JWSS - Journal of Water and Soil Science

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The operation of an irrigation network is the result of a decision-making system in which three elements, i. e. the physical condition of the structures, control capacity, and hydraulic behavior of canal system, have important roles. The impact of these components is incorporated in the hydraulic sensitivity concept. For this purpose, the sensitivity of structures could be considered as the most important factor in the hydraulic characteristics of a system. The sensitivity analysis approach is one of the flow analysis methods that is used to forecast the flow behavior in several irrigation networks. Baffle Modules are one of the most suitable structures for flow regulating and delivery. In this paper, hydraulic sensitivity equations are presented for this type of structure. Also, the quantitative variations of the sensitivity index have been evaluated under operating conditions and compared with those of theoretical conditions. Then the influence of the sensitivity index variations on the performance of structures has been studied. This study was carried out on some modules of the Qazvin network. The results indicated that the hydraulic sensitivity of these off-takes varies under operating conditions. In some cases, variations were estimated to be more than 100%. The range of discharge variations was twice the predefined acceptable value (20%) in some offtakes.

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Peat is the best known and the most widely used rhizobial carrier, but unfortunately, it lacks of sufficient sources in Iran. This research aimed at using some inexpensive materials as carrier instead of peat for producing the rhizobial inoculant for alfalfa. For this purpose, the physical and chemical properties of some materials to be used as carriers were determined and the viability of Sinorhizobium meliloti on these carriers during 6 months at +4 ºC was evaluated. The selected carriers were 1) Peat (control) 2) Vermicompost 3) Bilogical Filter Waste (BFW) 4) Vermiculite+Vermicompost (1:1w/w), and 5) Vermiculite+BFW (1:1w/w). Also to determine the suitable moisture content of carriers on prolongation of bacterial survival, two matric potential levels including –10 and –30 kpa were applied on the carriers. The results showed that vermiculite+BFW (1:1w/w) not only maintained a standard number of bacteria compared to the other treatment, but also caused good nodulation on alfalf seedling at the end of the 6^th month. Although BFW carrier maintained a high number of bacteria after six months storage, it can not be recommended as a suitable carrier because of its negative effect on nodulation. In this study, higher number of bacteria was maintained in the matric potential of –30 kpa than –10kpa.

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The effect of Bacillus thuringiensis var. kurstaki on different larval instars of Colorado potato beetle, Leptinotarsa decemlineata (Say) and the role of two plant materials, namely, caffeine and aqueous neem extract, in the enhancement of it’s efficiency was investigated under laboratory conditions. The experiments were conducted at 25±4 ^oC, 65±5 %(RH) and photoperiod of 16:8 (L:D).The larvae were provided from the colony established and maintained on host plant. The different larval instars were distinguished by measuring head capsule width.To evaluate susceptibility of different instar groups of larvae to B.thuringiensis, LC₅₀ values on (1-4) instar groups were determined. LC₅₀ values for 1st, 2nd, 3rd and 4th instar groups were, 183.86, 377.03 ,1297 and 3096 ppm, respectively. The synergistic effect of caffeine and aqueous neem extract with B.thuringiensis was investigated separately on 3rd larvae instar. A completely randomized design with 6 treatments and 4 replications was used. The results revealed that there was a striking synergistic effect of caffeine and neem on B.thuringiensis.The larval mortality percentage for mixture 618ppm of B.thuringiensis and 4000ppm of caffeine was 80% however, this was 10% and 20% for caffeine B. thuringiensis respectively when these compounds were used alone.The initiation of larval mortalitry in all mixtures was earlier than other treatments.Also the larval mortality for mixture B. thuringiensis with 35000 ppm of aqueous neem extract was 77.5% after 144 hours however, it was 22.5 % and 25 % for B.t. and neem alone, respectively. The mean weight of larvae treated with all synergists was significantly less than the control cohort, (p<0.05).

