JOURNAL OF AGRICULTURAL SCIENCE AND TECHNOLOGY (JAST)
Year:2019 | Volume:21 | Issue:3|Papers Count:22

Ant-aphid mutualism may increase or decrease plant yield. This depends on the relative cost of damage by ant-tended aphids versus the relative benefit of ant suppression of other (non-aphid) herbivores and associated yield losses. To evaluate the effect of mutualism between cotton aphid, Aphis gossypii, and brown ant, Lasius brunneus, on the productivity of cotton plant, a field experiment was conducted in the presence or absence of ants in the Cotton Research Center of Golestan province (Iran), in 2014. During the two-month test, the numbers of A. gossypii and visiting ants L. brunneus as well as Coccinella septempunctata and Helicoverpa armigera on each plant were counted in fourday intervals and, finally, the yield of cotton plants was measured. Ant presence significantly increased the abundance of cotton aphid, whereas the ant with suppression in presence of C. septempunctata and H. armigera significantly reduced their abundance. Regardless of the increase in the abundance of A. gossypii, cotton plant yields significantly increased in the presence of L. brunneus. This could be due to the effect of ant presence and the reduction of H. armigera abundance and the associated yield losses on cotton plant. In general, the results of the current study showed that indirect benefits of antaphid mutualism influence cotton plants by suppression of H. armigera damage. Since this pest causes serious damage on cotton plant, increasing attention to the role of ant predation is economically useful.

The genus Dolichogenidea was studied from the northern Iran during 2010– 2011. The specimens were collected using a set of Malaise traps. A new species Dolichogenidea fernandeztrianai Abdoli and Talebi sp. nov. is hereby described and illustrated. The new species can be distinguished by the following characters: fore wing vein R1 as long as or slightly longer than pterostigma and 4. 90× as long as distance of vein R1 to vein 3RSb; T1 more or less parallel-to subparallel sided, smooth, with a distinct protuberance on central area and its length 1. 70× posterior width; T2 smooth, transverse and rectangular; T3 longer than T2; ovipositor sheath with uniform width from base to apex and clearly longer than metatibia. An updated checklist for the Iranian species of this genus is provided in addition to their distribution data and references.

Control of environmental impacts which remain from agricultural activities is always a concern for communities. In Iran, wheat transportation takes place on roads that are dependent on fossil fuels and results in the release of a large amount of carbon dioxide. Accordingly, applying control policies for internalization of the external effects of releasing these pollutants seems necessary. One way to control this type of pollution is the use of tax instruments. Therefore, the aim of this study was to evaluate the economic effects of pollution tax on wheat market actors. This tax is proportional to the shadow value of pollution that happens due to energy consumption in the distribution sector. For this purpose, a Dynamic Spatial Equilibrium Model has been used to model the wheat market and Input Distance Function has been used to estimate carbon dioxide emission tax. The results showed that application of the tax payment policy would reduce wheat trade in the country by about 24 percent, while only 16. 2 percent of the wheat price was considered as tax. Therefore, carbon dioxide emission will be significantly reduced. On the other hand, due to increased transportation costs, economic surplus for customer declined and economic surplus for producers and government revenues increased. Hence, internalization of the external effects of carbon dioxide emission will increase the welfare of the society.

Uncertainty in staple food prices places the economy under jeopardy if not managed coherently and markets are not integrated. An attempt was made to analyze the wheat price behavior and extent of integration across selected wholesale and retail markets in India sourcing monthly data from FAO (July 2000-June 2016). Findings indicated that the price in wholesale and retail markets as well as its divergence was lowest in Patna, implying a major production and consumption zone, and highest in Chennai, indicating a negligible production. Monthly price indices exhibited a clear-cut seasonality linking with the arrivals of post-crop harvest. Extent of price integration was examined using Johansen’ s approach to know whether markets share a linear deterministic trend followed by testing the Law Of One Price (LOOP). The maximum likelihood test indicated a strong integration in different combinations of markets with some market pairs showing unidirectional-causality, while the rest exhibiting either bidirectionalcausality or no-causality. Barring Patna, Delhi, and Mumbai’ s retail and wholesale markets, the rest of the market combinations did not confirm the LOOP. The study advocates rational allocation of resources based on the extent of price integration and reducing the market distortion for improving the overall performance.

