Insecticidal activity of three diatomaceous earths on lesser grain borer,Rhyzopertha dominica F., and their effects on wheat,barley, rye,oats and triticale grain properties

This study aimed to evaluate insecticidal activity of three diatomaceous earths DEs, two originated from Serbia (DE S-1 and DE S-2) and one commercial formulation (Protect-It, Hedley Technologies Ltd. Canada) applied at rates of 0.5, 1.0 and 1.5 g/kg (500, 1000 and 1500 ppm) on Rhyzopertha dominica in wheat, barley, rye, oats and triticale grains and their effects on mass of kernels and several properties: adherence, hectolitre mass, moisture, protein and ash contents. Mortality of R. dominica adults increased with exposure duration and DEs rates. In all tested grains after the longest exposure period (21 days), 1.0 and 1.5 g/kg rates of Protect-It, and 1.5 g/kg rate of DE S-1 and DE S-2 (in barley) caused 95–100% mortality. Offspring reduction of ≥95% was recorded after the application of 1.0 and 1.5 g/kg of Protect-It and 1.5 g/kg of DE S-1. The lowest weight of damaged grain was found after applying 1.0 and 1.5 g/kg of DEs to all grain types, and the highest in rye and wheat treated with 0.5 g/kg DE S-1 and DE S-2, respectively. The highest DEs adherence of 83–95% was detected in wheat, and 87–92% in oats, and the lowest of 71–77% in rye and 59–73% in triticale. All DEs significantly reduced hectolitre mass of all grains, especially Protect-It, 3.6–8.8%. No negative effects of DEs were detected on moisture contents, and the contents of proteins and ashes in the grains. The changes were due to the activity of R. dominica.     

Impact of diatomaceous earth application on the rheological properties of wheat,triticale and rye flour dough

Although utilization of commercial products based on diatomaceous earth, an insecticide of the natural origin, plays a very important role in the integral protection of stored grains, the effect of their application on the rheological quality of small grains is poorly exploited. Therefore, the aim of this research was to employ GlutoPeak and Mixolab rheological devices in order to compare the impact of three diatomaceous earths (DEs) (Protect-It and two inert dusts originated from Serbia) application on the rheological properties of wheat, triticale and rye flour dough. While moisture and protein content did not differ in treated and untreated grain samples, application of all three DEs in two triticale varieties led to an increase in the wet gluten content and Mixolab water absorption, as well as a decrease in the gluten strength, as indicated by gluten index and GlutoPeak maximum torque values. Treated rye samples have also exhibited a decrease in dough maximum consistency and stability and greater protein structure weakening in comparison to untreated sample. The mentioned changes in rheological behaviour were not noticed in wheat varieties treated with DEs. The major changes were recorded in rheological behaviour of triticale and rye starch component which showed a decrease in maximum peak torque and hot paste stability after grain treatment with DEs. In general, the influence of DEs on rheological properties of small grains was highly species and varietal dependent, where more pronounced differences between treated and untreated grains were noticed in stronger varieties.     

Detection and prediction of Sitophilus oryzae infestations in triticale via visible and near-infrared spectral signatures

Triticale is a hybrid of wheat and rye grown for use as animal feed. In Florida, due to its soft coat, triticale is highly vulnerable to Sitophilus oryzae L. (rice weevil) and there is interest in development of methods to detect early-instar larvae so that infestations can be targeted before they become economically damaging. The objective of this study was to develop prediction models of the infestation degree for triticale seed infested with rice weevils of different growth stages. Spectral signatures were tested as a method to detect rice weevils in triticale seed. Groups of seeds at 11 different levels (degrees) of infestation, 0–62%, were obtained by combining different ratios of infested and uninfested seeds. A spectrophotometer was used to measure reflectance between 400 and 2500 nm wavelength for seeds that had been infested at different levels with six different growth stages from egg to adult. The reflectance data were analyzed by several generalized linear regression and classification methods. Different degrees of infestation were particularly well correlated with reflectances in the 400–409 nm range and other wavelengths up to 967 nm, although later growth stages could be detected more accurately than early infestation. Stepwise variable selection produced the lowest mean square differences and yielded a high R² value (0.988) for the 4th instars, pupae and adults inside the seed. Models were developed to predict the level of infestation in triticale by rice weevils of different growth stages. Overall, this study showed a great potential of using reflectance spectral signatures for detection of the level of infestation of triticale seed by rice weevils of different growth stages.     

