In order to study the effect of grapeguard on quality, quantity and control of storage diseases of grape in cold storage a completely randomized design with 3 replicate was conducted on two cultivators of Kolahdari and Kajanguri in Khorasan Agricultural Research Center. The fruits after harvesting were ...
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In order to study the effect of grapeguard on quality, quantity and control of storage diseases of grape in cold storage a completely randomized design with 3 replicate was conducted on two cultivators of Kolahdari and Kajanguri in Khorasan Agricultural Research Center. The fruits after harvesting were transferred to the sheltered place. Before keeping in cold storage, the temperature of fruits was reduced to 6oC during 6-24 hours precooling. The attributes including fungal contamination, berry decay, peduncle length, cluster length, cluster width, berry width, berry length, berry weight, cluster weight, soluble solids, titrable acidity and pH were measured immediately after harvest. Grapeguard sheets including 4, 7 and 10% sodium metabisulfite solutions were laid in two layers in bottom and middle of box. All the samples including control and the other treatments kept in 0oC and 90-95% relative humidity for 3 months, and all the tests were done again. Sulfur concentration, vitamin C and organoleptic characteristics were measured at the end of third month. The results revealed that fungal contamination and decay of grapes decreased by application of grapeguard sheets. These sheets caused to change TSS, decrease titrable acidity and prevent to increase pH during storage time. By increasing Metabisulfite sodium solution, the amount of vitamin C increased. Results of quality and quantity tests showed that application of grapeguard including 10 percent metabisulfite caused keeping quantity and quality characteristics in grape, but amount of sulfite dioxide was in standard limits and keeping quality of Kolahdary is better than Kajanguri, and 7% metabisulfite is in second order.
The Arya and Paris model is a commonly accepted method to translate a particle-size distribution curve into a corresponding soil moisture characteristic curve using scaling parameter (α). The scaling parameter, in the original model of Arya and Paris (1981), was assumed constant (α=1.38) ...
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The Arya and Paris model is a commonly accepted method to translate a particle-size distribution curve into a corresponding soil moisture characteristic curve using scaling parameter (α). The scaling parameter, in the original model of Arya and Paris (1981), was assumed constant (α=1.38) for all soil texture classes. In recent years, several studies have shown that α is not constant and its quantity depends on soil particle size distribution. The present investigation was conducted in order to determine the relationships between soil texture and scaling parameter. In this study, α, is considered as a function of scaled number of spherical particles to estimate the pore length in a natural soil. Results confirmed that α was not a constant value but changed with increasing particle size, especially for the sand fraction. Since the scaling parameter is difficult to determine, a regression equation (r2 = 0.96) was obtained to estimate scaling parameter. The predictive ability of the equation and that of the constant (α = 1.38) were compared on a few soils from Amol, Babol, and Karaj regions. Predictions of soil water content showed reasonable to excellent agreement with measured data, while use of a constant value (1.38) led to under-predictions in dry range and over-predictions in wet range.
In order to study the fluidization behavior of grains, a laboratory fluidized bed dryer (FBD) was designed and developed. Forward blade centrifugal fan with 1.5 kW electric motor, was selected to be used based on the highest pressure loss calculated at minimum fluidization condition and airflow rate ...
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In order to study the fluidization behavior of grains, a laboratory fluidized bed dryer (FBD) was designed and developed. Forward blade centrifugal fan with 1.5 kW electric motor, was selected to be used based on the highest pressure loss calculated at minimum fluidization condition and airflow rate at terminal velocity of the selected grains (paddy, soybean, millet and barley). The dryer was constructed with cylindrical chamber (0.144m diameter and 0.3m height), and 3.3 kW electric heater (with seven elements). Gas distributor bedplates were selected from the physical properties of the grain samples and then fluidization characteristic curves of the samples were obtained. Fluidization uniformity and drying of the samples showed that the dryer works properly and drying time of paddy at fluidized bed condition was shorter than that at fixed bed condition. The fluidization experiment results of the samples showed that the deviation between calculated and experimental pressure loss and minimum fluidization velocity for millet and soybean were less than the other grains, because of high sphericity.
Center pivot irrigation system is one of the modern irrigation methods, which is used in many parts of Iran. Due to the fast development and high utilization of this system, the concept of the optimal irrigation depth is really important for this system. This question are generally proposed that how ...
