Insecticidal control and economic damage of sugar-cane wireworm, Agrypnus variabilis (Candèze) in maize

Six insecticides (terbufos, chlorpyrifos, ethoprophos, phoxim, bendiocarb and lindane) were tested against sugar-cane wireworm Agrypnus variabilis (Candèze) in maize. The first five insecticides were applied at 0·25, 0·5 and 0·75 kg a.i./ha (2·27, 4·55 and 6·82 g a.i./100 metres of row) while lindane was applied at the registered rate of 0·29 kg a.i./ha (2·64 g a.i./100 metres of row). In addition, bendiocarb was applied as a seed treatment at the rates of 4000 and 6000 ppm. The insecticides were applied at planting as insecticide/fertilizer mixtures in 18 cm wide bands, 2–3 cm below the soil surface and 3–5 cm above the seed. The minimum effective rates were terbufos 0·25 kg a.i./ha, lindane 0·25 kg a.i./ha and chlorpyrifos and ethoprophos both at 0·5 kg a.i./ha. These treatments gave at least 5 weeks' residual control. The bendiocarb seed treatments were phytotoxic. No residues were detected in the cobs or grain at the minimum effective rates of the terbufos, chlorpyrifos or ethoprophos treatments. The positive linear relationship between plant population and yield showed that for every 1% loss in plant stand below the optimum range of 60 000–65 000 plants/ha, there is a 0·72-0·74% loss in grain yield respectively. Control measures would be economically justified with only a 2·3% reduction in plant stand (assuming $20/ha for cost of control and $150/tonne for maize).     

Increased severity of Rhizoctonia root rot in sugar beet treated with systemic insecticides

The systemic insecticides aldicarb 15G (15% granules) at 2·6 kg active ingredient (a.i.)/ha and phorate 1OG (10% granules) at 1·7 kg a.i./ha, applied as side dressings about 1 month after planting in 1979 and 1980, significantly increased the severity of root rot, caused by Rhizoctonia solani Kühn, in sugar beet (Beta vulgaris L.). Carbofuran 10G (10% granules) at 2·2 kg a.i./ha also increased root rot, but not significantly. Numbers of harvestable roots were reduced by all treatments but significantly by phorate only. Both aldicarb and phorate were slightly fungistatic to R. solani when the pathogen was grown on potato-dextrose agar incorporating 0·5, 5·0, and 25 μg a.i./ml. Trichoderma sp., a potential antagonist of Rhizoctonia, was slightly inhibited by aldicarb and phorate initially, but soon overcame the effect. Thus, the increase in disease severity in the field may be attributable to some metabolic or physiological effect of the chemicals either on the host or on the infection process of the pathogen. Indiscriminate use of these insecticides should therefore be avoided in areas where root rot is prevalent but where insects are not a problem.     

Residual effects of Bacillus thuringiensis and chemical insecticide treatments on spruce budworm (Choristoneura fumiferana Clemens)

Biochemical analysis has shown that populations of Choristoneura fumiferana Clemens (Lepidoptera: Tortricidae) which have survived treatment with chemical insecticides (organophosphates and carbamates) have greater energy reserves and vigour than those from untreated areas: conversely, populations surviving treatment with Bacillus thuringiensis (B.t.) are considerably less vigorous. Surviving pupae from untreated, organophosphate-treated and B.t.-treated areas gave, respectively, the following results on biochemical analysis: average weight, 69·5, 82·0 and 46·9 mg; Ca⁺⁺, 80·0, 114·5 and 54·0 mg/kg; total proteins, 27·6, 36·3 and 19·2 mg/kg; 3-hydroxybutyrate dehydrogenase, 1004, 1091 and 200 mU/g; alkaline phosphatase, 541, 580 and 251 mU/g. These analyses confirmed that B.t. treatments had a detrimental effect on survivors whereas chemical insecticides encouraged the resurgence of vigorous populations of C. fumiferana as a result of stimulation of these insects by sub-lethal dosages (hormoligosis).     

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.     

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.     