Influence of the degree of fusariosis on technological traits of wheat grain

The paper aims to enlarge the current knowledge about the dependence of technological traits of wheat grain on its degree of infestation (DI) with fusariosis. Samples of grain of four wheat cultivars were obtained from naturally grown crops (control) and from crops inoculated with Fusarium culmorum from which three degrees of kernel infestation were selected. Samples were determined for thousand kernels weight (TKW), total protein, starch and wet gluten (WG) contents, Hagberg falling number (HFN) and sedimentation value (SV). Content of protein and wet gluten showed higher values for moderately infested kernels (up to 15 and 25%, respectively, when compared to control grain) than for kernels lightly or heavily infested. All the remaining traits had values lower than that for control grain and showed a decrease with increasing DI. Decrease for the heaviest infestation was on average: 8, 29, 31 and 34% for starch, TKW, HFN and SV, respectively.     

Performance of diatomaceous earth and imidacloprid as wheat,rice and maize protectants against four stored-grain insect pests

Laboratory experiments were conducted in Pakistan to investigate the effectiveness of the diatomaceous earth (DE) formulation, Protect-It, at 150 ppm and imidacloprid, at 1.25, 2.5 and 5.0 ppm, alone or in combination, against the rusty grain beetle, Cryptolestes ferrugineus Stephens (Coleoptera: Laemophloeidae), the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the psocid, Liposcelis paeta Pearman (Psocoptera: Liposcelididae). The bioassays were conducted at 25 °C, 65% relative humidity (r.h.) and continuous darkness by using adults of each insect pest that were exposed on treated or untreated wheat, rice and maize. Adult mortality counts were performed 1, 2, 4 and 7 days post-exposure. Progeny production was also evaluated 62 and 30 days after the last mortality count for beetles and psocid respectively. Results showed that mortality was increased with the increase of dose and exposure interval. Imidacloprid was more effective at the highest dose than the DE alone. The combination of DE plus imidacloprid resulted to higher mortalities than DE or imidacloprid alone at almost all exposure intervals. There was higher mortality on wheat than on rice or maize. In general, T. castaneum was the most tolerant insect species to any treatment while L. paeta was the least tolerant. The highest progeny production was observed for T. castaneum (i.e., 33.1 individuals per vial) while the lowest for L. paeta (i.e., 11.1 individuals per vial) on maize treated with Protect-It alone. The findings of the current study indicate that the combined use of DE and imidacloprid, as wheat, rice and maize protectants, may provide adequate level of management to several important stored-product insects.     

Detection of External and Internal Insect Infestation in Wheat by Near-Infrared Reflectance Spectroscopy

Near-infrared spectroscopy (NIR) in the reflectance mode was investigated for the rapid, automatic and non-destructive detection of insect stored-grain pests external or internal to wheat kernels. Convincing calibration performance was obtained for external adult Oryzaephilus surinamensis (L) (saw-toothed grain beetle) in unmilled samples including varieties Beaver (soft wheat) and Mercia (hard wheat) at two moisture contents. With this large substrate variability, the method could differentiate between uninfested samples and samples with approximately 270 insects kg⁻¹ or more. Milling made no improvement. Large spectral differences were observed between uninfested kernels and kernels infested internally with Sitophilus granarius (L) (grain weevil) larvae or pupae, arising from both a changed chemical composition and physical structure. Single uninfested and infested kernels were discriminated by their second derivative (d²) spectra. For both external and internal infestation there was substantial evidence that insect protein and/or chitin and moisture were being detected. NIR should be useful as a rapid method of detection.     

