, and tits were excluded from the trunks and lower branches of eight trees by means of Terylene netting. Beetles had no significant effect on survival of larvae on trees, but only 8% of larvae survived to adulthood on trees exposed to blue‐ and great‐tits, whereas on trees protected from them 48% survived. Larvae were taken rapidly by the tits from the time larvae first built cocoons in summer and, by the time the majority of larvae had emerged from apples in late summer or autumn, tits had removed most from cocoons beneath flakes of bark glued to trees. Thus tits fed on larvae mainly in summer and autumn. On trees protected from tits, 8% of mature larvae were killed by fungi, of which Verticillium lecanii was most important. It was calculated that, of the larvae maturing in apples, 44% failed to build cocoons on the trees, 47% were taken by tits, then 1% were killed by fungi. Larvae failing to build cocoons on trees may build them on the ground. Of larvae in cocoons planted on or in the ground in 1975, only one (0.3%) persisted through the winter; 98.6% disappeared, and 1.1% were found dead, covered by fungi; in 1976, all larvae disappeared by December. Larvae disappeared even in the absence of predators, and are thought to have moved in response to damp ground conditions.
Epidemiology of maize rust, Puccinia sorghi
Authors: MAHINDAPALA R. 
Published: February 2008

SUMMARYThe development and spread of maize rust from an inoculated circular plot was studied during 1975. Results from a Burkard volumetric spore trap sited in the centre of the inoculated plot showed that the daily peak urediniospore concentration in the atmosphere occurred at about 1300 h. During the season atmospheric urediniospore concentration increased to a plateau and later decreased mainly through lack of host material.The spread of the pathogen away from the inoculated plot was related to the increase in atmospheric urediniospore concentration and warm temperatures. Disease gradients along the eight major compass directions demonstrated the influence of wind on the spread of the pathogen. As the season progressed gradients tended to flatten because of secondary spread of the pathogen.
Some effects of applied sodium and potassium chloride on yellow rust in winter wheat
Authors: RUSSELL G. E. 
Published: February 2008

SUMMARYIn glasshouse experiments with plants in pots, applications of potassium chloride to the soil at 0.5 g/plant, 4 days before inoculation with Puccinia striiformis, decreased the severity of yellow rust on several winter wheat cultivars in comparison with untreated plants. Conversely, yellow rust was encouraged by applications of sodium nitrate. Sodium chloride in solution (8.6 g/l) reduced yellow rust when applied to the soil at the rate of 20 ml/plant but not when it was sprayed on to the leaves.In small‐plot field experiments, sodium and potassium chlorides applied to the soil as dry powders in the spring at rates of 376, 1130 or 2260 kg/ha, significantly decreased the severity of yellow rust on most of the winter wheat cvs examined at each rate. The chlorides at these rates did not adversely affect the overall growth or yield in the absence of yellow rust.
Soil factors influencing chlamydospore formation by Fusarium solani f. sp. phaseoli
Authors: BANDARA J. M. R. S. , WOOD R. K. S. 
Published: February 2008

SUMMARYGel filtration and chromatographic separation of soil extracts gave three fractions which induced formation of chlamydospores by Fusarium solani f. sp. phaseoli. Depletion of nutrients had a similar effect.
Persistence of Phoma exigua xar. foveata and Polyscytalum pustulans in dry soils from potato stores in relation to reinfection of stocks derived from stem cuttings
Authors: CARNEGIE S. F. , ADAM JESSIE W. , SYMONDS CAROL 
Published: February 2008

SUMMARYThe incidence of Phoma exigua var. foveata and Polyscytalum pustulans in dry soil and dust from potato stores was assessed at 10 farms in Scotland producing virus‐tested stocks of seed potatoes derived from stem cuttings (VTSC). Samples were collected on three occasions during 1976: during the storage period (February‐March), soon after the potatoes were planted (May) and just before the new crop was lifted and stored (August‐October). Both pathogens were detected at all three sampling times but P. exigua var. foveata was more frequently detected at the last one than P. pustulans. Soil and dust from various sites within the stores, such as floors, ledges, graders and boxes, were contaminated by these pathogens. Propagules of both pathogens remained airborne for at least 12–17 min after the floors were swept.P. exigua var. foveata remained viable for at least 16 months in dry soil from tuber surfaces stored at 4–6°C. When VTSC tubers were dusted before planting with a dry store soil contaminated by P. exigua var. foveata the gangrene potential of the progeny tubers was much greater than that from untreated tubers or from tubers treated with an uncontaminated soil. The role of inoculum surviving in dry soil is discussed in relation to reinfection of VTSC stocks.