Physical and Cultural Weed Control Working Group of - European ...

9 th EWRS Workshop on Physical and Cultural Weed Control 76
Samsun, Turkey, 28 – 30 March 2011
Table 4. Regression parameters (Figure 1b) for plant injury of corn, green foxtail, soybean, and
velvetleaf as affected by various times of day at different propane dose at 7 d after treatment.
Regression parameters are estimated using Equation 2. a,b
Species Propane dose Regression parameters (± SE)
B C D I50
HAS90 c Time of
day d
Corn
29 –19.1 (8.3) 38 (1) 55 (7) 8 (2) 9 (2) 3 P.M.
Green
foxtail
Soybean
Velvetleaf
43 –12.3 (4.4) 51 (1) 68 (2) 9 (1) 10 (1) 4 P.M.
87 –15.7 (9.9) 59 (1) 74 (4) 8 (1) 9 (1) 3 P.M.
29 –13.9 (6.3) 25 (1) 42 (3) 9 (1) 10 (1) 4 P.M.
43 –7.9 (7.2) 28 (2) 45 (7) 7 (1) 9 (1) 3 P.M.
87 –5.0 (2.5) 56 (3) 81 (4) 6 (1) 9 (1) 3 P.M.
29 –16.9 (9.8) 25 (2) 46 (6) 8 (1) 9 (2) 3 P.M.
43 –14.4 (8.9) 39 (6) 71 (2) 9 (1) 10 (1) 4 P.M.
87 –2.3 (1.2) 70 (5) 89 (6) 6 (2) 12 (3) 6 P.M.
29 –15.6 (9.9) 55 (4) 75 (4) 8 (1) 9 (1) 3 P.M.
43 –21.2 (9.6) 68 (1) 78 (2) 6 (3) 7 (4) 1 P.M.
87 –16.9 (9.9) 79 (5) 92 (5) 8 (1) 9 (1) 3 P.M.
a Abbreviations: B, the slope of the line at the inflection point; C, the lower limit; D, the upper limit;
I50, the hours after sunrise resulting in a 50% response between the upper and lower limit.
b No treatment-by-experimental run interaction occurred; therefore, the data were pooled over two
experimental runs.
c The hours after sunrise when flaming resulted in a 90% of the maximum injury for weeds and
crops.
d Time of day is calculated by adding the corresponding HAS90 value with the sunrise hour on June
15, 2009. The time for sunrise was 5:50 A.M. on June 15, 2009 (Time from Custom Sunrise Sunset
Calendar for Lincoln/Omaha, NE, http://www.sunrisesunset.com/custom_srss_calendar.asp).