Probability distribution functions for unit hydrographs with optimization using genetic algorithm

A unit hydrograph (UH) of a watershed may be viewed as the unit pulse response function of a linear system. In recent years, the use of probability distribution functions (pdfs) for determining a UH has received much attention. In this study, a nonlinear optimization model is developed to transmute a UH into a pdf. The potential of six popular pdfs, namely two-parameter gamma, two-parameter Gumbel, two-parameter log-normal, two-parameter normal, three-parameter Pearson distribution, and two-parameter Weibull is tested on data from the Lighvan catchment in Iran. The probability distribution parameters are determined using the nonlinear least squares optimization method in two ways: (1) optimization by programming in Mathematica; and (2) optimization by applying genetic algorithm. The results are compared with those obtained by the traditional linear least squares method. The results show comparable capability and performance of two nonlinear methods. The gamma and Pearson distributions are the most successful models in preserving the rising and recession limbs of the unit hydographs. The log-normal distribution has a high ability in predicting both the peak flow and time to peak of the unit hydrograph. The nonlinear optimization method does not outperform the linear least squares method in determining the UH (especially for excess rainfall of one pulse), but is comparable

Surveying some strategies of cultural management on species growth indices and yield in the field of soybean

Introduction soybean (Glycine max L.) plays an important role in three major markets of grains, oil and meal. damage of weeds in soybean generally 13 to 60 and sometimes more than %80 have been reported Farming methods through proper management, sowing date and by use of optimum density could be a strategy for the development of ecological competitiveness of crops and inhibit weed growth are the comparison the growth indices to design interference models of weed and crop and estimate crop yield loss in competition with weed is essential and allow to plant breeding researcher to choice the more competitive varieties of crop in competition with weed. Materials and Methods With the aim of influencing sowing date and plant density on the growth indices and evaluation the competitive ability of soybean cultivar Williams with weeds, an experiment was conducted in 2013, at Agricultural Research Station, Ferdowsi University of Mashhad, as split-split based on a randomized complete block design with three replications. Main plot included three sowing dates levels (17 April, 12 May, 6 June) and sub - plots included four crop density (30, 40, 50 and 60 plant . m-2) and sub - sub plots included weed management of two level (weed infested and weedy control). First sampling was started at 35 days after planting and was every 14 days until the end of growth period. Leaf area index, dry matter, crop growth rate and the growth rate were calculated Results and Discussion The results showed that 11 species weed belonging to 9 families observed and identified. In the early stages of growth, leaf area index and dry matter increased slowly, but in the seven to eight leaf stage of plant growth (Log phase), leaf area index and dry matter increased rapidly, and a little upon entry to the plant Physiological maturity period (Early seedling) peeks, and again began to decline at the end of seedling. The sowing date 12 May in contrast to early sowing date (17 April) and delayed planting date (6 June) produced greater leaf area index, dry matter and growth rate. Low temperature in the early stage of growth early planting and the reduced length of the growing season due to the high temperature in delayed planting results in reduced leaf area index and dry matter. The more density, the later sowing date results in the more dry matter and leaf area index. Maybe, sowing date together with more density was compensated yield loss. The presence of weeds in soybean density from 30 to 60 plants per square meter, the leaf area index and dry matter increased. Most of crop growth rate (22.24) was observed in sowing date, 12 May and with 50 plants per square meter and without weed. The maximum growth rate (0.127) was observed on sowing date 6 June and 40 plants per square meter and in condition of weed control. difference between the dry matter, leaf area index, crop growth rate and the growth rate in condition of weed interference (all season) were significant Results indicated that the maximum economic yield is related to sowing date, 12 May and 40 plants per square meter. Also, in this situation improved growth indices and increased competitive ability against weed were observed. Conclusions The results of this study showed that dry matter, leaf area meter, crop growth rate and the growth rate in the presence of weed were declined. Early and late planting reduced dry matter, leaf area index and the rate of growth of soybeans. It̓̓s concluded that such t the low temperature in early growth period in early planting and reduced length of growing season delayed planting due to the high temperature reduced dry matter, leaf area index. The low density (density 30 and 60 plants per square meter) impacted growth indicators. There for, the density should be selected based on plant, ecological needs during environmental conditions and the growing season. In conclusion the sowing date 12 May and density 40 plants per square meter are the best condition that improve growth indices and increase the competitiveness of soybean against the weed, and these are as ecological solution for reduced pesticide usage and reduced the effects of environmental pollution and men's health

