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Fusarium head blight (FHB) is one of the most devastating crop diseases worldwide, significantly reducing the yield and quality of small‐cereal crops such as wheat and barley when favourable weather conditions exist during anthesis. Additionally, FHB‐associated mycotoxins significantly impact global food and feed safety. Controlling FHB with fungicides applied near anthesis reduces visual FHB symptoms and associated mycotoxin production, thereby lowering disease‐related costs. However, when weather conditions are unfavourable for FHB occurrence, fungicide application can be costly and environmentally undesirable. Thus, fungicides should be used sparingly only when the pathogen is present and weather conditions are favourable. Modelling of FHB risk using weather data has grown rapidly in recent decades and plays an essential role in integrated crop disease management. In this review, several weather‐based FHB models are selected and described in detail. The models were developed globally for assessing the real‐time risk of FHB epidemics in various regions/countries. Most of these models are site‐specific and predict FHB visual observations such as the incidence and severity of FHB, Fusarium‐damaged kernels (FDK), and also deoxynivalenol (DON) levels. The review also highlights the limitations of these existing models, including their narrow applicability, low accuracy for high‐risk contamination situations, and omissions of certain factors. Also discussed are potential avenues for improvement and enhanced predictive capabilities including consideration of additional disease risk factors as well as a broader range of varieties. These predictive models can assist producers, regulatory agencies, and industry to mitigate potential food and feed security and safety concerns. [ABSTRACT FROM AUTHOR]

Common root rot (CRR) caused by the soilborne pathogen Bipolaris sorokiniana (teleomorph Cochliobolus sativus) is becoming increasingly prevalent worldwide. Identification of CRR is difficult and time‐consuming for human assessors due to the non‐distinctive above‐ground symptoms, with browning of subcrown internodes and roots the most distinguishing symptom of infection. CRR disease has been recognized as a significant disease for cereal crops in many countries. In 2009, CRR in Australia was estimated to cause $30 million average annual yield loss for wheat and $13 million for barley. Recent evidence indicates CRR may be more prevalent than expected in Australian wheat cropping areas due to lack of research on this disease. Low levels of B. sorokiniana survive in the soil for up to 10 years and attack plants at early stages of growth. Therefore, mitigating CRR in wheat and barley may not be practical at the late stages of infection due to lack of effective methods; however, early detection might be viable to alleviate the impact of this disease. A comprehensive overview of CRR caused by B. sorokiniana, including disease background, worldwide economic losses, management methods, potential CRR detection using multispectral and hyperspectral sensors and the research focus over the past 50 years is provided in this article. This review paper is expected to provide thorough supplemental information for current studies about CRR and proposes recommendations for whole‐of‐field disease scouting methods to farmers, enabling reduced time and cost for CRR management and increasing wheat and barley production worldwide. [ABSTRACT FROM AUTHOR]

Non‐crop plants such as grasses and volunteer plants are an inseparable part of the flora of crop fields and can influence virus incidence in crop plants. The presence of grasses as virus reservoirs can lead to a higher probability of virus incidence in crop plants. However, the role of reservoirs as an inoculum source in agricultural fields has not been well studied for many viral diseases of crops. Grasses have been found to constitute potential reservoirs for cereal‐infecting viruses in different parts of the world. This study revealed that cereal‐infecting viruses such as wheat dwarf virus (WDV), barley yellow dwarf viruses (BYDVs), and cereal yellow dwarf virus‐RPV (CYDV‐RPV) can be found among ryegrass growing in or around winter wheat fields. Phylogenetic analysis showed that a WDV isolate from ryegrass was a typical WDV‐E isolate that infects wheat. Similarly, a ryegrass isolate of barley yellow dwarf virus‐PAV (BYDV‐PAV) grouped in a clade together with other BYDV‐PAV isolates. Inoculation experiments under greenhouse conditions confirmed that annual ryegrass of various genotypes can be infected with WDV to a very low titre. Moreover, leafhoppers were able to acquire WDV from infected ryegrass plants, despite the low titre, and transmit the virus to wheat, resulting in symptoms. Information from the grass reservoir may contribute to improving strategies for controlling plant virus outbreaks in the field. Knowledge of the likely levels of virus in potential reservoir plants can be used to inform decisions on insect vector control strategies and may help to prevent virus disease outbreaks in the future. [ABSTRACT FROM AUTHOR]

