JOURNAL OF AGRICULTURAL SCIENCE AND SUSTAINABLE PRODUCTION
Year:2005 | Volume:15 | Issue:2|Papers Count:20

One of the ways of estimation the agricultural development and production stability in agricultural regions is making use of the energy circulation method. For this reason, in year 2000-2001, seed propagation fields of dry land wheat varieties were studied as an index for this echological issue .To assess energy balance in these fields, all the data consisting inputs and outputs, converted into amounts equivalent to consumed and produced energies and then energy efficiency was calculated. In these fields the amount of energy for inputs and agents, were 6491589.5 kcal/ha, and output or produced energy, consisted of seed yield and, straw yield, were calculated as 2751 thousands kcal/ha and 2366 thousands kcal/ha. Also the amount of energy efficiency (output/input) for biological yield (seed + straw) was calculated 0.788. The amount of energy efficiency for seed and straw yield are 0.424 and 0.364, respectively. The data indicated that the highest consumed energy in these fields were related to nitrogen fertilizer, machinery consumed energy and gas soil fuel, respectively and the lowest belonged to human force. This could be attributed to climate conditions, topography and even particular subjects related to regional population and culture. The results indicated that in addition to a very high wast of energy in seed propagation fields of dry land wheat varieties in East Azerbaijan. continuing the existing conditions will pollute seriously the soil and water resources of these lands.

The influence of date of cutting, environmental conditions and auxin concentrations on rooting of the stem cuttings of Duranta repens L. was investigated. The leafy semi-hardwood cuttings of Duranta were taken from the mother plants in November 200 I and February 2002. The cuttings were treated with 0, 2000, 3000 and 4000 mg/l Indole-3-butyric acid (IBA) and Naphthaleneacetic acid (NAA) and then placed in rooting bed consisted of sand under mist conditions and polyethylene tent. The cuttings of Duranta that treated with 2000 mg/l NAA, showed the highest rooting percentage. Cuttings were taken in February and treated with 4000 mg/l IBA and or 2000 mg/l NAA gave the highest number of roots. Length of the longest root, root length, dry weight of roots and new growth of buds of Duranta cuttings were significantly the higher when the cuttings were –taken in February and treated with 4000 mg/l IBA. Cuttings collected in February and treated with auxins, had significantly higher rooting and new growth of buds. Rooting percentage of cuttings which treated with auxins under mist condition and polyethylene tent, were not significantly different but number of roots and dry weight of roots were higher in cuttings that placed in mist conditions. Root length of cuttings that treated with auxins and placed under polyethylene tent, was significantly higher than other conditions.

The aim of this study was to identify physiological traits related to low temperature resistance. Three wheat genotypes (Bezostaya, Boolani and Line 518) differing in cold resistance were germinated and grown at 20 and 10°C and were subjected to chilling (2°c) and then freezing (-10°C) stress at four- leaf stage. A split plot design with four replications in which growth temperature and genotypes were considered as main and sub plot, respectively, was employed. Measurements were taken before and after exposure to chillirig and also after exposure to freezing. Plants germinated and grown at low temperature (10°C) (LT) showed higher soluble carbohydrate (SC) content and lower tissue water percentage (WP) at all measurement stages and higher chlorophyl (CHL) content only at prehardening measurement as compared to those grown at higher temperature (Con.) (20˚C).The highest SC and WP were observed in Bezostaya (resitant) and Line518 (sensitive), respectively. Exposure to chilling increased leaf SC and CHL contents of plants grown at both 10°C and 20°c. Interaction effects between growth temperature and genotypes were observed, for se and CI-IL before and after exposure to chilling. It was also appeared that chilling induced increase in SC was more pronounced in plants grown at LT than those grown at Con. condition. Exposure to freezing, resulted in increased SC and decreasd leaf water potential, the highest reduction in WP and highest increase in SC being observed in Bezostaya. Damage to cell membrane, measured by solute leakage, due to freezing stress was greater in Line 518 than in Bezostaya. Traits measured in these experiments appeared to be correlated with cold resistance in the field condition.

