جستجوی مقالات مرتبط با کلیدواژه « onion » در نشریات گروه « کشاورزی »

The agricultural sector depends largely upon water and energy resources to fulfill sufficient water for producing adequate food for the rapidly growing world’s population. It requires great effort to improve water and energy productivity for agricultural products to provide consumers’ health as well as environmental protection. In this study, the volume of irrigated water, crop yield, water productivity, and the consumed energy for onion crops irrigated with sprinkler or surface irrigation methods under farmer management were measured and compared. The measurements were recorded from 2020 to 2021, on 17 farms across Esfahan Province where onion was a main crop in the region. The measured data from the foregoing two irrigation methods were statistically analyzed using t-test and Pearson correlation coefficients. The outcomes revealed that the volume of irrigated water as well as crop yield was greater for surface irrigation method compared to sprinkler irrigation, and the differences were statistically significant. Moreover, water productivity for onions irrigated with a sprinkler irrigation system was significantly higher (p<0.01) in comparison with onions irrigated with the surface method. In addition, the results indicated a significantly direct correlation between the volume of irrigated water and onion yield, whereas a significantly indirect correlation was observed between the volume of irrigated water and water productivity. A significantly inverse correlation was found between the productivity of energy for irrigation and energy consumption; so, an increase in the energy for irrigation resulted in a decrease in energy productivity. Based on the results of this study, the sprinkler method is more effective than the surface for irrigation of onion.

To study the effect of plant density and planting arrangement on yield and bulb size of two onion cultivars, a filed experiment was carried out as split factorial arrangement in randomized complete block design with three replications in the research field of Seed and Plant Improvement Institute, Karaj, Iran, in 2018-2019. Two onion cultivars, Morvarid and Zargan, were assigned to main plots, and inter row spacing of 10, 15, 20 cm and intra row spacing of 5, 7.5, 10, 12.5 cm as factorial were randomized in sub plots. Cv. Morvarid and cv. Zargan had the highest marketable yield in 15 × 7.5 and 15 × 10 cm planting arrangements (88.8 and 66.7 plant m-2, respectively) with 73.7 and 67.6 t ha-1, respectively. In cv. Morvarid and cv.Zargan, with decreasing the plant density, the proportion of small bulbs decreased from 38.31 to 6.57% and from 64.12 to 7.77%, respectively. In cv. Morvarid, with decreasing the plant density, large bulbs, doubles and thick neck bulbs increased from 3.19 to 19.85% and from 7.92 to 29.41%, respectively. In cv. Zargan, with decreasing the plant density to 66.7 plant m-2 (15 × 10 cm), the proportion of medium size bulbs increased from 35.87 to 80.15%. During the storage period, cv. Morvarid had lower percentage of bulb sprouting and decay than cv. Zargan in all planting arrangements. The results of this research showed that in cv. Morvarid and cv. Zargan, planting arrangements of 15 × 7.5 cm and 15 × 10 cm, respectively, could be recommended to onion producers, because less seedlings are required for transplantation when compared with higher plant densities.

Iris yellow spot virus (IYSV) is a member of the Eurasian phylogenetic group of the genus Orthotospovirus. Similar to other species in the genus, the viral particles contain three genomic fragments: small (S), medium (M), and large (L) RNAs. In the present study, the complete nucleotide sequence of the small fragment (S) RNA of two IYSV isolates from leek (Allium ampeloprasum ) (IYSV-Le1M) and onion (A. cepa) (IYSV-O2K) and the non-structural gene of the M RNA of the IYSV-Le1M isolate were determined. The results showed that based on nucleocapsid (N), small (NSs), and medium (NSm) RNA fragment non-structural genes, the isolates of Markazi Province are more closely related to each other than other IYSV isolates. However, the intergenic region (IGR) of the two isolates showed significant structural differences compared to other sequenced IYSV isolates. The IGR of the IYSV-Le1M isolate was longer than those of other IYSV isolates studied, while, for IYSV-O2K isolate, it was 440 nucleotides shorter. It was also found that for Indian and Dutch IYSV isolates, the IGR was 31 and 22 nucleotides shorter than that in the IYSV-Le1M isolate. These findings provide new information about the genetic diversity and phylogeny of IYSV isolates.

