JOURNAL OF AGRICULTURAL SCIENCE AND TECHNOLOGY (JAST)
Year:2013 | Volume:15 | Issue:1|Papers Count:16

Entomopathogenic fungi produce secondary metabolites which may bioactively help fungus in its virulence toward insect hosts. Beauveria bassiana produces several toxic low molecular compounds in vitro as well as in vivo, the most important of them is Beauvericin. The BEH isolate of the fungus was selected for Beauvericin assay. Beauvericin was obtained from surface and submerged cultures of the fungus in PDB and PDA, culture filtrates, and in vivo conidia harvested from insect cadavers. Results indicated that in vivo fungal conidia contained the most Beauvericin, causing a higher mortality toGalleria mellonella larvae as compared with in vitro fungal products in their different concentrations. Beauvericin chromatogram revealed that Beauvericin was in its greatest quantity in comparison with the other secondary metabolites of BEH isolate. The impact of Beauvericin on mean larval survival and on paralysis time was in agreement with bioassay data showing lower ST50 vs. higher PT50 in larvae treated with metabolites of the insect-derived conidia.

Agricultural sustainability refers to the ability of a farm to produce food indefinitely, without causing irreversible damage to ecosystem health. The main objective of this study was to formulate a structural model to analyze the effects of ecological, social, and economic factors on sustainable agricultural development in Qazvin Province of Iran. To achieve this aim, a structural model with 4 latent variables and 14 observed indicators was used. Required data were collected by questionnaire from 220 wheat cropping farmers who were selected through a stratified sampling design from four counties located in Qazvin Province. Linear structural relationships were used to calculate the impact of various factors on sustainability of agriculture. The computer software of LISREL was used to specify, fit, and evaluate structural equation model. The result of the analysis showed that ecological, social, and economic sustainability positively affected the agricultural sustainability, but, ecological sustainability had a greater impact on agricultural sustainability (0.642) than economic (0.604) and social (0.568) sustainability. The model gives right signals on what has been happening to agricultural development in Iran. The result of this study can also assist agricultural planners and policy-makers in identifying appropriate policies and in monitoring the effectiveness of policy interventions.

Common drying systems, including hot air convection, infrared, vacuum and IR-convective were employed to investigate and analyze the drying process of mulberry fruits. To evaluate the effect of pretreatment on the drying phenomenon, samples were pretreated by being subjected to: microwaves, chemical preparation, mechanical as well as blanching approaches. Results revealed that the microwave pretreatment, integrated with IR-convective dryer required the lowest time needed for drying mulberries. Furthermore, the experimental data were fitted to semi empirical as well as theoretical models to achieve the most suitable function governing mulberry drying process. Eventually, Page Model proved to perform best with regard to its high coefficient of determination, low value of c2 and root mean square of error.

In the course of this study, empirical models were developed for the pressure-density relationship in a large cubic baler for baling alfalfa and barley straw. Least squares regression analysis was employed to develop the empirical model and estimate the model coefficients by minimizing the summation of the squared differences between data resulting from the developed empirical model and the corresponding experimental data for a certain distance from the plunger. The effect of the flake size and load setting on the plunger pressure (pressure exerted on the bale via the plunger) as well as bale density were also determined for bailing alfalfa and barley straw. Results showed that the developed empirical model for either one of alfalfa or barley straw was a combination of a quadratic and an exponential equation which exhibited a good correlation with the experimental data (R2 of 0.89 for alfalfa and R2 of 0.94 for barley straw). Results also revealed that load setting significantly affected the plunger pressure and as well the bale density so that plunger pressure and bale density increased with increase in load setting (up to 70% for alfalfa and 100% for barley straw) in both of the forage materials. Flake size (position of the pre-compression sensitivity lever) had also a slight effect on the plunger pressure and on the bale density.

A selection program is being implemented to improve meat production in Makooei sheep. Increasing litter size per ewe is the main objective, but possible repercussions on weight traits of lambs should be considered. The aim of this study was to estimate heritability along with genetic and phenotypic correlations between ewe's reproductive vs. weight traits in Makooei ewes. Data were comprised of 5,364 records of body weight of lambs from 289 sires and 1,726 dams, plus 3,418 records of reproductive traits from 1,429 ewes collected from 1996 to 2009 from a Makooei flock at Makoo Station in West-Azerbaijan Province. The ewe reproductive traits investigated were Conception Rate (CR), Litter Size at Birth (LSB), Litter Size at Weaning (LSW), Litter Weight at Birth (LWB) and Litter Weight at Weaning (LWW). The lamb traits investigated were Weights at Birth (BW) and at Weaning (WW). Genetic parameters were estimated through REML procedure using ASReml program. The estimates of direct heritability for lamb body weights were 0.15±0.04 at birth and 0.16±0.03 at weaning. The estimates of heritability for reproductive traits varied from 0.05±0.02 for CR to 0.17±0.03 for LWB. Additive genetic correlations between BW and ewe's reproductive traits varied from small to moderate, ranging between –0.14 and 0.22. Additive genetic correlations between WW and ewe reproduction traits varied from moderate to high, positively ranging between 0.21 and 0.67. In conclusion, WW could be considered as a selection criterion in indirectly improving the ewe's reproductive traits in Makooei sheep.