The performance of a pluralistic extension and advisory system is strongly influenced by the presence of multidisciplinary professional actors and their executive interactions for synergistic achievements in a balanced institutional framework. The specific purpose of this study was to explore the institutional boundary of Iranian pluralistic extension system and the extent to which the multiple providers interact with each other in implementation of related programs. A sequential mixed methods research was developed. Qualitative data were collected via semi-structured interviews, and were analyzed by theme analysis. Quantitative data were gathered using a researcher-made questionnaire and were analyzed by social network analysis. According to the qualitative findings, multiple service providers were classified into 21 distinctive institutional categories. Also, findings showed that the current executive network was not satisfactory in terms of institutional coherence, such that a few dominant providers were very influential in the center, while most of the others had little linkages and thus power at the margin of the extension network. Such a highly centralized network is unsustainable and vulnerable from different viewpoints and cannot fulfill the tasks expected from extension system in Iranian heterogeneous agriculture sector. In this regard, establishing a multisectoral institutional platform to focus on enhancing mutual coordination and combining collective actions is recommended as an important structural adjustment in the current extension system. To this end, facilitating roles of the public extension agency as the most influential actor of the existing extension network will be extremely significant.

The aim of this paper was to evaluate the impacts of International Corporate Entrepreneurship (ICE) on general performance in Halal Food Industry, with moderating part of global environmental hostility. Our data comprised of 250 firms working in Halal Food Industry in Iran and they were studied utilizing the structural equation modeling. According to the results, the firms exploit ICE activities by accomplishing higher general performance in addition to promoting export and financial performance. The results underscore the significance of ICE for organizational achievement, both in general and in foreign markets. Also, the results suggest that the perceived nature of its environmental condition, especially hostility, will affect the link between ICE and performance fundamentally. This study explored the relationship between ICE and firm performance along with the role of hostility at the international environment in this relationship. The findings of this study help bridge the gap in the literature by assessing the impact of ICE on an organization's general performance with the hostilities at the international scale playing a moderating role in this regard. This paper makes huge contribution to the current works by exploring the connection between ICE, firm performance, and global environmental hostility.

In the present research, the health belief model was used as a framework for understanding the factors affecting farmers’ intentions to engage in the on-farm food safety practices in Iran. The suggested model was empirically tested using the data collected from a survey of 230 lettuce producers of Alborz Province in northern Iran. The structural equation modeling technique was utilized to test the hypothesized relationships in the research model and confirmatory factor analysis was used to examine the validity and reliability of the measurement model. The results revealed that the perceived barrier was the most reliable predictor of the farmers’ intentions to engage in the on-farm food safety practices. Further, the variables including perceived benefit, self-efficacy, and cues to action were among the main predictors of the intention. Most notably, the threat perception variables, i. e. perceived susceptibility and severity, had no significant effects on the farmers’ intentions to engage in the on-farm food safety practices. Overall, the main components of the health belief model explained about 45. 6% of the variance of intention. The findings gave preliminary support for the health belief model as a powerful framework for scrutinizing the intention to engage in food safety behaviors, offering a reasonable explanation for the farmers’ engagement intention in on-farm food safety practices, and providing practical information that can be incorporated into the development of more effective on-farm food safety interventions in Iran.