Soil salinity is an increasing problem in agricultural soils that mycorrhizal fungi in saline soils increase plants tolerance to salinity by symbiosos with their roots and improving their growth. In addition, mycorrhizae contribute to agglomerate stability through two main mechanisms, physical stabilization by trapping individual soil particles by extensive hyphae networks and chemical stabilization by adhesive-like secretions. Therefore, the aim of this study was to compare the root effects of three different plants, clover Terifoliom alexandrinum L., onion Allium cepa L. and parsley Petrocelinum crispum L. with and without mycorrhizal on soil aggregates stability in saline soils.

In order to investigate the effect of mycorrhiza fungi and different salinity levels on morphological characteristics, nutrient concentrations and soil aggregate stability in three plants: clover, parsley and onion, a factorial experiment in a completely randomized design with 3 replications were conducted in the greenhouse of Agricultural sciences and natural resources university of Khuzestan in 2018. factors were included mycorrhiza at two levels (no inoculation with mycorrhiza (NM), inoculation with mycorrhiza (M)), salinity at three levels (salinity 1 dS m-1 (S1), 3 dS m-1 (S2) and a 6 dS m-1 (S3)) and three levels of plant type (clover (TA), parsley (PC) and onion (AC)).

Accourding to the results, salinity stress caused a significant decrease in growth indices and plant colonization percentage, but inoculation with mycorrhiza fungus increased them significantly. Salinity stress in clover, parsley and onion reduced shoots dry weight 31%, 35% and 96% respectively, but inoculation with mycorrhizal faungus increased this factor 69%, 67% and 93% compared to non-mycorrhizal treatments. The increase of root dry matter of these three mycorrhizal plants compared to their non-mycorrhizal treatments was 65, 65 and 93%, respectively. Salinity stress also caused a significant decrease in the macronutrients (phosphorus and potassium) and micronutrients (iron, zinc and copper) concentration, while sodium concentration increased significantly. Mycorrhizal treatment increased phosphorus concentration significantly in clover, parsley and onion by 26, 27 and 41%, while salinity stress reduced it by 22, 24 and 26% respectively. Mycorrhizal inoculation increased iron concentratin 6, 12 and 66% in the above three plants, respectively. The results showed that the highest aggregate stability in clover, parsley and onion were seen with an average of 0.81, 0.75 and 0.93 mm in mycorrhizal low salinity level treatment and and the lowest aggregate stability by an average of 0.41 , 0.39 and 0.35 mm were obtained in non-mycorrhizal high salinity level treatment.

Based on the results of this study, salinity stress has a negative effects on plant growth characteristics and nutrient uptake by clover, parsley and onion, but mycorrhizal fungi inoculation reduces these negative effects. Also, the negative effects of salinity stress on aggregate stability in mycorrhizal treatments were less than non-mycorrhizal treatments. Among the studied plants, the highest amount of aggregate stability in mycorrhiza inoculation conditions was related to onion and the lowest amount of aggregate stability was seen in parsley. Its obvious from the results that onion, which has a higher mycorrhizal dependency, can further increase the aggregates stability. Thus, the use of mycorrhizal fungi, especially in saline soils, can increase the stability of aggregates and thus improve quality and soil physiacl properties.

Introduction and Objetive: 

Numerous plant bioactive substances have been shown to improve growth performance, antioxidant status and animal immune systems.Artichoke and onion are a rich source of natural antioxidants and  flavonoids  that have antimicrobial and antioxidant properties.

520 one-day-old commercial 308 chicks were randomly assigned to five treatments and four replications (26 chicks per replication) from 1 to 42 days of age. Experimental treatments included basal diet and basal diet plus 1.5% artichoke, 3% artichoke, 1.5% onion and 3% onion. Dried artichokes and freshly and peeled white onions,after grinding and mixing with corn, soybean meal and other ingredients were used. The effects of different levels of onion and artichoke plant on growth performance, gastrointestinal morphology and immune system of broiler chickens was investigated.

