Percentage Of Grains Research Articles

Susceptibilidad de poblaciones nativas de maíz y preferencia del gorgojo en Yucatán, México

Uno de los problemas con el almacenamiento de semillas en maíz es la presencia de plagas que merman la calidad. Para hacer frente a este problema, se emplean materiales con poca o nula susceptibilidad. Las variedades nativas de maíz en Yucatán son reservorios de genes para resistencia a plagas de almacén. El objetivo del presente estudio fue evaluar el ataque de gorgojo (Sitophilus zeamais Motschulsky) en ocho poblaciones de maíz y dos variedades testigo. Para determinar la susceptibilidad, 100 semillas de cada población se expusieron a la presencia de 100 gorgojos por 15 días, con 10 repeticiones, las variables fueron número de gorgojos vivos, pérdida de peso y porcentaje de grano dañado. La preferencia se determinó colocando en un mismo recipiente 100 semillas de cada población y 1 000 gorgojos, fueron almacenados por 30 días y repetido cinco veces. Se registró el porcentaje de grano dañado por color. La mayor susceptibilidad se presentó en las poblaciones Chichen Itza, Sac beh y Nal t’eel blanco, las dos primeras registraron el mayor porcentaje de grano dañado, con 15% por encima de las demás poblaciones evaluadas, mientras que la población Nal t’eel blanco registró 6.1% por encima de la menor pérdida. La preferencia del insecto fue hacia los granos de color blanco. El pericarpio (0.495) y escutelo (0.418) mostraron relación con la presencia de granos dañados. Existen diferencias en la susceptibilidad y preferencia de las poblaciones evaluadas, lo que indica variabilidad que puede aprovecharse en programas de mejoramiento genético.

Combined effects of a glycine-rich RNA-binding protein and a NAC transcription factor extend grain fill duration and improve malt barley agronomic performance.

Two key barley genes independently control anthesis and senescence timing, enabling the manipulation of grain fill duration, grain size/plumpness, and grain protein concentration. Plant developmental processes such as flowering and senescence have direct effects on cereal yield and quality. Previous work highlighted the importance of two tightly linked genes encoding a glycine-rich RNA-binding protein (HvGR-RBP1) and a NAC transcription factor (HvNAM1), controlling barley anthesis timing, senescence, and percent grain protein. Varieties that differ in HvGR-RBP1 expression, 'Karl'(low) and 'Lewis'(high), also differ in sequence 1KB upstream of translation start site, including an ~ 400bp G rich insertion in the 5'-flanking region of the 'Karl' allele, which could disrupt gene expression. To improve malt quality, the (low-grain protein, delayed-senescence) 'Karl' HvNAM1 allele was introgressed into Montana germplasm. After several seasons of selection, the resulting germplasm was screened for the allelic combinations of HvGR-RBP1 and HvNAM1, finding lines combining 'Karl' alleles for both genes (-/-), lines combining 'Lewis' (functional, expressed) HvGR-RBP1 with 'Karl' HvNAM1 alleles ( ±), and lines combining 'Lewis' alleles for both genes (+ / +). Field experiments indicate that the functional ('Lewis,' +) HvGR-RBP1 allele is associated with earlier anthesis and with slightly shorter plants, while the 'Karl' (-) HvNAM1 allele delays maturation. Genotypes carrying the ± allele combination therefore had a significantly (3days) extended grain fill duration, leading to a higher percentage of plump kernels, slightly enhanced test weight, and lower grain protein concentration when compared to the other allele combinations. Overall, our data suggest an important function for HvGR-RBP1 in the control of barley reproductive development and set the stage for a more detailed functional analysis of this gene.

COMPARATIVE EFFICACY OF SOME INSECTICIDES AGAINST MAIZE APHID (Rhopalosiphum maidis) AND ITS INFLUENCE ON NATURAL ENEMIES IN MAIZE ECOSYSTEM

