JOURNAL OF AGRICULTURAL SCIENCE AND TECHNOLOGY (JAST)
Year:2014 | Volume:16 | Issue:3|Papers Count:18

Efficiency in agricultural production is indicative of the efficiency level of farm households in their farming activities. Farmers in developing countries do not make use of all the potential technological resources, thus making inefficient decisions in their agricultural activities. Herein, technical efficiency in relation with the production of three types of rice crop (Boro, Aus and Aman) was evaluated, with some determinants of technical efficiency identified, in Bangladesh. It was attempted, throughout this study, to access the status of technical efficiency in rice production in Bangladesh for panel data while using the Stochastic Frontier Production Model with either of truncated normal or half-normal distributional assumptions. Both time-variant and time-invariant inefficiency effects models were estimated, one at a time. Collected data from agricultural sector pertaining to three main rice crops in Bangladesh for the period of 1980 to 2008 were made used of throughout the study. The results revealed that technical efficiency gradually increased over the reference period with the half normal distribution being found preferable to the truncated normal distribution as regards the technical inefficiency effects. The value of technical efficiency was found high for Boro rice while low for Aus in comparison with Aman rice in Bangladesh for both distributions in either of time-variant or invariant ones. It was observed that the most efficient rice production system has occurred for the case of Boro with a technical efficiency of 0.98. Year wise mean technical efficiency increased during the reference time periods.

Telenomus beneficiens is a common egg parasitoid of sugarcane top borer Scirpophaga excerptalis; however, in winter time the incidence of the parasitoid on top borer eggs is extremely low. T. beneficiens adults were released at various time durations into sugarcane plots to evaluate the parasitic potentiality of the parasitoid against sugarcane top-borer. The egg parasitoid T. beneficiens of sugarcane top borer Scirpophaga excerptalis (Walker), was released into four sugarcane plots as once, twice, thrice and quadruple time treatments to compare its parasitic potential as a biological control agent. The four releases of the adult parasitoid were made within a time interval of one month and at a rate of 500 adults per plot. Results revealed a significant control of the pest through all the four treatments. The highest mean parasitism of 42.36±10.84% and lowest mean infestation of 12.05±0.99% was recorded for the treatment of quadruple releases, followed by the triple release plot, where 41.38±10.07% of mean parasitism and 12.61±0.78% of mean infestations were observed. As for the double release plot, 26.56±3.72 and 14.46±1.92% mean parasitism and infestation were recorded respectively, whilst in the single release plot, the corresponding figures equaled to 21.94±2.98 and 16.82±2.38% as compared with the check plots (15.71±3.03 and 16.82±2.55 %). It is evidenced that triple release results almost coincide with the quadruple release ones, and hence the triple release of the adult parasitoid is effective enough and recommended for the control of sugarcane top borer, S. excerptalis.

Common Vetch (Vicia sativa L.) an annual forage, belonging to the Fabaceae family is one of the highly cultivated forage legumes in Iran. Drought stress is a serious adverse factor that limits plant growth and productivity, inducing a range of physiological as well as biochemical responses in plants. It may also lead to generation of oxygen activated species which in turn result in cell destruction. In this study, physiological and biochemical responses of six common vetch genotypes to two levels of drought stress (30 and 10% left of FC) were investigated at their early growth stages. Results indicate that drought stress significantly affects the Relative Water Content (RWC), Electro Leakage (EL), photosynthetic pigments, and total carotenoids. The obtained results indicated drought induced changes in the activities of such antioxidant enzymes as Catalase, Glutathione Peroxidase and Ascorbate Peroxidase. There was also found a reverse relationship between Catalase and Ascorbate Peroxidase activities in the studied genotypes. Obtained results clearly show that there are highly genotype-dependent responses to drought stress at biochemical level in common vetch genotypes, with each genotype responding to stress in a genotype-specific manner. These results may be helpful in breeding programs related to drought stress resistance.