Having knowledge about different developmental stages of a species and determining the number of its nymphal or larval instars is a very important factor in entomological studies. In population and toxicological studies, it is of very importance that we know the above topics and be able to recognize each of larval or nymphal instars. for instance, in a toxicological study, using larvae or nymphs belonging to different instars will produce incorrect results. because of their possible different sensivity. Studies carried out by entomologists, especially H.D. Dyar, have shown that the size of a sclerotinized part of body, especially head capsule, increase linearly in successive developmental instars and has a constant rate that varies from 1.3 to 1.7. In present study, we studied the number of larval instars "of the Mediterranean flour moth, Anagasta kuehniella, on its rearings on wheat Hour and under laboratory conditions. Number of larval instars were studied by two methods of "direct observations" and "measuring head capsule width and using Dyar's rule". Five instars were observed by the first method. In the second method, means of head capsule width of 1st to 4th instar larvae were 197, 288, 435 and 727 µm, respectively, and for 5th male and female larvae were 1114 and 1139µm, respectively. Dyar's rule constants were determined as 1.461, 1.510, 1.671, 1.532 and 1.566, respectively. These results indicated that according to Dyar's rule, there are five larval instars in this species. Comparison of the results obtained by these two methods indicates that the Dyar's rule can be used for determining the number of and recognizing the larval instars of A. kuehniella under laboratory conditions.

In this program, effect of oxalic acid, 3.5%, and two application methods of this compound were studied. Fifteen infested honey bee colonies with varroa mite, Varroa destructor A.&T., were chosen. These colonies were divided to 3 treatments and 5 replications, which treated with dehydrate oxalic acid, 3.5%, per liter sugar syrup I: I using spray and trickling methods. The control group didn't receive any chemicals or drugs. Results showed that oxalic acid has a high potential for control of varroa mites in Iran, especially in low temperature. The average mite mortalities were 98.59, 95.19 and 6.48% for spray, trickling methods and control, respectively. Average mortality in the first and second treatments were not significantly different, but they had significant difference with the control (P< 0.05). Also, the comparison between two methods showed that mite mortality were 97% and 3% in spray method. and 55% and 54% in trickling method during the first and second time of application. respectively. Therefore, we needed only one and/or two applications of oxalic acid, 3.5%, in spray and trickling methods, respectively.

In arid and semi arid areas, where available water for agricultural sector is limited, the main objective of this sector is to drive more yields and benefits from lower amount of irrigation water. In order to study the resp0I1ses of potato cultivars to limited water suply, an experiment was carried out with three potato cultivars (Agria, Morene, Cozima), and three levels of irrigation (400, 600 and 800mm per hectar and season), in year 2000. Factorial experiment based on randomized complete block design with three replications was used to study growth indices of different levels of irrigation, based on GOD, and relationships of yield, yield components and other characters were determined. Analysis of variance showed that different levels of irrigation influenced all cultivar characters differently except the number of shoots and tuber per plant. Except for the percentage of tubers with a diameter of smaller than 4cm, there was a negative effect of water shortages, at 400 mm level, on plant dry matter, dry matter of tuber, tuber number per plant, plant height, root dry matter, harvest index, tuber yield, the yield of tubers with a diameter of more than 7 cm and ware tuber yield. However, the results obtained from 800mm and 600mm irrigation levels were similar. Although there was no significant difference for total tuber yield between 600 and 800mm irrigation levels, the ware tuber yield at 600mm irrigation level was significantly greater than those of other two levels. Considering all these aspects, the 600mm irrigation level was recommended for all of the varieties under study.

