An effect of rust (Uromyces viciae-fabae) on the yield of spring-sown field beans (Vicia faba) in the UK

Rust (Uromyces viciae-fabae) has recently been noted with increased frequency and earliness on spring-sown beans (Vicia faba) at Rothamsted. In 1982 an experiment was made to assess the damage and yield loss, if any, being caused by the disease. Plots received benomyl sprays to control chocolate spot (Botrytis fabae) or not, maneb plus mancozeb (protective) or propiconazole (systemic) fungicide applied twice or three times to control rust, or no fungicide at all. Rust was first found on 7 July and sprays were applied from 9 July but by 19 August plants of all treatments were dead. Fungicides controlled disease development during July and at harvest overall yields were 4·51 and 5·43 t/ha in unsprayed and sprayed treatments respectively. The difference was accounted for by the weight of individual grains and not by the number of pods per plant or grains per pod. Previously rust has been considered unimportant in the UK but its potential for damage is considerable.     

Biological efficiency of small dicofol droplets against Tetranychus urticae (Koch) eggs,larvae and protonymphs

The influence of droplet size on mortality of Tetranychus urticae (Koch) eggs, larvae and protonymphs was evaluated using sprays of an oil-based 1% dicofol formulation. The effect of using droplets of fixed size but with varying concentrations of active ingredient (0·05%–4·0% a.i.) against eggs was also investigated. The relationship between LD₅₀ and droplet diameter was positive and curvilinear for the three developmental stages, with an LD₅₀ of 12 ng/cm² against eggs, 5 ng/cm² against larvae and 6 ng/cm² against protonymphs when applying droplets of diameter 20 μm. With droplets of 40 μm the LD₅₀ value increased approximately twofold against larvae, protonymphs and eggs: thus an increase in droplet size generally resulted in a decrease in the efficiency of sprays against all three developmental stages of the mite. A U-shaped relationship was found between LD₅₀ and concentration with a theoretical optimum concentration of 1·18% a.i. (i.e. 11·8 g/litre) when droplets of a fixed size were used against eggs. The efficiency of droplets with the minimum active ingredient content (0·05% a.i.) and those with the maximum concentration (4·0% a.i.) was reduced by more than three times compared with the efficiency of droplets with the optimum concentration.     

Decoy plantings for reducing blackbird damage to nearby commercial sunflower fields

Field tests were conducted in North Dakota in August, September and October 1981 to 1983 inclusive, to determine if decoy plantings of nine sunflower fields and one interplanted corn/sunflower field would reduce blackbird (Icterinae) damage to nearby commercial sunflower fields. Total seed consumption by blackbirds of sunflower (90 ha) and corn (7 ha) was 87860 kg, worth US$26533·72 based on the average 3-year market price of $0·302/kg. The average cost of planting a decoy field was $74/ha for a total cost of $7178. The yearly cost-benefit ratio varied from 1:2 · 1 to 1:4·7 with an overall study average of 1:3·7. From 1981 to 1983, the annual median seed consumption in decoy fields was 917, 1210, and 1121 kg/ha compared with surrounding commercial fields within 11 km of the decoy fields which had losses of 4,99 and 115 kg/ha, respectively. In 1981, a comparison of losses between sunflower fields in Bottineau County and commercial sunflower fields within 11 km of decoy fields provided statistical evidence (P =0·0651) that there was less damage to commercial fields surrounding the decoy crops; this difference in losses was attributed to the presence of the decoy fields. Average blackbird numbers observed entering decoy fields per minute per hectare were 69 (1981), 49 (1982) and 91 (1983). Peak roost populations associated with decoy fields ranged from 72000 to 215000 blackbirds. Overall, redwings constituted about 83% of all blackbirds observed in decoy fields.     