A field experiment involving red clover varieties K-39, K-17, Una and Viola was established on an acidic (pHH2O 4.8) soil to evaluate the effects of foliar application of cobalt (a beneficial nutrient for efficient nitrogen fixation) on seed yield, and on seed yield components. The foliar spray of the crop was carried out using cobalt nitrate [Co (NO3) 2] with the treatments: one application at the intensive growth phase during the first growth, while two others during the second growth within the second year of cultivation. Seed yield and yield components were recorded from the second growth within the second year of the study. Regardless of foliar cobalt application, the varieties produced a significantly higher seed yield in 2011, when the rainfall received from the onset of flowering until seed maturation was recorded as lower than that in 2010. The foliar treatment with cobalt was in general accompanied by a positive effect on seed yield and seed yield components in all the varieties. As compared with control, a significant increase in seed yield, in the cobalt applied treatment, was obtained only in Viola, mostly due to the significant increase in flower number i.e. seed number per inflorescence. The more favorable response of Viola to foliar cobalt application may have been attributed to a greater percentage of foliage cover during the treatment, as compared with the other varieties. This suggests that foliar cobalt treatment in future studies should be performed at the early stages of development i.e. during intensive growth throughout the first and second cuts, in order to stimulate nodulation and have greater nitrogen fixation in a needed timely manner.

Samples of grass pea seed (Lathyrus sativus) were prepared and analyzed for some chemical composition and as well for their anti-nutritional factors. The rumen degradability coefficients and post ruminal digestibility of dry matter and crude protein of unheatedvs. oven heated samples were determined, employing in situ and in vitro techniques. Results indicated that grass pea seed contained a considerable level of crude protein (36%). The process of heating reduced (P<0.05) tannins and Oxalyl DiAminoPropanoic acid (ODAP) content in grass pea seeds. Heat processing, especially 3 hours of heating, increased (P<0.05) the slowly degradable fractions of the seed. Ruminal disappearance of DM and CP occurred at a lower rate (P<0.05) for the heated grass pea seed than for the unheated seed. Heat processing did not affect the production of some such nutritional parameters (estimated through gas production method) as DOM, ME, NEL, SCFA and MP production (P>0.05). It was concluded that grass pea seed was of a substantial potential as a protein source in ruminant nutrition with its heat processing resulting in positive effects on its DM and CP digestibility.

The nutritive value of grass pea (Lathyrus sativus L.) hay was evaluated based on its chemical composition, Gas production, fractioning of protein in CNCPS and AFRC systems, Metabolizable Energy (ME), rumen degradability through in situ technique and in vitro digestibility through Tilley and Terry method. The Crude Protein (CP), Neutral Detergent Fiber (NDF) and Acid Detergent Fiber (ADF) values of grass pea hay amounted to 232.4, 397 and 300.6 (g kg-1 DM) respectively. Condensed Tannins (CTs) and b-N-Oxalyl –L-a, b-diAmino Propionic acid (ODAP) amounted 0.2 and 11.8 (g kg-1 DM) respectively. Grass pea estimated ME ranged from 6.86 (MJ kg-1 DM) to 12.03 (MJ kg-1 DM) by different methods. Metabolizable Protein (MP) content was found 534.7 g kg-1 of CP. A high level of CP and MP content followed by a high content of ME along with a high palatability, cause grass pea to be introduced as an alternative to sheep forage in drought conditions.

The Melanocortin-1 Receptor MC1R is encoded by the extension locus, playing a fundamental role in the determination of coat color in a number of mammalian species. However, so far there has been no report regarding the Single Nucleotide Polymorphisms (SNPs) of the MC1R promoter region and the potential association of its SNPs with coat color in sheep (Ovis aries). Throughout the present study, the promoter region of the MC1Rgene was screened using Single Strand Conformation Polymorphism SSCP and DNA sequencing in the Karakul breed of sheep. A total of 4 distinct SSCP patterns were observed which revealed 3 novel SNPs and an insertion/deletion of 26 nucleotides upon sequence analysis in the analyzed population. In silico analysis of the MC1R promoter sequence predicted no consensus TATA-box motif at an appropriate position but detected multiple putative transcription factor binding sites for Ets, AML-1a, NF-E2, MZF1, USF, Oct-1 and GATA-1. The analysis of identified polymorphic sites also showed that the polymorphism at nucleotide position -89 relative to the start codon abolishes the USF transcription factor binding site. The SNP identified at the -100 position is located within a putative AML-1atranscription factor binding site. The insertion of 26 nucleotides at position -126 made a putative binding site for the MOK2 transcription factor. The possible functional activity of the identified genetic variations could be confirmed using gene expression analysis.