The maize aphid, Rhopalosiphum maidis is one of the most serious pests of maize crop in Bangladesh. Nowadays, it becomes a major barrier for production of maize due to create hamper of pollination. In the present research investigation, the field efficacy of some insecticides was evaluated against maize aphid infestation and their toxic effects were also studied on some natural enemies in the maize ecosystem. To achieve the research goal, a field experiment was conducted on maize at the Entomology Field Laboratory, Department of Entomology, Bangladesh Agricultural University (BAU), Mymensigh during Rabi season of 2017-18. The experiment was set up in Randomized Complete Block Design (RCBD) with five treatments (Imidagold 20SL@ 0.1, 0.3 & 0.5ml/L; Ambush 1.8EC@ 1.5, 2.5 & 3.0ml/L; Hadhak 45WP@ 0.2, 0.4 & 0.6g/L; Suspend 5SG@ 0.5, 1.0 & 1.5 g/L and Heron 5EC @ 0.5, 1.0 & 1.5ml/L) and three replications for each treatment. Maize viz. BARI Hybrid Butta-09 was used as experimental crop. Data were collected on percent reduction of plant infestation & population of natural enemies, yield attributes and benefit cost ratio (BCR). Result clearly indicated that these mentioned parameters were highly significant with the application of insecticides. However, Imidagold 20SL@ 0.5ml/L resulted in the greatest (77.27%) percent reduction of maize plant infestation, the highest (623.51) number of grain per cob, the maximum (39.74g) 100 grain weight, the highest (10.02 t/ha) grain yield, the highest (63.27%) percent grain yield over control and maximum (1.56) benefit cost ratio compared to others tested insecticides which was statistically similar with the dose of 0.3ml/L of Imidagold 20SL. And then, this result was followed by Ambush 1.8EC, Hadhak 45WP, Suspend 5SG and Heron 5EC, respectively. Besides, the highest (93.67%) percent cumulative mean of maize plant infestation, the lowest (330.45) number of grain per cob, minimum (13.43g) 100 grain weight, the lowest grain yield (3.68 t/ha) and the lowest benefit cost ratio (0.95) were obtained from untreated control. With a view to know the toxic effect of different insecticides, the percent reduction of population of natural enemies was counted at 2 days, 5 days and 7 days after spraying. In all field trials, the harmful effects of the five insecticides were in the following rank order (least harmful to most harmful): Imidagold 20SL

Application of various types of local microorganisms to the growth and production of two rice varieties

An experiment was conducted to determine the effect of application of various types of local microorganisms (LM) to the growth and production of two rice (Oryza sativa L.) varieties. The experiment was conducted in the form of a 2-factor factorial design trial in the Randomized Block Design (RBD). The first factor was the variety, namely: Variety Mira-1 and Diah Suci. The second factor was 6 types of LM, namely: LM of gamal leaf, LM of vegetable waste, LM of fruit waste, LM of banana suckers, LM of cow urine and a mixture of those five LM ingredients; Therefore, there were 12 treatment combinations. The results showed that the Diah Suci variety gave higher yields than the Mira-1 variety on plant height, panicle length, number of grains, percentage of grain filled per panicle, 1000 grain weight, and grain production per hectare (11.42 tons/ha) The application of a mixture of the five types of LM resulted in a shorter flowering age of 66.33 HST, and a shorter harvest age of 102.33 HST. There are no results that indicate interactions between varieties and types of LM.

Scheduling of nitrogen fertilizer topdressing during panicle differentiation to improve grain yield of rice with a long growth duration

Topdressing at panicle differentiation (PF) according to soil fertility and regularity of rice nutrient absorption is an important agronomic practice used in cultivation of rice cultivars with a long growth duration. We studied the impacts of timing of nitrogen fertilizer application during PF on photosynthesis and yield-related agronomic traits in ‘Y-Liang-You 900’ and ‘Y-Liang-You 6’, which are representative rice cultivars with a long growth duration. Data for two years showed that timing of topdressing application during PF affected panicles per unit area, percentage grain set, spikelets per panicle, and leaf photosynthetic traits during the grain-filling period. Topdressing at the initial stage of flag-leaf extension resulted in higher grain yield (typically by 10.55–19.95%) than in plants without topdressing. Grain yield was significantly correlated with flag leaf photosynthetic rate and leaf SPAD value (r = 0.5640 and r = 0.5589, respectively; p < 0.01) at an advanced grain-filling stage (30 days after heading). Surprisingly, grain yield was not correlated with carbohydrate remobilization from the stem and sheath. For rice cultivars with a long growth duration, nitrogen-fertilizer topdressing must be applied at the initial stage of flag-leaf extension to delay leaf senescence during the grain-filling stage and realize the enhanced yield potential.