The effect of systemic fungicides,applied as seed treatments or early foliar sprays,on speckled leaf blotch of wheat, Mycosphaerella graminicola (Fuckel) Schroeter

Control of speckled leaf blotch (Mycosphaerella graminicola) of wheat (Triticum aestivum) with systemic fungicides used as seed treatments or foliar sprays was studied. Seed treatment with either imazalil (1·125 g/kg seed), nuarimol (0·2 g/kg), thiabendazole (1·5 and 0·75 g/kg), triadimenol (0·3 and 0·2 g/kg) or Shell WL 47675 (0·415 g/kg) reduced the number of infected plants by 28–62% when assessments were made 11 weeks after sowing. Thiabendazole (1·5 and 0·75 g/kg) and triadimefon (0·3 and 0·2 g/kg) slowed the development of speckled leaf blotch for c. 15 weeks after sowing. A single foliar spray of triadimefon (125 g/ha) slowed the development of the disease for c. 10 weeks, but a single spray of benomyl controlled it for the whole season. There was no additional benefit from combining a seed treatment of triadimefon (0·225 g/kg) with the foliar spray.     

Comparative field studies of Bactrocera oleae baits in olive orchards in Crete

Protein-based food attractants are used in Bactrocera oleae (Gmelin) (Diptera: Tephritidae) management for monitoring populations, estimating the time of bait sprays and for Mass Trapping. McPhail traps loaded with two trophical attractant solutions (two formulations of hydrolysed proteins equal to 55% and 75% w/w) at 0.5, 1, 2, 4 and 8% concentrations were tested for their attractiveness, which was indicated by the captures of flies in McPhail traps during two periods in successive summers. The results indicated that lower concentrations than the 2% concentration recommended for both tested proteins (highest captures of 31.4 olive fruit flies/trap/week were recorded at 1% for protein equal to 55% and 28.5 at 0.5% for protein equal to 75%) were also attractive to olive fruit flies, whereas 8% was the least attractive concentration for both attractants (18.7 and 9.9 olive fruit fly/trap/week respectively). In addition, the 2% attractant concentration for both proteins was evaluated for attractiveness over time compared with ammonium sulphate; three-day-old solution of the protein equal to 75% was significantly more attractive to flies (at least twice) than 7-, 10-, 14-, 17-, 20- or 24-day-old solutions while the 7-day-old solution of the protein equal to 55% did not display differences compared with other solution ages. The attractiveness of ammonium sulphate weakened as time passed (below 5 olive fruit flies/trap/week). On the other hand, olive stems sprayed with the tested proteins under field conditions attracted approximately 0.6–1.0 adults per day, as indicated by captures in yellow sticky panels, with the highest number of flies recorded on the first day (0.9–1.4 adults). Finally, changes of pH values of these trophical attractants after dilution to the water are also reported.     

EFFECTS OF FOLIAR APPLICATION OF COPPER SULPHATE ON THE COPPER CONTENT AND YIELD OF HAY

Foliar application of CUSO₄ to mature grass to increase the Cu content of the hay crop was markedly affected by rainfall within 24 h of the time of application. The mean Cu concentration of hay treated with 5·6 and 11·2 kg CuSO₄/ha was 100 and 208 ppm, respectively, when no rainfall occurred during this period, but only 24 and 41 ppm when rain fell within 24 h. Rain 4 or 5 days after spray application had no effect on the ultimate Cu concentration of the hay. It is suggested that sheep could safely graze the aftermath as, with one exception, concentrations of Cu found were only from 11·4 to 20·6 ppm. l±l kg CuSO₄/ha applied in dry conditions was sufficient to raise Cu concentrations in hay to levels which should preclude the occurrence of Cu deficiency when fed to cattle in winter. Reductions in hay yield following CUSO₄ applications in dry weather suggest a need to examine the use of more dilute sprays, or other means for increasing the Cu content of hay.     

