AGROECOLOGY JOURNAL (JOURNAL OF NEW AGRICULTURAL SCIENCE)
Year:2006 | Volume:2 | Issue:4|Papers Count:10

In artificial neural networks (ANN), the available methods of neural learning and calibration is according to multi-layer structure of perceptron, but these methods have some problems results from lack of convergence in learning methods, lack of stability in network weights in conditions that there is great criteria deviation in input data spectrum and finally need for much data and information for network learning. A new compound method of artificial neural network-non linear mathematical optimum was introduced in this research to overcome this problem and artificial neural network designed by using error back propagation method was introduced as a strong device for estimating the rate of sediment in the reservoir of ecbatan dam. According to that, the designed model by various knots in input and hidden layer was performed by using the equation of sediment discharge and water current and statistics of Yalfan station at Abshineh River. Calibration results show that 6 knots at input layer and 8 knot at hidden layer should be used to distribute sediment in reservoir of Ecbatan dam.

There is a direct relationship between production of honey bee and the rate of its colony. In fact, the more the population of the bee in the accumulation season of nectar, the more the rate of honey and nectar will be gathered, so that artificial nectar will be used instead of natural nectar to provide the energy requirements in time of lack of nectar in nature. In order to explain the effects of substituting the artificial nectar instead of natural one, factorial experiment on the basis of completely randomized design has been done with five treatments (four diets and a control group) and five replication on 25  colonies  .The results indicated significant differences among diets (p<0.01). But considering the number of larva, there was not seen significant difference between right and left sides of the honey comb. Also there was not a significant difference among  honey, starch + honey and sugar, so  in the respect of the food expense, sugar could be considered as the best food for increasing honeybee population and mixture of  starch + honey and honey placed at second and third levels. Conducted experiments on honey production indicated that there was a significant difference in confidence level of %5 among food treatments in honey production rate point of view. Comparison of means showed that food treatment with starch + sugar and starch + honey, with high means and non significant difference with each other, had better effects on the rate of honey production rather than other foods.

Intercropping of agricultural crops is one of the proper approaches for increasing of agriculture efficiency. To achieve this purpose in Guilan rice lands, sequential cropping of rice and soybean was assessed. In this experiment, rice as a main crop and soybean as a second crop were planted. Soybean seeds were sown and production of soybean transplants carried out before rice harvesting. Immediately after rice harvesting and preparation of rice land to plant the second crop, transplants of seven cultivars of soybean planted in related blocks. Traits of soybean cultivars assessed by randomized completely block design in three replications. Vegetative and reproductive stages of soybean transplants and plants studied from sowing date to harvesting time. Based on results, maximum transplants died, minimum seed yield, minimum plant height, maximum chlorosis due to deep water at base of the plants and minimum height of first sheath per plant related to SRF cultivar. Minimum transplants died in soybean nursery related to William’s cultivar with 96.6% safe plant). Plant height, lateral foliage number and seed yield traits had significant difference at confidence level of 0.01, while height of first sheath and seed numbers per plant had significant difference at confidence level of 0.01 among soybean cultivars. Results showed that Pashm-Baghala and L11 cultivars had maximum seed yield (194.5 and 196.1 gr/m2) while SRF cultivar had minimum yield.

In order to study of cause and effect relationships of agronomic characters in water stress and water non-stress conditions with Geometric Mean Productivity index (GMP), a research was conducted in experimental field of agriculture faculty of Zanjan University in the year 2003. In use Experimental design was split block design based RCBD with three replications that irrigation with two level (water non-stress and water stress) and rapeseed variety in sixteen level were experimental factors. The results of sequential path analysis indicated that for selecting under water non-stress conditions in order to breeding for grain yield GMP, essentially was after increasing number of branches and siliqua per plant and decrease of 1000-grain weight. Due to relationship between these three characters is necessary to put them in equilibrium together. Also for selecting under water stress conditions essentially was after increasing of seeds per siliqua and siliqua per plant and decrease of days to flowering. Indirect breeding for oil yield GMP in water non-stress conditions is possible by breeding to increase of number of branches and siliqua per plant and to decrease of 1000-grain weight and under water stress conditions by breeding to increase of seeds per siliqua, siliqua per plant and oil content.

