Journal of Agricultural Science and Technology
Volume:23 Issue: 6, Nov 2021

Adoption of agricultural technology is important for improving rice yield and household income in developing countries. Using fixed effects, random effects, and Instrumental Variable/Two-Stage Least-Squares (IV/2SLS) methods, this study examined the economic impacts of agricultural technology adoption by focusing on the case of hybrid rice varieties in rural Vietnam. The empirical results revealed that hybrid varieties adoption significantly increased productivity but induced higher intermediate costs. Meanwhile, there was no significant impact of adoption on value added. In addition, poor adopters had higher productivity and incur more intermediate costs than non-poor adopters. The findings suggest that the Vietnamese government should enact relevant policies to enhance the farmers’ access to better inputs and the effectiveness of rice farming activities.

Energy and agriculture sectors play a key role in Iranchr('39')s economy as the former provides considerable share of the public budget and the latter contributes significantly to employment, non-oil exports, and food self-sufficiency. Iranian government is following an energy subsidy targeting policy to increase energy (especially exhaustible ones) efficiency. Obviously, this will influence, among others, energy price and consumption, cost of production and, finally, food price. Therefore, the current study focused on the nexus between energy consumption and food price in Iranian agriculture. Since such relationships may differ as food consumption varies, the quantile regression model was applied and estimated using data for the period 1966-2017. Main findings revealed the direct and significant impact of energy consumption and globalization index on food price in the 0.75th quantile, while exchange rate showed the same effect in 0.25th and 0.75th quantiles. Furthermore, money supply was explored as another driver for food price in all quantiles.

The main purpose of this study was to identify strategies for adapting agricultural cooperatives to learning organization. Agricultural cooperatives are business organizations that fully examine all the economic, democratic and social dimensions of poverty reduction in rural areas simultaneously. This research is an exploratory research that was conducted in two parts: qualitative and quantitative. In the qualitative section, by holding several meetings with experts and through the method of brainstorming, the opportunities, threats, strengths and weaknesses for the adapting of the agricultural cooperative organization to learning organization were identified. Then, using the SWOT model, strategies and action plan were identified for adapting the cooperative organization to the learning organization. Also, in the quantitative part of the research that was conducted among the members of the cooperatives, through Structural Equation Modeling (SEM), the role of the identified strategies was evaluated and the designed model was approved. Based on the results, the predictive positive effect of identified strategies include: SO1 (β= 0.73, t-Value= 4.23, P< 0.001), SO2 (β= 0.79, t-Value=4.71, P< 0.001), SO3 (β= 0.81, t-Value=5.08, P< 0.001) and SO4 (β= 0.82, t-Value= 4.97, P< 0.001) on Adapting Cooperatives to the Learning Organization (ACLO). The findings showed that (R2= 0.69) the identified strategies determined 69% of the variance in the ACLO.

Lean production system is a new management approach and a business strategy that results in the elimination of waste (costs and time) and improvement of the performance and overall value of an organization. The main objective of this study was to investigate factors influencing implementation of Lean Production Principle (LPP) and its relation with the performance of Small and Medium-sized Food Industry Enterprises (SMFIEs) in Khuzestan Province. This study was a kind of descriptive-correlation and causal-relation that was conducted through a survey technique. Statistical population of the study consisted of all managers in Small and Medium Enterprises (SMEs) in Khuzestan food industry (N= 307). By using Krejcie and Morgan’s tables and stratified random sampling method, 170 person were selected as sample, of which 161 person completed the research questionnaires (return rate 94.7%). The results show that among the eight factors that influence the implementation of LPP, three variables of “customer relationship management”, "human resource management”, and “employees’ empowerment” have the most direct effects on LPP and, ultimately, the highest total effect on SMFIEs performance. The implementation of LPP could explain about 31 percent of variances in SMFIEs performance. Conducting justification and education workshops not only enhances the knowledge of SMFIEs managers, but also helps implement the LPP and, subsequently, improves the performance of SMFIEs.

An effective inter-row cultivator must destroy the weeds in the inter-row close to crop area without damaging the plants on the rows. Therefore, it is important to understand the soil disturbance of inter-row cultivation tools for optimizing the design and the use of inter-row cultivators. In this study, the performance of two different inter-row cultivators (the rotary inter-row cultivator and the tine inter-row cultivator) was investigated at three different working speeds (3.52, 6.11 and 7.82 km h-1) and at a working depth of 70 mm under corn planted field conditions. The performance indicators of inter-row cultivators included the soil burial Depth on crop (D), the unaffected strip Width around crop row (W), the Weeding efficiency (We), and the Damaged Plant ratio (DP). The results of the study indicated that the rotary inter-row cultivator could be operated at 6.11 km h-1 due to acceptable soil movement and low crop damage. However, the tine inter-row cultivator resulted in unacceptable soil movement and crop damage at 6.11 and 7.82 km h-1 working speeds.