We conducted a five‐year survey (2011–2015) of barley and wheat fields in Paraná state, Brazil, obtaining 754 Fusarium isolates from spikes with fusarium head blight (FHB)‐symptoms. Multilocus genotyping and TEF‐1α gene sequence analyses confirmed the dominance of the F. graminearum species complex (FGSC, 75.7%), but F. poae (11.5%), as well as F. avenaceum and related members of the F. tricinctum species complex (FTSC, 8.1%) appeared as substantial contributors to FHB. Within the FGSC, F. graminearum of the 15‐ADON genotype was dominant (63%), followed by F. meridionale of the NIV genotype (23.1%), F. cortaderiae of the NIV (7%) or 3‐ADON (2.6%) genotypes, and F. austroamericanum (3.8%) of the 3‐ADON genotype. Substantial variation in pathogen composition was observed across years, with F. poae and F. meridionale frequencies significantly elevated in some years. Most F. poae strains produced DAS, diANIV, and butenolide, but not neosolaniol, T‐2, or HT‐2. All FTSC species produced moniliformin. Enniatin production was widespread among FTSC species, with the single F. acuminatum strain found to be the strongest producer of enniatins. Our findings confirm FGSC as a major contributor to FHB and expand considerably our knowledge of the presence, frequency, and conditions under which other pathogens may emerge, altering the spectrum of toxins that may accumulate in grain. [ABSTRACT FROM AUTHOR]

Pratylenchus curvicauda, which was first described in metropolitan Perth in 1991, was recently identified in grain‐growing areas in Western Australia. The biology of this root‐lesion nematode, and especially its pest status, is unknown. We investigated its life cycle and interaction with host plants, because such information is essential for its management. The life cycle took 45 days to complete in a wheat cultivar maintained at 23°C. Over 10 weeks, the nematode multiplied in 26 of 61 genotypes; these host plants were all cereals and included widely grown cultivars of wheat and barley. Eighteen other cereal genotypes and 13 cultivars including canola, chickpea, ryegrass, lupin, soybean, and tomato, sustained the nematodes to different degrees without multiplication. Four cover crops were not suitable hosts. The patterns of attraction of the nematodes and penetration into roots of the host and tolerant plants were similar. The nonhosts attracted fewer nematodes, none of which penetrated the roots. Browning of infected roots was atypical—it occurred late in some roots, 55 days after inoculation, and in the presence of a fungus. The nematodes were confined to, and fed from, cortical cells. The ultrastructure of infected wheat and barley cells showed typical signs of damage caused by Pratylenchus spp. and included cell disorganization and lack of membrane integrity, disintegration of cytoplasm, hypertrophy of some nuclei, and deposition of tannin‐like granules. This detailed characterization of P. curvicauda–host interaction indicates the nematode is likely to be a pest of major crops, and attention should be given to its management. [ABSTRACT FROM AUTHOR]

This study investigated the distribution and characteristics of the Barley yellow dwarf virus (BYDV) species BYDV-PAS, which was recently separated from BYDV-PAV, the most commonly studied BYDV species. Throughout 3 years of experimental monitoring of BYDV incidence, PAS was the most frequently occurring species infecting cereals and grasses in the Czech Republic. Furthermore, Rhopalosiphum maidis and Metopolophium dirhodum were recorded as BYDV-PAS vectors, even though M. dirhodum does not usually transmit BYDV-PAV. In field experiments with barley and wheat, where virus accumulation, symptoms and effect on the yield were tested, BYDV-PAV was more severe than PAS. Infection with the BYDV-PAV isolate resulted in greater expression of symptoms and also in a greater reduction in plant height and grain weight per spike than BYDV-PAS. In a sensitive cultivar of barley (Graciosa), the amount of viral RNA of BYDV-PAV was also significantly higher than that of BYDV-PAS. In a tolerant line (Wbon-123), however, no such differences were found. In conclusion, although BYDV-PAS seems to be dominant in the Czech Republic, BYDV-PAV has the potential to cause more significant crop losses in barley and wheat. [ABSTRACT FROM AUTHOR]