It is highly desirable to employ biopreservatives of the antioxidant and antimicrobial properties to avoid the side effects associated with the use of synthetic preservatives. Cake batters containing essential oil extracts of some such Iranian native herbs as: Lemon balm (Melissa officinalis), Camel thorn (Alhagi maurorum) and Ajwain (Trachyspermum copticum), were prepared. The chemical compositions of the essential oil were determined through GC–MS experiments. The shelf lives of the cakes were estimated by TBA (ThioBarbituric Acid) along with mould count measurements at room temperature during a 6 week storage period. The results revealed that these essential oils were fully effective in retarding mould growth and fat rancidity in the cakes. It was therefore concluded that these essential oils are of the potential to be used in the food industry as promising biopreservatives.

Promotion of the dietary fiber of foods can enhance human health by reducing the risk of many serious diseases. Cakes are among the highly consumed foods but sadly of low fiber content. Therefore, increasing the fiber content in them is of great importance, and this was the aim followed in this study. Wheat flour was partially replaced at 0, 10, 20 and 30% (w/w) with corn Resistant Starch (RS), as a source of dietary fiber, and used in the production of sponge cake. Obtained results indicated that batter consistency increased while its density reduced with an increase in the level of RS. Increasing the level of RS caused an increase in cake density but a decrease in volume. Cakes became softer but their cohesiveness, springiness and chewiness reduced. They also became whiter, less reddish and less yellowish. Addition of less than 30% RS had no significant effect on the sensory attributes of the cakes. In total, it was concluded that a maximum level of RS in the sponge cake recipe to produce an acceptable product amounted to 20%.

System evaluations were performed on 48 center pivots in different parts of Saudi Arabia. These systems, located on different farms in four different regions of the country, namely: Riyadh, Jouf, Qassim and Eastern regions, were evaluated to study the effect of lateral configuration on water application uniformity as regards the originalvs. modified laterals. Lateral configuration modifications have been made by the local farmers through a chang of the position of the lateral and spray nozzles from the original design. Depths of water distribution along the lateral, Coefficient of uniformity (Cu) and Distribution uniformity of the low quarter (Du) were determined and compared for the original and modified laterals under field conditions. The average values of Cu for original systems ranged between 71.81 and 89.46% with an overall average of 82.69%, whereas the average values of Cu for modified systems ranging between 61.35 and 84.33% with an overall average of 78.05%. Also, the values of Du ranged between 54.14 and 81.81% with an overall average of 73.24% for the original systems, while these values for the modified systems ranging between 31.45 and 77.07% with an overall average of 66.87%. The results finally indicated that the values of uniformity for originalvs. modified laterals were significantly different indicating that there existed a noticble adverse effect of center pivot lateral configuration on the uniformity of water application.

High efficiency and uniformity of water and fertilizer application are usually, considered as the ultimate goals of an appropriate design and management of irrigation and fertigation systems. The objective followed in this paper was to present a simulation optimization model for alternatevs. conventional furrow fertigation. Two simulation models (surface fertigation and SWMS-2D models) along with an optimization approach (genetic algorithm) were employed. Inflow discharge, irrigation cutoff and start times as well as duration of fertilizer injection were chosen as decision variables to be optimized for maximizing two objective (fitness) functions based on water and nitrate application efficiency plus uniformity. Experiments were conducted to collect field data (soil water content, soil nitrate concentration, discharge and nitrate concentration in runoff, as well as advance and recession times) in order to calibrate the simulation models. The simulation-optimization model indicated that variable and fixed alternate furrow fertigations benefited from higher water and nitrate efficiencies than the conventional furrow fertigation. However, minor differences were observed between these types of furrow irrigation regarding water and nitrate uniformity. This approach substantially improved water and nitrate application efficiency as well as uniformity, taking into account the field experimental conditions. Water and nitrate application efficiencies ranged from 72 to 88% and from 70 to 89%, respectively. Christiansen uniformity coefficients for water and nitrate varied between 80 and 90% and from 86 to 96%, respectively. A higher improvement was observed in conventional furrow fertigation than those in both alternate furrow fertigation treatments. The potential of the simulation optimization model to improve design and management of furrow fertigation is highlighted.