Efficacy of diatomaceous earth formulations admixed with grain against populations of Tribolium castaneum

The efficacy of diatomaceous earth (DE) to control stored-products Coleoptera on stored grain was examined against several populations of the red flour beetle, Tribolium castaneum (Herbst). Four commercially available DE formulations were tested: INSECTO^®, Perma-Guard™, Protect-It^® and the diatomite used for the production of Dryacide^®, each at six concentrations (100-1000 ppm). A great variation of efficacy was observed among the DE formulations tested. Protect-It at concentrations up to 400 ppm was found to be the most effective formulation to control red flour beetle populations. However, a concentration of 1000 ppm of Protect-It was necessary to control all adults of all populations. Most T. castaneum populations, except one from Ivory Coast (Asm), were more than 90% controlled with INSECTO and Dryacide DE at 600 ppm. At this concentration, about 88% and 22% Asm adults died with INSECTO and Dryacide DE, respectively. Perma-Guard was the least efficient DE formulation to control T. castaneum adults with three populations exhibiting some survival at 1000 ppm. Reduced susceptibility to DE was observed in two populations, Asm and Lab susceptible from Kansas (Lab-S). As neither population had been previously exposed to DE, it is suggested that red flour beetles may naturally vary in susceptibility to DE. In addition, it was found that some populations can be satisfactorily controlled with some DE formulations but not with others.     

Susceptibility of Ethiopian wheat varieties to granary weevil and rice weevil infestation at optimal and sub-optimal temperatures

Integrating varietal resistance with temperature manipulation during storage may provide a better option for protection of stored grains and may decrease reliance on the use of synthetic chemicals. The current study was conducted to determine the susceptibility of different varieties of wheat seed to the infestation by the granary weevil, Sitophilus granarius (L.), and rice weevil, Sitophilus oryzae (L.), at optimal (30 °C) and sub-optimal (19 °C) temperatures. Kernels of six wheat varieties namely, Danda'a, Digalu, ET-13-A2, Kakaba, Millennium, and Pavon-76 were examined over a period of 90 d. Significant interactions were detected between wheat varieties and storage temperature for progeny emergence, percentage of insect damaged kernels, grain weight loss, and amount of powder produced per gram of wheat. Kernels of Danda'a, infested with S. oryzae at 30 °C exhibited significantly lower mean progeny counts (13.3 live insects), lower percentage of grain weight loss (4.2%) and insect-damaged kernels (6.4%), and powder production (1.5 mg/g). Kernel weight and hardness index were negatively associated with percentage of insect damaged kernels and grain weight loss. Kernel diameter was positively associated with both of percentage of insect damaged kernels and grain weight loss. Wheat varieties with high Zeleny sedimentation values had lower percentage of insect-damaged kernels and grain weight loss. These results indicated that kernel weight, hardness index, and protein content are predominant factors contributing to wheat resistance against S. granarius and S. oryzae. The varieties Millennium and Danda'a can be considered with other integrated pest management approaches to reduce stored grain losses of wheat in Ethiopia.     

Field trials on the efficacy of Beauveria bassiana,diatomaceous earth and Imidacloprid for the protection of wheat grains from four major stored grain insect pests