Chemical weed control in direct-seeded irrigated rice in the Lake Chad Basin,Nigeria

Two field experiments were conducted at Ngala in the Lake Chad Basin during the 1981 and 1982 wet seasons to investigate chemical weed control in direct-seeded, irrigated rice (Oryza sativa L.). Pre-plant-incorporated, pre- and post-emergence herbicides and their mixtures were tested in replicated, completely randomized block trials. Rice variety IR 28 was drilled each season at 125 kg/ha and fertilized with N (150 kg/ha) and P₂O₅ (40 kg/ha). In both seasons, the post-emergence herbicides propanil + oxadiazon at 3·0 + 1·0 kg a.i./ha, propanil+fluorodifen at 1·4 + 1·8 kg a.i./ha, propanil + bentazone at 3·6 + 1·5 kg a.i./ha and propanil at 3·6 kg a.i./ha as well as thiobencarb applied pre-emergence at 5·0 kg a.i./ha controlled the weeds effectively and gave similar grain yields to that from hand-weeding twice, and significantly higher grain yield than the unweeded control treatments. Grain yields similar to those from the ‘two hand-weeding control’ were achieved also by use of the herbicide dymrone at 3·0 kg a.i./ha, either soil-incorporated pre-sowing or sprayed before weed emergence. The herbicides gave satisfactory control of the weeds, which were predominantly the broad-leaved weed Luffa echinata Roxb., together with the grasses Sorghum aethiopicum (Hack.) Rupr. ex Stapf., Echinochloa colona (L.) Link, Eleusine indica (L) Gaertn, Digitaria sanguinalis (L.) Scop., Oryza longistaminata (Chev. & Roehr.), and sedges Cyperus rotundus L. and Cyperus esculentus L. The studies indicate that effective weed control by these herbicides and herbicide mixtures are dependable alternatives to hand weeding for direct-seeded, irrigated rice cultivation in the Chad Basin area.     

Yield response to pre-emergence control of broad-leaved weeds in winter cereals with isoxaben in France

A series of 59 trials was designed to assess the yield response to the control of broad-leaved weeds in winter cereals in the 1982/83, 1983/84 and 1984/85 seasons. When apllied pre-emergence to winter cereals, isoxaben provided season-long control of a wide spectrum of broad-leaved weeds including Veronica spp., Viola spp., Stellaria media, Aphanes arvensis, Papaver rhoeas and Matricaria spp. In 22 trials on winter barley and 37 trials on winter wheat treated pre-emergence with isoxaben in the autumn, mean yield increases of 0 · 22 t/ha and 0 · 14 t/ha respectively were recorded over that produced by herbicide combinations applied as post-emergence treatments in the spring. The mean yield increases with isoxaben over untreated controls were 0 · 30 t/ha and 0 · 26 t/ha on winter barley and winter wheat respectively.     

Residues of carbaryl,lindane and monocrotophos on rice treated for control of rice bug, Leptocorisa oratorius (Fab.)

This study investigated the correlation between insect mortality and insecticide residue levels in rice grain during the developing stages and at harvest, and also determined the relative toxicities of three insecticides, monocrotophos (Azodrin 16·8 EC), lindane (Agrocide 26 DP), and carbaryl (Sevin 85 WP) to Leptocorisa oratorius (Fab.), (Hemiptera: Alydidae). The insecticides were applied on field plots at 0·75 kg a.i./ha at the start of the milk stage of the developing grains. Sampling was conducted at 2 hours and 1, 2, 3, 4 and 5 days after spraying, which covered the milk stage to the soft dough stage. Mortality of insects exposed to the treated grain, the residue analysis of the treated grain during development and at harvest, and the LD₅₀s of the insecticides were determined. Monocrotophos was the most effective insecticide against the rice bug; lindane provided control for only one day; carbaryl was ineffective. Maximum residue levels of lindane and carbaryl in the harvested grains were below the established tolerance limits provided by FAO/WHO. There is no established tolerance for monocrotophos in rice.     