This study was done to evaluate the effect of edible coatings based on Aloe Vera (AV) in combination with ascorbic acid and lactic acid on the postharvest life and quality of tomato. Several coatings based on different natural components such as gum Arabic, carnauba, mineral oil, etc. have shown an increase in the shelf life with better retention in postharvest quality. Two edible coatings of natural Aloe vera gel (10%) along with Ascorbic Acid (AA; 1%) and Lactic Acid (LA; 1%) were applied to mature tomatoes as an edible coating and stored at room temperature (25-29°C) and 82-84% Relative Humidity (RH) for 30 days. After application, weight loss, total Titratable Acidity (TA), Soluble Solids Content (SSC), ascorbic acid content, pH value, total phenolic content, total antioxidant activity, and decay percentage were measured at 0, 7, 14, 21, and 30 days. Compared with untreated tomato, coated ones exhibited a significant (P≤ 0.05) delay in weight loss and higher retention of SSC, vitamin C, and titratable acidity. Between the two coatings applied to tomato, AV+1% AA+1% LA coating was found to be the most effective in delayed ripening and maintaining the postharvest losses. Results obtained in this study support using AV and AA+LA edible coating as an effective alternative to preserving tomato, delay ripening processes, and extend shelf life.

The two-spotted spider mite, Tetranychus urticae Koch, is a highly polyphagous pest that is considered a serious pest worldwide. Due to problems associated with chemical pesticides such as resistance to pesticides and environmental contamination, plant oils have been considered for use against mites’ control. However, their low solubility in water and phytotoxicity are the major constraints that limit their application. In this research, a developmental screening process was carried out on some commercial emulsifiers and stabilizers to obtain a safe acaricide from suitable vegetable oils including castor and soybean. Among eight emulsifiers, Nonylphenol Ethoxylate 6M (NPE6) had far more excellent emulsification ability and less phytotoxicity with some level of mite toxicity. Among vegetable oils, castor oil had greater toxicity in comparison with soybean oil. Also, Polyethylene Glycol 400 (PEG 400) had more thermal stability in the formulation. In the last step, the best ratios of NPE6, castor oil, and PEG 400 were evaluated for their toxicity, stability, and phytotoxicity. Finally, the ratios of 1:8:1 or 2:6:2 (NPE6: Castor oil: PEG 400) were found as the best end product that could be potent for use in a large scale rose greenhouse. Also, the efficacy of emulsifier-oil-stabilizer mixtures was investigated against T. urticae by two different methods. The results indicated that the petri dish test method caused overestimating in mortality rates compared to the standing leaf test method. New methods such as polymerization can show a new insight for pest control without chemical pesticides.

The Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae), is one of the most important and destructive pests of citrus in the world, because of its ability to vector bacteria Candidatus Liberibacter americanus and Candidatus Liberibacter asiaticus, the presumed causal pathogen of Huanglongbing (HLB) or greening disease. The biology and reproduction parameters of D. citri were studied at 27.5°C on four host plants corresponding to the four major varieties cultivated in Iran, namely, Marsh grapefruit (Citrus paradisi), local sour orange (C. aurantium), Mexican lime (C. aurantifolia), and Campbell Valencia orange (C. sinensis). The average developmental period of total nymphal stages and total cycle (egg to adult) were significantly longer on Campbell Valencia orange (21.2 and 24.1 days, respectively) than on other host plants. The mean of pre-oviposition period on four host plants varied (2.4-4.0 days) and was significantly longer on Campbell Valencia orange (4 days) than on other host plants. Oviposition rate and total eggs laid were not significantly different between the different hosts. Survival rate of D. citri was significantly lower on Campbell Valencia orange (42.1%) than on the three other varieties. The finite rate of increase (λ) and the rm value of D. citri were higher on Mexican lime (1.20 and 0.17, respectively) than on the three other hosts. Also, mean doubling time was higher on Marsh grapefruit (11.84 Days) than on other host plants. These new data give more insight about susceptibility of the different varieties of citrus to D. citri.