Patterns recognition methods to study genotypic similarity in flood-irrigated rice

ABSTRACT Genetic diversity studies are performed based on information on a set of traits measured in a group of genotypes, considering one or more environments. The pattern recognition methods allow classifying genotypes from a set of important agronomic information. Thus, this study aimed to present and compare pattern recognition methods to inquire about the similarity of environments and genotypes in flood-irrigated rice for the recommendation of cultivars. The experim>ents were performed in the municipalities of Leopoldina, Lambari, and Janauba, state of Minas Gerais, Brazil. To evaluate the pattern of similarity, 25 rice genotypes in three environments belonging to the flood-irrigated rice breeding program were used. Among these genotypes, five cultivars were used as an experimental control for the grain yield, the height of the plant, flowering, panicle length, grains filled by panicles, percentages of grains filled by panicles, in the 2012/2013 agricultural year. The methods us>ed were mixtures of multivariate normal distributions and density-based clustering algorithm. It was observed, therefore, that the genotypes are distributed in three distinct groups, in which there are intragroup homogeneity and intergroup heterogeneity for the agronomic traits of the flooded rice culture. The methods >used to assess the dissimilarity of environments using pattern recognition methods were efficient in classifying flooded rice irrigated environments.

Quality Enhancement of Falcataria-Wood through Impregnation

The purpose of this research is to determine the efficiency of impregnation usingphenol formaldehyde resin to enhance Falcataria wood’s stability and better mechanical properties. Impregnation process was carried out after moisture content stabilized at 12% on samples with a dimension of 20 mm × 20 mm × 300 mm at various concentrations and pressure time. Dimensional stability was evaluated by thickness swelling (TS) and anti-swelling efficiency (ASE) and the young’s modulus was conducted according to BS 573. The mechanical properties and dimensional stability of impregnated wood were evaluated. Dimensional stability and mechanical properties of Falcataria wood were successfully increased after impregnation. PF impregnation can improve the mechanical properties and the density from 0.26 g/cm3 to 0.30 g/cm3 even with only 10% of weight percent grain. Dimensional stability increases with increasing resin concentration and time pressure. The highest increase in mechanical properties was found at a higher concentration of PF. The penetration of PF into the wood’s cell darkens the color of impregnated wood.

Bioefficacy of some plants ethanolic extracts against maize weevil (Sitophilus zeamais) infestation of stored maize grains

The experiment was conducted to determine the efficacy of three plants ethanolic extracts against maize weevil (Sitophilus zeamais) on stored maize grains (Zea mays). Five different ethanolic concentrations (0.5 mg/L, 1.0 mg/L, 2.0 mg/L, 4.0 mg/L and 8.0 mg/L) were made from the leaves of Hyptis suaveolens, Alstonia boonei and Tephrosia vogelii with 0.0 mg/L as the control (ethanol) and applied onto the maize grains by dipping. Theexperiment consists of six treatments (including control) and was laid in completely randomized design (CRD) with three replications. Data were collected for adult mortality, number of eggs, larval development and percentage grain damage. The data were subjected to analysis of variance (ANOVA) at 5% probability level with Duncan's Multiple Range Test (DMRT) used to separate the means that were significant. The result obtainedrevealed significant difference (P≤ 0.05) between the concentrations over the control in terms of toxicity, oviposition, induced adult mortality and progeny suppression. However, the extracts from Tephrosia vogelii are the most toxic and produced the best effect with LC of 4.85 mg/L at 24 hours of exposure and 1.94 mg/L at 48 50 hours of exposure. Similar result was found in terms of adult mortality and oviposition suppression. The effectof the extracts is concentration-dependent increase with increase in concentration. The percentage decrease in weight due to the weevil's infestation was found to be reduced with increase in concentrations. Thus, 8.0 mg/L of the ethanolic extracts of Tephrosia vogelii is recommended for biological control of Sitophilus zeamais against stored maize grains.&#x0D; Key Words: Concentrations, Ethanolic Extracts, Maize, Weevil.