Chemical control of sorghum head bugs (Hemiptera: Miridae)

Eight contact and three systemic insecticides, and an enriched neem extract were tested for the control of sorghum head bug, Calocoris angustatus Leth. at the ICRISAT Center. The insecticides were applied at the complete-anthesis and milk stages (at 500 1/ha) with a knapsack sprayer. On the basis of effectiveness of head bug control, grain yield and 1000-grain mass, carbaryl (at 500 g a.i./ha) was the most effective insecticide followed by fenvalerate (at 50 g a.i./ha), and chlorpyrifos (at 250 g a.i./ha). Among the systemic insecticides, demeton-S-methyl (at 250g a.i./ha), was the most effective. Demeton-S-methyl and dimethoate were also effective for the control of other head bug species—Eurystylus bellevoyei Put. and Reut. and Campylomma sp. Plots sprayed with demeton-S-methyl gave higher grain yields than those treated with carbaryl, which was the best contact insecticide. Two sprays of carbaryl (at 500g a.i./ha) applied at the complete-anthesis and milk stages have been found to be effective for head bug control. Dichlorvos, fenitrothion and monocrotophos were highly phytotoxic and resulted in burning and drying of entire leaves. Dimethoate resulted in a slight drying of leaf tips and margins.     

Effect of six synthetic pyrethroids on two populations of potato tuber moth,Phthorimaea operculella (Zeller) (Lepidoptera: Gelechiidae), in Peru

The toxicity of six synthetic pyrethroids, permethrin, cypermethrin, flucythrinate, fenvalerate, cyfluthrin and deltamethrin, were evaluated on two populations of potato tuber moth (PTM) Phthorimea operculella (Zeller) in Peru. Deltamethrin was most toxic with an LC₅₀ of 120 μg/ml for male PTM from La Molina and 137 μg/ml for female PTM from San Ramon. Fenvalerate was least toxic and the other four insecticides were intermediate in toxicity. At field recommended concentrations (0·05-0·04%) none of the six synthetic pyrethroids were effective on the two populations tested.     

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.     

Herbicide evaluation studies in transplanted chilli pepper (Capsicum frutescens L.) in the Nigerian savanna

Field trials were conducted in the Nigerian savanna to evaluate the performance of various herbicide mixtures for weed control in chilli pepper (Capsicum frutescens L. var. Serrano chilli) during the wet seasons of 1982 to 1984 and in the 1982/83 dry season. Linuron at 0·5 kg or 0·75 kg a.i./ha in mixture with either alachlor at 1·5 kg, metolachlor at 1·5 kg, oxadiazon at 1·5 kg, or diphenamid at 3·0 kg, as well as metolachlor plus metobromuron at 1·0 + 1·0 kg and 1·5 + 1·5 kg a.i./ha all followed by supplementary hoe-weeding at 6 weeks after transplanting combined effective weed control with high chilli pepper fruit yields comparable to the hoe-weeded control in all the trials. Unchecked weed growth throughout the crop life cycle resulted in an 86–90% reduction in potential chilli pepper fruit yields.     

Systemic effect of aldicarb,dimethoate and ethiofencarb on mortality and population dynamics of the spirea aphid, Aphis citricola Van der Goot

A bioassay using detached citrus leaves, the petioles of which were immersed in solutions containing insecticides, was used to assess the systemic activity of aldicarb, dimethoate and ethiofencarb on the spirea aphid, Aphis citricola Van der Goot (Homoptera: Aphididae). At identical concentrations in the treatment solutions the order of toxicity to insects of these compounds was aldicarb > dimethoate > ethiofencarb. The toxicity of the residue of aldicarb in the leaves (LC₅₀=2·5 μg/g) resembled that of dimethoate (LC₅₀=1·8 μg/g) and both were more potent than ethiofencarb (LC₅₀=30 μg/g). The amount of aldicarb accumulated in the leaves, 3 days after application, was 25±0·5% of that present in the treatment solution, compared with 4±0·4% of dimethoate and 3±0·3% of ethiofencarb. Thus, the more efficient uptake of aldicarb may be the reason for its high toxicity. When sublethal concentrations of aldicarb incorporated in treatment solutions were taken up by detached leaves, a significant reduction in the pre-reproductive development time, and increased longevity and fecundity were observed. This hormoligosis phenomenon was further emphasized by a considerable increase in aphid weight. This effect seems to be plant mediated, as it was not observed when aldicarb was added to a synthetic diet. Dimethoate showed an effect similar to that of aldicarb, but less pronounced and not statistically significant, whereas ethiofencarb had no such effect.     