Malondialdehyde, DPPH and SOD were significantly affected by experimental treatments (p<0.05). So that the amount of malondialdehyde significantly decreased in treatments containing onions compared to the control treatment (p<0.05). Also, the percentage of DPPH in experimental treatments, especially in diets containing 3% artichoke and containing onion, increased significantly compared to the basal diet (p<0.05). Addition of artichoke and onion to the diet increased the antibody titer against influenza at 35 days (p<0.05). With the addition of artichoke and onion to the diet, the height of the villi increased and the depth of the crypts decreased significantly (p<0.05). Throughout the experiment, chickens fed onions (one and a half and three percent) showed higher weight gain (p<0.05). Experimental treatments had no significant effect on the percentage of breast, thigh and carcass weight of broilers. Adding artichokes and onions to the diet improved antioxidant status, anti-influenza antibody titers, and improved the height of the jejunal villi relative to the control.The best level was 1.5% dried artichoke or 3% fresh onion.

Flavonoid compounds are one of the compounds that will be commercially available in the future. Due to the improvement of antioxidant status indices of treatments containing artichoke and onion, it is recommended that onion and artichoke flavonoids  and other bioactive substances be extracted and the effects of using this substances purely in broiler diets be investigated.

Using plant resistance inducers leads to the reduction of disease incidence and severity. The effect of several resistance inducer compounds on onion downy mildew disease was tested in a factorial experiment with a randomized complete block design comprising of 10 treatments in 3 replications at Behbahan Agricultural Research Station. Treatments consisted of chemical indicers in five levels of 50mμ dipotassium phosphate, 80mμ nicotinic acid and 3mμ salicylic acid, and ridomil mancozeb fungicide (3g/L) and control that treated with water. Treatments were applied 5 times from mid-February when the plants were in 3 to 4 leaf stage until late April every two weeks. Genotypes were in two levels including modified onion of Behbahan and Early White Texas. Disease severity was calculated by evaluating 40 plants in each treatment when the disease index in the control treatment was more than 75% in two middle rows of each plot in each treatment. The highest percentage of disease severity (75.50%) was observed in the control treatment with no spraying and the lowest rate of disease severity was observed in the application of Ridomil with 14.17%. The severity of the disease was 28.33%, 33.33% and 23.33% in dipotassium phosphate, salicylic acid and nicotinic acid treatments, respectively. Therefore, the use of resistance inducers can be a substitute of fungicides.

 Storage potential is an important characteristic for onion. Annually, a large quantity of worldwide onion production deteriorated during storage. The storage ability of onion is influenced by various endo- and exogenous factors including cultivar and storage conditions specially, temperature. Based on literature, there is considerable genetic variation for onion storability in onion germplasms from different origins. Rivera Martínez et al. (2005) evaluated the storability of 18 local and 4 commercial onion cultivars in Spain. Their results showed that there was significant variation for storability among different onion cultivars, and interstingly the local cultivars had more storability than commercial ones. Onion storage could also affected by environmental conditions such as temperature. Benkeblia et al. (2000) studied the effects of various temperatures on respiratory parameters of onion. Their finding showed onion respiration were raised by increasing temperature. Likewise, the positive effect of higher temperature on enhancing the growth of sprouts and elevating transpiration has been reported (Miedema, 1998; Yoo et al., 1997). Although, Afghanistan is considered to be one of the origins of onion (Brewster, 1994) there are no reports on estimating the storability of Afghan local cultivars under different temperature conditions. So this research has been conducted to study the effects of various temperatures on storability of native onion cultivars of Afghanistan.

 In this research, the plant materials consisted of 10 onion cultivars consisting eight local varieties “Hanaaie Harat”, “Zard-e-Harat”, “Ghermrz-e-Harat”, “Mazar-e-Sharif”, “Kabul”, “Sar-e-Pul”, “Ghonduz” and “Balkhaab” originated from Afghanistan, an Iranian cultivar (“Ghermez-e-Azarshahr”), and a commercial cultivar “Sweet Grano”. The cultivars were stored at two different temperature regimes (5 ºC and ambient temperature), during six-time intervals of 20 days. The average temperature of ambient storage was 13 °C ranging from 8-18 °C. The experiment lasted from November 6th, 2011 to March 5th, 2012. This research was performed in a completely randomized design based on split factorial design, with three replications. For each replication, 50 healthy non-sprouted bulbs were packaged in plastic nets. Storage potential related characteristics such as sprouting percentage, weight loss percentage, sprout length, and sprout weight/bulb weight ratio in 20 days intervals were measured. All data were subjected to analysis of variance (ANOVA) using SAS statistical software. Mean comparisons were calculated at 5% probability level using LSD when the F-value was significant (Fisher’s protected LSD).

