THE SCIENTIFIC JOURNAL OF AGRICULTURE (SJA)
Year:2006 | Volume:29 | Issue:3|Papers Count:14

Saturated hydraulic conductivity is a soil physical property of importance in a wide variety of physical soil and water applications. When the water table is well below the - surface, Guelph permeameter method is recommended as the best and most efficient method for its measurement which can be performed quickly by one single person. Two ponding depth analysis of Guelph permeameter yield the two unknown parameters Kfs and a* from the sohition of two sets of equations. This method of solution ho ever most often yields a number of negative results which are unrealistic. This is due the nonhomogenuety of semultaneous equations. In this research single head laplace analysis (KL) with zero capillarity, single head of Richards with a*=12 analysis and reagresion single depth analysis of Richards (KR) are used to eliminate negative answer. The results show that the regression analyses of Richards with a single head measurement can yield seliable results. It was also shown that due to a large standard deviation of a* Value, it is preferred to assume its value to be contant.

To study milk production traits and estimate genetic related parameters, 3245 records of milk yield, fat yield and fat percentage of Khuzestan Holstein cows were used. The effects of the region, herd, parity, calving year, season and month of calving were evaluated on the traits. Also the effect of Herd-Year-Season (H-Y-S) was investigated on the traits in a mixed model including age of calving as a covariate. The effects of the region, herd and calving year were significant on all traits, but the effects of parity and calving season were not significant on fat percentage. The effect of H-Y-S was significant on all traits, too. The mean and standard deviation of milk yield, fat yield and fat percentage were 3851.57±1073.34 Kg, 136.08±43.51 Kg and 3.57±0.70 percent, respectively. Heritability of milk yield, fat yield and fat percentage were 0.24±0.10, 0.25±0.11 and 0.36±0.10 using univariate model and were 0.19±0.06, 0.30±0.08 and 0.31±0.05 using repeatable model Estimated. Repeatability was 0.32, 0.32 and 0.32 for milk yield, fat yield and fat percentage, respectively. The genetic, residual and phenotypic correlation were 0.70, 0.76 and 0.75 between milk yield - fat yield, -0.30, -0.32 and -0.31 between milk yield – fat percentage and 0.47,0.32 and 0.37 between fat yield - fat percentage. Lactation curves were studied for four calving seasons, using monthly records. The highest peak of milk production and the best persistency of lactation curve were found for winter calving cows and fall calving cows, respectively.

Karkheh Reservoir with an approximate 6950 million cubic meters capacity currently is the largest reservoir. HEC-6 (US army corps of engineers) and DEPO are the models that are employed to evaluate the sediment deposition in this reservoir. A lot of data including - geometry data, average daily river discharge, average sediment concentration data, average gradation curve of sediment inflow, stream bed grain size, and the other hydraulics data were collected for this propose. After preparing the input files and running the model, the output results are compared in a graphical illustration. The results show that the average sediment inflow to the reservoir is nearly 14.7 million cubic meters per year. The average volume reduction is obtained to be 0.00158 per year. Based on the results obtained from running the models, the volume of the reservoir after 100 years will be between 5400 to 6000 million cubic meters and the nearest distance of deposited sediment in the delta will reach 18-23 km from dam wall. Therefore to avoid any inconvenience, it is suggested that all of the reservoir facilities be installed in the distance between dam wall and the front of the predicted delta.

Since the first production of pharmaceutical protein in transgenic tobacco in 1986 a broad range of proteins with potential medical applications has been expressed in plants. Plants are more economical than other systems. There are not any human pathogens in plant systems, and heterologus proteins that were expressed in plants, conserved their original structure. In the present work we expressed recombinant single-domain antibody against MUC1 mucin in tobacco. In this study adequate primers were designed in regard to plant high expression sequences. Then VHH was cloned in a plant expression vector, pBI121. The plant expression vector, Containing VHH was amplified in E. coli and then transformed to Agrobacterium tumefaciens. The transformation of VHH to tabacco plant cell was conducted by agrobacterium. The regeneration of transgenic plants was performed on selective tissue culture media containing kanamycin and cefatoxim, and the resistant plants which were screened. Existence of VHH gene in transgenic plants was confirmed by PCR analysis with specific primers. Activity of produced VHH was proved with ELISA and Immuno Blotting tests. This is the first report of expression of active antitumor VHH in plants.