A method of inoculating seedlings with the fungus Ramularia collo-cygni, the causal agent of ramularia leaf spot (RLS), an increasingly important problem in barley in Europe and elsewhere, is described. Symptoms of RLS similar to those found in the field were reproduced on seedlings and the fungus was re-isolated from them, fulfilling the third and fourth of Koch's postulates. The method was similar to one used for the related fungus, Mycosphaerella graminicola (anamorph Septoria tritici), a pathogen of wheat. Briefly, plants were sprayed with a suspension of R. collo-cygni mycelium fragments, incubated at 15°C, first in darkness for 48 h then in a 16-h-light/8-h-dark cycle. Disease levels reached saturation when plants were sprayed to runoff with a suspension of 480 cm2 of mycelium, scraped from the entire surface of 7·5 Petri dishes (9 cm diameter) and sieved, in 50 mL water. Growth of seedlings in high light intensity (900  µmol m−2 s−1, 16-h daylength) before inoculation increased disease symptoms, but reduced disease when applied after inoculation. In contrast to M. graminicola, near-ultraviolet light after inoculation reduced symptom development. It is proposed that for the full development of RLS, plants should be grown in a stressful environment before inoculation. Nine barley lines were assessed for their resistance to RLS as seedlings and a subset were tested in field trials with natural infection by R. collo-cygni. There was cultivar-by-isolate interaction in the amount of RLS symptoms on seedlings. RLS levels on adult plants in field plots were correlated with RLS scores on seedlings formed by one isolate but not the other. [ABSTRACT FROM AUTHOR]

Rust diseases have caused significant losses to Australian cereal crops, and continue to pose a serious threat. Because Australian cereal crop yields are generally low, genetic resistance remains the most economical means of rust control. Resistant cultivars also contribute significantly to reducing over-summer rust survival. A policy of releasing only rust resistant wheats in northern New South Wales and Queensland has resulted in industry-wide protection from rust in this region for the past 40 years. The Australian Cereal Rust Control Program conducts annual pathogenicity surveys for all cereal rust pathogens, undertakes genetic research to identify and characterize new sources of resistance, and provides a germplasm screening and enhancement service to all Australian cereal breeding groups. These three activities are interdependent, and are closely integrated with particular emphasis on linking pathology and genetics to ensure breeding outcomes. Recent changes in the wheat rust pathogens, including the development of virulences for Yr17, Lr24, Lr37 and Sr38 resistance genes, and the introduction of a new pathotype of the wheat stripe rust pathogen, have provided new and significant challenges for wheat rust resistance breeding. Similar challenges exist in breeding barley and oats for rust resistance. Examples are discussed to illustrate the ways in which rust isolates are providing information that can be used in breeding for rust resistance. In future, as more markers linked to durable rust resistance sources become available, it is likely that the use of marker-assisted selection will become more common-place in rust resistance breeding. [ABSTRACT FROM AUTHOR]

Greenhouse trials conducted in 2003 and 2004 investigated the impact of trichothecenes on the severity of seedling blight and root rot in common wheat ( Triticum aestivum), durum wheat ( Triticum turgidum var. durum), barley ( Hordeum vulgare) and triticale (× Triticosecale 6x) using two trichothecene-producing and two trichothecene-nonproducing Fusarium graminearum strains. In 2003 seedling emergence and survival following soil infestation of the trichothecene-producing strain (Gz3639) were significantly reduced compared with the trichothecene-nonproducing strain (GzT40), while root-rot incidence and severity were increased significantly. In 2004, two trichothecene-producing strains (Gz3639 and GzT106) reduced seedling emergence and survival ( P ≤ 0·01) in eight of 10 crops/cultivars based on single-degree-of-freedom contrasts. However, when results from all strains were combined no significant differences were observed between two trichothecene-producing and two trichothecene-nonproducing F. graminearum strains. Inoculation with GzT106, a trichothecene-producing ‘add-back’ strain, resulted in more severe root rot symptoms in eight of 10 cultivars ( P ≤ 0·01–0·05) and lower seedling emergence and survival in seven of 10 cultivars ( P ≤ 0·01–0·10), compared with the wild-type parental strain Gz3639. The presence of trichothecenes may play an important role in the aggressiveness of F. graminearum. [ABSTRACT FROM AUTHOR]