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Data from the birth weight (BW), the average daily gain from birth to weaning (ADG) and the weaning weight (WW) of 1182, 1099 and 1099 lambs were respectively collected and applied to estimate the maternal effects on heritabilities as well as on the determination of the environmental factors. The data were collected from Shahrbabak Sheep Breeding Research Station within five year, from 1993 to 1998. The effects of the year of birth, the age of the dam and its sex on all the traits were significant. The type of birth had no effect on BW but it was significant for the other two traits. Estimates of (co)variance components and genetic parameters were obtained by restricted maximum likelihood, using single and two-trait animal models. Based on the most appropriate fitted model, direct heritability of BW, ADG and WW were estimated at 0.10± 0.06, 0.21 ±0.08 and 0.22± 0.09, respectively. The maternal heritability for the three traits was also estimated at 0.27± 0.04, 0.15 ±0.05 and 0.19 ±0.05, respectively. Direct genetic and phenotypic correlations between BW and ADG BW and WW ADG and WW were estimated at 0.85 and 0.41 0.82 and 0.48 and 0.99 and 0.99, respectively. Ignoring maternal effects in animal model caused overestimation of direct heritability. Thus maternal effects are significant sources of variation for early growth traits and their ignorance in the animal model causes inaccurate genetic evaluation of the lambs.

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The reaction of forty two barely landraces, mostly from Azarbijan Province and a susceptible cultivar, Zarjo, was studied under greenhouse conditions in the presence of four highly virulent isolates of Pyrenophora graminea, i.e. Marand 3, Ajabshir 2, Khasseban-Tireh, and Bostanabad. The experimental design was a split-plot based on randomized complete blocks with three replications. Landraces were considered as sub-plots and the isolates as whole plots. The seeds were inoculated by the sandwich method and responses of the landraces were evaluated by the method of Mathur and Bhatnagar. The resistance of landrace #1 to the isolates of Marand 3 and Ajabshir 2 and that of landrace # 27 to the isolate of Ajabshir 2 was observed. These landraces could be used as a source of vertical resistance in barley. Landraces 6, 8, 11, 12, 13, 15, 17, 25, 27, 28, 29, 31, 33, 34, 36, 37 and 41 were classified within the range of partial resistance to partial susceptibility, which may be utilized as the sources of horizontal resistance.

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A 2-year vineyard survey failed to the provide evidence that Uncinula necator (Schw.) Burr. survived winter as mycelium in dormant infected buds in Khorassan province. Ascospores of U. necator, were collected by a volumetric spore trap operating constantly in a vineyard for 55 days after the bud burst. The first powdery mildew colonies were consistently found on the leaves of the shoots (7.30 cm long) growing on the vine. Cleistothecia were found on all plant parts infected during the previous growing season. More than 35-45 % of the cleistothecia borne on the leaves and stems died during winter. Most of the ascospore discharge occurred between the bud burst and the blooming time. Ascospores were periodically released from cleistothecia on the leaves kept in vineyard from October to May, while the ascospores germinating on the glass slides germinated from October to January and then germination slowed down to zero in early March and the water content potential of ascospore cytoplasm decreased constantly during this period as well. The mass required to fracture the ascocarp wall during maturation was measured to be approximately 5g in autumn, 3g in winter and 2.5 g in early spring. The most rapid decrease in the strength of the ascocarp wall occurred during a 4-week period before dehiscence in the field. The effect of the pathogenic property ascospores on healthy leaves demonstrated their role as a primary inoculum source. Cleistothecia appear to be the principal means of overwintering of U. necator in Khorassan province vineyards.

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The fire blight with the bacterial causal agent, Erwinia amylovora (Burrill) winslow etal. is one of the most important diseases of the pome fruits that causes the economical losses to quince, pear and apple productions, respectively, in some parts of country. To determine the infection severity of the 43 raturally infected pear cultivars in collection of karaj horticulture research division and also for studing the reaction of these cultivars against disease, the evaluation was performed by the USDA standard system for these cultivars in collection. In this study, although the most of cultivars had been infected on the natural conditions, but disease severity was significantly different between them. By the USDA system, pear cultivars were divided in the 2 classes. Percentage of pear cultivars in very susceptible and moderately susceptible classes were 81.4 and 18.6 respectively. Also for dividing the pear cultivars, beside of USDA method, SPSS software and the cluster analysis were also by the UPGMA method and cultivars were divided into 3 clusters, but it seems that the classification of cluster analysis did not conform with USDA system. Correlation of I.V.S in the artificial tests and the disease severity by natural infection was very significant (r= -0.83).

