Journal of Food, Agriculture and Environment

Multiple regression analysis in competition between lambsquarters and rapeseed

Author(s):

Negar Valizadeh, Bahram Mirshekari ^*

Recieved Date: 2011-06-09, Accepted Date: 2011-10-06

Abstract:

In order to evaluate of inter-specific competition between lambsquarters (Chenopodium album) and rapeseed (Brassica napus) cultivars, an experiment was performed in a randomized complete block design with three factors including lambsquarters density (5, 10 and 15 weeds/m²), emergence time (simultaneously with rapeseed; 15 and 30 days after rapeseed emergence) and rapeseed cultivar (SLM046, Opera and Okapi). Results indicated that in higher weed densities and early emergence times weed green cover in plots of three cultivars was improved significantly, and increased values in Okapi and SLM046 were higher. When lambsquarters emergence time was delayed and density decreased, weed LAI experienced significant reduction in all rapeseed cultivars. With increasing of lambsquarters density, its leaf area at 75 days after emergence (DAE) decreased from 0.29 to 0.10 m² in Okapi, 0.36 to 0.12 m² in Opera and 0.40 to 0.14 m² in SLM046. Similarly, weed leaf area duration (LAD) was reduced from 0.4, 0.8 and 0.95 m²/day to 0.26, 0.63 and 0.72 m²/day in three studied cultivars, respectively. Yield loss in rapeseed varied from 4.3% with emerging of 5 lambsquarters plants at 30 DAE in Okapi up to 59% in long-season interference of 15 weed plants in SLM046. The stepwise regression analysis verified that the green cover percentage and LAI of weed had a marked increasing effect on the oil yield of rapeseed.

Keywords:

Green cover, interference, lambsquarters, rapeseed, stepwise regression

---

Journal: Journal of Food, Agriculture and Environment
Year: 2011
Volume: 9
Issue: 3&4
Category: Agriculture
Pages: 525-528

---

Full text for Subscribers

---

Information:

Note to users

The requested document is freely available only to subscribers/registered users with an online subscription to the Journal of Food, Agriculture & Environment. If you have set up a personal subscription to this title please enter your user name and password. All abstracts are available for free.

Article purchasing

If you like to purchase this specific document such as article, review or this journal issue, contact us. Specify the title of the article or review, issue, number, volume and date of the publication. Software and compilation, Science & Technology, all rights reserved. Your use of this website details or service is governed by terms of use. Authors are invited to check from time to time news or information.

---

Purchase this Article:   20 Purchase PDF Order Reprints for 15

---

Share this article :