Communities of fungi on roots increased in diversity between second and third cereals, and were more diverse on winter wheat than on winter barley in a field experiment conducted over 3 years. Seed treatment with formulations containing fluquinconazole or fluquinconazole plus prochloraz had little effect on these communities, which include potentially beneficial, antagonistic fungi. Seed treatment decreased take-all and increased yield of wheat, especially in the second wheat in which take-all was building up, and in the third wheat when take-all was at its peak. It was less effective in the fourth wheat when take-all appeared to be in decline in plots that had no seed treatment throughout the experiment, and in barley, in which take-all was usually less severe. Take-all increased in untreated fourth wheat crops grown after third wheat crops that had been treated, suggesting that treatment had delayed take-all build-up and eventual progress into take-all decline. [ABSTRACT FROM AUTHOR]

Wheat and barley crops were shown to be susceptible to Indian peanut clump virus (IPCV) under field conditions. In wheat, the Hyderabad isolate of IPCV (IPCV-H) induced symptoms resembling the rosette caused by soil-borne wheat mosaic virus, and these were apparent only three weeks after emergence. Early-infected plants were severely stunted and dark green, with chlorotic streaks on the youngest leaves, which turned necrotic as the plants aged; most of these plants died. Late-infected plants were also stunted and were conspicuous in the field because of their dark green appearance as a result of delayed maturity. The virus was detected by ELISA and nucleic acid hybridization in all plants with symptoms. These plants usually produced fewer tillers than healthy ones. Spikes were malformed, often did not emerge from the flag leaf, and they contained few, shrivelled seeds. Grain yield was decreased, on average, by 58%. In barley, IPCV-H caused severe stunting and general leaf chlorosis. As the plants aged, the leaves became necrotic and the few infected plants that reached maturity produced small spikes. IPCV-H antigens were detected by ELISA in every wheat seed from infected plants and the virus was transmitted through wheat seed at a frequency of 0·5–1·3%. Storage at 4°C for more than a year did not affect seed transmission frequency. The virus was detected in leaves and roots of seed-transmitted plants. Seed transmission was not detected in barley. The Durgapura isolate (IPCV-D) was detected in wheat crops (cv. RR-21) at 3 different locations in Rajasthan State, India. Infected plants showed reduced growth without any overt symptoms. [ABSTRACT FROM AUTHOR]

Ninety-eight isolates of Rhizoctonia spp. were obtained from barley and wheat grown in Erzurum, Turkey. Of these, 78% were Rhizoctonia solani (AG-2 type 1, AG-3, AG-4, AG-5 and AG-11), 10% were binucleate Rhizoctonia (AG-I and AG-K) and the remainder were Waitea circinata var circinata (Rhizoctonia sp.). Among the binucleate Rhizoctonia, AG-I was not recovered from barley. In pathogenicity tests on barley and wheat, the highest disease severity was caused by isolates of AG-4 and AG-11, whereas isolates of AG-2 type 1, AG-3, AG-5 and W. c. var circinata were moderately virulent. Isolates of binucleate Rhizoctonia were all nonpathogenic. This is the first report of R. solani AG-11 and W. c. var circinata from Turkey. [ABSTRACT FROM AUTHOR]