Sowing date and nitrogen supply determine the outcome of competition between dallisgrass (Paspalum dilatatum Poir.) and tall fescue (Festuca arundinacea Schreb.) in the Pampas region of Argentina

The effects of sowing date and nitrogen (N) fertilizer on the inter‐specific competition between dallisgrass (Paspalum dilatatum Poir.) and tall fescue (Festuca arundinacea Schreb.) in the humid Pampas of Argentina were investigated in two pot experiments where a constant soil moisture content was maintained. Tall fescue and dallisgrass seeds were sown either in the spring (October 2000) or in the autumn (March 2001) in mixed and mono‐specific stands with 0 or 100 kg N ha^?1. In the spring, competition from tall fescue depressed dry‐matter (DM) yield of dallisgrass from 1·53 to 0·36 g DM per plant and tiller number from 9·4 to 3·7 tillers per plant in mixed and in mono‐specific stands, respectively, while tall fescue had 3–4 times higher DM yields in mixed stands. Leaf extension rate (LER) of tall fescue was higher (1·3 mm d^?1) than that of dallisgrass (0·53 mm d^?1). In the autumn, inter‐specific competition did not affect DM yield of dallisgrass and N fertilizer increased DM yield from 0·53 to 2·07 g DM per plant, tiller number from 6·8 to 14·2 tillers per plant and LER at the beginning of autumn from 1·2 to 2·12 mm d^?1 in both species. As temperature decreased, LER was reduced in both species to 0·31 mm d^?1 by late autumn. The number of leaves per tiller was not affected by treatment. Nitrogen fertilizer increased N concentration of above‐ground tissues of both species (18 g kg^?1 DM in autumn and 20 g kg^?1 DM in spring). It was concluded that a productive mixed pasture of dallisgrass and tall fescue can be obtained by sowing early in the autumn. The application of N fertilizer in this season is essential to ensure a high herbage yield and quality.     

A comparison of monitoring systems used for Ceratitis species (Diptera: Tephritidae) in South Africa

For 16 years a bucket-type trap known as the Sensus fruit fly trap has been used to monitor three fruit fly pest species Ceratitis capitata, Ceratitis rosa and Ceratitis cosyra in South African fruit industries. The relative efficiencies of lures sold for monitoring fruit flies with the Sensus trap in South Africa were determined in field experiments where laboratory-reared C. capitata, C. rosa and C. cosyra were released in a mango orchard within a few metres of Sensus traps containing either Capilure (trimedlure or tert-butyl 4 (or 5) -chloro-2-methylcyclohexane carboxylate), Ceratitislure (protein hydrolysate plus β-caryophyllene) or Questlure (protein hydrolysate plus plant extracts). When using 12-day-old flies, Capilure caught 3 times more C. capitata males than C. rosa males and this difference was more extreme when 3-day-old flies were released. Ceratitislure caught significantly more 12-day-old C. cosyra males than 12-day-old C. capitata males, but the difference was reversed when 3-day-old flies were compared. Questlure showed the least differences between species and age but recovered the lowest proportion of released species. Further comparisons were conducted in an orchard with wild flies using other known attractants in larger yellow Probodelt bucket traps. Capilure caught more male C. capitata than BioLure Fruit Fly 3-component, but BioLure 2-component (trimethylamine and ammonium acetate) was more effective than Questlure for C. capitata females. The 3-component lure was also more effective than both Capilure and Questlure for male and female C. rosa, respectively. Ceratitislure was the most effective lure for male C. cosyra flies and BioLure 3-component was more effective than Ceratitislure and Questlure for female C. cosyra flies. The intervention threshold of 4 flies/trap/week previously used in citrus with Capilure for C. rosa was lowered to 2 C. rosa/trap/week when using the Sensus trap due to the lower sensitivity of this trap-lure combination found for C. rosa in this study. The 3-component lure, or the 2-component combination of trimethylamine and ammonium acetate in a ratio of 1:8 in the Sensus trap capsule, would be more effective for both sexes of all three Ceratitis species than the Questlure that is currently being used.     