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Center pivot irrigation system is one of the modern irrigation methods, which is used in many parts of Iran. Due to the fast development and high utilization of this system, the concept of the optimal irrigation depth is really important for this system. This question are generally proposed that how much is the optimal irrigation depth? This parameter is usually determined without considering distribution functions and environmental protection parameters. Regarding the environmental problems and the cost of refining it, the computed irrigation depth, which gives us the maximum yield is not the optimal irrigation depth necessarily. So environmental limitations should be considered in determination of the optimal irrigation depth and it,s necessary to determine data distribution function. In this research, according to ASAE standard, any data distribution function were determined. System layout was setup. Four radial lines of catch cans with 6m space were used. (two radial lines of catch cans A and B, were installed on the maximum slope with 3º between every two rows and two radial lines of catch cans C and D, were installed on the minimum slope with 3º between every two rows). Field data were collected with different speeds of the center pivot system. The amount of water in the catch cans were measured in different weather conditions (wind speed, weather temperature and relative humidity) proposed distribution function in sprinkler irrigation (normal, lognormal, specialized power and uniform distribution) were selected. Nonparametric statistic test (Kolmogorov-Smirnov) is used. Results show that specialized power and uniform distribution were failures at the 0.05 confidence level in all of the tests (20 out of 20). Lognormal distribution function had 17 cases of failures (17 out of 20) at the 0.05 confidence level normal distribution function had 5 cases of failures (5 out of 20) at the 0.05 confidence level. So, normal distribution function shows the best description for dispersion data. It is suggested that for center pivot irrigation system, the optimal irrigation depth should be determined by using normal distribution.
Potassium and calcium are two important nutrients determining fruit quality. In order to study of K/Ca ratio of fruits in firmness and storage shelf-life of fruits, an experiment carried out in RCBD on Golden delicious apple with 9 treatment in 5 replication in Naghadeh in 2001. The experimental treatments ...
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Potassium and calcium are two important nutrients determining fruit quality. In order to study of K/Ca ratio of fruits in firmness and storage shelf-life of fruits, an experiment carried out in RCBD on Golden delicious apple with 9 treatment in 5 replication in Naghadeh in 2001. The experimental treatments including: T1= control, T2 = T1+ micronutrients, T3= T2+MOP (based on soil test), T4 = T3+ 4 times 0.5% CaCl2 spray, T5= T3+ 8 times 0.5%CaCl2 spray, T6= T2+MOP (50% above soil test), T7 =T6+ 4 times 0.5%CaCl2 spray, T8 =T6+ 8 times 0.5%CaCl2 spray, T9=T2+ K2SO4 (50% above soil test)+8 times 0.5% CaCl2 spray.The results showed that foliar applications of CaCl2 solutions increased fruit firmness compared with fruits receiving high rates of potassium but no calcium. The greatest firmness was obtained with 8 times application of CaCl2 solution. Treatment 6, which involved the application of potassium at 1.5 times the soil test but no foliar application of calcium chloride, resulted in the lowest firmness. There were no significant differences among the treatments with regard to pH, TA and TSS; However the fruit calcium contents were significantly different in treatments..Fruits K/Ca ratio was 44 in control and increased about 58 in T6. But in T8 with optimal consumption of fertilizer and eight times CaCl2 0.5% spray, this ratio reduced to 20. The treatments did not affected on fruit firmness in 90 days after storage significantly. Therefore, in order to increase the calcium of fruits and to improve the fruit firmness 8 biweekly foliar applications of CaCl2 (beginning 3 to 4 weeks after full bloom) is recommended.
In order to obtain the maximum benefit, yield increasing and its stability a supplemental irrigation field experiment was conducted as split plot arranged in a randomized complete block design (RCBD) with three replications during 1999-2002 at Maragheh Agricultural Research Station of DARI. The treatments ...
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In order to obtain the maximum benefit, yield increasing and its stability a supplemental irrigation field experiment was conducted as split plot arranged in a randomized complete block design (RCBD) with three replications during 1999-2002 at Maragheh Agricultural Research Station of DARI. The treatments included four levels of irrigation (average of three years: 0, 95, 151 and 207 mm) as main plots and five N rates (0, 30, 60, 90 and 120 kg.N.ha-1) as sub plots, was carried out on rainfed wheat variety (Sabalan). Data analysed by Partial Budgeting, Marginal Benefit - Cost Ratio (BBCR), different states of water and irrigation prices, income functions and senario analysis of water productivities. Optimal level of supplemental irrigation was 95 mm water use combined with 60 kg.N.ha-1 resulted maximum water productivity (20.1 kg.mm-1). In spite of 20% reduction of yield in this treatment, maximum net benefit was obtained along with probability of 180% cropping area increasing which can be led to 74% increasing in total production grain yield. Limit of benefitability for optimum level of supplemental irrigation was determined as 2857 Rial.m-3.