Isolates of the take-all fungus, Gaeunannomyces graminis var. avenae, which affects oats, wheat and other grasses, and of G.g. var. tritici, which preferentially affects wheat, rye and barley, contain a high proportion of repeated sequences. Total DNA from 57 fungal isolates collected from many locations and different cereal hosts, and scored for virulence on wheat, rye and oats, revealed many restriction fragment length polymorphisms. These RFLPs were observed either by staining the DNA directly, by hybridization to radioactively labelled total fungal DNA, or by hybridization with labelled wheat ribosomal DNA. With only a few exceptions, the isolates with the same preferred cereal hosts showed more similar patterns of restriction fragments than isolates that had different pathogenicity properties on cereal hosts, irrespective of the geographical origins of the isolates. This was even the case for R isolates of G.g. var. tritici that were virulent on wheat and rye compared with N isolates that were virulent only on wheat. Isolates were identified by hybridizing DNA from infected root samples with 32P- labelled total fungal DNA. The restriction fragment polymorphisms involving families of repeated sequence can therefore be used as a predictive assay for host preference of an isolate, and have probably arisen by host selection of fungal lineages. The variation between isolates in different pathogenicity groups suggests that there is little gene flow between isolates that can infect different hosts, even though they can coexist in the same field. [ABSTRACT FROM AUTHOR]

Sixty-four strains of Septoria which had been isolated from a range of hosts at different locations and in different years were characterized for their adaptation to wheat or barley, growth at near-maximum temperature, fluorescence, colony morphology, conidial (pycnidiospore) length and hexokinase and alkaline phosphatase isozymes. For each character except conidial length, the strains could be divided into two or three discrete groups. The variation in these six characters was strongly associated, such that 60 strains could be classified into two groups, designated W-type and B-type. W-type strains are adapted to wheat, produce large colonies at 31 C. fluoresce, produce brown-pigmented colonies, and have fast isozymes. B-type strains are adapted to barley, produce small colonies at 31°C, do not fluoresce, produce pink-pigmented colonies, and have slow isozyrnes. A few strains differed from these norms in one of the six characters, but only one showed an atypical host adaptation. The four unclassified strains differed from W- or B-type in two or more characters. The many differences between the W-and B-types suggest they are genetically distinct populalions within Septoria nodorum. [ABSTRACT FROM AUTHOR]

Pythium heterothallicum, P irregulare, P. torulosum and P. ultimum var. sporangiiferum were compared for pathogenicity to seedlings of winter wheat, spring barley, lentils and peas in growth chambers at 5, 10, 15, 20 and 25 C. These four fungi are among the most commonly isolated Pythium species from wheat roots and wheat-field soils in eastern Washington and northern Idaho, USA, where wheat, spring barley, lentils and peas are grown in various rotations. Pathogenicity was determined in artificially infested soils (500 propagules per g) based on ability to cause pre-emergence death and post-emergence stunting of seedlings. P. ultimum var. sporangiiferum caused significant pre-emergence death only of peas and only at 5 C. With the possible exception of lentils at 25 C, P. heterothallicum and P. torulosum caused no pre-emergence death of any of the four plant species. None of the species caused pre-emergence death of spring barley. P. ultimum var. sporangiiferum caused the most post-emergence stunting of wheat, peas and lentils at 10 C and above. Pythium irregulare caused as much or more stunting than P. ultimum var. sporangiiferum on wheat, lentils and peas at 5 C, and was the most pathogenic species on barley at 10, 20 and 25 C. P. irregulare caused significantly more post-emergence stunting of wheat at 5 C with than without chaff (added as a food base for the pathogen); this was not offset by adding ammonium sulphate with the chaff. [ABSTRACT FROM AUTHOR]

The susceptibility of 24 winter and 17 summer crops to infection by Bipolaris sorokiniana was tested in a glass house experiment by growing them in soil amended with wheat-barley grain colonized by B. sorokiniana (0-2 g per 100 g soil). At anthesis, infection of both lessoned and randomly selected segments of roots and of crowns was determined by plating them on modified Czapek-Dox Agar. Incidence of infection in winter crops was higher than in summer crops. Guar, mung bean, soybean and sunflower were the least infected of the summer crops while chickpeas and safflower were the least infected of the winter crops. Amongst the taxonomic groups tested, the highest incidence of infection occurred in the gramineous species and the lowest in the leguminous species. Five summer crops growing in the field were sampled and infection by B. sorokiniana confirmed. Cultivars of wheat, barley, triticale and oats were also screened in a field experiment. Amongst these winter cereals, oats was the least susceptible in both field and glass house experiments. Differences between cultivars in susceptibility to common root rot, measured by the degree of lesion development in the subcrown internode, were identified in wheat, triticale and oats but not in barley. [ABSTRACT FROM AUTHOR]