The response of onion couch (Arrhenatherum elatius ssp. bulbosum (Willd.) Schub. & Mart.) to glyphosate and other foliage-applied herbicides

Two experiments were conducted in which foliage-acting herbicides were applied to onion couch (Arrhenatherum elatius ssp. bulbosum). The first experiment used an artificially established population and investigated the effects of straw burning on the performance of autumn-applied treatments of glyphosate, aminotriazole and dalapon. Spring barley was sown without cultivation. The second experiment, conducted on a naturally occurring infestation, compared the performance of glyphosate applied at alternative autumn timings and a single application of flamprop-methyl made in the following spring, in the presence of a winter wheat crop. In the first experiment, assessments made after 15 months suggested that straw burning resulted in increased growth. In addition, herbicide performance appeared less effective after burning. In neither case were these differences significant. Glyphosate at 1·0 and 1·5 kg a.e./ha gave the highest levels of control of both shoots and bulbs, whereas control from aminotriazole at all doses (1·5, 3·0 and 4·5 kg a.i./ha) was poor. Dalapon (6·0, 12·0 and 18·0 kg a.i./ha) was intermediate in its effectiveness. In the second experiment, applications of glyphosate at 1·0 and 1·5 kg a.e./ha resulted in high levels of control of both shoots and bulbs with no significant difference between application dates. Flamprop-methyl at 0·52 kg a.i./ha reduced the number of shoots and bulbs by 55% and 58% respectively. All treatments significantly reduced the number of inflorescences present in July.     

Cotton-pest control: a review of the introduction of ultra-low-volume (ULV) spraying in sub-Saharan French-speaking Africa

Ten cotton-producing countries in sub-Sahara French-speaking African have adopted ULV spraying and by 1985, 97% of the area protected was sprayed using this technique. Compared with knapsack spraying with horizontal booms, ULV sprays gave rise to an equivalent yield of seed cotton, with better or similar bollworm control. In the Ivory Coast, plant coverage obtained by ULV sprays at 3 1/ha with one pass every six rows is insufficient, so a four-row swath with the same amount of insecticide or an increase to 4 or 5 1/ha is recommended late in the season. ULV sprays at 1 1/ha reduce financial expenditure by 15–20% and are used in Cameroon and partly in Chad. This technique may be less effective against certain sucking insects, particularly Polyphagotarsonemus latus in luxuriantly growing cotton.     

Effects of spray application parameters on foliar uptake and translocation of daminozide and 2,4-D-triethanolamine in Vicia faba

The uptake and translocation of daminozide and the triethanolamine salt of 2,4-D(2,4-D-TEOA) were determined radiochemically 24 h after application to leaves of Vicia faba (field bean). Chemicals were applied in aqueous solutions as monosize spray drops of varying diameters (50–500 μm), the volume median diameter (VMD):number median diameter (NMD) ratio of the droplet spectra being < 1 · 03. Daminozide was applied at concentrations of 0·17–2·4 g/l in volumes of 10–90 l/ha, providing doses of 5–215 g/ha. 2,4-D-TEOA was applied at 0·20–5·0 g acid equivalent (a.e.) per litre in 20–190 l/ha to provide doses of 4–420 g a.e. per hectare. Uptake of daminozide was 9·3 ± 2·6% (mean ± standard deviation), of which 26 ± 4·4% was translocated out of the treated leaflet, with 25 ± 6·5% of the translocated ¹⁴C being redistributed in an acropetal direction. Equivalent values for 2,4-D-TEOA were: 16 ± 5·5% uptake, 70 ± 8·0% translocation and 12 ± 4·9% acropetal redistribution. The quantity of both chemicals taken up increased with increasing dose (r² > 0·92). Multiple regression analyses demonstrated that the efficiency of uptake (%) of both chemicals was not related to drop size or number, leaf coverage, concentration of active ingredient (a.i.) or application volume. For both chemicals, percentage uptake was inversely related to applied dose, and uptake and translocation were interrelated.     

Economic considerations of mouse-plague control in irrigated sunflower crops

During a localized plague of the house mouse (Mus musculus) the population within an irrigated sunflower crop was estimated to be 2716 mice/ha 7 weeks before harvest. These mice were estimated to have caused a reduction of 12·4% of the expected yield up to that time. The crop was then subjected to a variety of control techniques, the most successful of which resulted in a reduction of 90% in the mouse population. Using 3·4 g/day as the amount of sunflower seed each mouse would consume or damage it was estimated that a 90% effective control programme would result in an increase of 20·4% in the harvested yield. Similar estimates for other irrigated grain crops indicate that mouse-plague control is an economically sound proposition.     

