Study in Dallas – 2000
At Dallas, Prowl 3.3 EC (pendimethalin) was preplant applied and incorporated on 14 January 2000 at 1.5
quarts/acre (1.25 lbs a.i./acre). The soil type was a Houston Black Clay with pH 8.3. Fourteen soybean cultivars were
planted on 21 April 2000. The cultivars were selected because their upper leaves varied in size. The objective of the
study was to determine whether leaf size was related to a cultivar’s response to row spacing. Plots were 20 feet long and
12 rows wide using 14-inch rows and 6 rows wide using 28-inch rows. Prowl 3.3 EC, was the only pesticide applied.
Rain was plentiful through June 30, but there was no rain in July or August. Plots were end trimmed to 10 feet. The four
center rows of each 14-inch row plot and the two center rows of each 28-inch row plot were harvested using a
mechanical plot harvester. Yield was determined by obtaining seed moisture and adjusting weights to 13% moisture. No
clear relationship between leaf size and response to row spacing was found. The 28-inch rows tended to outyield the 14-
inch rows.