Subsoiling is used to loosen hardpan and increase rooting depth and water availability. This study evaluated cotton response to loosen hard pan and different irrigation frequency with canstant crop water requirements. The irrigation frequency as mainplots at three levels: W.R1 :35 and W.R2:50 and W.R3:65 milimeter water requirements and tillage systems as subplots at two levels as follows:(1): moldboard plowing plus disc harrow (MB.P) and (2): subsoiling to a depth of 45-50 cm plus moldboard plowing and disc harrow (SS+MB.P) were used with five replication. Yield and Yield components, cone index and bulk density were measured for all treatments. The results showed that different tillage methods had no significant effect on crop yield. Maximum yield was obtained in (SS+MB.P) method and there was also no significant difference in yield between use of (SS+MB.P) and (MB.P) methods. Maximum and minimum amount of yield was occurred when irrigation frequency was done at 50 and 35 mm crop water requirements, respectively.

In order to study gene dosage effect and comparison of resistance level to rhizomania, two resistance sources B. vulgaris subsp. maritima, WB42, and B. vulgaris subsp. vulgaris, Holly, were crossed with susceptible parents and F1, F2 and BC1 populations were obtained. WB42 as also hand-crossed in pairs with Holly ann Fl population was obtained. Individual plants of parents, F1, F2 and BC1 populations were assessed by DAS-ELISA in greenhouse and relation of gene dosage effect with the ratio of BNYVV -tree: BNYVV -infected plants was investigated. Also, number of viable plants in parents and F1 families were counted to compare the level of resistance. In segregating populations, a significant, relationship between the gene dosage effect and the ratio of BNYVV-free: BNYVV-infected plants was not observed. But, observed ratio of BNYVV-free plants in F1 population of Holly × WB42 was in agreement with the expected ratio of plants containing two genes. This result was probably related to the increase of resistance level by combining two different genes. Moreover, statistical comparisons of resistance sources showed that the viability in F1 families of WB42 was higher than Holly, although the difference between parents was not significant.

An experiment was conducted to evaluate the effects of dietary fat sources on the performance and abdominal fat deposition of two broiler strain (Arian and Ross). In this experiment 864 one-day old chicks from two strain (432 Arian and 432 Ross) were fed a common basal broiler diet from 1 to 21 days. On day 22 up to day 49 the chicks were fed the experimental diets, which contain 40 g/kg different fat sources or their combinations. The fat sources were: tallow, sunflower oil, poultry fat, sunflower oil+ tallow, tallow + poultry fat and sunflower oil+ poultry fat. Diets were formulated to be isonitrogenous and isoenergetic. Live weight gain, feed intake and feed conversion ratio (FCR) were measured weekly. The abdominal fat deposition was determined at the end of study. Dietary fat sources did not influence (P>0.05) live weight gain and feed conversion ratio (FCR). However, dietary fat sources had a significant effect (P<0.05) on feed intake. Live weight gain and feed conversion ratio (FCR) were not different (P>0.05) among chickens fed the various fat diets. However, significant difference was obtained in the abdominal fat deposition with higher rate in sunflower oil and lower rate in the tallow sunflower oil treatment. The strain had a significant effect (P< 0.05) on feed intake, live weight gain and abdominal fat, but feed conversion ratio (FCR) was not affected by strain. The data finding ti'om this experiment indicated that the using poultry fat in broiler diets as compared to other fat sources had superior effect on the reduction of abdominal fat.

Soil moisture characteristic curve (SMC) is an important hydraulic characteristics of soil in design of irrigation and drainage systems, determination of hydraulic conductivity, and contaminants transport study in porous media. Direct method in the derivation of SMC is often costly and time consuming. Hence, physical and empirical models are widely used to simulate SMC. The main objectives of the present study were to compare the actual SMC with those predicted from Arya and Paris (1981), Arya et. a1. (1999), and Tyler and Wheatcraft (1989) models and to modify the simulated results with scaling parameter (a) applicable for different types of soils. The input data for these models ara particle-size distribution and α parameter. In this study, nine different soil series from Urumie and Salmas regions representing wide range of soil texture class from loamy sand to clay were examined. Results indicated that the simulated SMC without modifying α parameter for particle size distribution are significantly different from the measured SMC, and the deviation in α for each type of soils is the major factor in the discrepancies. Hence, the scaling parameter α plays a major role in the simulation process. The parameter a is generally evaluated by a relationship in the form of αi = (a+blog (Wi/Ri3»/logni. In the present study, empirical coefficients a and b were determined for nine soil texture classes. Results indicated that with a= log (3/4 Лps» and b= 1.0156 e-0953, a could be calculated regardless of soil texture, thereby, the simulation of SMC could be accurately possible. Simulated SMC were in good agreements with the experimental ones, and the relative error was in the order of 0.79% indicating a great accuracy in SMC prediction.