The effect of date of primary growth harvest and levels of nitrogen and potassium fertilizers on the dry matter production of timothy (Phleum pratense)

Scots timothy was harvested three times a year for 3 years under four harvesting patterns and at all combinations of three levels of application of nitrogen and four of potassium. Harvesting patterns, H1, H2, H3 and H4, comprised cutting primary growth on 27–29 May or 14, 28 or 42 d later followed by cutting a first regrowth 8 weeks afterwards and a second regrowth on 15–16 October. N treatments, N0, N1 and N2, involved annual totals of 0,108 and 216 kg ha^-1 N in three equal doses. K treatments, K0, K1, K2 and K4, involved annual totals of 0, 54, 108 and 216 kg ha^-1 K also in three equal doses. Mean herbage DM yields in successive years were 8·90, 9·54 and 9·61 t ha^-1 containing92·4%, 93·1% and 94·5% timothy, respectively. Systems H3 and H4 had 24% higher yields than H1 and H2. The superiority of the late systems derived from higher yields of primary growth. Mean response to 108 kg ha^-1 N at 36·7 kg DM per kg N was significantly higher than the response to an additional 108 kg ha^-1 N. Response in primary growth to successive increments of 36 kg ha^-1 N averaged 53·9 and 27·5 kg DM per kg N. The first regrowth gave linear responses up to 72 kg ha^-1 N. The possibility is discussed of more effective use of N by increasing the proportion applied to regrowth. Response to K was low except in the third year when there was a marked response at N2. It was calculated that to maintain soil potash it is necessary to apply 23·9, 47·7 and 86·6 kg ha^-1 fertilizer K for each harvest at N0, N1 and N2 respectively.     

Distribution patterns of aerially applied ULV sprays by aircraft over and within the cotton canopy in the Sudan Gezira

A series of experimental ULV sprays by aircraft were conducted over four 35 ha cotton fields in the Sudan Gezira. The aim was to compare the pattern of deposit distribution over and within the cotton canopy when two ULV spray spectra designated for convenience as coarse (120 μm VMD) and fine (80 μm VMD) were released in the early morning (0600 h), mid-morning (0900 h), midday (1130 h) and mid-afternoon (1530 h). Results showed that early morning sprays produced a rather narrow useful swath from both coarse and fine sprays and high risk of drift from fine droplets. Both droplet spectra in the mid-morning spray, on the other hand, provided a good deposit pattern within the cotton canopy and had the least amount in the air at 100 m downwind. Furthermore, the fine spray gave a swath almost 50% wider than the coarse one. At noon the swaths were approximately intermediate to those of the early and mid-morning sprays. However, the variation of deposits at any one point was large and the amounts remaining airborne at 100m downwind were substantial. During mid-afternoon, wind over the Gezira was generally light and variable. As, in practice, the pilot flies invariably along the length of the field rather than across the wind direction, mid-afternoon sprays produced peaky deposits over a narrow swath. With regard to penetration of spray droplets into the canopy, the physical structure of the latter proved to be the determining factor. Turbulence generated by wind or the aircraft had no detectable effect.     

Herbage intake and milk production by grazing dairy cows 2. The effects of level of winter feeding and daily herbage allowance

Two experiments are described in which two levels of winter feeding and three levels of herbage allowance during the grazing season were imposed upon March/April calving British Friesian dairy cows. The winter treatments resulted in differences in live weight and milk yield at turnout of 35 and 53 kg and 3·4 and 3·2 kg d^-1 for the two trials. Subsequently, when grazed at generous herbage allowances, the cows were able to compensate for much of this difference but when herbage was restricted the milk yield differences were accentuated. Groups of cows from each winter treatment were offered 25, 50 or 75 (Experiment 1) and 30, 50 or 70 (Experiment 2) g herbage DM per kg LW daily during the grazing season. Daily herbage intakes on the three allowances in each trial were 14·1, 13·3, 10·7 and 12·5, 12·1, 11·5 kg OM and milk yields were 16·0, 15·3, 12·5 and 15·2, 14·3, 11·8 kg SCM respectively. Both intake and milk production were depressed once the cows were forced to consume more than 50% of herbage on offer or to graze the sward down to a mean height of less than 8–10 cm. Grazing behaviour observations indicated that under rotational managements the cows did not compensate for restrictions in available herbage by grazing longer. Highest levels of milk production per unit area were observed in both trials when production per cow was depressed by 20–25%.     