Genetic and environmental variation in the diastatic power of australian barley

Variation in the diastatic power of Australian barley, and the relationships between diastatic power and the starch-degrading enzymes contributing to diastatic power, were investigated in 11 cultivars of barley grown at six diverse locations in Australia. Diastatic power varied with genotype and location, with the levels ranging from 3·1 to 16·5 U/kg. For alpha-amylase activity, levels across cultivar and location ranged from 52 to 214 U/g, for beta-amylase activity they ranged from 201 to 1550 U/g; and, for limit dextrinase activity, they ranged from 56 to 636 U/kg. Alpha-amylase (r = 0·64) and beta-amylase (r=0·77) activities were correlated more strongly with diastatic power than was limit dextrinase (r=0·37). Grain nitrogen content was correlated positively with diastatic power (r=0·71), largely because of the relationship between nitrogen content and beta-amylase activity (r=0·82). High grain nitrogen contents were also associated with small grain sizes (r=−0·76) and low hot-water extracts (r=−0·75). The levels of alpha-amylase activity were correlated more closely with limit dextrinase activity (r=0·65) than with beta-amylase activity (r=0·28). The results indicate the need to select barley cultivars separately for alpha-amylase and beta-amylase activities to achieve high levels of diastatic power.     

Grass weed control in sunflower in the spring and kharif (summer) seasons under barani (rainfed) conditions in Pakistan

In field trials conducted at the National Agricultural Research Centre (NARC) near Islamabad and in farm fields, control of grass weeds including Cynodon dactylon (bermudagrass), Sorghum halepense (johnsongrass), Echinochloa colonum (junglerice) and Dactyloctenium aegyptium (crowfootgrass) increased yields of sunflower by 25–100%. The trials were conducted in the spring (February–May) and kharif (July–October) seasons in 1985 and 1986. Hand weeding generally resulted in the greatest yield response but this method was highly labour intensive and considered to be impractical by local farmers. The average time required to maintain 1 ha weed free in the spring and kharif seasons was 41 and 90 eight-hour man-days, respectively. In three of four trials conducted in the spring season, fluazifop-butyl at 0·25 and 0·5 kg/ha did not provide satisfactory control of grass weeds and did not result in significant increases in sunflower seed yields. The performance of fluazifop-butyl in these trials was adversely affected by hot dry conditions causing severe moisture stress after treatment. In contrast, in the fourth spring trial at NARC in 1986 and in all kharif season trials, fluazifop-butyl at 0·25 kg/ha effectively controlled both annual and perennial grasses and resulted in seed yields comparable to those obtained by hand weeding. Value/cost ratios indicate that, in the spring season under drought stress conditions, application of the herbicide would not be profitable; however, in the kharif season, herbicide treatment to control actively growing grass weeds would provide a cost-effective alternative to hand weeding.     

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.     

The control of weed,pest and disease complexes in cowpea (Vigna unguiculata (L.) Walp.) by the application of pesticides singly and in combination

Several pesticides were evaluated singly and in combination or mixtures for their effectiveness against insects, nematodes, diseases and weeds in cowpea at Ibadan and Amakama in Nigeria. Of the granular insecticides/nematicides, carbofuran at 3·0 kg a.i./ha applied at planting reduced the population of thrips (Megalurothrips sjostedti) below control level up to 42 days after planting, but did not appear to translocate to the pods. Ethoprofos, isazophos and phorate were ineffective against thrips. Carbofuran also showed excellent control of the root-knot nematode, Meloidogyne incognita. The herbicides metolachlor and fluorodifen generally kept the plots weed-free up to 35 days after planting but had no effect on the nematodes. The fungicide benomyl applied as a seed treatment was not effective against web blight (Corticium solani) and brown blotch (Colletotrichum truncatum) but, when applied as a wettable powder in combination with monocrotophos as a foliar spray, offered effective control of the diseases and the combination gave the best grain yield across locations. The possible use of carbofuran with a cowpea variety that is resistant to larvae of the pod-boring moth (Maruca testulalis) is discussed.     

Influence of different tillage methods and pre-emergence herbicides on weed control in cowpea (Vigna unguiculata (L.) Walp.)