Biofertilizer has been recognized as an alternative to chemical fertilizer to improve soil fertility and crop production in sustainable agriculture. The objective of this field study was to evaluate the effects of bio and chemical fertilizer on qualitative and quantitative characteristics of Thymus kotschyanus Bioss. & Hohen. The experiment was conducted during 2019 at Imam Khomeini International University, Qazvin, Iran, and treatments included control (no fertilizer), chemical fertilizer (NPK), and four types of microorganisms including Funneliformis mosseae (AMF), Azotobacter chroococcum strain 5, Pseudomonas stutzeri strain P-16, and Pseudomonas putida strain 41. The results showed that AMF and NPK positively affected plant height, number of branches per plant, and photosynthesis pigments contents compared to other treatments. However, maximum plants’ fresh and dry weight, proline, total phenolic and flavonoid contents, DPPH inhibition, essential oil percentage, and carvacrol quantity were obtained from plants that were inoculated with AMF. Also, the activities of Catalase (CAT) and Superoxide Dismutase (SOD) were increased by the application of AMF. According to the obtained results, there were no significant differences in P concentration between plants treated with P. stutzeri, Pseudomonas putida, AMF, and NPK. Maximum N amount in T. kotschyanus leaf was obtained in plants treated with AMF, NPK and Azotobacter chroccucum. Plants inoculated with AMF had higher Ca uptake compared to the other treatments, and the maximum total K accumulation in T. kotschyanus were obtained in plants inoculated with AMF and NPK. Hence, the use of organic and biological inputs instead of chemical fertilizer for improving crop efficiency and quality with the aim of alleviating pollution and accomplishing sustainable agriculture is highly encouraging.

The effect of various amounts of nitrogen (N) fertilizer (0, 50, 100, 150 and 200 kg ha-1) on the growth and quality characteristics of Mentha x piperita and Mentha spicata species was studied under Turkey’s Uşak ecological conditions in 2017-2019. In the study, harvests in the vegetation period of 2018 and 2019 were combined and the average plant height and essential oil content, total fresh and dry herbage, dry leaf and essential oil yields, and the composition of the essential oil was examined. The plant height, total yields and essential oil content of both mint species increased significantly with N fertilizer applications. The highest total yields and essential oil contents in both mint species were obtained from 200 kg N ha-1. The main components of the essential oil were identified as menthol and menthon in Mentha x piperita and carvone and limonene in Mentha spicata. The highest menthol content (44.66%) was obtained from 100 kg N ha-1, while the highest carvone content (59.90%) was obtained from 200 kg N ha-1. The total yields of Mentha x piperita increased significantly with increase in N fertilization up to 200 kg ha-1, while the total yields of Mentha spicata increased with increase in N fertilization up to 150 kg ha-1.

The first experiment was performed to study the effect of foliar application of spermidine, citric acid and proline (0, 50 and 100 mg L-1) on some metabolites and enzymatic activities of Calendula officinalis L. under drought stress (No stress: Control, 25, 50, and 75% field capacity). The second experiment was performed to study the effect of foliar application of spermidine, citric acid and proline (0, 50 and 100 mg L-1) on the post-harvest shelf life of flowers (beginning of the experiment, 5, and 10 days post-harvest). The experiments were factorial in a completely randomized design with 3 replications. All treatments had a significant effect on the measured variables. In the first experiment, FC 25% reduced all traits, FC 75% increased carotenoid, carbohydrate, phenol, flavonoid, protein, Peroxidase (POD) and Superoxide Dismutase (SOD) activities. The highest vitamin C was observed in the control FC. Also, foliar application of 100 mg L-1 proline, increased carotenoid, carbohydrate and phenol, 50 mg L-1 proline increased protein content. Also, 100 mg L-1 of spermidine increased flavonoid and 100 mg L-1 of citric acid increased vitamin C, SOD and POD activities. In the second experiment, all evaluated traits were reduced ten days after harvest, the highest post-harvest life was for 100 mg L-1 of citric acid (9.7 days) and the lowest was for the control (5.3 days). The study results showed that application of 100 mg L-1 spermidine, citric acid and proline with FC 75% improved biochemical properties, nutritional traits, and post-harvest life of Pot marigold.

For the first time, the nearly complete genome sequence of onion yellow dwarf virus (OYDV) was found in Iran from garlic (Allium sativum L.) by deep RNA sequencing. Complete coding sequence of the Iranian isolate of OYDV (MN528769) consists of 10,212 nucleotides (nt), encodes a polyprotein with 3,403 amino acids (aa). Pairwise sequence comparisons showed that IR-Kh2 shares 74.84-97.39% identity at the nt level and 75.67-98% identity at the amino acids level, respectively with other OYDV isolates deposited in the GenBank previously. According to the phylogenetic analysis, the OYDV isolates were divided into two main groups based on the coding sequence of genome and the Iranian OYDV isolate cluster together with the Australian (MS/SW1), Spanish (SG1), Chinese (G78 and G37-2), and Indian (RR1) isolates. Furthermore, a genetic recombination analysis was also performed, in which a putative recombination event was detected in the nuclear inclusion body b (NIb) gene.