Biology,seasonal occurrence,host range and damage potential of the castor hairy caterpillar,Euproctis lunata Walk. (Lymentriidae : Lepidoptera)

The castor hairy caterpillar, Euproctis lunata Walk. in Bangladesh has six larval instars that averaged 3·3 ± 0·07, 3·5 ± 0·08, 3·7 ± 0·11, 4·7 ± 0·12 and 5·0 ± 0·15 days respectively; 204 ± 6·5 eggs were laid per female; 97·2 ± 0·37 eggs hatched. Male and female moths lived 4·00 ± 0·16 and 4·45 ± 0·13 days, respectively. Most larvae were found in September and October with castor the most preferred host. The fifth- and sixth-instar larvae consumed more leaves than did those of the first four instars. When larvae were released on plots there were subsequently fewer late-instar larvae where most had been released. Yields were significantly reduced if there were two or more larvae per plant.     

In vitro rumen methane output of perennial ryegrass varieties and perennial grass species harvested throughout the growing season

The selection and feeding of perennial ryegrass (Lolium perenne L.) varieties (PRV) or perennial grass species (PGS) may affect enteric methane (CH₄) output because of changes in the fermentation dynamics in the rumen as a result of differences in herbage chemical composition. The objective of this study was to determine the effects of PRV and PGS harvested throughout the growing season on herbage chemical composition, and in vitro rumen fermentation variables and CH₄ output per unit of feed using a batch culture technique. Seven PRV (Experiment 1: Alto, Arrow, Bealey, Dunluce, Greengold, Malone, Tyrella) and six perennial grasses [Experiment 2: perennial ryegrass (Navan), perennial ryegrass (Portstewart), cocksfoot, meadow fescue, tall fescue, timothy; defined as PGS], managed under a simulated grazing regime, were incubated for 24 h with buffered rumen fluid in two separate experiments. The CH₄ output per unit of feed dry‐matter (DM) incubated was not affected (P > 0·05) by PRV (range of mean values across PRV of 23·9–25·3 (SEM 0·41) mL g^?1 DM) or by PGS (25·6–26·6 (SEM 0·37) mL g^?1 DM). The CH₄ output per unit feed DM disappearing during the in vitro rumen incubation was not affected by PRV (33·9–35·1 (SEM 0·70) mL g^?1 DM), and although there was an overall PGS effect (P < 0·05; 37·2–40·3 (SEM 0·71) mL g^?1 DM), none of the paired contrasts between PGS were significant when analysed using Tukey adjusted comparisons. This outcome reflected either small‐scale or a lack of treatment effects on individual herbage chemical composition (e.g. 454–483 g NDF kg^?1 DM, 215–224 g CP kg^?1 DM and 94–122 g water‐soluble carbohydrate (WSC) kg^?1 DM across PRV; 452–506 g NDF kg^?1 DM, 208–243 g CP kg^?1 DM and 73–131 g WSC kg^?1 DM across PGS) and in vitro rumen fermentation variables. Hence, these results provide no encouragement that choices among the grasses examined, produced within the management regimes operated, would reduce enteric CH₄ output per unit of feed in vivo. However, the technique utilized did not take account of animal × PRV or PGS interactions, such as potential differences in intake between animals, that may occur under farm conditions.     