Twenty promising barley lines were evaluated at seven research stations in Iran, during two cropping seasons. The analysis of variance on grain yield data showed mean squares of environments, genotypes and Genotype×Environment Interaction (GEI) as significant, respectively accounting accounted for 60.38, 4.52 and 35.09% of treatment combination sum of squares. To find out the effects of GEI on grain yield, the data were subjected to Additive Main effects and Multiplicative Interaction (AMMI) and Sites Regression (SREG) GGE biplot analysis. Mega-environmental investigation is the most suitable way to utilize GEI. "Which-won-where" pattern was followed with three distinct mega-environments found in the barley assessment. Entries G5 and G6 showed general adaptability while G7 and G13 exhibited specific adaptation to Neishabour and Esfehan, respectively. Considering both techniques, genotype G1 revealed high grain yield along with yield stability. With regard to barley assessment, Esfehan was identified as a location with larger main effects interaction, making it a less predictable location for barley variety evaluation. The results finally indicated that AMMI and GGE biplot are informative methods to explore stability and adaptation pattern of genotypes in practical plant breeding and in subsequent variety recommendations. In addition, finding mega-environments help to identify the must suitable barley cultivars that can be recommended for areas within the mega-environment in either one or more test locations.

Throughout the present study, some Bacillus spp. were isolated from soil, and the effectiveness of the medicinal plant Cuminum cyminum L.'s essential oil extracts were tested against the isolated bacteria. The Bacillus spp. were identified through 16S rDNA sequence analysis and the antibacterial activity of various organic solvent extracts as well as the essential oils of C. cyminum L. determined in vitro using agar diffusion method and Minimal Inhibitory Concentration (MIC) tests. The hydrodistilled essential oil was analyzed through GC-MS. Twenty-seven compounds representing 92.61% of the total oil were identified. Oxygenated monoterpenes and scsquiterpene hydrocarbons constituted the major components of the oil. The inhibition zones of essential oil (extracted through organic solvent) against the tested bacteria were found within the range of 14.4 to 20.2 mm. Organic extracts of C. cyminum L. also revealed a great potential of antibacterial activity against Bacillus spp. Among all the extracts, ethanol extract showed the highest activity against Bacillus megaterium with an inhibition zone of 22.9 mm and MIC value of 500 mg ml-1. In most cases, the essential oil and organic extracts exhibited either similar or higher antibacterial activity in comparison with the standard drug Erythromycin. The results finally suggest that the essential oil as well as organic extracts of C. cyminum L. can act as sources of natural antimicrobial agents with potential applications in food and pharmaceutical industries.

Relative resistance of 43 Iranian as well as introduced apple cultivars to blue mold (Penicillium expansum) was studied within years 2010-2011. The fruit physicochemical traits were also evaluated as measures of potential resistance to decay. Local P. expansum strains were isolated from decayed apple fruits and the most aggressive isolate (5, 000 spores ml-1) used as inoculum. Fruits were wound-inoculated, and after four months stored in cold storage, decay lesion diameter was recorded. Force to break epidermis, cortex firmness, Total Soluble Solids (TSS) and Titratable Acidity (TA) were determined and their correlation with decay severity detected. Based on the obtained, results significant differences were observed in decay diameters in cultivars and for both years of the study priod. Mashhad was rated as the most susceptible cultivar while Granny Smith as the most resistant one. Relatively, 11.3% of cultivars were rated as susceptible, 54.5% as moderately susceptible, 31.8% as moderately resistant, and finally 2.2% resistant. The cultivars were significantly different in all the physicochemical traits studied. Correlation studies indicated weak negative correlations between decay diameter and TSS, TA, cortex firmness as well as epidermal toughness. Cortex firmness was directly correlated with epidermal toughness and is probable to influence blue mold severity.

A begomovirus, tentatively named Tobacco leaf curl Japan virus -JpU (TbLCJV-JpU), was isolated from Lonicera japonica (Honeysuckle) Plants Grown in Utsunomiya showing veinal chlorosis symptoms. The TbLCJV-JpU genome with 2, 761 nt showed a highest identity with TbLCJV-Jp3 and was also close to TbLCJV and as well to TbLCJV-Jp2. The overall nt identity with TbLCJV-Jp3 amounted to 92.94%, while the identities in encoded amino acid (aa) sequence of Coat Protein (CP) and putative products of AC1 and AV2 ORFs were as high as 98.05, 92.54 and 93.96%, respectively. Low sequence identities were observed in the Intergenic Region (IR) of TbLCJV-JpU as compared with TbLCJV, Ageratum yellow vein Taiwan virus-Kochi isolate and Honeysuckle yellow vein virus -Kagoshima isolates. Recombinations were detected in the 5´end (2650 to 2761) and extreme 3´ portion of the genome (220 to 350). Both regions demonstrated high identities with AYVTV-Kochi and HSYVV-Kagoshima. To the best of our knowledge this is the first report of isolation of TbLCJV fromL. japonica.

