Asieh Siahmarguee; Benjamin Torabi; Eid Mohammad Sohrabi Rad; Syed majid Alimagham
Abstract
To investigate the factors affecting soybean yield loss in comparison to the attainable yield, an experiment was conducted in 50 fields in the township of Kalaleh in summer of 2016. Sampling of weeds were taken in early growing season of soybean based on W pattern. In this study all agronomic management ...
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To investigate the factors affecting soybean yield loss in comparison to the attainable yield, an experiment was conducted in 50 fields in the township of Kalaleh in summer of 2016. Sampling of weeds were taken in early growing season of soybean based on W pattern. In this study all agronomic management information including land area, farmers experience, seed bed preparation, sowing date, cultivar and provided seed source, sowing methods, seed rate, weeds control methods, amount and time of applied herbicide and wheat harvest time were collected during growing season by preparing questionnaire and complete them with farmers. In evaluated fields, 13 weed species belonged to 11 families were observed. Among the various parameters, field area, seed rate, certified seed application, planting date, Asian spider flower (Cleome viscosa L.) and Johnson grass (Sorghum halepense L.) had the significant effects on soybean yield. The minimum and optimum predicted yields with model were 1039 and 2036 kg/ha-1, respectively. Thus there was 996 kg/ha-1 gap between minimum and optimum predicted yield in this township. Results showed certified seed (23.07 percent), delay planting date(15.04 percent), low seed rate (11.54 percent), low field area(7.62 percent), present of Johnson grass(12.47 percent) and asian spider flower(30.25 percent) weeds were the most effective factors on this yield gap. With optimizing mentioned agronomic managements could reduce yield gap and increased yield to double.
Vahid Rahimi; Mehdi Mohebedini; Alireza Ghanbari; Shiva Azizinia; Mehdi Behnamian
Abstract
In order to assessment the relationship between traits affecting yield of garden cress, an experiment was conducted in lattice square design with three replications in Eyvanekey Jihad Farm in 2016. The ANOVA showed that the difference among accessions was significant for all traits. There was a significant ...
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In order to assessment the relationship between traits affecting yield of garden cress, an experiment was conducted in lattice square design with three replications in Eyvanekey Jihad Farm in 2016. The ANOVA showed that the difference among accessions was significant for all traits. There was a significant phenotypic correlation between yield and most of the traits. The highest value of phenotypic correlation was obtained between leaf height and leaf width (0.92). The regression analysis showed that the highest effect on the yield was due to leaf height and numbers of seeds per silique of lateral branches and main axis, as these three traits were about 93% of total yield changes and leaf height was the first trait that entered to the model and explained 91% of the variation. The path analysis of phenotypic correlation showed that the leaf height had the greatest direct effects on the yield (6.81). Leaf length, in addition to the direct effect on yield, through the rest of the traits has a positive indirect impact. In factor analysis, three independent factors explained about 70% of the yield variation. The first factor consists of number of silique per plant, number of seeds per silique of lateral branches and main axis has named seed factors. The purpose of this study was detection of phenotype correlation between yield and yield components, estimation of direct and indirect effects of yield components on yield and its part in diversity justification.
Hossein Ghorbani Mandolakani; Manoochehr Khodarahmi; Farrokh Darvish; Mohammad Taeb
Volume 12, Issue 1 , May 2010, , Pages 59-67
Abstract
In order to determine the relationship between yield and some morphological and physiological traits, as well as important traits that affect grain yield in bread wheat, a field experiment was conducted at Cereal Research Farm, Seed and Plant Improvement Institue, KaraJ in 2007. Three hundred and thirty ...
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In order to determine the relationship between yield and some morphological and physiological traits, as well as important traits that affect grain yield in bread wheat, a field experiment was conducted at Cereal Research Farm, Seed and Plant Improvement Institue, KaraJ in 2007. Three hundred and thirty five bread wheat recombinant inbred lines were evaluated in an Alpha Lattice design with two replications. Grain yield was positively correlated with all of the yield components, but was negatively correlated with days to heading, days to anthesis, days to ripening, extrusion peduncle length and second internode length. In stepwise regression, grain production rate was the first variable entered in the model and explained a higher percentage variation in grain yield. Path analysis showed that grain production rate and biological yield (0.534 & 0.532) exerted the most direct effects on grain yield. On the basis of these result, it is suggested that criteria such as number of spike per m2, number of grain per m2, seed weight per spike, biological yield production rate , grain production rate and biological yield could be considered as effective criteria for selecting towards grain yield improvement in bread wheat.