Reducing yield asymmetry in a wrought Mg–9Al alloy by randomized texture achieved via multi-directional forging

This study shows that tension-compression yield asymmetry in a wrought Mg–9Al alloy can be reduced and even eliminated by multi-directional forging. After multi-directional forging and solution treatment, the texture was found to be randomized and maintained its features during grain growth. With this texture, the asymmetry ratio was tested to be 1.1 and 1.0 when the grain size was 7 and 30 μm, respectively. After peak aging, the ratio shifted to 1.2 and 1.1, respectively. The low asymmetry ratios were attributed to the low percentage of grains oriented for {101‾2} twinning and the balanced twining activity between tension and compression. A brief summary of studies on yield asymmetry was also conducted to present the various approaches and their effectiveness on this subject.

Reducing competition in a crop–livestock–forest integrated system by thinning eucalyptus trees

AbstractThe goal of this study was to evaluate the effects of thinning eucalyptus trees on yield and nutritive value of corn for silage and palisadegrass in a crop–livestock–forest integrated system and to evaluate the total aboveground biomass yield in systems with and without trees. Plant variables, as well as the incidence of photosynthetically active radiation (PAR) and soil moisture, were evaluated between October 2016 and March 2018 in São Carlos, Brazil, in a crop–livestock–forest and a crop–livestock system. In the crop–livestock–forest system, eucalyptus trees (Eucalyptus urograndis clone GG100) were planted in April 2011, in single rows, with 15 × 2 m spacing. In 2016, the trees were thinned, and the spacing was changed to 15 × 4 m. The treatments comprised measurements at 0.00, 3.75, 7.50, and 11.25 m from the trees of the North row in the integrated crop–livestock–forest (iCLF) system and integrated crop–livestock (iCL) system. Palisadegrass (Urochloa brizantha) was sown after harvesting the corn. Corn yields were similar between treatments, with an average of 13.6 Mg ha−1. Corn for silage presented a higher percentage of grain in total biomass in the crop–livestock–forest positions (41.4 and 42.1%) than in the crop–livestock system (35.6%). No differences in forage accumulation were observed. Crude protein content in corn for silage and palisadegrass was higher in the crop–livestock–forest treatments than in the crop–livestock system. Such results indicate that thinning was favorable to production in the crop–livestock–forest system. Total aboveground biomass yield was higher in the iCLF system, indicating better land use for this type of integrated system.

Genetic variability, heritability and correlations for milling and grain appearance qualities in some accessions of rice (Oryza sativa L.).

Poor milling and grain appearance is a common feature of locally produced rice (Oryza sativa L.) in West Africa. Development of genotypes with high yield and uniform milled grain size will enhance the market for the locally produced rice. One hundred rice accessions were evaluated to assess genetic variability, heritability and correlations for 11 milling and appearance quality traits and grain yield. The field was laid as a 10 × 10 alpha lattice design with three replications following standard cultivation practices. ANOVA revealed significant differences for the traits studied. The genotypic and environmental variances showed significant differences for all characters studied. Phenotypic coefficient of variation was greater than its corresponding genotypic coefficient of variation for each studied trait. Heritability at broad-sense varied from 14.1% for milling degree to 73.8% for milled grain length-to-width ratio (L/W). Genetic advance as percent of mean ranged from 2.2% for brown rice recovery to 129.6% for percentage of grain with chalkiness (PGWC). In general, genotypic correlations ranged higher than their corresponding phenotypic correlations. Brown rice recovery had significant positive phenotypic and genotypic correlations with milling recovery and head rice recovery. Consequently, brown rice recovery, milling recovery and L/W could be used as selection criteria for the improvement of head rice recovery. Genotypes BETIA and CRI-AMANKWATIA had the desirable PGWC and degree of chalkiness, therefore, they are recommended for the improvement of high yielding varieties with high amount of chalkiness.

High post-anthesis temperature effects on bread wheat (Triticum aestivum L.) grain transcriptome during early grain-filling