Hop stunt viroid (HSVd) isolates have been reported as the causal agent of citrus cachexia in Mazandaran Province and recently shown to be associated with yellow corky vein disease of sweet orange and split bark disorder of sweet lime in the Fars Province, Iran. In the present work isolation and partial characterization of viroids from citrus trees affected by gummy stem blight is reported from Kohgiluyeh–Boyerahmad (KB) Province of Iran. Fifteen samples of citrus trees from Dehdasht area (KB Province) showing bark necrosis, gum exudation and die-back as well as seven citrus symptompless trees from the same area were tested for the prevalence of viroids, through Reverse Transcription Polymerase Chain Reaction (RT-PCR) followed by sequencing of PCR products. They were also tested for Citrus tristeza virus through Double-Antibody Sandwich Enzyme Linked Immunosorbent Assay (DAS-ELISA). Two variants of HSVd which differed from GenBank isolates in nucleotide sequence and two variants of Citrus Bent Leaf Viroid (CBLVd) were identified in any of the symptomatic samples. Moreover, a Citrus Exocortis Viroid (CEVd) was found only in symptomatic sweet lime. An HSVd isolate from KB (HSVd-bn1) was selected and used for comparison with a number of HSVd variants from Iran (Fars and Mazandaran Provinces) and the related accessions from GenBank. On the basis of nucleotide sequence and secondary structure analysis, HSVd-bn1 and HSVd-bn2 belong to non-cachexia variants of HSVd and have about 95% similarity to Citrus gummy bark viroid, a sub-species of HSVd. CTV was not detected in the diseased plants. It is yet to be determined whether bark necrosis of sweet lime and of sweet orange plants is caused solely by the associated viroid (s) or other factors are involved as well.

In agroforestry landscapes, land use, and the associated management practices exert strong impacts upon soil organic carbon stocks. Data on the soil organic carbon were collected for different land-use types within a small watershed, El Salado, located in Lanjaron (SE Spain). Eight land-use types namely: farmland planted in olive, almond, and cereals; forest with Pinus halepensis Mill. and Pinus sylvestris L. stands; shrubland; grassland; as well as abandoned farmland were taken into consideration. Of the land-use types investigated, forest, shrubland, as well as grassland exhibited the highest average soil organic C stocks (100-63 Mg ha-1) in contrast with the abandoned farmland (28 Mg ha-1), with farmland representing a go-between situation (51-49 Mg ha-1). The environmental factors precipitation, temperature, and elevation significantly influenced (P<0.01) the soil organic C stock, with the contents tending to be higher in mountain soils with respective intermediate values of 600-800 mm, 10-15oC, and 1, 000-1, 500 m asl. Thus, the present approach offers a comparison of C-sequestration patterns as related to the land-use types in a Mediterranean agroforestry landscape, where the main challenge is to integrate the forest trees and the crops within their harmonious interacting combinations.

Microbial calcium carbonate, by bridging sand particles, can play an important role in sand dune stability. A study was carried out on the cementation of sand grains and infilling of pore spaces by CaCO3. Two bacterial species (Sporosarcina pasteurii and Sporosarcina ureae), three reactant concentrations (0.5, 1 and 1.5M), and six reaction times (12, 24, 48, 96, 192 and 288 hours) were tested in factorial experiment. Bacterial inocula and reactant solutions were added daily to sandy soil columns (6.5 cm height and inner diameter of 7.7 cm), while precipitation of CaCO3 being investigated within 0-1.5, 1.5-3, 3-4.5 and 4.5-6 cm intervals. Chemical and micromorphological analyses revealed that CaCO3 formation, inorganic C sequestration, and depth of cementation were more profound for S. pasteurii as compared with S. ureae. Both microbial CaCO3 precipitation and inorganic C sequestration increased with increase in reaction time from 12 to 288 hours. Increase in reactant concentration also caused an increase in CaCO3 precipitation (by 12%). Micromorphological observations showed a high degree of calcite crystals’ bridging, coating on sand particles and as well infilling of pore spaces. S. pasteurii is thus recommended for being used in stabilization of sand dunes; due to its significant effects on CaCO3 deposition and as well on sand grain cementation.