bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effects of the deficiens allele on ear development and yield in barley
Authors: HABGOOD R.M. , CHAMBI J.Y. 
Published: February 2008

SUMMARYLines partially‐isogenic for the deficiens (VtVt and two‐rowed (VV) barley ear types were developed in the genetic background of cv. Kym, for comparisons of ear development and yield components.The suppression of lateral floret growth by the Vt allele during pre‐anthesis ear development occurred at a relatively late stage and only occasionally was median floret survival enhanced in the deficiens line. The final size of lateral florets in both deficiens and normal ear types appeared to be largely governed by assimilate supply. At anthesis, the lateral florets comprised about 10% of the dry matter of normal ears, whereas in the deficiens ears the median florets were correspondingly heavier. After anthesis, grain growth in the deficiens line was slower than in the normal line, although final grain weight was not affected.In another experiment the Vt allele occasionally increased the number of grains per ear, but consistently decreased the weight per grain. In drilled plot trials, the mean yield of the deficiens line was 8% lower than the normal. Excision of lateral florets at anthesis showed that photosynthesis in these organs did not contribute to the yield advantage of the normal ear type.It is suggested that the inferior performance of the deficiens type was attributable to the greater physical constriction of endosperm expansion imposed by the development of thicker, more rigid, palea and lemma tissues.
Effects of straddle‐harvester design on cane blight (Leptosphaeria coniothyrium) of red raspberry
Authors: WILLIAMSON B. , RAMSAY A.M. 
Published: February 2008

SUMMARYA new fruit catching device developed for raspberry straddle harvesters to reduce wounding of young canes and their consequent infection by Leptosphaeria coniothyrium was tested. During picking the young canes were contacted only by the foam rubber on a pair of belts which moved backwards along the harvester at the same speed that the machine advanced. The incidence of canes with cane blight lesions in 1981 was 18% following the use of the new device in 1980, and 79% following the use of a conventional commercial harvester equipped with overlapping metal fruit‐catching plates. In comparison with the latter plates, the new device avoided wounding the cane surface directly: when the belt marks on these canes were inoculated with mycelium, however, the disease incidence was 77%. The new device caused wounds in 1980 by ripping leaves from nodes. In comparison with the commercial harvester the new device led to smaller lesions in 1981 and a lower percentage of canes dead above the fruit‐catching zone.A modified new catching device tested in 1982 made barely detectable pressure marks on the young canes without bruising them. Only 6·6% of these canes developed vascular lesions after inoculation, an incidence similar to that for unwounded control canes (2·5%). The modified new device is advised for regions prone to cane blight where the cropping system has young and fruiting canes growing together.
Sterilisation of the potato moth, Phthorimaea operculella (Lepidoptera: Gelechiidae) by fumigation with thiotepa
Authors: NABI M. N. , HARRISON R. A. 
Published: February 2008

SUMMARYThe chemosterilant thiotepa was used in fumigation chambers for sterilisation of male and female potato moths. Its effectiveness was registered by recording egg production, egg hatch, longevity of moths, and mating frequency. Also studied was the effect on the persistence of the chemical of temperature, exposure time and concentration.The tests showed that it was possible to sterilise fully male and female moths with thiotepa without adverse effects on mating and longevity. Generally, males were more susceptible to sterilisation than females. No definite relationship was found between dosage and egg production, longevity and mating frequency of moths. The compound did not lose its sterilising activity when used successively up to five times during the same day or once weekly for a total of 4 wk. The sterilising activity was related to temperature, exposure time, concentration and rates of airflow of the circulatory fumigation chambers.Some reduction of fertility occurred when F, adults paired with untreated moths.
Soil‐applied fungicides for controlling take‐all in field experiments with winter wheat
Authors: BATEMAN G. L. 
Published: February 2008

SUMMARYSoil treatment fungicides were tested against take‐all (Gaeumannomyces graminis var. tritici) in three field experiments with winter wheat. Fungicides were applied as drenches either before sowing in autumn, and incorporated by rotary harrowing, or to the crop in spring. The most effective treatments were autumn applied benomyl (20 kg/ha) and nuarimol (0·55‐4·4 kg/ha). However, the highest nuarimol concentration depressed yield. Benomyl sometimes induced a resurgence of take‐all in the second wheat crop after treatment. Nuarimol had no adverse effects in subsequent crops, and neither fungicide hindered the onset of take‐all decline in a third crop after treatment. The possible value of soil treatment in future control strategies is discussed.
Immunodiagnosis of plant viruses by a virobacterial agglutination test
Authors: CHIRKOV S. N. , OLOVNIKOV A. M. , SURGUCHYOVA N. A. , ATABEKOV J. G. 
Published: February 2008