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In orther to determine the critical period for weed control in the Chitti bean (Phaseolus vulgaris) line KS-21467 a field study was conducted at the Bean Research Station of Khomein by a randomized completele block design in 2001 and 2002. The treatments included weed free and weed infested period until 20, 28, 36 and 44 days after planting (DAP) with two weed free and weedy checks. The results indicated that the critical period at 5% allowable yield loss was 20-53 DAP (between first-trifoliate and flowering stages) in 2001 and 35-51 DAP ( between blossom and flowering stages) in 2002. Weed dry weight decreased averaglly 81% in weed-free period until 44 DAP compared to the weedy check. Yeild decreased averaglly 63% in weedy check compared to the weed free check. Weed competition increased the height of bean, wherease 100-seed weights and the number of seeds per pod were not substantially affected. There was a negative and significant correlation of weed dry weight with the number of pods per plant, the number of seeds per plant and yeild.

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Greenhouse whitefly, Trialeurodes vaporariorum West., is one of the most important pests of field crops and ornamental plants in greenhouses which usually controlled by chemical insecticide and/or by biologic control factors. In this study the effect of singular and integrated use of Confidor and predator, Chrysoperla carnea (Steph.) against different nymphal instars of the pest on tomato plant was investigated. This experiment was carried out in 7 treatments, each in 3 replicates. Treatments included predator alone, the use of insecticide alone, and 4 integrated treatments of both the predator and insecticide. The predator was released at 5, 10, 15 and 20 day intervals after insecticide application. The control (water), insecticide spray and release of the predator were repeated each 10 days. In integrated treatments, insecticide was applied only once at the beginning of the experiment. The results showed that there was a significant difference between treatments. Pest control was not achieved with one or two attempts of release of predator or spray of insecticide. Pest elimination was only observed after third spray in insecticide treatment and 3 releases of predator beginning 20 days after spray in integrated treatment. These two treatments were shown to be of equal effectiveness in pest control. Also pest population was controlled after 5 releases which began 5 days after insecticide application. The use of the alone predator was statistically found to be less effective than treatment with the insecticide alone. Generally, integrated treatment is a promising alternative approach to pest control in longterm. It has clear advantages over chemical control in terms of pest resistance, environmental and general pest control issues. .

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Flow structure at water intake is very complicated and three-dimensional. Due to this the application of one and two-dimensional equations can not sufficiently explain the flow structure at water intake. In this study, the simulation of flow structure at a 45 degree water intake was investigated numerically and experimentally. Here, the characteristic of separation zone and velocity distribution at 45 degree water intake were investigated using Standard k-ε and RNG k-ε models. It was found that the Standard k-ε model enables to estimate the flow and separation zone at water intake. Also, the location of separate zone at the inlet of water intake was studied using experimental and numerical approach. It was found that the separation zone at 45 degree water intake occurs at the downstream of the inlet.

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A major source of photoassimilates deposited into the seeds is the closest photosynthetic source to the latter sinks. While the contribution made to grain yield by floral parts and the adjacent photosynthetic surfaces has been determined for a number of crop plants, such information lacks regarding safflower. Thus the present study was aimed at estimating the contribution of photosynthesis of safflower head and the two adjacent leaves to the grain yield of this oil seed crop. A 4-replicate RCBD field experiment was conducted at Lavark Research Farm, Isfahan U. of Tech., using four genotypes (Nebraska10, Kouseh, Arak2811 and K12) and three levels of shading (heads only, heads and the two adjacent leaves and control) on safflower heads following pollination, using khaki paper bags. Genotypes differed in terms of days to heading and maturity, height, number of heads per plant, number of seeds per head, 1000-seed weight, seed weight per head and grain yield per plant. Shading on safflower head and the two adjacent leaves led to a significant decrease in number of seeds per head, 1000-seed weight, seed weight per head, grain yield per plant and harvest index. There was not a significant difference between the two levels of shading treatment. It could be concluded that, with the environmental conditions experienced during spring 2003 at Isfahan, the photosynthetic products of safflower head and the two adjacent leaves may contribute to grain yield per plant by as much as 37 percent.