 The results showed that there were significant differences among cultivars for storage characteristics (weight loss percentage, sprouting percentage, length of sprouts and sprout weight/bulb weight ratio). “Ghonduz” and “Ghermrz-e-Harat” local cultivars had the most and least storage ability, 50% of bulb sprouting after 105 and 35 days, respectively. Rivera Martínez et al. (2005) and Ramin (1999) also reported Spanish and Iranian local cultivars had more storability compared to commercial cultivars. In 5 °C, weight loss of onion bulbs followed a linear model during storage period. But, in ambient storage, it was higher at the beginning and the end of storage period, showing the adverse effects of high temperatures on bulbs weight loss during storage. The interaction between cultivar and time was also significant. It showed onion weight loss differs in various intervals.  It could be attributed to the genetic variation and morphological difference such as number and thickness of dry scales of onion bulbs. In ambient storage condition, onion sprouting percentage showed a sharp increase in early storage intervals and became stable in the late intervals. Under 5 °C treatment, it raised as a linear model with very slow slope. It seems that weight loss and sprouting of onion bulbs in ambient storage is dependent on temperature and relative humidity of environment. This finding is in agreement with previous reports (Baninasab and Rahemi, 2006; Forudi, 2005). The sprout length and the ratio of sprout weight to bulb weight was lower in 5 ºC than ambient temperature. Abdalla and Mann (1963) and Yoo et al. (1997) also reported that smaller sprouts were observed in lower temperatures. 

 In this experiment, the effects of temperature on storability of some local cultivars of onion originated from Afghanistan were studied in different intervals. It was found that the storage potential of onion bulbs could be influenced by genetic factors and environment conditions such as temperature. Findings of this research showed that sprouting percentage, weight loss percentage and onion sprout growth were less under 5 °C treatment than ambient temperature. Therefore, it was concluded that storing onion bulbs in low temperature conditions can reduce the onion spoilage and improve their storage life. Additionally, cultivars showed highly significant variations for all characteristics related to storage ability. Our findings showed that some local cultivars are more storable than commercial cultivars. Among the cultivars, “Ghonduz” cultivar has more storage potent as compared to all studied cultivars. Our results confirmed that local cultivars can be a good source of desirable genes related to storability. Subsequently, they can exploited to broaden the genetic base of breeding matreials.

Introduction

Planting onion sets instead of seeds or seedlings in situations where factors such as physical and chemical quality of soil and water are very limiting, is the safest planting method to achieve maximum plant establishment in the ground. In order to determine the appropriate planting date and density (in the treasury), storage conditions of bulbs in storage and the response of cultivars belonging to the long day type to this method of onion production, the present plan was implemented to optimize the conditions of production and storage of anions. Appropriate means, it is possible to compare the agricultural problems of this production method with common methods such as direct seeding and planting seedlings in the present study.

In order to determine the optimazation of dry onion sets production and to examine the storage capacity of produced dryonion sets, a field experiment was carried out in Kabutar Abad Research Station in Isfahan during 2015-2016 in a split- split plot experiment based on RCBD with three replication.The effects of nursery planting date (30 March, 30 April, 30 May), plant density (15 and 30 g m-2) and variety (Dorche, White Kashan and Sweet spanish) on dry onion sets pruduction in long day condition, this experiment. In a separate experiment, three planting date (9 May, 9 June and 10 July) and two plant density (15 and 30 g m-2) in a short variaty was examinated. Also, in order to investigate the possibility of using heat treatment to reduce or stop bolting, another experiment was conducted in a completely randomized design with three replications for the three cultivars. In each repetition, 400 anions (randomly with a size of 10 to 20 mm) are distributed in plastic nets and in a warehouse whose temperature is supplied by a gas heater and between 28 and 32°C was, for a period of two months (from February 10 to April 10) and the number of surviving onion sets was calculated after removing those that were rotten, green and hollow. Experimental data were analyzed by SAS software version 9.4 and the means were compared based on Duncan's multiple range test.

