Wheat and Soybean Response to Controlled and Uncontrolled Field Traffic.

Wheat and soybean response to controlled and uncontrolled field traffic

Tyler K. Black, David L. Holshouser, Wade E. Thomason, Mark M. Alley, and Bee Kim Chim

Abstract

                High yield wheat (Triticum aestivum L.) and soybean (Glycine max L.) management systems often rely on late-season crop protection. The objectives of this research were to determine wheat and soybean yield loss, yield compensation and yield components at specific distances from tramlines (controlled traffic) and uncontrolled wheel traffic.  In 2014, wheat (June) and soybean (November) experiments were conducted near Warsaw and Blacksburg, VA.  Experimental design was a randomized complete block with four replications (three replications for soybean in Blacksburg).  At both locations, ‘Jamestown’ soft red winter wheat and Asgrow ‘AG4934’ soybean, maturity group 4.9, were planted in 20 cm rows.  Wheat studies consisted of trammed and un-trammed treatments at Zadoks growth stage GS 45, GS 54, and GS 45 and GS 54.  A GS 32 treatment was un-trammed only.  Soybean treatments consisted of trammed and un-trammed traffic at V5, r R3, R5, V5+R3, V5+R5, V5+R3+R5, and R3+R5.  A solid planted, un-trafficked check was included for each timing.  At harvest maturity, one meter of row from two and four rows on each side of the wheel traffic in wheat and soybean, respectively, was cut at ground level.  For both crops total plant dry matter was determined, wheat heads were counted, bundles threshed, and total grain weight and weight of 1000 kernels measured.  For soybean, nodes, fertile nodes, branches, branch pods, and main stem pods were counted on a three-plant subsample before threshing.  Total grain weight, total seed number and 500 seed weight were measured.