BackgroundHigh post-anthesis (p.a) temperatures reduce mature grain weights in wheat and other cereals. However, the causes of this reduction are not entirely known. Control of grain expansion by the maternally derived pericarp of the grain has previously been suggested, although this interaction has not been investigated under high p.a. temperatures. Down-regulation of pericarp localised genes that regulate cell wall expansion under high p.a. temperatures may limit expansion of the encapsulated endosperm due to a loss of plasticity in the pericarp, reducing mature grain weight. Here the effect of high p.a. temperatures on the transcriptome of the pericarp and endosperm of the wheat grain during early grain-filling was investigated via RNA-Seq and is discussed alongside grain moisture dynamics during early grain development and mature grain weight.ResultsHigh p.a. temperatures applied from 6-days after anthesis (daa) and until 18daa reduced the grain’s ability to accumulate water, with total grain moisture and percentage grain moisture content being significantly reduced from 14daa onwards. Mature grain weight was also significantly reduced by the same high p.a. temperatures applied from 6daa for 4-days or more, in a separate experiment. Comparison of our RNA-Seq data from whole grains, with existing data sets from isolated pericarp and endosperm tissues enabled the identification of subsets of genes whose expression was significantly affected by high p.a. temperature and predominantly expressed in either tissue. Hierarchical clustering and gene ontology analysis resulted in the identification of a number of genes implicated in the regulation of cell wall expansion, predominantly expressed in the pericarp and significantly down-regulated under high p.a. temperatures, including endoglucanase, xyloglucan endotransglycosylases and a β-expansin. An over-representation of genes involved in the ‘cuticle development’ functional pathway that were expressed in the pericarp and affected by high p.a. temperatures was also observed.ConclusionsHigh p.a. temperature induced down-regulation of genes involved in regulating pericarp cell wall expansion. This concomitant down-regulation with a reduction in total grain moisture content and grain weight following the same treatment period, adds support to the theory that high p.a. temperatures may cause a reduction in mature grain weight as result of decreased pericarp cell wall expansion.

GWC1 is essential for high grain quality in rice

Appearance quality is an important determinant of rice quality. Many genes that affect grain appearance quality have been identified, but the regulatory mechanisms that contribute to this trait remain unclear. Here, two grains with chalkiness (gwc1) mutants, gwc1−1 and gwc1−2, were identified from an EMS-mutagenized population of indica rice cultivar Shuhui498 (R498). The gwc1 mutants had poor grain appearance quality consistent with the measured values for the percentage of grains with chalkiness, square of chalky endosperm, the total starch, amylose and sucrose contents. Milling quality and grain size were also affected in the gwc1 mutants. The gwc1−1 and gwc1−2 were found to be loss-of-function allelic mutants. GWC1 was mapped to the long arm of rice chromosome 8 using the MutMap strategy and incorrectly annotated in the reference genome for Nipponbare (MSU). The GWC1 gene corresponds to the WTG1/OsOTUB1 gene, which encodes an otubain-like protease with deubiquitinating activity that is homologous to human OTUB1. GWC1 transcripts accumulated to high levels in early endosperm after fertilization and developing inflorescences, and GWC1−green fluorescent protein (GFP) signal was detected in the nucleus and cytoplasm. GWC1 is likely to regulate grain appearance quality through genes involved in sucrose metabolism and starch biosynthesis. Overall, the present findings reveal that GWC1 is important for grain quality and yield due to its effects on grain chalkiness and size.

English

Azolla tissue contains 5% N, which is slowly released into the soil upon decomposition. Timing of incorporation is therefore important for maximum benefit to a crop. The effect of time to incorporate Azolla biomass on growth and yield of rice was investigated in Mwea-Kenya. Treatments consisted of 7.5 t ha-1 Azolla biomass applied at transplanting, 7.5 t ha-1 Azolla applied at 21 days after transplanting (DAT) and 30 kg N ha-1 inorganic N applied in splits at O, 21 and at 55 DAT. There were control treatments without Azolla and without inorganic N application. The treatments were laid out in a Randomized Complete Block Design (RCBD) with three replications. Phosphorus and potassium were applied at 50 Kg ha-1 each as P2O5 and K2O. Plant height and tiller numbers were recorded at 21 (rooting/tillering), 32 (tillering), 42 (maximum tillering), 60 (flowering) and 75 DAT (heading) while yield parameters were determined at physiological maturity (120 DAT).&nbsp; Data were analysed using SAS software and means separated using the least significant difference test (p&le;0.05). Azolla incorporation at transplanting significantly enhanced panicle m-2, grain weight and grain yield while incorporating it at 21 DAT only significantly enhanced panicle m-2. Higher environmental temperatures enhanced Azolla effect. The effect of Inorganic N significantly increased plant height, tiller number, grain weight and spikelets panicle-1. However, percentage grain filling was reduced. The effect of interaction between Azolla application and inorganic N was significant on spikelets panicle-1 and grain weight. Observations therefore indicate that the effect of Azolla on yield and yield components was more when incorporated at transplanting. Key words: Azolla, incorporation time, inorganic fertilizer, rice yields. &nbsp

