Effect of Management Operations on the Thermal Time of Velvetleaf (Abutilon theophrasti Medicus.) Emergence in Soybean (Glycine max L.)

Subject Areas : Weed Research Journal

rahman khakzad ¹ , Mohammad Taghi Alebrahim ² , Mostafa Oveisi ³

1 - University Mohaghegh Ardebili
2 - Associate professor and Director of Scientific and International affairs University of Mohaghegh Ardabili
3 - academic member university of tehran

Received: 2019-06-27 Accepted : 2019-10-05 Published : 2019-02-20

Keywords: emergence rate, seeding rate, no-till, herbicide dose, Conventional tillage,

Abstract :

In order to evaluate the effect of different management practices on the emergence time of vevetleaf, a split-split plot experiment was conducted in a completely randomized block design with three replications in Dasht-e-Naz Sari in 2016 and 2017. Two tillage systems (Conventional tillage and no-till), three soyabean seeding rates (200,000; 300,000 and 400,000 seeds ha-1), and three doses of imazethapyr (SL 10%) (0, 50, and 100 g ai ha-1) were considered as experimental factors. The velvetleaf emergence was significantly affected by management practices including tillage system, soybean seeding rate, and imazethapyr dose. No-till system, a density of 400 000 seeds ha-1 and a 100 g a.i. ha-1 imazethapyr dose not only resulted in the lowest velvetleaf seedling density m-2 but also caused the longest delay in the time to reach 50% of seedling emergence, thus resulting in a long lag phase of velvetleaf emergence early in the season. Findings from our study may facilitate the development of effective P. oleracea management strategies.