Herbicidal Activity of Coumarin When Applied as a Pre-plant Incorporated into Soil

<p class="Continutabstract">Due to having a short half-life and novel site of action, the herbicidal potential of natural compounds are lionized. Coumarin is a secondary metabolite from <em>Lavandula</em> sp., family Lamiacae. The impact of eight concentrations of coumarin (0, 100, 200, 400, 800, 1600, 3200 and 6400 ppm) were separately used as a pre-plant incorporated into soil on six plant species under greenhouse conditions. Generally, coumarin had phytotoxic effect against all plant species. The phytotoxic effect was concentration-dependent. The high concentrations could inhibit the emergence of seedlings (probably by stopping germination of seeds). Based on ED₅₀ parameter, the ranking of plant species for tolerance to coumarin was <em>S. halepense</em> &gt; <em>Z. mays</em> &gt; <em>C. album</em> &gt; <em>A. retroflexus</em> &gt; <em>E. cruss-gali</em> &gt; <em>P. oleracea</em>. Based on selectivity index, coumarin at a concentration of 365.69 ppm can control <em>P. oleracea </em>without damaging <em>Z. mays</em>, whereas any concentration it cannot control other weeds without damaging <em>Z. mays</em>.</p

Evaluation of saffron flower and corm yield affected by different maternal corm weight and sowing depth

In order to study the effects of different weights of mother corm and sowing depth on flower and corm yield of saffron (Crocus sativus L.), an experiment was conducted as a factorial layout based on complete randomized block design with three replications at the Agricultural Research Station, Faculty of Agriculture, Ferdowsi University of Mashhad, Iran during 2015-2016 growing seasons. The experimental treatments were all combination of four mother corm weights (4-6, 6.1-8, 8.1-10 and 10.1-12 g) and three planting depths (10, 15 and 20 cm). In the first year, criteria such as flower and corms yield were evaluated, and in the second year only flower yield were recorded. The result revealed that in both years the interaction between corm weight and planting depths was significant on most traits of the studied flower. Flower, stigma and style yield significantly increased by increasing corm weight and planting depth. The maximum dry stigma yield was obtained in 10.1-12 g corm weight and 20 cm planting depth which was 0.1095 and 0.5393 g.m-2 in the first and the second year, respectively. The interaction between treatments was not significant on daughter corm but the individual effects of each treatment was significant. The higher corm yield (1181.6 g.m-2) was related to 10.1-12 g corm weight treatment. Deeper planting (20 cm) produced the high corm yield (938.86 g.m-2). Eventually, the high excellence of yield in corm weight and planting depth treatments of higher, we recommend corms with higher weight and deeper sowing depth for cultivating saffron

The Effects of Row Intercropping Ratios of Chickpea and Saffron on Their Quantitative Characteristics and Yield