We assessed the insecticidal efficacy of Beauveria bassiana, diatomaceous earth (DE) and the neonicotinoid Imidacloprid against four major insect species of stored grain pests during field trials conducted on small farms located in four districts of Punjab, Pakistan. In each district, a 40 kg lot of wheat grain was admixed with B. bassiana (3 × 10¹⁰ conidia kg⁻¹), DE (150 ppm) and Imidacloprid (5.0 ppm) alone and in different combinations. Each lot was divided subsequently into four equal parts (10 kg each), packed in polypropylene bags, artificially infested, labeled and stored at the farms under natural environmental conditions up to 6 months. Sampling was carried out every 30 d to record the total number of dead and alive adults, as well as the percent of grain damage in treated and untreated (control) grains. Results revealed a significant difference among the treatments, test insect species and the storage period. For each district, the combined treatments provided better control of all tested insect species compared with each treatment alone. The least number of surviving adults and minimum percent grain damage was observed for Imidacloprid and DE combination, but was outperformed by the DE treatment with B. bassiana for long-term protection. For all grain protectants, we obtained the same order of susceptibility level among the test species (i.e. Liposcelis paeta > Cryptolestes ferrugineus > Rhyzopertha dominica > Tribolium castaneum). The results of the present study suggested that DE, insect pathogenic fungi and Imidacloprid can be effectively used for the protection of wheat stored at small-scale farmer's fields.     

Use of wheat,triticale and rye flours in layer cake production

In this study, the capacity of obtaining high quality layer cakes from rye and triticale lines was analysed and compared to wheat lines. The samples were characterised considering grain hardness, flour composition and quality parameters as protein, pentosan, damaged starch, pasting viscosity and functional predictive test – solvent retention capacity test. Cakes were analysed in weight, symmetry, volume, volume index (VI) by measuring the height in different points of the cake, crust and crumb colour, crumb structure and texture. Wheat and triticale cakes showed similar characteristics. Rye cakes showed higher volume and lower weight than those with crumbs darker in colour, higher adhesiveness, springiness and resilience. The multiple regression analysis was used to develop an equation for cake volume index prediction. The best‐fit linear regression model was: VI = 14.75 – 0.14 × protein + 0.93 × water soluble pentosan – 0.27 × total pentosan. Despite the differences, high quality cakes can be elaborated with rye, triticale and soft wheat cultivars.     

Effect of Protease Addition on Starch Recovery from Steeped Sorghum and Maize

The effect of protease addition on starch recovery from steeped white regular sorghum (RSOR) compared to yellow maize (YMZ) was determined. An in vitro wet milling method standardized to test dosages from 0 to 1.5 Anson units (AU/100 g grain) indicated that starch yields increased proportionally as enzyme concentration increased. The yields were significantly lower for RSOR. A factorial experiment with a level of confidence of P < 0.05 was performed to study the effect of protease addition (1.25 AU/100 g grain) to coarsely ground kernels for 4 h after 20 h or 44 h SO₂ steeping of whole grains. Calcium oxide (CaO) was used to increase the pH of the steep solution to 5.5 and improve enzyme activity. The in vitro and laboratory tests indicated that the enzyme treatment significantly improved starch yields and recoveries; the effect being more pronounced in RSOR. Protease‐treated kernels yielded 3.2% more starch than those steeped regularly. RSOR steeped for 20 h and then treated with the enzyme for 4 h yielded 6.7% more starch than the counterparts steeped regularly. When steep times were compared, kernels soaked regularly for 48 h produced 1.6% more starch than counterparts steeped for 24 h. The protease treatment reduced the amount of inseparables (gluten‐starch complexes) to zero and also lowered the gluten content of starch by about 1.5%. A comparison of protein and ash contents for the refined starches indicated that the process was more efficient for YMZ than for RSOR and for grains steeped regularly for 48 h. YMZ starch started gelatinization at a lower temperature, required less time to reach peak viscosity and had less shear thinning than RSOR.     