According to the results, the best planting date was 30 April by the mean 616 onion sets pruduction for all three variety in long day types and 9 may by the mean 311 inion sets in short day types and the effect of seed weight (15 and 30 g m-2) was nonsignificant. In two separate experiments, storability of onion sets was examinated in ambient storage (6-28 °C) after 118 days and warm storage (> 30 °C) after 60 days. The cause of this phenomenon can be traced to the reaction of the onion plant to the length of the day, so that the cultivar in question, due to its short day, in the face of long and hot days, without being able to develop and produce enough leaves, enters the production stage. They are fried and of course their size will be very small. Results indicated that 84%, 64% and 61% of onion sets survied in the first condition for three population (Dorche, kashan and Sweet Spanish). What was evident in this experiment was that most of the surviving onion sets were those who had completed the maturation process in the field, and conversely, the higher storage losses were in those that had leaves and leaves at harvest. Growth has been observed. Such a phenomenon was also observed in edible bulbs, so that bulbs with thick necks and green leaves are more susceptible to the entry and establishment of pathogens during storage during harvest. An observational estimate in this experiment indicates that the percentage of green onion sets is not more than normal storage and the main losses are due to depletion and water loss. As reported in the storage of edible onions, very high temperatures (about 38 °C) and very low temperatures (about 0 °C) both prevent flowering and sprouting of bulbs.

Based on the results obtained from the four experiments, in the first planting date, due to the existence of sufficient time (from emergence to harvest) and coincidence of leaf production with favorable environmental conditions (high temperature and long day length), a larger share of total yield to shoots Coarse was allocated and as a result the number of onion sets was reduced. Finally, they did not enter the phase of coagulation and anion production. In summary, spring sowing of long-day onion cultivars by onion sets with a treasury date of 10 May and a seed density of 15 g m-2 is recommended.

Downy mildew caused by Perenospora destructor is one of the most important onion diseases. In this research, the efficiency of Poltiglia Bordolese (Bordeaux Mixture WG 20%) at the rate of three, four and five kg/ha and Infinito SC 687.5 (flopicolide + probamocarp) at the rate of two L/h used to control downy mildew of onion disease and compared with control. The experiment was conducted in a randomized complete block design with six treatments in four replications in Jiroft and Behbahan, Iran. The results indicated that, in terms of effect on reducing the severity of the disease, Poltiglia showed a significant difference in compare with control. The comparison of effectiveness of treatments showed that it was related to those of poltiglia five kg/ha which was 63.5 %. In case of Infinito fungicide which used in Behbahan and Jiroft regions, it was 61.97% and 53.22 %, respectively. The comparison of the area under the disease progress curve (AUDPC) showed that in the control treatment with water spraying, this index recorded 21.4 and 20.1 unites per day in Behbahan and Jiroft respectively, and in the control treatment without water; this index was 20.4 and 16.9 per day, respectively. It indicates the role of free moisture in increasing the severity of the disease. The AUDPC index in Behbahan and Jiroft was 9.6 and 10 respectively, and belonged to the treatment of 5 kg/ha of Poltiglia fungicide. The Poltiglia fungicide at the rate of four Kg/h is recommended for controlling onion downy mildew disease.

This study was conducted to evaluate the application of poultry manure and urea fertilizer in onion in the randomized complete block design with three replications during 2018 and 2019. The treatments were:1-Control (276 kg/haN), 2-Recommended optimal nitrogen limit for the region crop (184 kg/haN)+Optimal consumption of other nutrients, 3- nitrogen consumption 25% more than the optimal limit+Optimal consumption of other nutrients, 4-Consumption of nitrogen 25% less than the optimal limit+five t/ha of poultry manure+optimal consumption of other nutrients and 5-Consumption of nitrogen 25% less than the optimal limit+tent/ha of poultry manure+Optimal consumption of other nutrients. The results showed that the effects of treatments on yield, the concentration of other elements, and nitrate residuals in onion bulbs and leaves were significant at the level of 1% probability. The control had the lowest yield (43.3t/ha) and the highest nitrate residuals (184.3 and 571.2mg/kg, respectively) and the lowest concentrations of potassium, iron, zinc, and manganese in bulbs and leaves. Also, treatment five showed the highest yield (25.1% increase compared to the control), and no significant difference in yield was observed between treatments four and five. The lowest nitrate residuals in bulbs were in treatment four, which was 69.9%, 21.7, 43.3, and 3.4% less than treatments one, two, three, and five, respectively. The application of treatment four, while reducing the consumption of urea fertilizer by 50% and as a result of reducing nitrate in bulbs to less than the critical level and increasing the yield by 18%, resulting in about 11% more revenue than the control.