Effects of the planting arrangement on the yield, its components, seed oil percentage and certain agricultural properties of safflower (Carthamus tinctorius L.) were studied in Gogan (located in east Azarbayjan) during 1381 – 82. The space between rows were 15, 30, 60 centimeters and the distances between the plants were 5, 10, 15 centimeters and Genotypes involved IL111, Kj818 and Arak-2811. The experiment was done based on factorial with randomized block design in 3 replications. During the experiment different properties were studied including plant height, the number branch in plant, number of bolls, number of the seeds in a boll, seed yield , harvest index, thousand seed weight and seed oil persent. Analysis of variance showed significant differences among genotypes in number of the seed in capitulum, number of capitula in the plant, thousand seed weight, plant height and seed yield. At the same time the planting arrangement had significat effect on number of capitulum in the plant, number of seed in a capitulum and seed yield. The 15 cm resulted in the highest yield. It can be said that the Arak-2811 with 4/34 ton seed yield/ha was the best. It seems that, development of this plant is of great value especially in medium and poor soils of Ourmieh Lake edges (e.g. Gogan) to obtain an acceptable production.

In order to comparisation of yield, yield component sand morphologic characteristics of maize hybrids in second cropping in Khoy region, an experiment was carried out in summer 2004 in research farm of Islamic Azad University, Khoy branch. In this experiment, seven hybrids of maize including very early ripening hybrid K.S.C 108, early ripen hybrids K.S.C 301, K.S.C 303, hybrid K.S.C 404, semi delay ripening hybrids K.S.C 600, K.S.C 604 and K.S.C 647 comparised by randomized complete block design in four replications. Tenth of July was determined as Planting date of all experimental varieties. Maximum dry matter, fresh fodder, leaf dry weight, stem dry weight, stem height and stem diameter obtained in 647 three way cross hybrid and highest leaf area index obtained in K.S.C 404. uppest ear/shoot ratio obtained in K.S.C 303 and the highest ear dry weight obtained in 600 hybrid variety. Result of this study showed that 647 T.W.C hybrid com is the best silage com hybrid for secondary cropping in khoy region.

Factor analysis is one of the multivariate statictical methods which can reduce a large number of correlated variables in small number uncorrelated factors. In order to determain the morphological and physiological effective characters on drought resistance of lentil, twenty lentil gnotypes evaluated on the basis of 18 morphological and physiological characters in a split plot design with 3 replications at the Zanjan University research farm during the spring of 2004. Factor analysis based on mean values over two stressed and non-stressed environments distributed 18 variables in four factors. For easy in explanation, only those factor coefficients that were greater than 0.38, were selected as signification without considering their sign. The first factor could explain 20.28 percent of total variance. The most important coefficients in this factor were related to plant dry weight, leaf dry weight, steam dry weight, leaf area and days to flowering. Significant and positive correlations were observed for all these traits. The second factor explains 15.61 percent of total variance. In this factor, plant height in before flowering time, harvesting time, canopy width and number of primary branches were the most important traits. There were negative and signification correlations between plant height in flowering, before flowering and harvesting time with canopy width and number of primery branches. There was also positive and significant correlation between conopy width and number of primery branches. The third factor explained 14.03 percant of total variance. The most important traits in this factor were extracted as harvest index, seed yield, pods per plant, water content of leaves and seeds/plant. The fourth factor explained 10.66 percant of total variance. The most important traits in this factor were selected as biological yield, leaf temperature and 100 seed weight. There was a negative and significant correlation between seed yield and leaf temperature, also a positive and significant correlation between 100 seed weight and seed yield was seen.

The present study examines the effect of NaCl salinity with various concentrations on cultivars of the champa rice, Oryza sativa L. (i.c. Zayandehrood, Sazandegi, Sorkheh and Nougaran) in various stages of growth by randomized block design with three replication. Height of plant at the time of harvest, cluster length, cluster branches, number of seeds in each cluster, weight of thousand seeds, number of clusters per square meter and nitrogen and protein contents of each seed were studied. Under salinity stress conditions, the plant height reduced generally, but the cluster length did not show significant changes. Number of flowers in each cluster was greatest in Zayandehrood and smallest in Sorkheh.The number of flowers reduced significantly under NaCl salinity. Sazandegi and Nougaran produced greatest number of seeds. The weight of thousand seeds reduced significantly and the number of clusters per square meter was highest in Nougaran and Sazandegi cultivars. Nitrogen and protein content of seeds also increased in all cultivars. Results indicated that under salinity stress, Sazandegi and Nougaran had highest and Zayandehrood and Sorkheh had lowest yield. More conducted tests to determine the most resistant cultivars to salinity with respect to proline rate revealed that 45 day of growth stage was preferable than 15th day for salinity shock application. It was also established that Nougran and Sazandegi increased the proline rate at high salinity levels (EC of 15 decisiemens per meter), whereas two other mentioned cultivars increased proline content at low salinity levels.