In order to study the effect of additive intercropping series of chickpea (Cicer arietinum L.) with saffron (Crocus sativus L.) on their growth criteria and yield, a field experiment was done based on a randomized complete block design with three replications at the Agricultural Research Station, Faculty of Agriculture, the Ferdowsi University of Mashhad during two growing seasons of 2012-2013 and 2013-2014. The treatment included 100% saffron+20%chickpea, 100% saffron+40%chickpea, 100% saffron+60%chickpea, 100% saffron+80%chickpea, 100% saffron+100% chickpea and their monoculture. The trait studied were plant height, yield components, biological yield and seed yield of chickpea and the number of flowers, fresh weight of flowers, fresh weight of stigma and dry weight of stigma for saffron. The results showed that saffron intercropping series had a significant impact on plant height, number of branches, number of pods, number of seeds per pod, number of seeds per plant, biological yield and seed yield of chickpea (p≤0.01). The highest biological yield and seed yield of chickpea were observed in monoculture with 608.3 and 282.9 kg.m-2 and the minimum of these were obtained in 100%saffron+100% chickpea with 122.5 and 55.94 g.m-2, respectively. The number of flowers, fresh weight of flower, fresh weight of stigma and dry weight of stigma for saffron were significantly affected by intercropping with chickpea (p≤0.01). The highest flower number and stigma dry weight of saffron were achieved in monoculture with 103.89 and 0.47 g.m-2 and the lowest of these were obtained in 100%saffron+20% chickpea with 28.94 flowers.m-2 and 0.14 g.m-2, respectively. By increasing the chickpea ratio from 20 to 100% at additive intercropping series with saffron, the dry weight of stigma was increased by 142, 116, 41 and 5%, respectively. Therefore, we may conclude that intercropping of saffron with nitrogen fixation plants such as chickpea seems to be a rational ecological approach for sustainable management of saffron

Effects of soil and foliar applications of nutrients on corm growth and flower yield of saffron (Crocus sativus L.) in six-year-old farm

Saffron (Crocus sativus L.) is one of the most important crops and medicinal plants in Iran. Appropriate application of nutrients has special important role on replacement corm growth and flower yield of saffron. In order to investigate the effects of different levels of soil and foliar nutrients applications by using mixture fertilizer on replacement corm production and flower yield of saffron, an experiment was conducted by using a factorial layout based on complete randomized block design with three replications at the Agricultural Research Station, Ferdowsi University of Mashhad during 2011- 2012 growing season. The experimental treatments were all combinations of four levels of soil nutrition (0, 50, 100 and 150 kg.ha-1) and three levels of foliar spray (0, 5 and 10 per 1000). Results of variance analysis showed that the soil application of treatments had positive significant effects on weight of replacement corms and number and weight of flower and stigma yield of saffron but these treatments had no significant effects on total corm number. The number and yield of replacement corms and flowers were not affected by simple effect of foliar spray and soil and foliar applications interactions. The results of this research showed that the using 150 kg.ha-1 of nutrients soil application in early March had more positive and significant effect on yield of fresh and dry flower (120 and 963 kg.ha-1, respectively), yield of fresh and dry stigma (45.5 and 7.90 kg.ha-1, respectively) and weight of replacement corms (1646 g.m-2) than other treatments but foliar application of nutrients in this time had no significant effects on flower and corm yield of saffron

Evaluation of integrated management of soil fertilizers and summer irrigation on agronomic criteria and flower and stigma yield of saffron

In order to evaluate the effects of organic, chemical and biological fertilizers and summer irrigation on growth characteristics, corm yield, flower yield and stigma yield of saffron, field experiment was conducted as factorial based on a randomized complete block design with three replications at Agricultural Research station, Faculty of Agriculture, Ferdowsi University of Mashhad during three growing season of 2013-2014, 2014-2015 and 2015-2016. The first factor included of animal cow manure (a1), chemical fertilizer (such as Nitrogen, P and K) (a2), Thiobacillus (a3), sulfur (a4), a3+a4 and control (a5) and the second factor was summer irrigation in three levels such as conventional irrigation (A: without summer irrigation), A+ once summer irrigation (23 July), A+ twice summer irrigation (22 June+23 July). Studied characteristics were number and fresh weight of flower, dry weight of stigma, corm diameter, corm weight in four groups (16 g), corms with contractile roots, number of flowering buds per corm, leaf length, dry weight of leaf and dry weight of tunic of saffron. The results in the third of experiment revealed that the interaction effect between fertilizers and summer irrigation were significant (P≤0.01) on all studied traits of saffron except stigma dry weight, corms with weight more than 16 g and dry weight of daughter corms. The highest flower number (282.7 per m2), flower fresh weight (103.2 g/m2), stigma dry weight (1.73 g/m2), leaf dry weight (13.33 g/m2), buds dry weight (4.61 g/m2), flowering buds number per corm (2.627), corm percentage with cractile roots (58.41%), corm diameter (2.97 cm) and corms in different weight were obtained in animal manure and A+once summer irrigation. About simple effects, the highest stigma dry weight and dry weight of daughter corms were observed in animal manure and the highest amount of this traits were obtained in treatment A+once summer irrigation. It seems that summer irrigation increased the flower and stigma yield of saffron due to decreasing soil temperature