Drying is one of the oldest methods of food and agricultural products preservation, which increases their shelf life by removing a part of the product water content. Long-term storage, minimizing the storage and packaging needs, reducing the transport costs, and producing a variety of products are the most important reasons of food drying. Application of some pre-treatments before drying such as osmotic dehydration is suggested to improve the quality of the dried food products. Osmotic dehydration is a process that used for partially dehydration of fruits and vegetables, by immersing them in a concentrated solution of sugar or salt (Sutar and 2007). Reducing the drying time, limiting the heat damages, improving the textural quality and vitamin retention, flavor enhancement and color stabilization are some advantages of the osmotic pretreatments (Sutar and Sutar 2013). Osmotic dehydration removes water from the fruits and vegetables up to a specific level, which is still high for food preservation, so this process must be followed by further processes in order to lose the most portion of the fruits and vegetables water content. Air drying can be used to remove the remaining water from the osmo-dehydrated product (Shahade et al 2015). Salts and sugars are the common solutes that mostly used for osmotic treatment. The quality characteristics of final product in salt-treated samples are higher than sugar-treated products and the preventing of the undesired reaction products formation are from advantages of salt over other solutes (Shahade et al 2015). Onion is a famous spice that is grown all over the world and consumed in various forms. This vegetable is used as an appetizing, healthful and digestive food because of its high nutritional quality and therapeutic properties. Onion is a product that is consumed throughout the year, but its production is seasonal. This product is a perishable food due to its high moisture content. Some environmental factors such as microorganisms, enzymes, and surface vaporization of moisture content leads to spoilage of onion during the storage (Shahade et al 2015; Sahu et al 2017). Drying is a major processing operation in the food industry that can be used to enhance the storability, improve the quality and minimize packaging and handling costs of onion. Drying of onion with the usual drying method causes undesirable changes in sensorial properties such as texture, color, taste and serious decreases in nutritional value of dried product. Pre-drying treatments, such as osmotic dehydration has been suggested to improve the quality of dried onion. It seems that the osmo-air drying can be an appropriate method to increase the shelf life and improve the quality of dried onion without adversely affecting its sensorial and nutritional value (Sahu et al 2017). The effect of osmotic dehydration process parameters on onion dehydration kinetics and optimization of process conditions has been investigated by some researchers (Alam et al 2013; Hussein et al 2018; Patil et al 2012; Revaskar et al 2014; Shahade et al 2015). But the few studies on the characteristics of dried onion with osmotic pretreatment have been done. The purpose of this study was investigating the effect of osmotic solutions compositions on dehydration amount and quality attributes of osmo-air dried onion slices.

