Simulation of corn yield loss in nitrogen levels under Pigweed densities
Journal Title: International Research Journal of Applied and Basic Sciences - Year 2013, Vol 4, Issue 8
Abstract
In order to simulate corn yield loss per unit area at different levels of nitrogen under different weed densities, two experiments in split plot based on completely randomized blocks with three replications were conducted in 2010 and 2011 at the Islamic Azad University of Astara. Nitrogen in four levels of 0 (control), 100 (recommended nitrogen amount in the), 160 and 220 kg N.ha was the major factor; and the sub factor was density of redroot pigweed at four levels (0 (monoculture corn), 5, 10 and 20 plants per square meter). The results showed that the effect of red root pigweed density on corn seed yield loss per unit area was gained by three parametric Gompertz sigmoidal equation. In this equation the coefficient (a) that showed the maximum loss of corn yield, has the most appropriate accordance with quadratic polynomial equation. Therefore, the integration of these two equations, equations of corn yield loss at different levels of nitrogen and different red root pigweed density, was simulating as the following model: f=(a+b*x+c*x^2)*exp(-exp(-(y-yo)/d)In this equation; f: Corn yield loss (percentage), a: maximum asymptotic value, yo: turning point of the curve, x: amount of nitrogen, y: pigweed density, and b, c, d are the coefficients of equation.The result showed that the density of 10.5 weed plant per square meter can reduce corn yield in nonconsumption of nitrogen 20%, and by consuming 220 kg N.ha reduce it 40%, in comparison with control.
Authors and Affiliations
Ali Vahedi*| Department Of Agronomy and Crop breeding, Astara Branch, Islamic Azad University, Astara, Iran, Dr.Alivahedi@yahoo.com, Zohre Bakhshi| Department Of Agronomy and Crop breeding, Rasht Branch, Islamic Azad University, Rasht, Iran, Rasoul Fakhari| M.Sc. Student of Weed Science, University of Mohaghegh Ardabili, Ardabil, Iran, Hamid Reza Vahidipour| M.Sc. Student of Plant Physiology University of Mohaghegh Ardabili, Ardabil, Iran.
Keywords
Related Articles
- EP ID EP5619
- DOI -
- Views 278
- Downloads 9
Application of biological and integrated fertilizers mitigates the adverse effects of drought stress on barley
Reaching high yield using new soil management operations in areas with scarce water resources and low soil organic matter is a promising necessity in sustainable intensive agriculture. The objective of this research was...
Valuation of organic dairy products, proteins and factors affecting willingness to pay study fittings in the city of Shiraz
Many studies show that organic products do not have adverse effects common products. Due to the absence of a specific market for organic products in Iran, this study, using contingent valuation approach and method to est...
The investigating of development of e-banking in Iran
Present age is communication and information technology age. One of the most important phenomena of this age is Revolutionizing of traditional banking. Development of electronic communication and access of large numbers...
Factors preventing proper recognition to establish meritocracy system at the level of professional managers of Government agencies the city of Ahwaz
The present research has been done to have a survey Inhibitory factors in understanding to establish meritocracy at the level of competent professional manager's government agencies has been considered the city of Ahwaz....
Assessment of medical waste management in Karaj hospitals, Iran
In some countries, especially in developing countries such as Iran, medical wastes are not properly managed. Proper medical waste management decreases the risk of spreading infections, environmental hazards and public he...