SUMMARYA new virobacterial agglutination (VBA) test for the immunodiagnosis of plant viruses is described. The test is based on the agglutination of Staphylococcus aureus cells by virus particles after treatment of the cells with homologous antiserum. The agglutination occurs within 1–5 min. The sensitivity of the test is 0·1‐0·4 μg virus/ml and is not affected by the shape of the virus particle. The use of affinity purified antibodies for sensitisation of S. aureus cells increases the sensitivity of the reaction 50‐fold and enables the detection of tobacco mosaic and cucumber green mottle mosaic viruses at a concentration of 2 ng/ml. The VBA test allows the estimation of potato viruses X, S, M and Y in the eyes and sprouts of infected tubers and in the leaves of infected plants. The diagnosis of carnation mottle virus in carnation plants and of mushroom viruses in mushroom (Agaricus bisporus) fruit‐bodies and mycelium are also described.
Glucose phosphate isomerase polymorphism in field populations of the potato cyst nematodes, Globodera rostochiensis and G. pallida
Authors: FOX P. C. , ATKINSON H. J. 
Published: February 2008

SUMMARYThe isozymic variation of glucose phosphate isomerase (GPI) was compared in 20 field populations of potato cyst‐nematode (PCN) and related to variation in reference pathotypes of PCN. Populations pathotyped as G. rostochiensis Ro 1 by conventional differential cultivar tests were found to be different from populations of G. pallida. Variation within populations pathoptyped as G. pallida was seen and three populations were found to be similar to the reference G. pallida Pal pathotype. This seemed to be confirmed for two populations using cysts formed on a cultivar resistant to the Pa 1 pathotype when an isoenzyme pattern characteristic of G. palida Pa2 and Pa3 was found. The feasibility of the use of isozyme identification of PCN pathotypes is discussed in the light of these results.
Diffusive conductance of rice (Oryza sativa) leaves during gradually induced soil water stress
Authors: SAINI B. C. , RATHORE T. R. 
Published: February 2008

SUMMARYThe diffusive conductance (Cs) of rice (Oryza sativa cvs Jaya and Bala) leaves was measured during a soil drying cycle from flooding to decreasing soil water potential (φs) in a controlled‐environment chamber. Plants were grown continuously under 5 cm submergence up to 69 days after transplanting and thereafter were subjected to gradual soil drying for a period of 17 days in the vegetative growth stage. In both the cultivars, the values of Cs were generally more on adaxial than abaxial leaf surfaces. This response of stomata during the period of soil drying was independent of leaf rolling. Further, the slopes of the curves (Cs, vs φs) also did not differ significantly (P= 0·05). The total Cs, of both cultivars during flooding was almost equal (0·60 cm s‐1) but at the end of the soil drying cycle, the values of total Cs, were 0·11 cm s‐l at ψs of ‐1·3 MPa and 0·08 cm s‐1 at ψs, of ‐0·8 MPa in cvs Jaya and Bala, respectively. For total Cs, slopes differed significantly (P = 0·05). A close relationship between total Cs, and ψs, in both cultivars (Cs, = 0·58‐0·40 ψs, for cv. Jaya and Cs= 0·46‐0·56 ψs, for cv. Bala) indicated that stomata were sensitive to increasing soil water deficit.
Tiller dynamics and assimilate partitioning in Lolium perenne with particular reference to flowering
Authors: COLVILL KAY E. , MARSHALL C. 
Published: February 2008