Single-spore cultures of wheat- and barley-adapted isolates of Septoria nodorum were serially passaged through detached leaves of wheat or barley. Rare instances of change in host adaptation were observed after passaging but associated changes in other characters, including heterokaryon compatibility, identified the changed isolates as contaminants. Inoculation of progressively more dilute spore suspensions to detached leaves revealed that some isolates were highly infective to the host to which they were adapted, with a high probability of a single spore initiating infection. Inocula deliberately contaminated with a small proportion of spores of opposite host adaptation revealed changes when passaged on wheat that mimicked the rare changes observed on passaging pure wheat- or barley-adapted isolates. These results suggest that adaptation to wheat or barley is a stable property of pure cultures of S. nodorum and that the occasional changes in host adaptation observed on passaging result from selection of contaminants. [ABSTRACT FROM AUTHOR]

Dryland root rot of wheat and barley in South Australia is a syndrome from which the associated fungi Fusarium equiseti, F. acuminatum, F. oxysporum and Bipolaris sorokiniana were isolated consistently. Fusarium infections were concentrated on the subcrown internodes, crown roots and culm bases, and occurred with equal frequency on wheat and barley. Bipolaris infections were more numerous on barley than on wheat, and were concentrated on culm bases and subcrown internodes. Recoveries of each of the four fungi showed a pattern of infection that was neither randomly nor evenly distributed. Each fungus had preferences for certain sites which resulted in a stratified distribution over the roots and crown. When two barley cultivars were compared, the patterns of infection were different; the subcrown internode was attacked more severely, and there was a substantial increase in the amount of infection by all four fungi on one of the cultivars. Pathogenicity tests on barley and oats showed that all four species of fungi were capable of causing damage to roots, but there were differences between isolates of each fungus and differences in their ability to damage barley and oats. [ABSTRACT FROM AUTHOR]

Five barley-adapted and five wheat-adapted isolates of S. nodorum, each derived from a single spore, were passaged five times through seedlings of both wheat and barley grown under stringent conditions of isolation. Some isolates carried genetic markers to permit confirmation of their identity after passaging. Reisolations were made after passaging and the characteristics of reisolates (host preference, colony morphology, fluorescence and genetic markers) were compared with those of the parent isolates. Those reisolates showing a change in host preference were tested for heterokaryon compatibility with the original unpassaged isolates. Most reisolates were unchanged, but six obtained after passage through the alien host were changed in host preference and in at least some of the other observed characteristics. Each of the changed reisolates resembled, and was heterokaryon compatible with, one of the other parent isolates used in the experiment, but was incompatible with its original parent isolate. These results indicated that the observed changes resulted from cross-contamination followed by selection of adapted contaminants by the host. [ABSTRACT FROM AUTHOR]

A single-spore wheat isolate of S. nodorum was passaged once through barley and a barley isolate passaged once through wheat. Reisolations from barley leaves were designated as either 'original-type wheat' (OTW) and resembled the wheat isolate used for inoculations in morphology, or 'sector-type barley' (STB) resembling the known morphology of barley isolates. Reisolations from wheat were similarly designated either OTB or STW. Sub-cultures of STB were significantly more pathogenic to barley in a glasshouse experiment than OTW, and vice versa. Similarly STW was significantly more pathogenic to wheat than OTB, and vice versa. A single-spore wheat isolate was also passaged 0, 1, 2, 3 or 4 times through barley and a barley isolate passaged similarly through wheat. Disease assessment and yield data from a field experiment showed that the pathogenicity of the passaged wheat isolate remained largely unaltered from that of the original isolate. However, the barley isolate responded after the third wheat passage by causing significantly less disease and significantly higher yields in barley than the unpassaged isolate; conversely, on wheat, disease levels significantly increased and yield significantly decreased after the second wheat passage. Data obtained are discussed in the context of cultural observations made on colony morphology during host passage sequences and possible genetic mechanisms responsible. [ABSTRACT FROM AUTHOR]