This study was conducted to investigate the effect of Aflatoxin B1 (AFB1) on performance and egg quality in broiler breeders and the abatement of its deteriorative effect through its counteraction with Herbal Mycotoxin Binder (HMB). Thirty-six, 28-wk-old broiler breeder hens were allotted to one of the three treatments of: (1) basal diet (control), (2) control plus 500 mg kg-1 AFB1 and (3) control diet plus 500 mg kg-1 AFB1+0.2%HMB for three periods, each of a duration of three weeks and when from 28 to 36 weeks of age. Results revealed that 500 mg kg-1 AFB1 significantly (P<0.05) reduced feed consumption, feed efficiency, egg production as well as egg weight. Supplementation of HMB partially restored feed consumption and egg production alleviating some side effects of AFB1.

This study was conducted to evaluate seasonal concentrations of macro-minerals in serum or plasma of sheep under grazing conditions to establish mineral deficiencies and excesses over a two-seasonal grazing period (fall-winter and spring-summer corresponding to the rainy and dry seasons) according to variations of year, region and animal classes in Sabalan, Iran. In each flock, ten sheep (38-50 kg body weight, three females groups: yearlings, growing and mature, in addition to one male group) were selected for the study purpose. Approximately 10 ml blood samples were collected in two stages by jugular vein, which were then centrifuged, and plasma or serum were obtained. Plasma phosphorous (P) was determined by the colorimetric method. Serum Ca and Mg were measured by atomic absorption spectrophotometry. Overall, means of serum Ca, Mg and plasma P concentrations were 11.73, 3.24 and 4.92 mg dl-1 in dry season and 12.01, 3.17 and 5.3 mg dl-1 in rainy season, respectively. Year, season and region significantly affected (P<0.001) serum concentration of Ca but region had no effect (P>0.05) on Plasma P. Unlike season, year effect on Mg concentration was significant (P<0.05). These macro-mineral concentrations of serum and plasma were not different (P>0.05) between animal classes. Ca and P deficiencies were higher in rainy than the dry season (6.24 vs. 3.38 and 16.52vs. 15.2 percent, respectively). Although overall mean of serum Ca and P had higher values than the critical levels of these minerals in sheep blood, our results indicate that sheep in Sabalan need a common salt Ca and P supplement to enhance the blood level of these essential minerals in some sheep.

This study was performed to determine the effect of copper on growth performance, blood metabolites and claw health in young Holstein bulls in a humid area in north of Iran. One hundred and two young Holstein bulls (Initial body weight= 377.3±17.1 kg) were randomly allocated to two treatments in a completely randomized design for 56 days. The treatment groups received: (1) the basal diet of no supplemental Cu (control; n=50); (2) basal diet plus 30 mg of Cu kg-1 of Dry Matter (DM) as CuSO4 (n=52). Animals received fresh total mixed ration for ad libitum feeding allowing 10% refusals. The groups’ Dry Matter Intake (DMI) was assessed daily. The Body Weights (BW) were recorded and jugular blood samples collected on days 0, 28 and 56. All claws of young bulls were examined every two weeks for an identification of claw lesions. Copper supplementation improved Average Daily Gain (ADG) and gain: feed (G:F; P<0.05). Serum cholesterol decreased with Cu supplementation (P<0.001). Serum Zn, Cu, and urea N were not affected by supplementation of Cu; however, plasma total protein (P<0.001), and albumin (P<0.001) were increased by a supplementation of Cu. The prevalence of lameness was 19.6% and control group had the highest Odds ratio (OR=2.43). As a result, it is concluded that supplemental Cu might improve growth performance in the finishing bulls and decrease the prevalence of lameness.

