Journal of Agricultural Science and Technology
Volume:3 Issue: 4, Oct 2001

ABSTRACT The most commonly used utility functional forms are reviewed and their properties compared. Then, using data collected from West Azarbaijan province, utility functions are estimated and absolute risk aversion coefficients measured. Exponential and expopower utility functions classified all farmers as risk averse, but quadratic and cubic utility functions classified 75% and 65% of farmers as risk-averse, respectively. Findings in this study indicated that alternative utility functions may classify farmers’ risk attitudes in different ways.

ABSTRACT In recent years, the Russian Wheat Aphid, has been included worldwidely in the list of the important pests of cereals, particularly wheat plants. In addition to direct serious damage, the aphid is the main vector of Barley Yellow Dwarf, Barley Mosaic, and Sugarcane Mosaic Viruses. The pest was reported from East Azarbaidjan province (Iran) a few years ago and it is now widespread in Tabriz, Ahar and Kaleybar wheat fields. In the present study, the possibility of any resistance was looked for at the tillering stage in Sardari, Sabalan, Alvand, Zarrin and Alamoot, the most extensively planted varieties in the province. The experiment was conducted under glasshouse conditions of 24.4±1.6 oC with 50- 60% R.H. and a photoperiod of 14:l0(L:D). Antibiosis was determined by studying the percentage survival of the nymphs, their developmental time, and fecundity (total number of progeny per /female produced within the first 10 and 15 days of the reproductive cycle) calculating the relevant intrinsic rate of natural increase (rm values). The analysis of variance indicated that, regarding the last two parameters, there were significant differences (P<0.05) between the varieties. The highest (43.21±5.45) and the lowest (34.43±8.91) average numbers of progeny within the first 10 days were observed in those reared on the Sardari and Zarrin varieties respectively but the figures obtained within the first 15 days were found to be 49,43±13.31 on Alamoot and 58.86±9.45 on Sardari. Also the highest mean “rm” value (0.3399±0.01) was estimated for rearings on Sardari with the smallest (0.2889±0.03) on the latter. At present, Sardari seems to be more likley susceptible to the aphid amongst the others. Field trials and experiments on later phenological stages of the wheats and potential role of other resistance mechanisms is going on.

ABSTRACT The harvested walnut has a relatively high moisture content of 30% compared with the safe storage moisture content of 8%. One of the common means of reducing the moisture content is by drying. For design of drying and other aeration systems for agricultural products including walnuts, the relationship between the drop in pressure and airflow velocity must be known. An airflow resistance apparatus was designed and manufatured to measure the airflow resistance of walnuts. This apparatus consisted of an air compressor, a rotameter, a cylindrical bin and an inclined U-tube manometer. The pressure, drops at airflow velocities of 0.085 to 0.55 (m3/s)/m2, were measured at a constant depth of the nuts. Airflow resistance equations were fitted to the measured data. The results showed that, by increasing airflow rates, an increased drop in pressure was achieved through out walnut column. To study the effect of walnut moisture content on airflow resistance, the drop in pressure was measured at different moisture contents levels of 8.6%, 15.5%, 21.3% and 27%. Results indicated that the drop in pressure decreased with increasing moisture content, especially for high airflow rates.

ABSTRACT The objective of the present field experiment was to examine how plant density and enhanced source, i.e. thinning treatments, may affect grain yield and its components for a non-prolific maize hybrid, SC704. The environment of the hybrid maize crop was changed at intervals over its life cycle by removing every other plant in rows equispaced at 75 cm apart with a population of 13.34 plants m-2. The plants were grown with no water or nutrient restrictions. Results showed that earlier thinning was associated with greater stem, leaf, shoot and ear dry weight accumulation, ear kernel weight (EKW) and kernel number per ear row (KNER). In this ways the greatest of these characteristics were obtained in thinning at sowing i.e. 6.67 plants m-2 throughout. Delay in thinning until the 12-leaf stage reduced stem dry weight and EKW significantly. Thinning at tasseling also resulted in significantly lower stem dry weight accumulation compared to thinning at sowing. At final harvest, the stem dry weight of plants thinned at tasseling was 20.47% (P<0.05) lower than those thinned at sowing. Similar effects were found upon delay in thinning until tasseling on leaf, shoot, and ear dry weight accumulation. Delay in thinning until the 12-leaf stage or later, also reduced EKW significantly compared to plants thinned at sowing. This reduction was attributable to decreased KNER and 1000-kernel weight. According to these results, KNER and 1000-KW were found to be yield components sensitive to light environment.