The effect of Heterodera avenae Woll. upon the early growth of cultivars of oats, wheat and barley was measured. During the first two weeks the rate of root growth was retarded in some barley cultivars although shoot growth was stimulated in all the oats and in two cultivars each of barley and wheat. Later, infestation slowed growth of all the cultivars grown, except Drost barley. When uninfested, some cultivars resistant to H. avenae grew more slowly than did susceptible ones. [ABSTRACT FROM AUTHOR]

Data comparing the amount of infestation in eastern England on wheat, barley and oats by saddle gall midge are given for the years from 1967 to 1972. The level of infestation decreased in 1971 and 1972. The changes in the numbers of overwintering larvae in several fields, with their cropping, are recorded. In 1971 and 1972 the first adult was trapped on 18 and 19 May respectively; the peak flights occurred on 31 May 1971 and on 11 June 1972. It was not possible to obtain an overall relationship between the amount of galling and yield. It is suggested that the individual effects of the many factors which can affect yield can only be assessed from detailed experiments. In a small-scale trial in 1972, a fenitrothion spray applied in June prevented galling of barley. [ABSTRACT FROM AUTHOR]

Commercial-scale field trials on farms in North Hampshire over four seasons (1963 to 1968) showed that nitrogen applied to wheat or barley stubble after harvest in the autumn failed to reduce the incidence of take-all and eyespot in the succeeding wheat or barley crop, or produced only minor reductions in the spring which were not maintained up to the stage of crop maturity. There were no consistent significant differences in levels of disease between rate or form of nitrogen applied as urea/ammonium nitrate spray at 0, 12, 24 or 48 units/acre (1 unit/ac = 1.25 kg/ha), ammoniacal gas liquor spray at 48 units/acre and anhydrous ammonia injected at 40 units/acre. Burning-off stubbles with high-output flame cultivators did not significantly reduce the incidence of either disease. [ABSTRACT FROM AUTHOR]

This article describes the occurrence of cephalosporium stripe on wheat and barley in England. The disease is caused by Cephalosporium gramineum. Infection of the plant fungi greatly decreased grain yield and there was a significant negative correlation between yield per pot and number of infected plants per pot. It is usually assumed that severe damage is caused only when stems are bitten. Adding wireworms to soil inoculated with C. gramineum increased the percentage of wheat plants that became infected with the fungus. It is suggested that wireworms facilitate infection by injuring roots or other underground parts of the plants.

This article examines the unusual frost injury to winter-sown wheat and barley in Aberdeen, Scotland. Extensive damage was noted to winter wheat and winter barley plants in experimental plots in Woodlands field. The primary shoots were lying on the surface soil, being completely severed from the plant. It is suggested that the cause of the damage was the substantial drop in surface temperature immediately following the appearance of the primary shoots. The frost lift which occurred at this young stage of growth was responsible for breaking the primary shoot within the basal sheath. Subsequent thawing out deposited the broken shoots on the soil surface and damage remained unnoticed until snow cover completely disappeared.

This article presents the results of experiments on the survival of Cercosporella herpotrichoides on naturally infected straws of wheat and barley, being carried out on two sites at Rothmasted Experimental Station in Harpenden, Herts from 1957-1959. The incidence of disease in April each year was closely related to the amount of sporing material on the soil surface in late winter; in none of the years did a low level of inoculum cause a high percentage of infected plants in April. Most of the infections diagnosed at this time were probably primary, that is, infections by spores produced on the straw bases on the soil surface. The observations support the conclusion from rotation experiments that one year without a cereal host is too short to bring C. herpotrichoides.