This study was designed to investigate the effects of physical forms and hay contents of diets on gene expression of insulin-like growth factor (IGF) I and II in rumen epithelium of Holstein calves. Twelve male calves were assigned to 4 treatments: ground (GR), texturized (TX), pellet (PL), and ground+10% forage (GF). Calves were weaned on day 50 of age and then slaughtered on day 70 after birth. Rumen epithelial tissue samples were immediately collected for quantification of mRNA abundance. Results indicated that only IGF I expression was influenced by the dietary treatments. A significant (p<0. 05) correlation between IGF I expression and each of histological parameters denoted as length of rumen villi and diameter of keratinocyte layer was observed. No significant correlation between IGF II expression and rumen histological parameters was found (p>0. 05). Regarding the results, higher IGF I expression in PL and TX treatments despite the low growth rate might be due to the challenging condition of developing rumen in calves. In fact, the rumen tissue attempted to maintain rumen pH at least by induction of a higher IGF I expression.

Four hundred strains isolated from Tunisian sheep and goat raw milks were initially screened for their ability to survive the GastroIntestinal Tract (GIT). Forty-three among the four hundred bacteria were resistant to pepsin, pH 2, pancreatin and bile salts at 0. 3%, even after 5 hours of incubation. Identification using 16S rRNA gene sequencing was established and we obtained as a species Lactobacillus plantarum (29 isolates from sheep milk and 11 from goat milk) and Lactobacillus pentosus (2 isolates from sheep milk and 1 from goat milk). We showed the ability for auto-aggregation and/or hydrophobicity properties. Finally, both M63 and C78 strains showed an important level of adhesion to three intestinal epithelial cells Caco-2 TC7, HT29-MTX, and HT29-CL. 16E. Taken together, these properties allow the lactobacilli strains to be considered promising beneficial strains for developing functional foods for consumers.

Experiments were conducted to study the color change kinetics of green bell pepper during vacuum-assisted microwave (VAM) drying at three levels of microwave power (100, 200, and 300 W) and vacuum (200, 400, and 600 mmHg). The color change, measured by a tristimulus colorimeter, in VAM dried sample was found better with least browning at lower microwave power and higher vacuum level combinations. L*, Δ E* and H* were fitted well to zero-order kinetic model, while a*, b*, C* and BI* followed a firstorder kinetic model. All these color parameters were fitted to a quadratic equation as a function of microwave and vacuum level ratio. Both Δ E* and BI* increased with the increase in microwave power and decrease in vacuum level, whereas other color parameters decreased under the same condition of the process variables. The rate constant was assumed to have Arrhenius-type dependence on power density. The activation energy was calculated for color change kinetic parameters by using an exponential expression based on Arrhenius equation. The activation energy values were calculated and found within the range of 3. 20-13. 58 Wg‒ 1, except for b* (Ea = 26. 708 Wg‒ 1) and C* value (Ea = 20. 4105 Wg‒ 1). The b* and C* values obtained were relatively higher and thus were more sensitive measures of color change, which must be taken care of during postharvest drying of green bell pepper for getting a quality product.

Using immature embryos that undergo somatic embryogenesis, we studied the effects of different hormonal compounds and media on controlling secondary somatic embryogenesis (SSE) in Persian oak (Quercus brantii L. ). To this end, we focused on the immature embryos that were subjected to several treatments including chilling (at 4 ℃ ) period and SH, MS, 2, 4-D, IBA, BAP, and glutamine concentrations in 5 separate sequential experiments. The results showed that, by extending chilling period to 8-weeks, SSE induction was reduced (68. 75%). In different MS concentrations or MS containing PGRs, the lowest globular embryo (66%) and the secondary embryo induction (87. 5%) were observed in embryos treated with MS+IBA+BA. Adding 0. 75 mg L-1 glutamine to MS resulted in a decrease in the secondary somatic embryogenesis (56. 25%). Among MS and SH media, 1/2 SH almost entirely controlled this phenomenon (6. 25%). The highest maturation progression was obtained in the SH+glutamine treatment, which had the highest conversion to plantlet percentage (100%) and vigor index of plantlets (51. 93) compared to the use of SH alone. We found that nutrient and PGR concentration were critical in embryo maturation and conversion percentage and stop the embryo induction cycle that plays a major role in secondary embryogenesis.