ABSTRACT An in vivo experiment was conducted to determine the effect of dietary betaine supplementation (Betafin®) as a replacement for methionine on broiler performance and carcass characteristics. In a completely randomized design (CRD) with five treatments of betaine levels (at 0, 25, 50, 75, and 100% in replacement for methionine) and five replicates of 10 birds/replicate, two hundred fifty-day-old Ross broiler chicks were randomly distributed in cages and fed the experimental diets from 0 to 49 days of age. Feed and water were provided ad libitum. Feed intake and body weight were recorded weekly. At 49 days of age, one bird from each replicate was killed for comparison of carcass characteristics. Betaine replacement for methionine had no effect on feed intake and feed to gain ratio but decreased body weight gain at 0 to 3 (P<0.0465) and 0 to 7 weeks of age (P<0.01). Betaine as a replacement for methionine decreased the breast weight (P<0.025) and tended to reduce the abdominal fat pad (48.9 vs 40.4 grams, 100% methionine vs 100% betaine replacement for methionine). The present findings do not support the hypothesis that betaine can effectively replace methionine.

ABSTRACT Wastewater planning management is a complex problem involving agricultural, rural and industrial interests. In countries facing rapid population growth, identifying methods that can allow them to take good decisions among several competitive alternatives is of utmost importance. The purpose of this paper is to present a methodology for a wastewater planning management system using a Multi-criterion Decision-making (MCDM) method based on utility function. It allows one to take into account a multiple conflicting multi criterion context in terms of objective specification, criteria, criterion scales and construction of a payoff matrix that consists of the alternative versus criteria array. These objectives deal with groundwater protection, effluent quality, wastewater reuse, system reliability and resources needed. A number of wastewater treatment techniques are presented as alternative action plans from which the most satisfying alternative is to be chosen. In order to select on appropriate management scheme, we propose to use the UTA (Utility Additive) method. This method is interactive and permits the decision maker (DM) to select the best solution according to his viewpoint. The UTA method proceeds in two steps: the assessment of optimal utility using piecewise linear programming techniques and sensitive analysis using a post - optimal procedure. An application of UTA method in wastewater planning management system is presented for the first time and some extensions of the method are discussed.

ABSTRACT Seed protein profiles of 47 accessions belonging to eleven species and four tribes of grain legumes were studied, by extracting the total proteins from ten single seeds in each accession and performing SDS-Polyacrylamide gel electrophoresis. All eleven species were clearly recognizable from their protein banding patterns, but only Phaseolus vulgaris expressed high intraspecific variations, followed by Lathyrus sativus. Variation among accessions of other species was very limited. Cluster analysis, after quantifying the protein bands, using UPGMA procedure, showed phylogenetic relationships which were in a good concordance with species classification based on morphological characters. Accessions of tribe Vicieae formed one cluster (Vicia faba, Lens culinaris, Pisum sativum, Lathyrus sativus and Vicia ervilia) having nearly equal amounts of three categories of polypeptide: high, moderate and low molecular weight. The second cluster was a small tribe of Cicereae (Cicer arietinum accessions) having moderate and low molecular weight polypeptides. Accessions of Phaseoleae tribe formed the third cluster (Phaseolus vulgaris, Vigna unguiculata and Vigna radiata), having predominantly high molecular weight polypeptides. Finally, the more distinct tribe, Aeschynomeneae (Arachis hypogaea accessions), formed a separate cluster exhibiting a special banding pattern. A unique discrepancy was observed about Glycine max, which belongs to Phaseoleae but was clustered with Cicereae.

ABSTRACT The influence of initial moisture content on wood decay at different levels of atmospheric oxygen concentration was studied. Three fungi, Coriolus versicolor (C. versicolor) a white rot, Coniophora puteana (C. puteana) a brown rot, and Chaetomium globosum (C. globosum) a soft rot, were chosen. The mycelia of the fungi were inoculated in to mini blocks of Fagus sylvatica (beech) and Pinus sylvestris (Scots pine). Incubation was conducted under four levels of oxygen concentration (1,5,10, and 21% O2) at 22o C. At low oxygen concentrations, an increase of moisture content had a negative effect on the wood decay process by both the Basidiomycetes (C. versicolor and C. puteana) in Scots pine and beech. In air, the effect of initial moisture content on wood decay by these fungi depended on the characteristics of the fungi and the wood species (such as fungal biology and physiology). When C. globosum was used as a colonizer, increasing moisture content generally increased weight loss in the wood blocks (especially in beech). When the moisture content in the wood blocks was increased, more sporulations by C. globosum were also observed on the wood samples. However, the role of oxygen in inceasing wood decay was more important than the moisture content effect.