Mohsen Seilsepour
Abstract
In a field experiment, the effects from application of nitrogen and boron on quantitative and qualitative characteristics of Varamin cotton variety have been studied at Tehran Agricultural and Natural Resources Research Center in 2016. The experiment has been carried out, using a randomized complete ...
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In a field experiment, the effects from application of nitrogen and boron on quantitative and qualitative characteristics of Varamin cotton variety have been studied at Tehran Agricultural and Natural Resources Research Center in 2016. The experiment has been carried out, using a randomized complete block design with factorial arrangement with three replications, with the main factor being nitrogen at four levels (0, 100, 200, and 300 kg ha-1) and the sub-factor, involving boron at three levels (no leaf spray, one leaf spray, and two leaf spray). The effects of nitrogen and boron and the interaction of nitrogen and boron on the quantitative traits of cotton, namely the mean number of bolls per plant, average boll weight, fiber yield, and fiber gin out, with the qualitative traits including fiber length and strength. Highest seedcotton yield (5233 kg ha-1), fiber yield (2080 kg ha-1), fiber percentage (40%), fiber length (31.3 mm), and fiber strength (29.7 g/textile) belong to 200 kg N per hectare and twice spraying of boron. There is a correlation between the qualitative properties of the fibers and nitrogen, whose regression relation follows the quadratic equation. Results show that in soils with less than 0.5 mg/kg boron and less than 0.81% organic carbon storage, nitrogen and boron application significantly increases seedcotton and fiber yield and the fiber quality is also improved. Therefore, in such soils, it is recommended to utilize 200 kg N with two times of foliar boron application from boric acid source with a concentration of five per thousand at flowering stage for two weeks thereafter.
Majid Rahimizadeh
Abstract
A field experiment was conducted to evaluate and compare the effects of N and P chemical fertilizers with biological N and P fertilizers on competition between cotton and weeds with split plot arrangement in a randomized complete block design with three replications during the years 2014 and 2015. The ...
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A field experiment was conducted to evaluate and compare the effects of N and P chemical fertilizers with biological N and P fertilizers on competition between cotton and weeds with split plot arrangement in a randomized complete block design with three replications during the years 2014 and 2015. The main plots consisted of two levels of weed management practices including weed free and weedy check. Sub plots had five treatments included integrated application of biological and chemical fertilizers:1-Control (Without fertilizer) 2-Urea+Triplesuperphosphate (TSP) 3-Nitroxin+50% urea+100% TSP 4-100% urea+Barvar2 +50% TSP 5-Nitroxin+Barvar2+50% urea+50% TSP. In the first year, control of weeds increased LAI and number of boll per plant to 34 and 22 percent, respectively and cotton yield increased by 67 percent in the first year and 50 percent in the second year. Fertilizer treatments had a significant effect on stem length, LAI, number of sympodial branches and boll per plant, and yield of cotton. Under weed interference condition, use chemical fertilizers alone reduced cotton growth and yield due to increasing competitive ability of weeds. But reducing urea consumption by half and replace it with nitroxin, increased cotton yield by 61% compared to the chemical fertilizer treatment due to increasing number of boll per plant. This result indicates that the use of biological fertilizers reduce the negative effects of chemical fertilizers and increase crop competitiveness against weeds
Ahmad Raefizadeh; Mohammad Armin; Matin Jamaimoeini
Abstract
To determination of critical time of weed control in Cotton (Gossypium hirsutum L.) (Khordad cultivar) in conventional and ultra-narrow row spacing conditions, a field experiment was arrange as a factorial arrangement in a randomized complete block design with three replications in Sabzevar in 2015. ...
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To determination of critical time of weed control in Cotton (Gossypium hirsutum L.) (Khordad cultivar) in conventional and ultra-narrow row spacing conditions, a field experiment was arrange as a factorial arrangement in a randomized complete block design with three replications in Sabzevar in 2015. Factors were cultivation systems (conventional (70 Cm row spacing) and ultra narrow row (20 Cm row spacing) and duration of weed interference (0, 30, 45, 60, 7 days after emergence and weedy in full season. The results of the experiment showed that in ultra-narrow row condition, seed cotton yield losses of 2.5, 5 and 10 percent were estimated to occur on 27.4, 36.1 and 44.7 day after emergence, respectively and in conventional condition yield losses of 2.5, 5 and 10 percent were estimated to occur on 8.1, 13.5 and 24.4 day after emergence, respectively. The onset of seed cotton yield an lint yield loss was earlier (46.3 and 53.7 days after emergence, respectively) in conventional condition while in ultra-narrow row condition the onset of seed cotton yield and lint yield loss was postponed to 57.9 and 65.9 days after emergence, respectively, Overall, the results of the experiment showed that cultivation of cotton in ultra-narrow row spacing in weed interference conditions could provide a better seed cotton yield than conventional spacing.