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A chick bioassay with chemically defined amino acid (AA) diets was conducted to compare four different AA profiles: the NRC 1994, Feedstuff 2002, Rhone Poulenc Animal Nutrition 1993(RPAN) and Illinois Ideal Chick Protein (IICP) AA profiles. This battery study involved male and female chicks during 7 to 21 days of age. Indispensable AA were rationed to lysine according to requirement ratios presented in the four profiles. Digestible lysine set at 1.07 and 0.98 % of diet for male and female respectively. This experiment was carried out in a completely randomized block design using 2 5 factorial arrangement with for replicate per each diets were kept isonitrogenous (2.6 % N ) by varying levels of L-glutamic acid. All diets were checked to have at least 0.3 % proline and 0.6 % glycine. Diets for all profiles contained 3200 kcal ME/kg and a positive control diet were used according to NRC 1994 recommendations. Chicks fed a common corn-soybean meal diet for 160 h and were raised in the floor pen. Then chicks weighted individually and allocated to battery pens so that most uniformity between pens occurs. Four battery pens of five chicks were fed one of four different profiles or positive control diet in both male & female. Weight gain and feed efficiency measured for each pen at day 21. Results indicate an improved weight gain and feed efficiency in male rather than female (p<0.5). Chicks fed positive control diet weighted more (p<0.5). Between semi purified diets chicks fed diets formulated with NRC AA ideal ratios had significantly (P<0.5) better weight gain and gain: feed in both sexes relative to IICP and RPAN, but not to Feedstuff. RPAN had worst weight gain and feed: gain in females. Results of this experiment indicated that new ideal ratio of theronine (relative to lysine) in IICP for starter period may be under-estimated.

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Conventional soil survey methods for soils within the watersheds in Iran require a significant budget with many soil surveyors and much time. Additionally, no accurate and reliable information exists on the spatial variability of superface soil parameters in order to predict the soil loss by different models (RUSLE, PISAC, EUPOSEM, MORGAN). Also information on planning and management activities is lacking. These limitations call for methods of estimating soil properties using minimum sampling derived from important terrain parameters. This study was performed to develop soil-landscape models in three geological units (E2Sc, Ku, Plc), in a part of Mehr- watershed, Sabzevar. Six soil variables selected for this study were topsoil clay, gravel, sand, organic matter content, field capacity and bulk density measured at 316 sites on a regular 100m grid. Topographic attributes were calculated by a digital elevation model with 100m spacing. Finally, multiple linear regression analyses relating soil to topographic attributes were performed and then models were validated by additional sample points (78 of 316). The developed regression models showed significant relationships between surface soil properties and topographic attributes such as elevation, slope, aspect, wetness index, stream power index and sediment transport index. The mean errors and root mean square errors in the validation of the models were low and acceptable. The regression equations could explain only 26 to 72 % of the variability measured in the soil attributes in the watershed scale with 100m spacing.

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To determine genetic diversity among some Iranian local varieties of alfalfa, six geographically diverse populations including: Bami, Rahnani, Nikshahri, Yazdi, Hamadani (from Isfahan), Hamadani (from Shiraz) along with Ranger, an American commercial variety, were evaluated using a set of 24 EST-SSR primers developed from cDNA library of Medicago truncatula and three microsatellite loci, identified from genomic library of M. sativa. Of the pairs of primers tested, four loci from EST-SSRs (AW9, BEE, TC6 and TC7) and genomic microsatellite (Afctt32), were found appropriate for assessing genetic diversity between these alfalfa genotypes. In total, 46 alleles were detected from the five loci in the samples of alfalfa examined. The number of alleles per locus in populations ranged from six to eleven and genetic diversity indices of loci were variable from 0.62 to 0.87 for the populations. Genetic relationship analysis of EST-SSR data revealed separation of Iranian populations from Ranger. It is likely that the parental origin of primary population from which Ranger has been derived is different from that of Iranian populations. Iranian local populations of alfalfa in this study were grouped in two main clusters. Alfalfa populations Hamadani and Rahnani, which are adapted to cold claimates, were grouped in one cluster and populations Bami, Yazdi and Nikshahri, belonging to the trpoical areas, were placed in the next cluster. The positioning of EST-SSR loci in coding regions of genome, possibly increases the usefulness of these markers to clarify inter specific genetic relationships among alfalfa populations.