Life table parameters of Lipaphis erysimi (Kaltenbach) (Hemiptera: Aphididae) were determined on four canola (Brassica napus L. ) cultivars (Nathalie, Neptune, Danube, and Okapi) at 25± 1 ˚ C, 60± 5% RH, and 16L: 8D hours photoperiods. Data were analyzed using the female age-specific life table. There were significant differences in duration of nymphal developmental time and fecundity of aphid on the experimental canola cultivars. The shortest (7. 13± 0. 07 day) and longest (8. 91± 0. 15 day) nymphal developmental time were on Nathalie and Okapi, respectively. The rm value of L. erysimi ranged between 0. 30 on Nathalie and 0. 21 day-1 on Okapi. The highest values of rm (0. 30± 0. 00 day-1), R0 (30. 62± 1. 35 offspring), finite rate of increase (1. 35± 0. 01 day-1), and the lowest mean generation time (11. 54± 0. 12 days) and DT (2. 34± 0. 03 days) were recorded on Nathalie. Shorter nymphal developmental time, longer adult longevity as well as greater intrinsic rate of increase, net reproductive rates, finite rate of increase, fecundity and survivorship revealed that this pest performed well on Nathalie, Neptune and Danube cultivars. Consequently, the results indicated that canola cultivars had significant effect on life table parameters of L. erysimi and the Nathalie, Neptune, and Danube cultivars were suitable hosts for population growth of the pest.

The study investigated the toxicity of Parthenium extracts in comparison with Neem extracts against 3rd and 4th instar larvae of the diamondback moth, Plutella xylostella L. . The side effect of Parthenium extracts was also examined against larval parasitoid, Cotesia plutellae. Extracts obtained from their respective plants were dissolved independently to get stock solutions, which were further diluted to different concentrations (1%, 2%, and 3%) with distilled water. The experiment was laid out in completely randomized design with four treatments, including the control, and replicated six times in vitro. Results showed that Parthenium crude extracts was very effective in comparison with the control against P. xylostella, whilst the highest mortality was recorded at 3% concentration of Neem in comparison with Parthenium extracts against both stages of P. xylostella. Overall, the highest mortality was recorded at 3% concentration of Neem extracts followed by 2% Neem extracts, 3% Parthenium extracts, 1% neem, 2% and 1% Parthenium extracts. The lowest mortality was noted in the control (i. e. 70%, 58. 33%, 51. 67%, 35%, 33. 33%, 18. 33% and 16. 67% in case of 3rd instar mortality whilst 61. 67%, 50%, 41. 67%, 30%, 16. 67% and 15% in case of 4th instar mortality, respectively). Less harmful effect was observed for larval parasitoid, C. plutellae. Finally, it was concluded that all the treatments had the ability to control P. xylostella to some extent, but Parthenium crude extract was less efficient in comparison with Neem extract, as 3% crude extract of Neem had a sufficiently toxic effect on the P. xylostella.

Onosma dichroantha Boiss. is a local medicinal herb in Iran, belonging to the Boraginaceae family that is used mainly for wound healing due to the presence of shikonin in its root cortex. Optimization of Onosma spp. in vitro cultures and shikonin production is encouraged as an alternative to harvesting the plant from its natural habitats. The present study evaluates the growth rate, several biochemical properties, and shikonin content of O. dichroantha plants treated with various concentrations of silicon (in the form of potassium silicate) in a hydroponic medium. Silicon application up to 0. 5 mM increased the fresh mass, chlorophyll a/b, carotenoids, soluble proteins in shoots, and the lignin content in roots; however, phenolic compound contents were not significantly affected. In addition, silicon nutrition increased catalase and soluble ascorbate peroxidase activities, whereas polyphenol oxidase activity was not affected in roots and shoots. Interestingly, the shikonin content of O. dichroantha roots treated with increased concentrations of Si was 2-fold higher than that in the control plants, while the activity of phenylalanine ammonia lyase, a key enzyme in shikonin biosynthesis, was not affected. This suggests that the observed increase in shikonin in response to the silicon treatment could be due to increased stability or more accumulation sites of shikonin in roots. These data may be used for improvement of shikonin production in cell cultures of O. dichroantha under experimental or industrial conditions.