Fresh yellow onion was procured from the local market. The onions were peeled carefully and washed and then cut into 3.0±0.1mm thick slices using a manual stainless steel cutter. The osmotic solutions of different compositions were prepared by dissolving required amounts of salt, sugar and citric acid in distilled water. Five solutions of different compositions were used for osmotic dehydration of onions (T2 (10% NaCl), T3 (10% NaCl and 10% sucrose), T4 (1% citric acid), T5 (10% NaCl and 1% citric acid) and T6 (10% NaCl, 10% sucrose, and 1% citric acid). Solution to sample ratio was kept as 2.5:1 in each experiment. The samples were immersed in osmotic solutions for 1 h at room temperature (25 °C). All Samples were weighed after removal from osmotic solutions and dried in a laboratory oven at 65 °C until to reach 6% moisture content (Shahade et al 2015). The moisture content of the fresh and osmotically dehydrated onion slices was measured by oven drying method at 105 °C and the amount of water loss, solid gain and weight reduction of the samples were calculated. The dried onion slices were evaluated in terms of physicochemical (rehydration rate, pH, color, vitamin C and total phenolic compounds) and sensorial (Color and appearance, texture, Taste and flavor and Overall acceptability) properties. The rehydration ratio of dried onion was calculated after flooding 10 g of dried samples in 1000 mL of distilled water at 22±1 °C for 5 h (Patil et al 2012). The pH value was measured by a digital pH meter. The color measurement was done using a colorimeter (TES-135A, Taiwan). In order to determine the total phenolic contents, the Folin–Ciocalteu method was employed and measurements were done at 765 nm with a spectrophotometer (UNICO 2802, China) (Taga et al 1984). The vitamin C content was determined by Indophenol method and measurements were done at 515 nm with a spectrophotometer (Klein and Perry 1982). The sensorial evaluation was carried out by 5-point Hedonic Scale. The dried onion slices were investigated for the sensorial attributes by 20 trained panelists. The panelists were asked to evaluate the samples and score them between 1 (most disliked) to 5 (most liked). The statistical model that used was completely randomized design. The experiments were performed in 3 replications and analysis of variance (ANOVA) of data was conducted using MSTAT-C software. Differences between the means values were also determined using Duncan’s Multiple Range test (p < 0.05).

The results of this research showed that the compositions of osmotic treatments had a significant effect on weight loss, water loss, solid gain, physicochemical characteristics and sensorial properties of dried onion slices. The highest weight loss, water loss and solid gain were related to the pretreated onion by the solution containing three solutes (salt, sucrose and citric acid). The presence of citric acid in the osmotic solutions significantly decreased the pH value of the final product. Although the osmotic pretreatments decreased the L* value, but the dried onion slices pretreated with sucrose and salt solution had the highest b* value. The Millard's browning reactions produced brown pigments in the dried product and the evaluation of the browning index showed that the application of the osmotic pretreatments especially with citric acid containing solutions increased the browning index of the dried onion slices. The least undesirable color changes were observed in onion slices pretreated with salt solution. Also, the osmotic dehydration with T6 treatment (salt, sucrose and citric acid) had the greatest effect on preserving of vitamin C and total phenolic compounds. As compared with control the use of the osmotic pretreatment reduced the rehydration ratio of the product. The most rehydration ratio after control was related to onions treated with citric acid solution (T4). Also, the results showed that the presence of sucrose in the osmotic solution increased the rehydration ratio of dried onion slices.Althoughthecolorscoreofosmoticdriedonionsliceswaslowerthanthecontrol, butthe osmoticpretreatmentsimprovedthetasteandincreasedtheoverallacceptabilityofthedriedproduct.

Osmotic pretreatment of onion slices with a multi-component osmotic solution (salt, sucrose and citric acid) caused the optimal results in terms of sensory and physicochemical properties.

Integrated control is a program that uses several methods to reduce the consumption of high-risk chemicals and is cost-effective. The aim of this study was to investigate the combined control of trichoderma fungi and chemical toxins (carbendazim and mancozeb) in onion gray rot caries. For this purpose, isolation of Trichoderma from fungal onions in Kahnouj city was carried out on a specific medium and isolates were identified using Gaussian and Twenty keys. Also, gray rot fungi were isolated and identified from onion molds infected with gray mold from the warehouses of Kahnouj city. Then, combined control of gray rot fungi was investigated by Trichoderma and two Mancosb and Carbendazim toxins. The results showed that the average inhibition of growth of Trichoderma fungi against Botrytis was 51.61percent in vitro. The average inhibitory percentages for growth of volatile metabolites were 38.14percent and nonvolatile metabolites in two treatments of 5 and 10 ml, respectively. The results of the analysis of catalase and peroxidase enzymes in onion samples treated with trichoderma showed an increase in both. Simultaneous use of trichoderma and two carbendazim and mancozeb toxins 100percent inhibited the growth of Butrititis in laboratory and storage conditions. Whereas, application of Trichoderma alone 68.18percent inhibited the growth of Botrytis in laboratory conditions. In addition, the concentration of the pesticides used was 500 ppm, which is lower than that of the conventional pesticides. Therefore, the results indicate that the fungal control of gray rot factor by trichoderma and the two toxins carbendazim and mancozeb are successful.