The possibility of replacing chemical fertilizer with organic manure in saffron cultivation at different levels of corm density under Northern Khorasan climatic conditions

Due to climate change it seems that the suitable area for production of saffron is shifting towards the Northern area of Khorasan. On the other hand, corm density and nutrient management are important factors in saffron production. To find out the credibility of this assumption, an experiment was conducted based on a randomized complete blocks design arranged in split plot with three replications in a field located 10 km of Shirvan during the 2013-14, 2014-15 and 2015-16 growing seasons. Corm density (50, 100 and 150 corm.m-2) and different amounts of chemical and organic manure [No fertilizer (Control), amount of urea, triple super phosphate and potassium sulfate 100, 100, 50 (C1), 200, 200, 100 (C2) and 300, 300, 150 (C3), cow manure consumption based on 100 kg.ha-1 urea (3066 kg.ha-1), based on 200 kg.ha-1 urea (6132 kg.ha-1) and based on 300 kg.ha-1 urea (9198 kg.ha-1)] were allocated to the main and sub-plots, respectively. Three year average of harvest showed that flower and corm traits improved with increasing corm density and cow manure consumption, while the highest density compared to minimum density caused increasing flower number, fresh flower yield, dried stigma yield, daughter corm number and corm yield by 35, 61, 29, 180 and 122 percent, respectively. Also the highest amount of cow manure compared to control increased flower number, fresh flower yield, dried stigma yield and corm yield by 32, 51, 38 and 51 percentages, respectively. Therefore, more flower and corm yield were obtained in 9198 kg.ha-1 cow manure consumption with 150 corm.m-2 planting density. Therefore, it seems that the production of saffron is suitable using with organic manure compared with chemical manure. Moreover, saffron planting with high corm density is a solution for improving the yield of saffron in the early years of planting

Evaluation of radiation use efficiency of common bean (Phaseolus vulgaris L.) cultivars as affected by plant density under Mashhad climatic conditions

In order to determine the effect of different plant densities in bean cultivars, an experiment was conducted as factorial layout based on a randomized complete block design with three replications at Agricultural Research Station, Ferdowsi University of Mashhad, during growing season the 2014-2015. Factors included four bean cultivars (such as Akhtar, D-81083Line, Naz and Goli), and three plant densities (including 13.3, 20 and 40 plants.m-2). Study has addressed some indicators including leaf area index (LAI), amount of absorbed radiation, dry matter accumulation and radiation use efficiency (RUE) in bean cultivars at different plant densities. The trend of increasing dry matter accumulation in all cultivars entered to the linear growth phase on the 20th day after planting and reached to its maximum on the 70th day after planting. The highest dry matter was obtained in Goli (300.4 g.m-2) and Naz (285.1 g.m-2) cultivars which was 32 and 30% higher compared to Akhtar and 30 and 28% higher compared to D-81083 Line cultivar, respectively. The highest radiation use efficiency (2.2 g.MJ-1) was obtained in treatment at density of 40 plants.m-2 and was in Goli (2.01 g.MJ-1) and Naz (1.98 g.MJ-1) cultivars. With increasing plant density, maximum leaf area index in bean cultivars increased gradually to its highest level (40 plants.m-2) and due to plants ghosting, continued to decrease. This result can be used for modeling of leaf area. With increasing plant density due to increasing of leaf area index, the amount of absorbed radiation increased and therefore the time to reach maximum dry matter accumulation decreased and dry matter accumulation increased