SUMMARYThe fate of 100 seedling plants of Lolium perenne L. was studied over a period of 2 years in a field plot. The birth and death of tillers and the production of inflorescences was followed, and the components of seed yield were recorded in detail in the first year. The pattern of distribution of 14CO2 assimilated by the main shoot was examined at monthly intervals and during the first flowering season the distribution of 14C‐assimilate from individual leaves and from the inflorescence was also studied. The capacity of individual tillers to assimilate 14CO2 prior to flowering and the re‐distribution of previously accumulated assimilate during seed growth were also assessed.Plants died at a more or less constant rate with time and only 54 survived to the end of the 2–yr period. First year mortality was associated with severe grazing or cutting but in the second year the death of ungrazed plants was observed. There was great variability in the production of tillers by surviving plants. In both years the number of live tillers per plant increased from July to the end of April with particularly rapid tillering in March and April establishing the maximum value for each year. There was a similar phase of rapid tillering after flowering in July. The number of live tillers per plant declined by 50% during stem elongation and inflorescence emergence and the majority of dead tillers were young secondary (in the first year) and tertiary (in the second year) tillers with a mean age of 40 days. Such tillers had poor assimilatory capacity prior to the onset of death and were not supplied with assimilate from the main shoot. Most of the plants surviving at the end of the experiment flowered in both years and one quarter of the maximum number of live tillers per plant recorded in April of each year produced inflorescences. The earlier a tiller was produced the greater was its chance of flowering and the greater its production of seed. The greater weight of seed produced was associated with the development of more seed‐bearing florets per spikelet. There was relatively little export of “C‐assimilate from the flowering main shoot, and the lower internodes formed the major sink for post‐anthesis assimilate. The growth of seeds appeared to be relatively independent of the leaves for current assimilate. There was some evidence that assimilate accumulated in lower internodes was remobilised and utilised in the growth of seeds and new tillers.Overall, the results confirm the view that the grass plant is a dynamic population of short‐lived tillers and indicate that increasing competition for assimilate at flowering exerts a major influence on the production and survival of tillers.
The performance of carrot seeds in relation to their viability
Authors: GRAY D. 
Published: February 2008

SUMMARYThe germination and emergence characteristics, and early seedling growth, of carrot seeds cv. Chantenay red‐cored from different sources with a range of germination from 54–94%, was compared.Seeds from protected crops (mean temperature of growth 21°C, r.h. 45–70%) gave higher percentage germination than those from crops grown outdoors (mean temperature 15°C, 70–100% r.h.). Germination was also higher from mature (seed moisture content at harvest 20% or lower) than immature seed (seed moisture content at harvest between 20 and 60%). High percentage germination (>90%) was associated with low mean germination times and low spreads of germination times whilst the reverse was true for low percentage germination. Similar relationships were found for seedling emergence characters in the field although a lower proportion of the viable seeds produced seedlings from slowly than rapidly germinating seed lots. In general, seed lots having a low percentage germination gave greater variability in plant weight than those of higher percentage germination. There was no effect of seed source on radicle or shoot relative growth rates or on post‐emergence seedling growth rates.
Effects of powdery mildew on grain filling in spring barley in contrasting environments
Authors: JENKYN J. F. 
Published: February 2008

SUMMARYCircumstantial evidence from field experiments at Rothamsted suggested that effects of powdery mildew on grain filling in spring barley may be determined partly by temperature during the grain‐filling period. An experiment was, therefore, done which compared the effects of fungicides applied to control powdery mildew on grain filling in early‐ and late‐sown spring barley plants kept either out‐of‐doors throughout their growth (‘cool’ environment) or under the same conditions until the start of grain filling and then transferred to a heated glasshouse (‘warm’ environment) until harvested. Fungicides that controlled mildew increased the total grain yield of the late‐sown barley more than that of the early‐sown and much more in the warm environment than in the cool. On average, the effect of the fungicides in the cool environment was to increase grain yield by 17·7%. Small increases in numbers of grains/ear (+ 3·4%) and thousand‐grain weight (TGW) (+ 2·3%) contributed to this increase but it could be attributed principally to an average increase in numbers of ears/plant of 12·4%. Contrastingly, fungicides increased average grain yield in the warm environment by 58·2%. Effects of the fungicides on numbers of ears/plant (+ 27·8%) and on numbers of grains/ear (+ 4·5%) were not significantly different to those in the cool environment, and the much greater responses in the warm than in the cool environment could be attributed mostly to much larger effects on grain size (+ 19·2%)The greater benefits of the fungicides and, by implication, the greater damage done by powdery mildew in the warm than in the cool environment cannot, unequivocally, be attributed to differences in temperature during grain‐filling because the two environments clearly differed in other ways and especially in light intensity. Nevertheless, the results obtained do illustrate the potential risks involved in using data obtained under one set of circumstances to predict what will happen in another, especially when environments differ as greatly as glasshouses and fields.
Epidemiology of three viruses infecting the rose in the United Kingdom
Authors: THOMAS B. J. 
Published: February 2008