Effect of iron deficiency on the growth, development and grain yield of some selected upland rice genotypes in the rainforest

Iron deficiency is a major production constraint of upland rice in the tropics despite is abundance in the soil. This investigation aimed to explicate the effect of iron deficiency on the growth, development, grain yield and its attributes of some selected upland rice in the rainforest. Field experiments were established at Africa Rice sub-Station, Ibadan, Nigeria. The treatments consisted of 35 upland rice genotypes and availability of iron in the soil (Fe-sufficient and Fe-deficient). The treatments were arranged in alpha lattice design with three replications. It was observed that upland rice sown in iron (Fe) deficient soils had significantly lower growth (plant height, number of tillers and seedling vigor), flowered later, with significantly lower yield attributes (1000 grain weight, filled grain) and grain yield than those sown in Fe-sufficient soils. Conversely, the number of unfilled grains were significantly higher in upland rice sown in Fe-deficient than those in sufficient soils. Percentage yield loss was in the range 98.00% to 22.95% for China best and Faro 65 respectively. Genotypes were identified to be tolerant (Faro 65, NERICA 3 and IRAT 109) and susceptible (Ofada 2, NERICA 5 and China Best) to Fe-deficiency based on their percentage grain yield loss. These evidences suggested that despite the increased phenology of upland rice sown in Fe-deficient soils their reproductive growth was suppressed through increased number of unfilled grains as witnessed in China Best and Faro 64.

Performance Assessment of a Self-propelled Paddy Grain Thresher under Different Threshing Functional Parameters

HighlightsThis research was aimed at assessing the performance of a self-propelled paddy grain thresher.Increasing cylinder speed increased the threshing percentage and percentage of broken grains of the machine.More broken grains were obtained at a lower concave clearance.The feed rate did not have much significance on the performance parameters that were evaluated. Abstract.This research was conducted to assess the performance of a self-propelled mini combine harvester, model number 4LZ-0.8 under different threshing functional parameters such as cylinder speed, concave clearance, and feed rate. An indoor experiment was conducted using the mini combine with an axial flow threshing cylinder and tangential feeding of material. These functional parameters were set at 5 levels each. The responses were obtained in terms of threshing percentage, percentage of unthreshed grains and percentage of broken grains. Response values were analyzed using the response surface tool (rstool) in MATLAB. Analysis of variance was done to determine the significant effects of the factor variations on the response values. MATLAB was used to present response surface graphs that were used to describe the variations of the responses as the factors changed from one level to the other. Results showed that with an increase in cylinder speed from 697 to 1202 rpm, the percentage of broken grains increased significantly from 0.0384% to 3.4052%, respectively. At cylinder speeds of 697 and 1202 rpm, the percentage of unthreshed grains increased from 0.1515% to 0.2162%, respectively. Furthermore, an increase in feed rate decreased the threshing percentage. The highest threshing percentage was obtained at an average concave clearance of 27 mm. Furthermore, it was realized that increasing the concave clearance from 18 to 35 mm, equally increased the percentage of unthreshed grains from 0.1478% to 0.3177%. The percentage of grain damage decreased from 3.2758% to 0.0268% with an increase in concave clearance from 18 to 35 mm, respectively. From the results obtained, it was tested and suggested that operating the threshing cylinder at a cylinder speed of 1100 rpm, concave clearance of 27 mm and feed rate of 0.9 kg s-1 offered the best machine performance. At these suggested values of the operating parameters, the threshing percentage was 99.9801%, the percentage of broken grains was 0.0134%, and the percentage of unthreshed grains was 0.0199%. Keywords: Assessment, Axial threshing unit, Cylinder speed, Concave clearance, Feed rate, Functional parameters, Threshing percentage.

Evaluation of different wheat germplasms against rice weevil Sitophilus oryzae (L.)