Mortality and progeny production of four stored-product insect species on three grain commodities treated with Beauveria bassiana and diatomaceous earths

Laboratory bioassays were conducted to estimate the effectiveness of the entomopathogenic fungus Beauveria bassiana (Bals.-Criv.) Vuill. (Hypocreales: Cordycipitaceae) at 1.5 × 10⁸ and 1.5 × 10¹⁰ conidia/kg grain alone or mixed with the diatomaceous earths (DEs) Protect-It at 150 ppm and DEBBM at 50 ppm against adults of the rusty grain beetle, Cryptolestes ferrugineus Stephens (Coleoptera: Laemophloeidae), the lesser grain borer, Rhyzopertha dominica (F.) (Coleoptera: Bostrychidae), the red flour beetle, Tribolium castaneum (Herbst) (Coleoptera: Tenebrionidae) and the psocid, Liposcelis paeta Pearman (Psocoptera: Liposcelididae). The adult insects were exposed to treated grains for 7, 14 and 21 days. For progeny emergence data, the treated units were remained under the same conditions for 62 days for all beetles and 30 days for psocids. The results revealed significant differences in mortalities of insect species among treatments and grains. The combined use of B. bassiana, at the highest dose, and DE increased adult mortalities of all species. In general, the treatments were least effective against T. castaneum and most effective against L. paeta. More numbers of dead insects were found on wheat than on rice or maize. The emergence of progeny was considerably reduced on grains treated with B. bassiana, at the highest dose, plus DE. The results of the present study suggest that the effectiveness of B. bassiana is fortified by the addition of DEs, but it varies among exposed insect species and commodities.     

The efficacy of different surface applications of wettable powder formulation of Detech® diatomaceous earth against the rice weevil,Sitophilus oryzae (L.) (Coleoptera: Curculionidae)

In this study, the insecticidal activity of the wettable powder formulation of Detech® diatomaceous earth against the rice weevil, Sitophilus oryzae (Coleoptera: Curculionidae), an important stored grain pest, was investigated. Detech® diatomaceous earth was applied on concrete and wooden surfaces at doses of 0.25, 0.5, 1 and 2 g/m² and the mortality of S. oryzae adults was observed at time intervals of 24, 48, 72, 96, 120, 144, 168, 192, 216, 240, 264 and 288 h. In the first 24 h of application on the concrete and wooden surfaces, no death was observed. At the 48^th hour, no effect or very low mortality was observed on the concrete and wooden surface at all doses. While the increase in dose and exposure time on the concrete and wooden surface increased the mortality rate of the adults, complete adult mortality was obtained on concrete surfaces after 288 h. The wettable powder formulation of Detech® diatomaceous earth at a dose of 2 g/m² is highly effective against rice weevils on wood and concrete surfaces at laboratory conditions, though with greater success on concrete, but the longer DE exposures increase the efficacy on both surfaces.     

Adhesion of diatomaceous earth dusts on wheat and corn kernels

Insect infestations are a major threat to the quality of stored grain. One method of insect control is to apply diatomaceous earth (DE), a non-chemical, inert dust that is composed of the ossified remains of diatoms. Diatomaceous Earth kills insects via abrasion and desiccation when the insect is exposed to a sufficient quantity of DE from contact on the grain surface. Therefore, good dust adhesion is desirable to ensure that the DE will come in contact with insects in sufficient quantity to provide the insect control expected. This study considered the adhesion ratio of three types of DE, Celite, Dryacide, and Diafil, on wheat and corn kernels. All three types of DE adhered better to wheat than to corn, and to higher moisture grain than lower moisture grain, and moisture content affected the adhesion on corn more than wheat. Dryacide had the lowest adhesion of the three DE tested at each condition. Dryacide's adhesion was significantly lower than at least one other DE in each test and was lower than both other DE for 12% moisture corn and 15% moisture wheat. Celite had the highest adhesion measured in each trial except for 15% moisture corn but was only significantly higher than Diafil for 12% moisture wheat. Additionally, higher surface roughness correlated with higher adhesion percentages, indicating that rougher diatomaceous earth formulations will be better at adhering to grain particles.     