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The sensitivity analysis approach should be regarded as a new means which has recently been proposed for assessing flow of the irrigation networks. This approach uses the flow steady state equations and the physical conditions of irrigation channels to evaluate the response of the system to input perturbations. In this paper, some structural hydraulic sensitivity indicators were developed and utilized in studying the flow of an irrigation channel. For evaluating the efficiency of indicators and proposed analysis method, a real case was simulated by SOBEK model. Using the simulation results and introduced indicators, the flow regulation and distribution process within channel was studied. The results indicated a successful application of sensitivity indicators in evaluating system's potential in relation to alternative operational scenarios. With the calculation of these indicators, a comprehensive information system could be provided and applied in the analysis of the response potential of channel to structural perturbations, estimation of structure setting accuracy, and in the choice of suitable operation frequency there of.

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Stabilizng sand dunes has been one of the main challenges in the arid regions. So far, different kinds of mulches have been used extensively for sand dune stabilization. This study was carried out to determine the optimum composition, concentration and thickness of clay mulch for sand dune stabilization. For this purpose two soil samples from clay flats of a playa with different amount of salinity from Ardestan area were used to make clay mulches. A sand dune sample was selected as bed for applying the mulch. To select the right ingredient and treatments, clay samples were mixed with sand and different amount of water, and sprayed on sand dune bed. In addition, wheat straw was added to some mixture to test its effect on stability of the mulch. Treatments with lowest crack and highest penetration of mulch in sand bed were selected for the experiment in this study. Mulch treatments contained (1): 250g sand dune + 250g clay + 25g straw (2) 250g clay + 25g straw (3) 250g sand + 250g clay (4) 250g clay (5) 125g sand + 125g clay and (6) 125g clay. All treatments were mixed with 500ml water. The experimental design was a CRD with a 6(mulch) * 2(thickness)* 2 EC factorial method with 3 replications. The results showed that clay mulch were resistant to wind erosion, but erosion took place when they had been bombarded with sandblast. The mulches with straw showed the highest resistance to erosion as compared to other treatments. With increasing the number of mulch layers, resistant to erosion also increased. The added stability of mulch was due to the increase in mulch thickness and also increases in clay and silt content. The overall result of this study shows that the mulch with two layers and higher mixture of clay and sands was the best treatment for the stabilization of sand dunes.

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Overgrazing is the most important agent which causes accelerated soil erosion and land degradation in arid and semi-arid zones of Iran. Appropriate planning and land use in these areas based on land suitability evaluation provide a suitable base for conserving the land and controling desertification. Land evaluation identifies possible alternatives in land use which will more effectively meet national or local needs and assists in assessing the consequences of these alternatives. Extensive grazing refers to the land utilization type in which animals feed in natural pastures. This study was performed to evaluate physical potential of the given watershed for grazing by sheep and goats, and assess the limiting factors for the land utilization type in Mehr watershed, Sabzevar, Khorasan province. Land qualities which were evaluated include accessibility to animals, soil erodibility, moisture availability, rooting conditions, salinity and alkalinity, and drinking water availability for animals. Above mentioned land qualities were assessed by appropriate land characteristics. The requirement of grazing land utilization type was defined in terms of rated land characteristics. Matching of requirements of LUT with the land qualities of each pixel of DEM (prepared in 200×200m by GIS software) resulted in a rating for every land characteristics. Some characteristics such as slope, aspect, and distance to drinking water for animals were calculated directly by GIS. Land index for every pixel was calculated by square root method. Finally, qualitative and physical land suitability classes were determined based on land indices and classified to polygons which would be suitable in grazing management. The results were interpreted under two different scenarios. In the first scenario, drinking water for animals was supplied by permanent sources and in the second one, the supplying of water was developed to temporary rivers besides the permanent sources. With the analysis of spatial modeling it was possible to assess the land suitability with higher accuracy. Overall results showed that the given area was not highly suitable for grazing at all. The most limiting factors included moisture availability for plant growth, slope, rock fragment and outcrops and distance to drinking water. Also during the late winter, spring and early summer, when the seasonal rivers were supplying the drinking water, the limitation of given area was decreased.