Thirty wheat germplasms were tested against Sitophilus oryzae (L.) and NW-6056, DPW-62150 and BRBW-3759 were found highly susceptible to S. oryzae on the basis of percentage of grain damage, percent weight loss and population build up. DBW-39 was found to be leaft susceptible one. The results revealed that percentage of grain damage, percentage of weight loss and population build up caused by Sitophilus oryzae was more in summer season as compared to the winter season. From the present studies it is evident that percentage of grain damaged and percentage of weight loss kept on increasing from first day of observation (i.e., 7 days after exposure of grain to Sitophilus oryzae). The percentage of grain damaged and percentage of weight loss due to Sitophilus oryzae was found to be the highest on the 56th day of experiment. The loss due to grain damage was found to be 29.17 and 17.36% and loss in weight was estimated at 25.07 and 15.54% during the summer and winter seasons, respectively.

Microbiological quality of grain cultivated in the North Caucasus region in 2019

The microbiological quality of 23 grain samples of wheat and barley harvested in the North Caucasus in 2019 was analysed on the basis of the percentage of grains infected by fungi and the amounts of trichothecene-producingFusariumDNA andAlternariaDNA. The mycotoxins produced by these fungi were also determined.AlternariaandFusariumfungi were the predominant fungi in the mycobiota of grain, accounting for at 93% and 14% of the observed fungi, respectively. Alternariol produced byAlternariafungi was detected in 65% of samples, and its content (11-675 ppb) was positively correlated with the abundance of fungi of sectionAlternariain grain.F. langsethiaewas found in wheat grain from the Chechen Republic for the first time. The T-2 toxin produced by this fungus was found in 25% of samples, and its content in one barley grain reached 650 ppb, which exceeded the permitted level for this mycotoxin. The mycotoxins deoxynivalenol and zearalenone, which are mainly produced byF. graminearum, were also identified in 13% of the grain samples. The positive correlation between the amounts of both these mycotoxins and the DNA of Tri-Fusariumwas established.

Evaluation of different herbicides on weed control, yield and yield components of soybean (Glycine max L.)

In order to investigate the effect of weed control with common herbicides on yield and components of soybean yield (Glycin max L.) in the second crop, two experiments were conducted as a randomized complete block design with three replications at the Agricultural and Natural Resources Research Center of Moghan during 2016-2017 and 2017-2018. The treatments consisted of Ethalfluralin, Imazethapyr, Trifluralin, Metribuzin, Bentazone and Alacolor herbicides with and without weed control. The results showed that the number of pods per plant, biological yield, grain yield and soybean protein percentage were statistically significant, but for chlorophyll index, 1000 seed weight and oil percent grain, the difference was not statistically significant. The highest number of pods per plant (333.92), biological yield (1221 g.plant-1) and grain yield (2792 kg.ha-1) were obtained from hand weeding. The results of the analysis of variance showed that the treatments had a significant difference in terms of the percentage of the effect of herbicide, density and total weed dry weight. The results showed that one month after spraying, the Trifluralin and Ethalfluralin herbicides had the highest effect on the weed control and two months after spraying, the rest of the treatments also showed their effect and all herbicide treatments were in one group. In this study, all weed control treatments significantly reduced the density and dry weight of weeds than without control, but their effect was less than hand weeding. The highest grain yield (1896 kg.ha-1) and the highest biological yield (784.9 kg.ha-1) were observed from Ethalfluralin herbicide

Interface layer deformation thickening analysis of hot rolling carbon steel–stainless steel clad plate

In this study, a stainless steel –carbon steel clad plate was rolled on a two-high mill. The microstructure and thickness of the bonding interface before and after the tensile test were observed through scanning electron microscopy. Results showed that the sample underwent plastic deformation via slipping in the static tension test, resulting in the rapid decrease in the Schmid factor (SF). However, the weighted average value of 1/SF increased from 2.1 to 2.2 after the tensile test. Consequently, the size of the grains with diameters between 12 and 120 μm decreased, whereas the percentage of grains with diameters of less than 5 μm sharply increased to 76.7%. The carbide layer in the bonding interface easily produced stress concentration and formed a fibrous region during the subsequent tensile test. The carbide particles in the bonding interface extended along the slip direction rather than the tensile direction, resulting in increased carbide thickness. The carbides hardly entered the SS but easily extended into the soft ferrite area of the CS surface. The deformation energy increased with a decreased in grain size, and the increase in the part size was the increment of the surface energy of the small grains.