Influence of commodity on the population growth of the larger grain borer,Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae)

In this study, we compared different amylaceous commodities for their suitability for population growth of the larger grain borer, Prostephanus truncatus (Horn) (Coleoptera: Bostrychidae), which is an important pest of stored maize in the tropics. In this context, we conducted three different series of tests. In the first test, we compared whole grains: whole barley, peeled barley, maize, whole oats, peeled oats, peeled rice, rough rice, rye, triticale, and wheat. Only maize was found suitable for P. trunctatus to reproduce and significantly increase its population, but there were certain commodities where surviving adults were found. In the second series of tests, we evaluated the percentage of cracked maize kernels on P. truncatus population growth. In this test, we found that the numbers of alive P. truncatus adults in the vials that contained 100% cracked kernels was higher than these with lower percentages of cracked kernels (5–50%) or no cracked kernels (0%). Finally, in the third series of tests, we compared eleven different types of amylaceous commodities with maize. These commodities were: whole maize (whole kernels), whole oat flakes, maize flour, whole barley flour, pasta, white soft wheat flour, whole soft wheat flour, white hard wheat flour, whole hard wheat flour, whole rye flour, and semolina. The results indicated that only whole maize and maize flour were suitable for P. truncatus population growth. Nevertheless, in some of the other commodities tested, there was a low number of adults and immatures that were able to survive 60 days after the incorporation of the parental adults. The results of the present study indicate that from the commodity range tested here, only maize was suitable for P. truncatus population growth. Nevertheless, the marginal numbers of surviving individuals in the non-maize commodities and the role of these substrates as potential “non-preferred food vehicles” that may contribute to further spread of this species should be tested in more detail.     

Population growth of the khapra beetle,Trogoderma granarium Everts (Coleoptera: Dermestidae) on different commodities

We evaluated the population growth of the khapra beetle, Trogoderma granarium Everts (Coleoptera: Dermestidae) on different grains, cracked wheat containment categories and amylaceous materials by conducting three series of laboratory bioassays. In the first series, peeled barley, whole (raw) barley, peeled oats, whole (raw) oats, peeled rice, rough rice, rye, triticale and hard wheat were tested. In the second series, six cracked wheat containment categories were tested: wheat containing intact kernels only (0% cracked kernels), wheat containing 5% cracked kernels and 95% intact kernels, wheat containing 10% cracked kernels and 90% intact kernels, wheat containing 25% cracked kernels and 75% intact kernels, wheat containing 50% cracked kernels and 50% intact kernels and wheat containing 100% cracked kernels. In the third series, the following amylaceous commodities were tested: hard wheat (intact kernels), whole oat flakes, maize flour, whole barley flour, pasta, white soft wheat flour, whole soft wheat flour, white hard wheat flour, whole hard wheat flour, whole rye flour and semolina. Significantly more dead adults were found on wheat than on peeled barley, maize, whole oats, rough rice and rye. Significantly more larvae alive were found on wheat and triticale, than on the other grains, with the exception of oats, both whole and peeled. The increase of the percentage of cracked wheat kernels increased population growth, except in the case of 10% cracked wheat kernels. In vials that contained 100% cracked wheat kernels, 584.1 individuals per vial were found, which was 3.7 times more than the respective number of larvae alive in vials with intact wheat kernels only. Significantly more dead adults were found on whole barley flour than on the other commodities. More than 1213 larvae per vial were recorded on whole barley flour, which was 1.3–15 times higher than the other commodities. The lowest number of larvae alive was found on pasta, followed by the white soft wheat flour. The findings of the present work show that some commodities are more prone to spread T. granarium than others, a fact which should be seriously taken into account in international trade of grains and related amylaceous products.     