In this research work, land suitability as one of the first step in sustainable agriculture was done to find urgency of utilization type change in Horand region. Also, different aspects of qualitative and quantitative land suitability methods were discussed to determine and improve the involved criteria in sustainable agriculture evaluation.  

Qualitative and quantitative land suitability of common utilization types in study area such as rainfed and irrigated wheat and onion carried out by providing climate, landscape and soil information. Chi-square test, Pearson correlation and Regression relationship were performed to test accuracy and validity of evaluation methods. The suitability zoning of study area was completed for different land utilization types and behind interpretation output maps, the management level was analyzed.  

Dominant climate and slope limitation with other studied factors which had role in decrease of suitability in some case, caused to suitability classes of N for rainfed wheat, S1to N for irrigated wheat and N for onion. Statistical studies confirm the accuracy of the evaluation methods. Determined middle and low levels of managements are keeping with field conditions.  

Unsuitability and in some cases low suitability of the region, indicates the urgency of change in common utilization type. There isn’t so important difference between qualitative and quantitative suitability evaluation methods in high limitation with unsuitable class. Environmental and management factors which have indirect effects on limitations should be considered behind yield value in land management index determining.

Cytotoxic and genotoxic effects of extract and essential oil of medicinal plants are evaluated by cytogenetic experiments and parameters like mitotic index and chromosomal aberrations. Evaluation of cytotoxicity and genotoxicity of aqueous extracts of Securigera cecuridaca seeds, Adiantum capillus-veneris leaves, and Trachyspermum ammi fruits on meristem cells of Allium cepa root and its growth was the aims of this study. Twenty gram of powdered samples were poured in to separate Erlenmeyer flask and 100 ml of distillated water were added. The flasks were covered by aluminum foil and shacked for 24 hours. Then extracts were filtered and centrifuged. In order to determine percentage of mitotic index and chromosomal aberrations 3000 cells were countered for each treatment and by division of mitotic cells and chromosomal aberrations numbers to total cells multiply to 100 were calculated. The results showed that the reduction of mitotic index and root growth of onion are related to extract concentration. The highest cytotoxicity and genotoxicity are related to aqueous extracts of A. capillus-veneris leaves and S. securodaca seeds, respectively. The extracts of three plants induced chromosomal aberrations such as C-mitosis, chromosomal stickiness, loss and laggard chromosome, chromosomal bridge, micronucleus and also cell death in the root meristematic cells of onion. The extract of S. cecuridaca seeds had the highest genotoxicity. Root of Allium cepa test is a rapid and efficient method for evaluation of cytotoxicity and genotoxicity of aqueous extracts of medicinal plants. This study shows that consumption of medicinal plants must be with precaution.

This study was conducted to increase onion storage life in Hormozgan province. For curing onions, the Primavera and Texas Early Grano cultivar were placed in sunshine for two days. The bulbs were packed in a plastic net for three months in three traditional storages: optimized storage with a temperature of 33 ± 2°C and a relative humidity of 49 ± 4%, controlled storage with a temperature of 9 ± 1°C and a relative humidity of 65± 5%, and storage at a temperature of 5 ± 1°C and relative humidity of 70 ± 5%. Every 15 days, qualitative characteristics of the onions were measured, including: weight loss, germination percentage, total soluble solids, dry matter, and firmness. The results showed that during storage, significant changes were observed in qualitative traits of both onion cultivars. The percentage of soluble solids, firmness and dry matter of onions during storage were nonlinear. Total soluble solids of Primavera cultivar increased after 15 days and then decreased. After two months of storage, Texas Early Grano, comparing Primavera, showed higher storage life due to its higher solid soluble matter and higher dry matter content. At ambient temperature, after three months, the weight losses of both onion cultivars were one and a half times higher than that the initial maximum (11.51%), and in cold storages, after three months, the weight losses of both varieties were less than 2%. Both cultivars faced no decay after 45 days of storage in traditional aeration, with a weight loss of less than 3%.