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In 1973, 103-108 adults of the Colorado beetle, Leptinotarsa decemlineata (Say), were found, of which 51 were alive. This is the largest annual total for 20 years. Details of these finds are presented. The outstanding feature is the large number (74-79) associated with French wheat. [ABSTRACT FROM AUTHOR]

Pot-grown plants of spring wheat, cultivar Maris Dove, Were subjected, commencing at ear emergence, to different, constant levels of infestation by Metopolophium dirhodum (Wlk.) in a glasshouse. Infestation with six aphids per stem over 11 days had no significant effect on yield. Infestations with either six or 50 adult aphids or their equivalents, when maintained until ripening, resulted in lower yields of both grain and straw dry matter. Loss of grain was due to reduction in both 1,000 grain weight and the average number of grains per fertile spikelet. Harvested dry matter content of leaf blades was unaffected by infestation, but the dry matter, content of stems was reduced in infested plants. In breeding aphid-resistant cereals for Britain, resistance characters restricting aphid multiplication are most likely to reduce yield losses due to aphid attack. [ABSTRACT FROM AUTHOR]

Foliar sprays of fungicides were evaluated in a field where winter wheat cv. Joss Cambier was subject to a severe natural infection of yellow rust (Puccinia striiformis Westend.). Almost complete freedom from the disease was achieved on the leaves from repeated applications of BAS 3170F. This material prevented the development of appreciable disease for up to four weeks after spraying. Other chemicals gave varying degrees of protection but most lacked persistence. Control of ear infection was less satisfactory. The untreated crop, which was heavily attacked by yellow rust, showed a yield reduction of 34 per cent compared with the crop receiving greatest protection. The relationship between yield and yellow rust at growth stage 11.1 was statistically significant; the loss of yield recorded was 0.022 t/ha for each one per cent increase in the level of yellow rust on the flag leaf. [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]

A greater prevalence of European wheat striate mosaic was reported in English winter wheat crops in 1970 than in any previous year and loss of yield in one crop was probably as much as 10 per cent. At Rothamsted, infected plants were first found at the beginning of May and symptoms appeared in others until the middle of June. Most infections probably occurred before spring cereals emerged but a few plants became infected in spring-sown crops. Most infected plants produced no grain. The mild autumn of 1969 and a previous crop of spring wheat may have been partly responsible for the unusually prevalent infection at Rothamsted. [ABSTRACT FROM AUTHOR]

Regression analyses of the effect of cereal cyst eelworm (Heterodera avenae Woll.) on spring-sown wheat, barley and oats in two fields during 1963 and 1964 showed that the eelworm attack had reduced the yields of all three cereals in both years. For every ten eggs of H. avenae per g of soil before cropping there was an approximate loss of 3 cwt/acre (376 kg/ha) of oats and 1.5 cwt/acre (188 kg/ha) of wheat, but only 0.6 cwt/acre (75 kg/ha) of barley. Thus the loss of oats was about twice that of wheat and five times that of barley. These results are compared with those of other workers some of whom used resistant cultivars or soil fumigants. [ABSTRACT FROM AUTHOR]

This article focuses on a research on two isolates of Rhizoctonia solani Kü from wheat. Two strains of Rhizoctonia solani which were distinctly different in their morphological characters and their pathogenicity were isolated from wheat and wheat stubble. The isolates from several hosts were found to exhibit little or no host specialization. However, previous work on cereals indicated the existence of a number of specialized strains of R. solani. Several researchers was able to detect the presence of more than one specialized strain in one particular locality.

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 presents the results of an experiment on the comparison of systemic insecticides as seed treatments against aphids. In glasshouse tests, 13 insecticides were applied as seed dressings to wheat, kale and sugar beet seeds. None of the insecticides affected the growth of kale, but 18133, 4536, dimethoate and phorate delayed the emergence of wheat seedlings. In contrast, the emergence of beet seedlings was stimulated by 18133, 4536, dimethoate, disyston and phorate. Dimethoate was the most persistent and toxic, but demeton, disyston and phorate were good. Isolan, tested only on kale, was toxic and persistent. Menazon and 18133, would have probably been effective at higher rates. Schradan and Trithion were ineffective.

This article discusses several trials used to control slugs on arable fields. Six trials were done to compare standard metaldehyde and bran baits with other materials, known to have molluscicidal properties, used as sprays or dusts for the control of slugs before drilling wheat on heavy soils in the autumn. Of the spray treatments, dinitro-o-cresol and metaldehyde showed some promise, and copper sulphate applied as a powder also gave a good result in one of the trials. Soil conditions often make control measures difficult on heavy land in autumn and treatments would almost certainly have to be applied before ploughing. Because of weather and soil conditions, wheat could not be drilled on two of the trials. In the three trials where wheat was drilled and slug populations were high enough to cause damage there was no evidence that less damage had occurred on the treated plots.

