Mechanical and/or chemical weed control in field pea
G. J. Endres, B. G. Schatz, and S. F. Zwinger
The trial was conducted at the Carrington Center in 1996-97 to determine if a harrow or rotary hoe may be effectively used toreduce herbicide use for weed control in field pea. Treatments included: 1) untreated check, 2) herbicide check [PPI Sonalan (2pt/ac)/POST Pursuit (2 fl oz/ac)], 3) harrow 1x, 4) harrow 2x, 5)harrow 1x/Pursuit (1.5 fl oz/ac), 6) rotary hoe 1x, 7) rotary hoe 2x, and 8) rotary hoe 1x/Pursuit (1.5 fl oz). The harrow and rotary hoe were initially used 3 to 5 days after planting (DAP) to control emerging weeds. The second pass was performed 10 to15 DAP.
Predominant weed species and control in the trial are listed in Table 1. Weed control generally was highest at 92 to 97% control with the herbicide check. Two tillage passes generally improved weed control compared to one pass. Weed control generally did not differ between tillage implements.
Pea density was reduced 6 to 12% with 2 tillage passes compared to the untreated check (Table 2). Seed yield and economic return were highest with the herbicide check. An advantage with weed control between the two tillage and one tillage/Pursuit treatments was not evident. However, yield and economics were improved with one tillage/Pursuit treatments. This likely was due to longer-season and more broad-spectrum weed control with Pursuit.