Synchrotron based infrared imaging study of compositional changes in stored wheat due to infection with Aspergillus glaucus

Fungi are one of the serious causes of spoilage in stored grain including wheat. Aspergillus spp. is one of the most common storage fungi that spoils stored wheat. The damage caused by fungi adversely affects the quality of wheat and reduces its nutritional composition. Present methods of analysing chemical composition of wheat and other cereals using wet chemistry are destructive and use bulk grain and thus rely on bulk analysis. Grains, similar to other biological materials, are highly non-homogenous, hence, bulk analysis which causes damage to intrinsic structure of kernels, cannot be used for characterization of single kernels and studying the compositional distribution within a single kernel. In the present work, synchrotron based high resolution infrared imaging was used to study the compositional changes in stored wheat due to fungal damage. Clear differences between healthy and damaged wheat endosperm spectra were observed at peaks around 1740, 1595, and 1250 cm⁻¹. The difference in the absorption of infrared radiation was likely caused due to reduced lipid (1740 cm⁻¹), lignin (1595 cm⁻¹) and cellulose (1250 cm⁻¹) content in damaged wheat endosperm.     

Different diets affecting biology,physiology and cold tolerance of Trogoderma granarium Everts (Coleoptera: Dermestidae)

Biology, some physiological processes and cold hardiness of Trogoderma granarium Everts (Coleoptera: Dermestidae) on ten diets (barley, corn, millet, rice, rye, sorghum, triticale, wheat groundnut, and walnut) were studied under laboratory conditions (33 ± 1 °C with 65 ± 5% RH, 14L: 10D). According to the results, the insects reared on triticale had shortest development time, and the highest fecundity and fertility. By contrast, the longest development time, and the lowest fecundity and fertility were on groundnut. The survival rates ranged from 40 to 87% with the lowest values observed on groundnut. T. granarium larvae fed on triticale and millet had the highest amylolytic activity. In contrast, groundnut-fed larvae possessed the lowest amylolytic activity. The highest and lowest proteolytic activity was on rice and millet, respectively. Different diets had a significant effect on larval energy reserves (total body sugars, glycogen, lipid, and protein), which were at the highest levels on triticale and rye, and lowest levels on sorghum. The highest level of trehalose was on triticale, groundnut and rye, and the lowest level was on barley and sorghum. The supercooling point (SCP) of larvae reared on triticale was −20.6, which was significantly lower than on the other diets. Exposures to −5 and −10 °C/24 h were somewhat endured by larvae fed on triticale, rye, walnut, and groundnut whilst exposure to −20 °C/24 h caused 100% mortality in these food groups. These results suggest that larval food quality can affect biological and physiological characteristics and influence the supercooling point and cold hardiness of T. granarium.     

Volatile metabolites in various cereal grains

To date, studies on volatile metabolites in cereal grain have focused mainly on a single species. In this paper, results are presented of the analysis of volatile compounds in five cereal grain species (spring wheat, durum wheat, triticale, rye, oats and barley) based on representative sampling of at least 15 cultivars of individual species. Profiles of volatile compounds were determined using solid phase microextraction (SPME) and GC–TOF (time of flight mass spectrometry). Many of the volatile compounds were only present in single samples; however, several dozen were found in over 50% of samples and 46 volatiles were found in all samples. Among them there were six alcohols, 10 aldehydes and ketones, six terpenes, seven hydrocarbons and 11 benzene derivatives. The highest concentrations of these compounds were found in durum wheat, while the lowest were observed in triticale and rye.     

Effect of the degree of fusariosis on the physical characteristics of individual wheat kernels

This work aims to determine dependencies of single‐kernel (SK) physical traits on the kernel degree of fusariosis. The measurements were taken on samples of grain of six wheat varieties cultivated during 1–3 years. For SK mass, volume and width this dependence resulted in lowered (by at least ten to more than 25% for mass and volume, and ca. 5 to more than 15% for width) values in Fusarium culmorum infested grain as compared with the non‐inoculated control. In addition, moderately infested kernels tended to be of higher mass and size than kernels with no symptoms of infestation. An unexpected effect was a lack of dependence of SK density on the degree of infestation. Moisture content was lower for infested kernels by 6–8%, hardness tended to increase a little for moderate infestation, while it noticeable decreased for the heaviest infestation.