Following favourable agro-ecological conditions, powdery mildew becomes a destructive disease in wheat worldwide. Efficiency of the most common control methods (fungicide application and plant resistance) for wheat powdery mildew improves by using a better understanding of the effects of highly influential agronomic practices and weather factors on disease development. Disease severity was rated at plot scale according to a manageable number of agro-ecological variables in Kermanshah province, Iran in 2013 to 2017. Disease severity rating was varied by cultivar, disease-assessment date, and sowing time. Kruskal-Wallis one-way ANOVA determined a high area under disease progress curve (AUDPC) based on disease severity rated in 2016. A greater AUDPC was detected for early disease onset than late onset. Later sowings had greater AUDPC values compared to earlier sowings. From Principal Component Analysis (PCA), four principal components accounted for 88% of data variance. From PCA-based regression analysis, earlier powdery mildew onset corresponded with further rainy days and higher wind speed in spring, later sowing and maturity, lower disease resistance, and warmer growing season of commercial wheat cultivars. The present findings recognized proper sowing time as effective as genotypic resistance for sustainable management of wheat powdery mildew and provided valuable information on cultivar, disease, maturation, sowing date, and weather interactions.

The aim of this research was to study soil structural stability indices of clay loam soil treated with organic amendments, using High Energy Moisture Characteristic (HEMC). For this purpose, three sizes of soil aggregates (0.5-1, 1-2, and 2-4 mm) were treated with three rates (0, 1.5, and 3 %) of vermicompost and urban waste compost. After three months of incubation, water retention of the slow (2 mm hˉˡ) and fast (100 mm hˉ ˡ) wetted soil aggregates were measured at six pressure heads from 0 to 50 hPa, and HEMC stability indices such as Volume of Drainable Pores (VDP), Stability Index (SI), and Stability Ratio (SR) were determined. The results showed that only the stability of 0.5-1 mm aggregates was significantly (P< 0.01) affected by organic treatments. The stability indices were significantly influenced by the rates of amendments, and increased with increasing their rates. However, the type of organic amendments had no significant effect on stability of aggregates. The mean ​​of VDP, SI, and SR decreased by increasing diameter of the aggregates and decreasing the rate of the organic amendments, due to breakdown of macro-aggregates and decrease of macropore fraction. In general, to increase structure stability of clay loam soil in arid regions of Iran, application of at least 3% organic amendments is recommended.

Accurate estimation of Evapotranspiration (ET), as a key component in the hydrological cycle, is essential in agricultural water management. In the current study, an approach based on the Bayesian Model Averaging (BMA) was used to combine eight ET empirical models, namely, Blaney-Criddle, Makkink, Penman, FAO-Penman-Monteith, Priestly-Taylor, Thornthwaite, Turc and Wang to improve the accuracy of ET estimations compared to individual models. The results of eight models and 247 combinations of them (without replacement) were compared to the results of the Water Balance (WB) model as the reference of comparison. This study was performed using warm season (April-September) data of 2005-2014 from Gorganrood-Gharesoo Basin, north of Iran. The performance of the eight models and all possible combinations were evaluated based on four statistical metrics i.e. Root Mean Square Error (RMSE), Kling-Gupta (KGE), Coefficient of Determination (R2), and Bias. Then, the best-performing combination, (BMA-Best), was determined. Based on the WB method, the BMA-Best combination had better performance than the single models according to most of the metrics. In a few cases in which individual models showed slightly better performance than BMA-Best combination, the differences were not statistically significant. On average, the BMA-Best combination increased the R2 by more than 50% and decreased RMSE by more than 70%. According to results of the current study, BMA provides a more reliable estimation of ET and it is recommended for use rather than the individual models. Moreover, the BMA-best combination mostly consisted of energy-based ET models, suggesting that these models have a better performance in climatic conditions of the study area.

As a salt adsorbent, biochar could remove/isolate salt ions e.g. Na through physiochemical adsorption to mitigate the salinity of brackish water, but little is known about its magnitude and mechanisms. The current study aimed to examine the effects of biochar on: (1) Na-adsorptive capacity and mechanism and (2) Electrical Conductivity (EC) and K displacement. Six pyrolysis temperatures (250, 350, 450, 550, 650, and 750ºC) were applied to produce biochars from rice husk. The biochars were then used as adsorbents to adsorb Na from salty water varying in NaCl concentrations. The Langmuir isotherm Model (LMM) and Dubinin-Radushkevick isotherm Model (DRM) were used to quantify the dependence of adsorbed Na on Na concentration at equilibrium. The LMM quantification revealed that the maximum Na-adsorptive capacity of biochars increased from 25.8 to 67.8 (mg g-1) upon increased temperatures. The EC was reduced and the K amount displaced from biochar was increased with an increase in pyrolysis temperature. The DRM quantification revealed that the Na-adsorptive mechanism was mainly a physical process. A significant relationship between the Na amount adsorbed and the K amount displaced from biochar suggested that the ion-exchange mechanism could co-exist. In brief, the findings indicated that the salinity of the brackish water could be significantly mitigated by the biochar treatment through mainly physical adsorption leading to a reduced EC and increased K: Na ratio.