The aim of the present study was to compare three reducing sugars (D-glucose, D-arabinose, D-mannose) with respect to the antioxidative activity characteristics of their Caramelisation Products (CPs) prepared by monitoring UV-absorbance, browning intensity, ferric ion reducing capacity, Fe2+ ion chelating activity as well as DPPH radical scavenging activity. Moreover, the effect of CPs from D-glucose on prevention of lipid oxidation and improvement of sensory characteristics were examined in Indian shrimp flesh (Penaeus indicus) during its frozen storage for a duration of 6 months. The reducing sugars were heated at 100oC at pH 10 for 100 minutes to generate CPs. Results revealed greater antioxidant activity of the hexoses, D-glucose and D-mannose, than that of the pentose sugar, D-arabinose, as evidenced by the higher UV-absorbance, browning development, reducing power, chelating as well as DPPH radical scavenging activity. Results of the chemical analysis including TBARs and FFA proved that the addition of CPs from glucose (G-CPs) could retard the formation of compounds produced over lipid oxidation in G-CPs-added shrimps (P<0.05). More desirability in sensory attributes of the shrimps treated with G-CPs was expressed than in the untreated samples during the 6 months of storage. These results reflect that G-CPs can be utilized as additives in seafood with appropriate antioxidative and techno-functional properties.

The adoption of food safety systems (FSSs) is of major significance in the food industry, and that approach is especially of more promience in dairy and meat processing firms. In this study the aim was to introduce the factors affecting the probability of adoption of FSSs in the dairy and the meat processing plants in Aydin, western Turkey. It was observed that ten out of twenty-eight dairy businesses had implemented one or more FSSs, and eight out of twenty-six meat processing firms had also implemented one or more of the FSSs. In total, thirty-six enterprises had not adopted any food safety system intended for safe food production, eighteen of which were involved in dairy and eighteen in meat processings. Binomial logistic regression model was employed throughout the study. The results indicated that plant characteristics and activities play a major role in determining the relative importance of various incentives in adopting food safety practices. The results also indicated that the larger business plants benefitted from a greater marginal probability of being adopters of FSSs as compared with the other business properties. The businesses that had employed ten to fourteen, fifteen to twenty, or more than twenty employees along with a food engineer and/or a veterinarian as a permanent employee were more likely to adopt FSSs than firms that were employers of fewer staff. Moreover the study indicated that care of hand disinfection had a positive and statistically significant relationship with the decision of any firm to adopt FSSs. On the other hand, the positive and significant impacts of such other factors as knowledge of risk resources, presence of wastes, sufficient air ventilation, and also firm specialties like fewer ordinary employees, as well as the type of business sector (dairy or meat firms) did not prove possible to be verified.

Due to the positive effects of fiber on human health, production and distribution of high fiber containing foods is on the increase. Amongst different foods, bread is a suitable option to convey fiber in human diets. Flat breads which are very common in Asian countries, are mainly produced from white flour and hence are low in fiber. The main objectives followed in this study were to produce high fiber Barbari bread (a popular flat bread) using wheat bran, while minimizing the adverse effects of inclusion of bran in the bread recipe. To achieve this, wheat bran of different levels (0-20%, w/w flour basis) and particle sizes (170, 280, 425 and 750 mm) were added to Barbari bread recipe. Using Brabender Farinograph, it was found that with increase in bran level and its particle size, the water absorption of the dough increased. Color determination results showed that the bread crust color became darker as the level of the bran and its particle size increased. The results of determination of the bread texture using Texture Profile Analyser, showed that the bread became harder and less cohesive with increase of the fiber in the dough and for each bran particle size. According to the panelists, barbari breads constituted the most appropriate breads with up to 15% bran with particle sizes of shorter than 280 mm. In total, it was concluded that by a control of the level and particle size of the bran, it is possible to increase the fiber content of the bread without any significant adverse effects on the quality.

Rheological properties of chocolate are important in manufacturing process for obtaining high-quality products with well-defined texture and are directly influenced by composition and their refining time. Soy protein benefits from nutritional and functional properties to be used in different foods. Effects of different replacement levels of skim milk powder by soy flour, (from 0 to 100%) and ball mill refining time (105 and 135 minutes) on particle size and rheological properties of compound chocolate were investigated. Considering four rheological models, it was found that compound chocolate behaved as a Casson fluid. Overall, the results indicated that Casson plastic viscosity values ranged between 1.36 and 5.47 (Pa s) and replacing skim milk powder with soy flour led to a significant (P<0.05) increase in Casson plastic viscosity in either of the refining time treatments. Casson plastic viscosity and apparent viscosity also increased for all the replacement levels with increase in refining time from 105 to 135 minutes. Values of Casson yield ranged from 11.23 to 38.88 (Pa). By replacing soy flour, Casson yield value increased significantly (P<0.05). Casson yield value also increased with increase in refining time in samples containing only skim milk powder, but it decreased in samples containing soy flour.