Field performance of seeds is one of the most important factors in seedling growth, field surface covering and finally having higher yield. Seeds usually exhibit different percents of germination in laboratory and emergance in field which can be related to differences in their vigour. The objective of this experiment was to study the effects of seed vigour on seed germination and emergance of two chickpea (Cicer arietinum) types under saline condition. The laboratory experiment was done using three factors, genotypes (Kaka, Pyrouz, Jam and line-12-60-31), seed deterioration levels (non, 20 and 25 days, were exposed to accelerated ageing, based on the results of preliminary experiments) and salinity (non, 3 and 6 dim). The experiment was repeated in the greenhouse in pots. The results indicated that increasing the levels of deterioration and salinity lead to decreasing seedling root and shoot length, germination percentage and rate, emergance percentage and seedling stablishment and increasing abnormal seedlings percentage, in all genotypes. But the responses were different between the types and genotypes. The genotypes belonged to Desi type as compared to the genotypes from Kaboli type, showed better field performance. In addition, Kaka (Desi) and line-12-60-31 (Kaboli) indicated higher seed emergance percentages than other genotypes. It seems that measurement of seedling length in laboratory as an indirect vigour test, could be an efficient indicator of the ability of seedlings for emergence and establishment in field.

In order to study the response of grain yield and its components in soybean cultivars for delaying planting time in Shirvan region, an experiment was conducted in 2002 at Research Field of the Faculty of Agriculture of Shirvan, Mashhad University, Iran. In this study nine soybean cultivars (Habit, Hack, Blackhack, Cencutry, Cloumbos, Clark, Sahar. Zane and Willams) were planted on three (22 May, 6 June and 22 June) planting dates with factorial arrangement in randomized complete blocks. Nine traits were measured as: plant height, number of nods, number of secondary stems, number of pods per secondary stem, number of pods per plant, number of seeds per pod, number of seeds per plant, 100 seed weight and grain yield. The results indicated that grain yield and its components were significantly reduced by delayed planting. The first planting date (22 May) had the highest grain yield (2343 kg/ha). Reduction in grain yield at the second and third planting dates could be related to reduction in plant height, number of seeds per pod, number of seeds per plant and 100 seed weight .There were significant differences between soybean cultivars in grain yield and its components expect for number of pods per secondary stem, number of seeds per pod and number of seeds per and plant. Zane cultivar had highest grain yield. Sahar cultivar had the lowest grain yield due to reduced number of seeds per pod and 100 seed weight and increased. plant height, number of nods, number of secondary stem, number of pods per secondary stem, number of pods per plant, number of seeds per plant. Results showed that there was a significant positive correlation between grian yield with number of nods, number of secondary stems, number of pods per plant and number of seeds per plant and 100 seed weight. The results also indicated that delay in planting causes reduction in grain yield. However, Zane, Blackhack, and Hack cultivars showed highest grain yield in all planting dates.