SUMMARYStudies on the epidemiology of arabis mosaic (AMV), prunus necrotic ringspot (PNRSV) and strawberry latent ringspot (SLRV) viruses were made in relation to commercial production of standard and bush roses. AMV or SLRV apparently induced either symptomless infection in rose cultivars and Rosa spp., or leaf symptoms ranging from small chlorotic flecks to severe chlorotic mosaic and, occasionally, plant death. Infection of R. canina ‘inermis’ or R. corymbifera by an isolate of SLRV from R. corymbifera also severely depressed flowering and hip formation. In addition, whereas this isolate could be graft‐transmitted to all Rosa spp. tested, isolates from R. rugosa and R. multiflora failed to be graft‐transmitted to R. canina ‘inermis’ or R. corymbifera. No difference was detected in graft‐transmission tests of Rosa spp. with several isolates of AMV or PNRSV.In plantings of up to 7 yr none of the viruses was transmitted through pollen to healthy roses grown in nematode‐free soil, and only SLRV was readily seed‐transmitted, particularly in R. rugosa. Nevertheless, in soil containing viruliferous nematodes, AMV and/or SLRV were transmitted to c. 80% of healthy plants.AMV and particularly SLRV were each damaging to field‐grown maiden rose bushes cv. Fragrant Cloud. SLRV delayed the onset of flowering, and reduced the number and size of blooms. Diseased bushes were less vigorous, and half or none of the AMV‐ or SLRV‐ infected bushes respectively, conformed to the British Standards Institution specifications for maiden bush roses.These results are discussed in relation to the commercial production of field‐grown roses in the UK.
Differential control of potato cyst‐nematodes, Globodera rostochiensis and G. pallida by oxamyl and the yields of resistant and susceptible potatoes in treated and untreated soils
Authors: WHITEHEAD A. G. , TITE D. J. , FRASER JANET E. , NICHOLS A. J. F. 
Published: February 2008

SUMMARYIn sandy loam infested with Globodera rostochiensis (2–95 eggs g‐1 soil) the yield of Desiree potatoes was decreased by 8·2 t ha‐1 for every increment of 20 eggs g‐1 soil. Oxamyl incorporated in the seedbed at 5 kg ha‐1 before planting prevented significant loss of yield and damage to the tubers and minimised nematode increase. Cara and Maris Piper potatoes, which were resistant and tolerant to G. rostochiensis usually responded less to oxamyl than did susceptible cultivars. In a range of cultivars, yield responses to oxamyl treatment of soil infested with G. rostochiensis often differed from those in soil infested with G. pallida. In field experiments, oxamyl controlled G. pallida less than G. rostochiensis. In pots, such differential control of the two species by oxamyl was not observed.
Effects of aldicarb and benomyl on nematodes, vesicular arbuscular mycorrhizas and the growth and yield of forage maize
Authors: WILLIAMS T. D. , BEANE J. 
Published: February 2008

SUMMARYThe effects of aldicarb and benomyl on plant‐parasitic nematodes, vesicular arbuscular mycorrhiza and the growth of forage maize were measured in 1980—1982 in two field experiments at Woburn, Bedfordshire and in a pot experiment using loamy sand soil from the field site. The most numerous migratory nematode, Tylenchorhynchus dubius increased three to four‐fold during each season in untreated soil and was effectively controlled by aldicarb. Pratylenchus species were fewer but equally well controlled. The cereal cyst‐nematode (Heterodera avenae), a serious maize pathogen in Northern France, was relatively scarce in untreated roots and was further decreased by aldicarb treatment; post‐harvest H. avenae egg numbers were not affected by treatments; they declined equally because maize is such a poor host. Significant yield benefits (up to 37%) followed aldicarb treatment and were ascribed to nematode control in the absence of attribution to insect or other pests. Benomyl did not increase yields nor did it significantly affect the incidence of mycorrhiza.The results confirm that considerable losses of forage maize can be caused by nematodes in light soil and that aldicarb is an effective nematicide even at the rate of 1·7 kg a.i./ha.
Laboratory tests for leaf resistance to Botrytis squamosa in onions
Authors: CURRAH LESLEY , MAUDE R. B. 
Published: February 2008

