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Effects of Amaranthus retroflexus L. root on cotton cv. Varamin using ordination methods
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Elahe Esfanjani *   , Behnam Zand , Kamalsadat Asilan , Mina Rabie , Mohammad Hassan Jafari Sayyadi , Javad Esfanjani |
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Abstract: (4564 Views) |
Abstract
Introduction: More than 90% of cultivated cotton worldwide is the main source of textile fibers and is also grown to produce oilseed. Cotton is a widely cultivated plant and has important economic value because of its fiber and oil. The aggressive growth and allelopathic activity of red root pigweed plants allow them to compete strongly against other plants and significantly reduce crop yield and quality. The main goal of this study is using ordination method in order to study the effects of pigweed allelopathy on cotton in the field and laboratory conditions.
Materials and Methods: Field study was carried out in a randomized complete block design with 9 treatments (emerging tome of pigweed including: time coincided with cotton emergence, two-leaves stage of cotton, four-leaves stage of cotton and density of 3, 6 and 12 pigweed per square meter) and three replications. Laboratory study was conducted in a randomized completely design with five treatments (control, 20%, 40%, 80%, 100% root and leaf extracts concentrations) and three replications.
Results: The initial analysis was performed using DCA (De-trended Correspondence Analysis) method, and since gradient length was less than 3 in both phases, so PCA (Principle Correspondence Analysis) method was used. In the field, the results showed that the leaf area index, leaf biomass, weight of twenty boll and cotton yield had a negative and high correlation and it correlated negatively and low with height, stem biomass and number of cotton bolls. The results of laboratory phase showed that the concentration of extract with germination percentage, germination rate, root length and number of buds have a negative and high correlation.
Conclusions: Control of red root pigweed in cotton fields, due to reduction in germination traits, growth characteristics and yield of cotton in the presence of weed, is necessary from the beginning. According to the results, ordination methods by identification most important factors affecting the quantitative and qualitative growth of cotton can be used in order to create accurate management approaches for improvement and restoration of agricultural fields under the influence of weeds.
Keywords: Biomass, Allelopathy, Gradient length, Correlation |
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Full-Text [PDF 1030 kb]
(1226 Downloads)
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Type of Study: Research |
Subject:
Ecophysiology
Received: 2017/11/20 | Accepted: 2017/11/20 | Published: 2017/11/20
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