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To facilitate the interpretation of data from a genotype by environment experiment (GE), a cluster method is proposed to group genotypics according to their response to the environments especially when the GE interaction is large. The interaction structure of two-way classification data often can be identified if the data stratified into homogeneous subsets. In this paper four GE interaction cluster methods are proposed for this purpose. The stability of the 10 maize hybrids including 9 hybrids that were the best hybrids in yield trials and KSC 301 (check hybrid) were evaluated for 2 years in 4 locations of Iran. The randomized complete block design with 4 replications was conducted for each environment with different layouts. Simple analysis of variance revealed significant genetic differences between hybrids for grain yield. The results of combined analysis of variance indicated that genotype × year, genotype × location, and genotype × year × location interaction effects were significant (P < 0.01). Results also showed that models 1 and 3 and models 2 and 4 had the same responses. Hybrids 8 (K1263/1 × KE8212/12) with high yield stability in both models 1 and 3 were in one group and other hybrids were in another group. In models 2 and 4 results led to 3 groups: Group1 included hybrids 3, 7 and 9 that were very stable and had high yield group 2 included hybrid 1 alone that had medium stability and yield and group 3 included other hybrids that had low stability and yield.

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Safflower (Carthamus tinctorius L.) is an oilseed crop and can have a considerable contribution to vegetable oil production in the country, since it has a high adaptability to different environmental conditions. This crop is grown in summer time as a second crop in Isfahan province. Therefore, this study was carried out to investigate the agronomic characteristics of the safflower breeding lines which were isolated from local populations of Iran in early spring and summer planting dates. Seven genotypes were evaluated at two planting dates, early spring (16 March) and summer (21 June), using a randomized complete block design (RCBD) with 4 replications at the research farm of Isfahan University of Technology. The results showed that the number of days to emergence, days to flowering and maturity and plant height decreased considerably in the summer planting date. However, the harvest index, seed yield per plant and seed yield per plot and oil yield increased in this planting date. Yield components were not significantly different in the two planting dates, except that 100-seed weight was significantly and considerably more in the second planting date. The average seed yield of genotypes was 2498 and 2845 kg/ha in spring and summer planting dates, respectively. In the first planting date, seed yield varied from 1876 Kg/ha, (for Kouseh genotype as check variety) to 2908 Kg/ha for E2428 line (selected from Isfshan population). In the second planting date, seed yield had a variation of 2124 to 3186 Kg/ha for the genotypes of S3110 (selected line from Khorasan population) and C111 (selected from Kouseh population), respectively. In the second planting date the check variety (Kouseh population) had a seed yield of 2965 Kg/ha. In both first and second planting dates, genotypes of E2428 and C116 (selected line from Kouseh population) had the maximum oil content in the seed, (33.9% and 32.3%د respectively). Genotype by planting date interaction was significant for seed yield and oil yield, since late planting date reduced seed yield in genotypes of S3110 and E2428, but it increased these traits in other genotypes.

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During years 2000 and 2001, biology and population changes of two- spotted spider mite (T. urticae) was studied on five bean cultivars of two species at 25±1ºC temp., 45±4% RH and 15: 9 (L:D) photoperiod, using leaf disks made from 2-, 6- leaf and flowering stages of the plants. The mite mass rearing was carried out on tomato plants under the same environmental conditions and the effects of feeding on 4 cultivars of phaseolus vulgaris namely Chiti Var. Zanjan, Picher, Sunray, Contender and Vigna unguiculata, Var. Kameran as host plants. Biological features as fertility, percentage of egg hatch, duration of embryonic and larval development, percentage were also Studied of lraval mortality, duration of nymphal stages, developmental period from lava to pre- oviposition stages, oviposition period, adult mite longevity, number of progenies, their percentage mortalities, and sex ratios were determined. The results indicated that the two cultivars Chiti Var: Zanjan, Contender, and species Vigna unguiculatat Var. Kameran at 2- leaf stage appeared to be suitable hosts causing higher egg production and hatches, lower embryonic and larval developmental time and lower rate of larval mortality, lower nymphal developmental period, lower duration from larval stage to preoviposition, extended oviposition period and higher adult longevity. In contrast, the cultivars, Sunray and Picker were shown to be unsuitable hosts. Regarding 6- leaf stage, the cultivar Contender and Vigna unguiculatat, were considered as suitable hosts in relation to embryonic developmental time, number of larvae, duration of larval stage, and rate of mortalities, nymphal developmental time and duration from larval stage to pre- oviposition, extended oviposition stage, sex ratio and adult longevity. But the cultivars Chiti, Picker and Sunray appeared to be unsuitable hosts. In relation to the number of eggs and percentage of egg hatch, number of larvae and nymphs, nymphal mortality rates and sex ratio, the cultivars, Picker and Sunray were considered as suitable hosts at their flowering stage but Vigna unguiculatat and Contender were identified as unsuitable ones.