Weed dynamic in agroecosystems had a key role in weed threshold management. Also, crop rotation and weed free period are the ecological approaches in integrated weed management. To evaluate the effects of previous crop and time of removal on weed communities, a two-season field research was conducted in Mashhad. The experimental design was split plot on the bases of randomized complete block design with three replications. The two previous crops were the main plots (wheat and canola) and time of weed removal as sub-plots (i. e. 20, 40 and 60 days after planting). The results indicate that the effect of previous crop and time of removal on weed density and dry matter were significant. First time removal caused highest weed density and dry matter. Weeds shoots in this treatment also had a highest nitrogen, phosphorus and potassium. In most cases, board leaf weeds had more density and dry matter than grasses. Canola was a volunteer crop in sorghum weeds flora.

Locusts such as Schistocerca gregaria (Forskal), Locusta migratoria migratorioides, Reiche and Fairmaire, Dosciostaurus maroccanus Thunberg are separated from other species of Acrididae (grasshoppers) because they produce gregarious phase. In this article it is speculated that ecological stress is the main factor for changing grasshoppers into locust. Locust outbreak and phase change are characterized by changing their hormonal system. Locust outbreak in relation to the phase polymorphism has been the subject of many studies and reviews. Density dependent factors in locusts change their morphometrics, physiology (colouration, enzymes), reproduction, cytogenetics and development as a result of phase transformation. There are some similarities between changes of locust to gregarious phase and insect outbreak after feeding on stressed plants. All stressors such as poor soil and dry season affecting plants can have some effects on locust phase transformation. Stress is a response to nonspecific environmental demand, and pathogen or parasites also produce stress response in locust. Environmental cues can produce reaction in stressed locust by gene expression and produce or change the endocrine and enzyme secretions. Therefore, polymorphic variation observed in locust populations during phase transformation is their response to local climate or host plant conditions. Factors affecting the fitness of locust can select special life history traits and may have been the reason for selection of locust life cycles as compared to grasshoppers

The socio-economic factors such as ecological factors have effects on the development of integrated pest management programs. In this research, the effects of these factors on control of date pests and diseases and reduction of the injuries among them were studied in date garden Khuzestan province during 2001 - 2002. The statistical community was the whole Khuzestan date growers. Sampling was conducted by random cluster sampling method. Sixty-five date growers were selected. The results showed that land holding, the ratio of irrigated to total land, the number of fertilized trees to the number of growers, yield per tree, percentage of yield sold, and crop benefit and ownership of tractor have negative and significant effects on pests and diseases injuries and positive effects on growers motivation to pests and diseases control. To obtain non-agricultural employment factor had redundant and significant effect on pests. Four factors including irrigated to total land, value of crop benefit, the number of fertilized trees to the number of growers and non-agricultural employment had the most effective approach on date pests and diseases control program, respectively.

The main objective of this study is to compare economic condition of crop sustainable rotations, and the risk that is caused by using this rotation by farmers. Risk programming method of TMOTAD was used for determination and comparison of these rotations. Data were collected from different organizations such as Agricultural Organization of Fars Province, Darab city and statistical paper of Fars Province agriculture. Findings showed that the risks of various crop rotations are different form one another. Here we studied rotation of Corn-wheat-Corn-wheat-fallow which included the lowest risk in the region. Comparison between the results of approximate patterns with present situation of farmers revealed that there is a quite difference between cultivation model of farmers and optimal pattern with or without rotation. The results of TMOTAD in comparison with linear programming method with or without rotation showed that optimal programs that are obtained from TMOTAD, at the highest level of risk, approximate its linear optimal pattern.

This experiment was conducted to study the effect of changing time from starter to grower diet (14th  & 21st day), grower to finisher diet (35th day & non-finisher diet) and dietary lysine level (NRC, 1994 & 115% NRC, 1994) on broilers performance in a completely randomized design with a 23 factorial arrangement. Four replicates of 16 day old Ross of 308 male broilers were allotted to each of 8 experimental treatments. Broilers were raised on the litter floor and their performance, protein and energy efficiency ratio were tested during 1 to 42 days. Reducing the time of starter diet from 21st to 14th day resulted in an increase in feed intake, feed conversion ratio and decrease energy efficiency ratio (P<0.05), but had no significant effect on other experimental parameters. Early feeding of finisher diet from 35th day significantly reduced protein intake, energy intake and increased protein efficiency ratio (P<0.05) but did not have any significant effect on other characteristics. Increasing dietary lysine level resulted in an increase in body weight gain (P<0.05) and improved feed conversion ratio, protein efficiency ratio, and energy efficiency ratio (P=0.07).The results of this study suggest that feeding the starter diet from 14th, finisher diet from 35th day and increasing dietary lysine level to 115% NRC, 1994 recommendation, improve broiler performance and some benefits may be obtained.