SUMMARYTwo laboratory methods of testing for resistance to Botrytis squamosa in Allium cepa, A. fistulosum and hybrid material derived from them were developed. In one method, seedlings were sprayed with conidiospores, incubated for 3 days at 15°C (2 days at 100% r.h.) and the numbers of lesions per leaf assessed. This test was destructive. The second method was non‐destructive, the plants being retained for breeding purposes. Leaf segments (25 × 15 mm) or leaf discs (14 mm diameter) were inoculated individually with a drop (0·014 ml) of spore suspension, and maintained at 15°C and 100% r.h. with a 12 h photoperiod. The length of the latent period, denned as the number of days for 50% of the leaf portions to produce lesions bearing visible mycelium, was determined for each onion line in a test. The reciprocal (1/t) of the latent period was used to test for significant differences between lines by analysis of variance.With both test methods, spores were applied at concentrations that discriminated relative resistance most readily.In both seedling and leaf segment tests A. fistulosum was more resistant than A. cepa to B. squamosa. The leaf disc test indicated that cultivars of A. fistulosum differed in their resistance. In hybrid material resistance was intermediate or more like that of A. fistulosum.
Soil compaction and the growth of vining peas
Authors: DAWKINS T. C. K. , HEBBLETHWAITE P. D. , MCGOWAN M. 
Published: February 2008

SUMMARYThe effects of differing soil conditions at two sites on the growth of vining peas are described. The work was carried out over several seasons having contrasting rainfall at the time of crop emergence.Topsoil compaction induced by tractor wheelings reduced plant population and yield of vining peas by up to 70%. On the compacted plots peas were unable to compensate for the low population which was demonstrated by the inclusion of a non‐compacted treatment thinned to the same population as the compacted plots.The severity of compaction was greatest when soil conditions were dry at emergence and least severe when wet. It is suggested that compaction resulted in increased ethylene production in the root and shoot tissues and this may be a causal agent of the observed growth modifications.Recultivation of a compacted seed bed prior to sowing resulted in better establishment and higher yields than with the topsoil compacted but final yields were variable when compared to a ploughed control.Double digging did not increase yield above a ploughed control. In one year a 25% yield reduction was attributed to this treatment. The reasons for the reduction in yield are complex but it is suggested that the causal agent was modfied soil and plant water relations resulting in altered crop physiology.Tramlining the crop reduced yield in one year but when the frequency of wheeling damage is considered they would be unlikely to affect productivity.
Biological effectiveness of electrostatically charged rotary atomisers.
Authors: ARNOLD A. J. , CAYLEY G. R. , DUNNE Y. , ETHERIDGE P. , GRIFFITHS D. C. , PHILLIPS F. T. , PYE B. J. , SCOTT G. C. , VOJVODIC P. R. 
Published: February 2008

SUMMARYElectrostatic sprayers charged to 30kV and placed 20 cm above the crop increased the chemical deposition of permethrin in field beans and improved control of the pea and bean weevil, Sitona lineatus. Control of the black bean aphid, Aphis fabae, was improved by electrostatic sprayers only when a systemic chemical, demeton‐S‐methyl, was used. In spring barley, sprays applied electrostatically or hydraulically gave similar control of barley mildew, Erisyphe graminis.
Effect of gibberellic acid, kinetin and naphthylacetic acid on the growth of coconut seedlings
Authors: REMISON S. U. 
Published: February 2008

SUMMARYThe effects of three growth regulators, namely gibberellic acid (GA3), kinetin (6‐furfuryl‐aminopurine) and α‐naphthyl‐acetic acid (NAA), each at five concentrations (0, 25, 50,102 and 103 mg/litre) on the growth of coconut seedlings (Cocos nucifera) were examined. GA3 at 25 mg/litre increased growth in height; higher concentrations had no significant effect. Kinetin at 102 and 103 mg/litre and NAA at all concentrations reduced height growth compared with the control. No treatment caused a significant increase in total dry weight.