In 1995, yield was not significantly affected by either system, WTRT, or their interaction (Table 4).
2535 2295 Between System LSD 95 Among WTRT LSD 145 System within WTRT LSD 210 WTRT within system LSD 205 1995 WTRT([dagger]) NR WR Av.
In both NR and WR, the addition of either PRE or POST grass herbicides to either PRE of POST broadleaf herbicides (WTRT 4 and WTRT 5 vs.
The large amount of money spent for weed management in WTRT 6 was spent on unnecessary herbicides, since yield from this treatment was low.
On the other hand, WTRT 10, the most expensive weed management treatment at $175, $175, and $138 [ha.
This was true even though late-season weed infestations occurred in WTRT 1 in NR in 1996 (Table 3).
Abbreviations: CSPS, conventional soybean production system; DAP, days after planting; ESPS, early soybean production system; MG, maturity group; NR, narrow-row system; NETRET, net return; PFA, preplant foliar-applied; POST, postemergence; PRE, preemergence; WR, wide-row system; WTRT, weed management treatment.
Uncontrolled weeds will reduce yield of soybean; thus, there was no comparison of the selected WTRTs to a weedy check.
The selected WTRTs assumed that broadleaf weeds but not necessarily grass weeds in a dryland environment must be controlled.
The intent in selecting the WTRTs was to have weed management options that differ in cost, and broadcasting of herbicides in NR vs.
In WR, yield differences among WTRTs were small and usually not significant (Table 4).