This study was conducted in 2014-2015 to determine the effects of nitrogen (N) fertilization on yield, quality traits, and storage ability of two tomato cultivars, namely, ‘ Calista’ , for processing, and ‘ Volna’ , for fresh market. N was applied in doses of 0, 50, 100, and 200 kg N· ha-1. Significant interactions were found between the studied years, N fertilization, and cultivars. Both tested cultivars produced high and similar yields in the year with good growing conditions during vegetation period. In the year with unfavorable weather conditions (lower average temperature, more total rainfall, and a smaller sum of GDD), cv. ‘ Volna’ produced a significantly lower yield compared to the cv. ‘ Calista’ . N fertilization had a significant impact on yield, however, the reaction of cultivars varied in each years. In 2014, quadratic positive regression was found between N rates and yield of cv. ‘ Calista’ (R2=0. 90) and linear relation for cv. ‘ Volna’ (R2=0. 77). In 2015, however a linear positive regression was found for cv. Volna (R2=0. 71) and cv. Calista (R2= 0. 44). The chemical and physical parameters of tomato quality varied depending on the year of cultivation. On average for the studied years and cultivar, increasing N fertilization affected the lycopene and soluble polyphenols content, as well as total flavonoids and ascorbic acid content and antiradical activity. N rate did not affect dry matter and soluble solids content, fruit firmness, fruit redness, and acidity. Cultivar ‘ Calista’ had significantly higher lycopene content and better fruit firmness than cv. ‘ Volna’ for fresh market. Furthermore, the storage ability of tomatoes cv. ‘ Calista’ was significantly better than cv. ‘ Volna’ .

Phylogenetic analysis of Triticum L. and Aegilops L. species was performed using the nuclear ribosomal Internal Transcribed Spacer (ITS) sequences. The full length of PCR products for ITS1 and ITS2 ranged from 650 bp to 700 bp, respectively. Sequence divergences between species were estimated following aligning. The average G+C contents of the ITS regions was 60. 8% for ITS2 and 61. 5% for ITS1. The phylogenetic analyses were constructed using the Neighbor-Joining (NJ) method based on pairwise genetic distances. The resulting NJ tree successfully separated Triticum and Aegilops species and displayed three clusters, einkorn wheats, polyploid wheats, and Aegilops. Our results confirmed that the A genome of bread wheat is more related to T. urartu than T. boeticum. In the case of the D genome, the affinity between Ae. tauschii and bread wheat was greater than other D genome-bearing species of Aegilops (Ae. crassa and Ae. cylindrica). Obtained results also revealed that Ae. speltoides was separated from Aegilops cluster and grouped with polyploid wheats. The close relationship between Ae. speltoides and polyploid wheats indicates that the former is the most likely donor of the B genomes to wheats. The present study verified the potential of ITS regions in phylogenetic studies and strongly supported the evolution of cultivated wheats, which occurred through hybridization and polyploidization between Triticum and Aegilops species.

Fifteen endemic ecotypes of the fenugreek were evaluated under well-watered and water deficit stressed conditions in the lysimetric system. Results of analysis of variance revealed that there was significant genotypic diversity for all of the traits, except root branch number. Also, ecotype × water treatment interaction was significant for all traits, except days to ripening, canopy temperature, and grain weight. Based on structural equation modeling, predictors in the causal diagram could explain 59%, 29%, 65%, and 51% of the total variation of dependent traits consisting root length, stem diameter, shoot dry weight, and percent assimilate partitioned to grain, respectively. These dependent traits had high broad sense heritability and explained 100% variation of grain weight. Transpiration efficiency had a positive effect on grain weight through stem diameter, root length, shoot dry weight, and percent assimilate partitioned to grain. Results of membership function value of drought tolerance index and heat map clustering revealed that Jahrom ecotype was a highly drought susceptible ecotype, and Yazd and India were drought susceptible ecotypes. Also, Tiranchi and Shiraz were identified as drought tolerant ecotypes. Overall, under water stress conditions, the drought tolerant ecotypes had deeper roots than the other ones. Therefore, these ecotypes might be considered as donor parents in fenugreek breeding programs.