In the early and late cropping seasons of 1983, three different methods of tillage (minimum tillage, conventional tillage, and tilled and ridged) were evaluated for their influence on the performance of some pre-emergence herbicides used during the production of cowpea. Four varieties of cowpea (Ife Brown, H 144-1, TVx 3236, and Black-eyed bean) were planted in the early season while five varieties (Ife Brown, H 144-1, TVx 3236, H64/3 and Vita-5) were planted in the late season. A single spray application of 3·0 kg/ha alachlor, 3·0 kg/ha metobromuron + metolachlor and 3·5 kg/ha metolachlor was carried out one day before planting. Cyanazine at 3·0 kg/ha was included in the late season trial. The plots were either minimally tilled, conventionally tilled or tilled and ridged at the Teaching and Research Farm of the University of Ife. Results showed that the performance of all three herbicides used in the early season, as measured by weed control and grain yields, was best on the conventionally tilled, while the performance of the four herbicides in the late season was best on tilled and ridged plots. Metobromuron + metolachlor performed consistently better than each of the other herbicides irrespective of the method of tillage during both seasons. Conventional tillage enhanced the performance of metobromuron + metolachlor over minimum tillage plots and tilled and ridged plots in the early season; however, in the late season, the performance of metobromuron + metolachlor was best on tilled and ridged plots. Alachlor did not effectively control competing weeds in both seasons but did not injure any cowpea line. On the other hand, cyanazine did not control weeds effectively but was phytotoxic to Ife Brown variety of cowpea. In both seasons, the control of the broad-leaved weeds Ageratum conyzoides, Amaranthus spp., Euphorbia heterophylla, Ipomoea spp., Spigelia anthelmia, Synedrella nodiflora and Talinum triangulare was not adequate. The control of the grassy weeds Brachiaria deflexa, Cynodon dactylon, Imperata cylindrica and Eleusine indica was, however, effective.     

Effects of incorporating cowpea in a subtropical grass pasture on forage production and quality and the performance of cows and calves

The increasing cost of N fertilizer has stimulated an interest in sourcing protein from warm‐season legumes among beef cattle producers in the tropical/subtropical areas of the world. The objective of this study was to evaluate effects of two strategies of incorporating cowpea [Vigna unguiculata (L.) Walp.] into bahiagrass (Paspalum notatum Flügge) pastures on the herbage characteristics and performance of grazing cow–calf pairs. The study was conducted in Ona, Florida, USA, from May to August in 2007 and 2008. Experimental units were 1·0 ha. Treatments were bahiagrass pasture alone (control), 50:50 bahiagrass–cowpea pasture (cowpea), bahiagrass pasture with a cowpea creep grazing area (0·1 ha, creep grazing) and bahiagrass pasture with a creep‐fed concentrate [(creep feeding; 10 g kg^?1 body weight (BW)]. The cowpea pastures had lower herbage mass [HM, 1·8 vs. 3·7 t ha^?1] and herbage allowance [HA, 0·8 vs. 1·4 kg DM kg^?1 live weight (LW)] compared with the other treatments. Cowpea had greater CP (CP, 160 g kg^?1) and in vitro digestible organic matter (IVDOM), (600 g kg^?1) than bahiagrass (110 and 490 g kg^?1 respectively); however, cowpea HM was only 0·9 t ha^?1 in May and 0·7 t ha^?1 in June, but it did not persist in July and August. Calves receiving the creep feeding treatments had greater average daily gain (0·8 vs. 0·7 kg d^?1) than calves in other treatments. Further research is necessary to exploit the superior nutritive value of cowpea in grazing systems in the south‐eastern USA.     

Determination of Some Metals Which are Important for Food Quality Control in Bread

This study is the small part of the big project related to the metallic contamination in foodstuff. The work presented here allowed determination the level of iron, copper, zinc, lead and cadmium in bread samples obtained from 20 bakeries in Ankara and Samsun, Turkey. The atomic absorption spectrophotometry method was used to determine these metals. The mean values of iron, copper, zinc, lead, and cadmium levels were found as 19·2±8·1 mg/kg-dry weight (dw), 2·1±1·0 μg/kg-dw, 10·0±3·0 μg/kg-dw, 86·8±176·0 μg/kg-dw, and 12·2±6·1 μg/kg-dw, respectively. No significant differences were found in copper and lead levels of samples obtained from bakeries in general, and in copper and cadmium levels of the samples from different provinces (P>0·05), while they were considered significant in iron, zinc, and cadmium levels of samples in general, and in iron, zinc and lead levels of samples from different provinces (P<0·05).