This article discusses the field trials conducted on wheat blossom midge at the Hertfordshire Institute of Agriculture in Saint Albans, England from 1954-1956. During the years 1954-56 field trials were carried out on the wheat blossom midges Contarinia tritici Kirby and Sitodiplosis mosellana Gehin to obtain information on wheat yields in relation to larval abundance in commercial crops and to investigate problems in assessing the larval infestation. In 1956, the trial was enlarged to include an assessment of cereal thrips. Based on the trials, attacks by wheat blossom midge were very slight on the experimental sites in all years and caused no detectable loss in grain yield. In the virtual absence of any pest attack yields were in fact consistently lower on the sprayed plots, indicating that the dichlorodiphenyltrichloroethane sprays had reduced grain yields.

This article summarizes recent work undertaken to test methods of assessing rabbit damage to wheat in England and Wales from 1950 to 1952. It has long been recognized that rabbits are an important pest, but in some districts their meat and sporting values have often been offset against the damage they do. Looking at the result of the pilot survey carried out on spring wheat in Kent in 1950, and the subsequent country-wide survey on winter wheat in 1952, it is clear that a reliable technique has been worked out for estimating rabbit damage to cereals. However, the problem of effectively protecting a complete field from rabbits is very different from that of fencing a small plot within a field. To be effective, protection by fencing probably has to be combined with drastic reduction or control of the local rabbit population, particularly as rabbits in an infested area will be strongly attracted by the fresh growth in protected fields.

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 discusses a study about the field infestation caused by wheat bulb fly on alternative host plants. Observations were made in the spring of 1957 on a permanently fallow plot situated in the centre of Bones Close Field at Rothamsted in England. The occurrence of a considerable infestation of wheat bulb fly eggs in the fallow plot is in itself a point of interest and provides a striking example of the attraction of even a relatively small area of fallow to the ovipositing females. There is some experimental evidence to suggest that this is so for other graminaceous species. By comparing the numbers of larvae subsequently found in the test species with those found in the wheat plants, a measure of their susceptibility to attack relative to wheat was obtained.

This article describes the control of wheat bulb fly in winter wheat through seed dressing and granule treatments in Suffolk, Holland during 1963-1964. On November 8, 1963, a randomized block was drilled on a clay-loam. A table is presented in this article which shows treatment details and the summary of the results. It notes that the Bayer 37289 seed dressing delayed germination but the crop recovered and good control of wheat bulb fly was obtained.

This article focuses on the control of wheat bulb fly in winter wheat during trials in Suffolk, Holland and Isle of Ely in 1963-1964. On March 27, 1963, a randomized block trial was laid down in Suffolk in a field where 97 percent of the plants were attacked and there were 1.7 shoots per plant. By this time 50 percent of the larvae were in the second instar. Treatments were applied as soon as the plots had been demarcated and larval assessments were made eight days later. The other trials were done in early March 1964. In Holland, 50 percent of the plants were attacked at the time treatments were applied, and in the Isle of Ely 72 percent were attacked. Plant samples were examined four weeks after treatment, and no yield assessments were made because all plots recovered from the attack.

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.

This article describes the trials conducted in Essex, England and the Isle of Ely during 1963-1964. The trial in Essex was laid down on a clay loam while the other on a peaty loam in the Isle of Ely. All seed dressings were used at 2 ounce per bushel of seed. A liquid mercury dressing was applied to the seed used on the dimethoate spray and the control plots. On the clay loam site Bayer 37289 was highly phytotoxic, more so at one end of the trial where the soil contained a sand fraction. Bayer 38156 looked promising early in the season but the plants succumbed during the secondary attack. On the peaty loam site Bayer 37289 delayed germination but the plants recovered by mid-March. This treatment again gave reasonable control, as did Bayer 38156.

This article describes seed dressings in Yorkshire. On July 1963, a trial was laid down at High Melton, Yorkshire in England, on medium loam following a bulb crop. Cappelle Desprez wheat was drilled in a randomized block layout. Seed dressings were used at 2 ounce per bushel except for the liquid aldrin which was applied at 3 ounce per bushel of seed. The Bayer 37289 seed dressing was phytotoxic, germination was poor, and there were insufficient plants in April 1963 to obtain an estimate of wheat bulb fly damage. The Bayer 38156 seed dressing was not phytotoxic but gave poor control of wheat bulb fly and a low yield.

This article focuses on the damage caused by frit fly on wheat. It was learned that at the beginning of July 1954, damaged ears of spring wheat were received from Lawshall, West Suffolk in England. The damage was confined to the tips, extending from half an inch to 1½ inches down the ear. The affected spikelets were under-developed, with the grain entirely missing, atrophied, or occasionally partly destroyed. There were also signs of feeding on the rachis. A very clear line of division could be seen between the affected and the healthy portions of each ear. The damaged part appears like a whip tail on top of the broader, normally developed portion. A single larva and several pupae were found on the damaged ears. The adult flies were identified as Oscinella frit.