A comparison of a hybrid stubble turnip (cv. Appin) with other cruciferous catch crops for lamb fattening. 2. Animal performance and toxicological evaluation

Forage brassica catch crops can provide a valuable source of additional feed in the autumn when supplies of other feed are limited. Weaned lambs grazed either (A) a novel hybrid crop, stubble turnip cv. Appin, or (B) a sequence of crops consisting of fodder radish cv. Nerys, followed by forage rape cv. Canard. Forty, 60 or 80 g of crop DM per kg current live weight (LW) were allowed daily and the performance, intake and carcass yield of the lambs were monitored. Lamb LW gains were lower on treatment A (45, 65 and 72 g d^-1) than on B (78, 111 and 117 g d^-1) at the 40-, 60- and 80-g DM d^-1 allowances respectively. Intakes of forage crops, however, did not differ significantly, probably because the estimates of intake were made in the middle of each 14-d allocation period of the crops. The intake values are thus an indication of the potential intake when a relatively plentiful supply of food is available; they were 19·2, 17·2 and 18·2 g OM kg^-1 LW for treatment A and 16·2, 19·2 and 19·2 g OM kg^-1 LW treatment B at the 40-, 60- and 80-g DM d^-1 allowances respectively. Mild anaemia occurred in lambs feeding on both crops. Anaemia was more marked on treatment B, which was consistent with the higher concentrations of S-methyl cysteine sulphoxide (SMCO) but as the performance of animals was superior on treatment B, SMCO intake and anaemia are not thought to be the first or the most important factors in limiting animal performance. Goitrogenic changes in thyroid glands occurred on both crops. Mean weights of paired thyroid glands were 3·22, 4·28 and 4·21 g on treatment A and 3·29, 5·27 and 5·21 g on B at the 40-, 60- and 80-g DM d^-1 allowances respectively; the effects of both treatment and allowance were significant (P <0·21). Thiocyanate concentrations were higher on treatment A than B, indicating differing glucosinolate concentrations. While this was consistent with animal performance, it was not consistent with the weight of thyroid glands. However, the goitrogenic responses may have been complicated by the ingestion of soil iodine because very high faecal ash values were recorded. Thus, glucosinolates appear not to have affected lamb growth rate by their goitrogenic effect but the possibility remains that they may have influenced performance by other means.     

Phytotoxicity of isazophos,lindane and heptachlor to sorghum applied as in-furrow and broadcast-incorporated treatments

Isazophos applied as an in-furrow spray at 0·5, 0·75 and 1·0 kg a.i./ha (4·65, 6·98 and 9·3 g a.i./100 m of row) reduced the establishment of Yates NK 212 sorghum by 37, 61 and 75% respectively. Similarly, heptachlor at 1·12 kg a.i./ha (10·42 g a.i./100 m of row) and lindane at 0·29 kg a.i./ha (2·7 g a.i./100 m of row) reduced establishment by 24 and 57% respectively. Heptachlor and isazophos, applied at the same rates but as broadcast-incorporated sprays and the lowest rate of isazophos applied as an in-furrow spray (0·25 kg a.i./ha, 2·33 g a.i./100 m of row) were not phytotoxic.     

First documented pest outbreak of the herbivorous springtail Sminthurus viridis (Collembola) in Europe

Sminthurus viridis (Collembola: Sminthuridae) is a native of grasslands across Europe and feeds preferentially on clover (Trifolium spp.) and lucerne (Medicago sativa), although its abundance does not normally reach damaging pest levels (as occurs in Australasia). This research note describes the first quantitative assessment of a pest outbreak of this springtail in Europe, which occurred within an existing experiment investigating the effects of cultivation practices on forage establishment. Using sticky traps to assess the incidence of S. viridis, we found a significant outbreak consisting of catches that were 10‐fold greater than background levels in nearby undamaged fields. Within the experimental area, lucerne established by direct drilling with herbicide had the highest incidence (105 (± 4·9) individuals per trap) compared to other treatments [79 (± 3·9)]. Results are discussed in terms of how cultivation practice may have imbalanced the ecosystem; for example, herbicide use may have diminished potential refugia for predators during forage establishment. This paper highlights the potential of a currently innocuous, widely established invertebrate to become present at damaging levels in agricultural crops.