The effect of land use type on soil functioning within an ecosystem can be assessed and monitored using soil quality attributes. Such studies, which are carried out to create a balance between the biological production and the maintenance and improvement of land resource quality, provide a framework for land degradation control and also for identification of sustainable management. The objective of this paper was to investigate the effect of conventional management systems on soil quality indices in Boroojen area in order to identify the most sustainable practices. Five management systems including a protected rangeland, an overgrazed rangeland, an abandoned dry land farm, an irrigated wheat farm and an alfalfa farm were selected. Organic matter (OM), phosphates activity (PA), microbial respiration (MR), total nitrogen (TN), saturated hydraulic conductivity (Ks), bulk density (Db), texture, carbonates and pH were measured in the surface soil samples of each site. PA and OM were maximum in alfalfa farm and minimum in both abandoned dry land farm and overgrazed rangeland. The highest rate of MR and TN content were obtained for alfalfa and wheat farms. The lowest potential of MR was measured in protected and also overgrazed rangeland, while the lowest amount of TN was determined in overgrazed rangeland and abandoned dry land farm. The hydraulic conductivity (Ks) was found to be more sensitive to land degradation, as compared to Db. It was highest in alfalfa farm and lowest in overgrazed rangeland. The findings of this study indicate that continuous wheat cultivation, as the most prevalent management system, decreases soil quality. This study also shows that abandoned dry land farming is ecologically the least sustainable land use in the area. Besides, soil phosphates activity, organic matter content and hydraulic conductivity seem to be the most reliable soil quality indices for the area

Due to low tannin content and low astringency, Barhee is one of the most important date cultivars suitable for consum5ption at Khalal stage but due to the high moisture content, ftuits are very perishable with low storage ability. In the present experiment the effect of vacuum and modified atmosphere packaging (MAP) on the shelf life of Barhee dates under two storage temperatures (4 and 25oC) were studied. Fruits were analyzed in three time intervals after packing (0, 10th and 20 days) and evaluated for quality characteristics such as weight loss, flesh firmness, total soluble solids (TSS), water activity, titrable acidity, juice PH, percentage of Rutab fruits and percentage of crumbled fruits. The results showed that fruits in MAP treatment had less than 1% weight loss, lowest percentage of Rutab fruits (14.7%), highest water activity (0.957), and marginally had low changes in the other parameters tested. However, in the vacuum packaging weight loss and the amount of crumbled fruits were minimum but large part of fruits changed to Rutab (22.4%) and fruit firmness significantly reduced.

A faunastic survey of eriophyoid mites (Eriophyoidea) was conducted in Khuzestan province during 2004 - 2005. A total of 12 species belonging to 9 genera from 4 subfamilies and 2 families were collected from field crops, fruit trees and weeds from which 7 species were new for Iran. Among the collected mites three species belong to genera: Aceria (Eriophyidae, Eriophyinae), Phytoptus (Phytoptidae, Novophytoptinae) and Thamnacus (Eriophyidae, Phyllocoptinae) were new records for the world, and their description are in progress. Among the collected species those with (**) and (*) astriskes are considered as new records from Iran and Khuzestan province respectively which are as follow:A) Family: DIPTITOMIOPIDAE, subfamily: Rhyncaphytoptinae1) Rhyncaphytoptusficifoliae KeiferB) Family: ERIOPHYIDAE, 1) subfamily: Phyllocoptinae.1) Aculus solani**Boczek & Davic, 2) A. schlechtendali* Nalepa, 3) Aculops lycopersici Tryon 4) Oxycenus maxwelli** Keifer, 5) Notalus neri**Keifer2) subfamily: Eriophyinae1) Aceria sacchari Wang, 2) A. melongena ** Zaher & Abou –Awad3) A. eucricotes** Nalepa, 4) Eriophyes rotundae** Mohanasondaram3) subfamily: Cecidophyinae1) Colomerus vitis Pagenstecher, 2) Cecidophyopsis hendersoni **KeiferAll species were deposited in Acarology Collection, Department of Plant protection, College of Agriculture, Shahid Chamran University, Ahwaz, Iran.