Planning for optimal distribution of Zayandehrud Dam water to six Irrigation Networks (INs) located downstream of this dam was carried out based on a hydro-economic model under water scarcity conditions. The hydro-economic structure was developed through coupling the hydrologic simulation model (MODSIM) and economic optimization modelling approach (Positive Mathematical Programming, PMP). Water distribution priorities to the INs are based on the economic value of water used by crops in the current cropping pattern under different scenarios of normal (base year, 2014-2015) and drought conditions. Results showed that, in addition to the change in the priorities of water distribution throughout the six INs, the existing cropping patterns should also change. The order of water delivery to the six INs starts from Rudasht IN and ends with the Traditional IN. Also, the highest reduction in the area under cultivation in the base year, compared to the optimum cultivation, is related to alfalfa (in Nekoabad and Mahyar-Jarghouyeh INs), clover (in Rudasht and Abshar INs) and forage corn (Borkhar and Traditional INs). Beans cultivated area increases by 14 and 21% for Abshar and Rudasht INs, respectively. Based on the results, the economic value per m3 of water will rise on the average, if water is allocated on the basis of its shadow prices. Moreover, under drought conditions, the highest and the lowest increase in the economic value of water will take place in the Nekoabad IN (4, 660 Rials m-3) and Rudasht IN (3, 890 Rials m-3), respectively.

Developing materials to improve the efficiency of fertilizers and increase their performance is one of the main areas of research in the agricultural science. To the best of our knowledge, this is the first time that Mg-modified zeolite is used for modification of composting process of urban organic solid waste. Natural zeolite was clinoptilolite with a particle size smaller than 250 μ m modified with MgCl2. 6H2O salt. Different ratios (i. e. 5, 10, and 15%, on a weight basis) of natural and/or Mg-modified zeolite were used to modify the Municipal Solid Waste (MSW) compost. Experimental results revealed that the pH of the final compost product with the Mg-modified zeolite was effectively buffered at 7. 7. Furthermore, in comparison to the control treatment (without zeolite), the compost with natural and Mg-modified zeolite showed 32. 13 and 41. 25% reduction in electrical conductivity, respectively. Ammonium retention of the compost containing 15% natural and Mg-modified zeolite was increased by 64. 51 and 110. 10%, respectively. Metals mobility test of the matured composts also revealed that adding zeolite, especially the Mgmodified zeolite, could decrease the mobility of Cu, Pb, Zn, Fe, Ni, and Mn metals. The most decrease in the mobility of metals was observed in Cu, which was about 44. 16 and 47. 82%, in the compost with the natural and Mg-modified zeolite, respectively.

Wild pepper (Capsicum frutescens L. ) could be a source of variation to improve cultivated pepper due to its unique traits with adapting challenges caused by adversity. Interspecific hybridization has been used as an effective way of pepper introgression breeding, which transfers genes of interest from wild relatives to cultivated crops. Here, eight fertile hybrids F1 were produced from pepper (Capsicum annuum L. ) and the wild relative (C. frutescens), as female and male, respectively, by interspecific hybridization. Interspecific hybrids were identified using conventional morphological descriptors and SSR molecular markers. The results showed that significant differences in agronomic traits existed among cultivated pepper, wild relatives, and interspecific hybrid F1. Interspecific hybrid F1 presented intermediate values, although they were closer to the wild species in most of the agronomic traits. Analysis of SSR markers clearly showed that interspecific hybrid F1 had bands from the paternal and maternal accessions, which indicated that F1 hybrid was heterozygous. Our results provide hybrid for breeder to transfer genes of interest from wild relative, C. frutescens, to cultivated pepper, which is an important step for introgression breeding.