Chrysanthemum is one of the most cultivated flowers around the world to produce cut-flowers. In Iran flower producers pay much attention to this flower. Regarding the economic importance of increased longevity of chrysanthemum cut flowers, this study was conducted using completely randomized design on 153 uniform cut flowers all in the full scean phases. Chrysanthemum cut flowers were incubated in 16 treatments of preservative solutions and distilled water as control for 72 hours and then all transfered to distilled water containers. The effects of applied treatment on longevity of chrysanthemum cut flowers were evaluated using the measurement of cut flower longevity, fresh weight, flower diameter, amount of water uptake and number of yellow leaves. The results indicated that the treatments especially with sucrose (%3) + aluminum sulfate (%0.2) + silverthiosulfate (%4)+ citric acid (150 ppm), and also sucrose (%3)+ aluminum sulfate (%.0.2) and citric acid (150 ppm) significantly increased the longevity of chrysanthemum cut flowers.

The effect of six concentrations (0.25, 0.5, 1, 2, 4, and 6 mg/l) of Abamectin was evaluated on 1 and 4-day eggs, different nymphal instars, and pupae of Bemisia tabaci Gennadius (Hom.: Aleyrodidae) and also eggs, larvae, pupae, and adults of Eretmocerus mundus Mercet (Hym.: Aphelinidae) as the efficient parasitoid of B. tabaci. Morphological and biological effects of the insecticide were also studied on first and second generations of the parasitoid. The susceptibility of one-day eggs of B. tabaci to the insecticide was more than tour-day eggs, and also early nymphal instars (1 st and 2nd) than 3rd and 4th instars, and pupa. Application of abamectin in larval stage of parasitoid, affected the head capsule width, fecundity, and longevity. The effect of insecticide on pupal stage of the parasitoid had significant effect on head capsule width, antelmal sensilla, developmental time, longevity, and fecundity, but no significant effect on the adult eclusion percentage. The effect of insecticide on I-day eggs of the parasitoid increased mean developmental time of immature stages. The insecticide residues had significant effect on longevity and sex ratio, but did not affect fecundity, survival percentage, and morphological characters of 2nd generation individuals. Results of the present research indicated that abamectin has the destructive and sever effects on E. mundus. Therefore, application of the insecticide, meantime of observance of suitable concentration (2 mg/l) and golden time application (early nymphal stages of B. tabaci, and contemporaneously pupa of E. mundus) is possible in integrated pest management programs of sweetpotato whitefly.

Study of the flora of East Azarbaidjan Province was begun in 1986, and last report represented in 1999. During this period, two new species for the first time in the \vorld and several new species in the flora of IRAN and East Azarbaidjan were distinguished. At the present, five new species are being introduced. One Sagebrush (Artemisia marschalliana) species from Compositae, for the first time from IRAN, and four new species include Ammi (Ammi visnaga) from Umbelliferae, Pond weed (Potamogeton nodosus) from Potamogetonaceae, Pink, (Dianthus armeria) and Chickweed (Stellaria pallida) from Caryophyllaceae, for the first time from northwest of IRAN were introduced.

The number of adults, nymphs, eggs laid and eggs production in ovariols of 0. niger and also the number of eggs, larvae and adults of Haplothrips tritici were determined at the phenological stages of booting, ear emergence, flowering, early milk, late milk, dough development and ripening of three wheat cultivars. The higher population density of O. niger (sum of eggs, nymphs and adults) was appeared in Alvand, Roshan and Sardari cultivars, respectively (p<5%). Also, the population density of O. niger was highest at the flowering stage in comparison with other phenological stages of three wheat cultivars. Within different developmental stages of 0. niger, the highest number of eggs, nymphs and adults were observed at the flowering, milk development and dough development stages of three wheat cultivars, respectively. The higher population density of H tritici (sum of eggs, larvae and adults) was appeared in Roshan. Alvand and Sardari cultivars, respectively (p<5%). Also, the population density of H tritici was highest at the flowering stage in comparison with other phenological stages of three wheat cultivars. Within the different developmental stages of H tritici, the highest number of eggs and adults were recorded at the ear emergence and the highest number of larvae was recorded at the flowering and early milk of three wheat cultivars. With regard to the interaction of cultivars and the phenological stages of wheat, the highest population density of H. tritici was observed at the flowering stage of Roshan and the highest population density of O. niger was appeared at the flowering stage of Alvand.