During 2004–2007 various own rooted vineyards were inspected to study the fungi associated with vine trunk diseases in Iran. Samples from declining vines showing yellowing and reduced growth and different symptoms in wood, including browning of the wood, necrosis, brown and black streaking and white rot were collected. Fungal isolations were made from affected tissues onto Malt Extract Agar (MEA) supplemented with 1 g l–1 streptomycin sulphate (MEAS). Based on morphological and molecular characteristics, the following species were identified: Phaeoacremonium (Pm.) aleophilum, Phaeomoniella (Pa.) chlamydospora and less frequently Pm. parasiticum, Pm. inflatipes, Pm. cinereum, Cylindrocarpon liriodendri, Diplodia seriata and Neofusicoccum parvum. Results of the pathogenicity tests under field conditions showed that Pa. chlamydospora and Phaeoacremonium spp. caused large wood discoloration 10 months after inoculation without any external foliar symptoms. Phaeomoniella chlamydospora caused larger lesions than Phaeoacremonium spp. All inoculated species were re-isolated from the margin of the lesions completing Koch’s postulates. This study represents the first comprehensive work that investigates the molecular and morphological identification and pathogenicity of Phaeoacremonium spp. and Pa. chlamydospora associated with vine decline in Iran. This is also the first report of Pm. inflatipes, N. parvum and D. seriata associated with grapevine decline in this country.

The diallel cross design is frequently utilized to obtain information on genetic effects, estimates of General and Specific Combining Ability (GCA and SCA) and to identify promising heterotic combinations as well as heterotic patterns. In the present study, heterotic crosses were identified for specific alkaloids in opium poppy (Papaver somniferum L.) following Yan’s GGE Biplot model by use of 5×5 full diallel data. The results obtained through biplot analysis were compared with those obtained through Griffing’s to check and confirm the accuracy of Yan’s GGE biplot model. Parents A (papline), B (NB5KR40-7/2-3), and E (58/1) were identified as good general combiners. The crosses B×C, B×E and E×B for morphine, C×D and C×E for narcotine, and A×B, A×C and A×E were identified as heterotic combinations. None of the crosses were found heterotic for codeine and thebaine.

Achillea millefolium belonging to the Astreaceae family is an endangered medicinal plant of Jordan and of its neighboring countries. As an alternative to seed propagation, an efficient micropropagation of A. millefolium and its subsequent rooting were developed as an option for its in vitro conservation. A maximum of 5.9 shoots per microshoot were obtained on Murashige and Skoog agar medium supplemented with 0.9 mg L-1 of 6-Benzyl Amino Purine (BAP). The effect of different types and concentrations of auxins were tested, i.e. IBA (Indole-3-Butyric-Acid), IAA (Indole-3-Acetic-Acid) or Naphthalene Acetic Acid (NAA). Maximum root number (20.8 roots ex-plant-1) was obtained from media containing 1.2 mg L-1 of IBA. A survival of 70% was obtained when rooted explants were acclimatized in vivo in equal portions of perlite and peat soil. In vitro, A. millefolium shoots were successfully stored for up to 32 weeks on MS medium supplemented with different concentrations of either sucrose, glucose or fructose, at 24±2oC. After 32 weeks past, 88.6% of the shoots survived on the medium supplemented with 3% sucrose. Moreover, 85.3% of the shoots were able to re-grow when stored under light conditions. Cryopreservation through vitrification was successfully achieved (80% re-growth) when shoot tips precultured on a medium supplemented with 0.4M sorbitol and 0.1M sucrose for 1 day, followed by loading shoot tips with concentrated plant vitrification solution 2 (PVS2) for 20 minutes, then being dehydrated with PVS2 for 60 minutes at 0°C prior to storage in Liquid Nitrogen (LN).

While the hydrological balance of forest ecosystems has often been studied, quantitative studies on the seasonal variability of rainfall Interception (I) and Canopy Storage Capacity (S) by individual trees are less frequently reported. Hence, the effects of the seasonal variation in I and S by individual Persian oak trees (Quercus brantii var. Persica) in the Zagros forests of Iran were studied over a 1-year period. Annually, I accounted for 84.9 mm (20%) of Gross Rainfall (GR) that significantly differed between the in leaf (47.4 mm or 30% of GR) vs. leafless (37.7 mm or 14% of GR) periods. Negative logarithmic correlations existed between I: GR and GR both for in leaf (r2= 0.808) and leafless (r2=0.709) periods. An indirect method, outlined by Pereira et al. (2009), estimated S to be 1.56 mm in the in Leaf Period (LP) and decreased considerably to 0.56 mm in the Leafless Period (LLP). The results indicate that while I decreased during the LLP, it still exerts considerable influence on the hydrology of forests. Hence, measurement of I in both the LP and LLP is essential when assessing the water balance on the catchment scale.