Selective Herbicides for Cultivation of Eucalyptus urograndis Clones
Table 3
Prevalence of ground cover by vegetation groups 30, 60, and 90 days after treatment (DAT) for herbicides applied over newly planted Eucalyptus urograndis rooted cuttings either prior to weed emergence (PRE) or after weed emergence (POST). Treatments were evaluated at the end of the month indicated for each application timing and periodic assessment.
Treatment
Ground cover (%)1
Herbicide
Rate
30 DAT
60 DAT
90 DAT
(g ha−1)
Grasses
Sedges2
Forbs
Vines
Grasses
Sedges
Forbs
Vines
Grasses
Sedges
Forbs
Vines2
Applied PRE weed emergence3
May
June
July
Flumioxazin
290 ai
17 c
9
0 a
0 a
52 ef
9 d–f
0 a
0 a
76 e
5 d–e
0 a
0 ab
Flumioxazin
430 ai
14 c
6
0 a
0 a
49 ef
5 a–d
0 a
0 ab
59 c–e
3 b–d
0 a
0 a–c
Imazamox
140 ae
3 ab
6
17 e
0 a
36 c–e
14 f
12 cd
1 a–c
44 bc
8 e
21 cd
2 b–e
Imazamox
210 ae
2 ab
7
12 de
0 a
17 bc
11 ef
19 c–e
0 ab
34 a–c
6 d–e
29 de
0 a–d
Imazapic
140 ae
1 ab
3
3 c
0 a
6 ab
2 ab
13 c–e
0 a
27 ab
1 ab
36 de
0 a
Imazapic
280 ae
0 a
3
3 c
0 a
3 a
2 a
11 c
0 a
20 a
1 a
38 de
0 a
Oxyfluorfen
1120 ai
34 d
6
1 a–c
2 b
75 g
6 a–e
2 ab
3 d
81 e
3 b–d
2 ab
9 fg
Oxyfluorfen
2240 ai
5 b
6
0 ab
0 a
42 d–f
12 ef
1 a
1 b–d
80 e
4 c–e
1 ab
4 d–f
Sulfometuron
26 ai
2 ab
4
10 de
0 a
16 b
8 c–f
24 e
2 cd
47 b–d
5 d–e
30 de
4 e–g
Sulfometuron
53 ai
0 ab
4
9 d
0 a
5 ab
6 b–e
23 de
0 a–c
25 ab
5 d–e
37 de
3 c–f
Sulfometuron
105 ai
0 a
2
2 bc
0 a
3 a
3 a–c
12 c–e
0 a–c
29 ab
4 c–e
32 de
3 c–f
Nontreated control
37 d
7
17 e
8 c
61 fg
7 b–e
9 bc
8 e
72 de
2 a–c
8 bc
10 g
Complete weed control
0
0
0
0
0
1
1
1
1
0
0
6
Applied POST weed emergence3
June
July
August
Flumioxazin
290 ai
71 f
4
1 a
3 bc
68 f
2 a
1 a
4 bc
66 de
1 a
2 a
3
Flumioxazin
430 ai
70 f
3
2 a
3 b
66 f
1 a
2 a–c
1 ab
65 de
0 a
2 a
1
Imazamox4
140 ae
53 de
4
7 bc
0 a
54 c–f
5 ab
9 b–e
1 a
47 c–e
1 a
12 a–c
1
Imazamox4
210 ae
32 bc
7
7 bc
0 a
37 b–d
9 b
9 c–f
2 ab
42 b–d
7 c
10 a–c
2
Imazapic4
140 ae
38 b–d
4
7 bc
0 a
35 bc
1 a
20 f–h
0 a
34 bc
0 a
27 c–e
1
Imazapic4
280 ae
17 a
6
10 c
0 a
10 a
1 a
34 h
0 a
11 a
1 a
46 e
1
Oxyfluorfen
1120 ai
74 f
6
3 ab
8 de
57 d–f
3 a
3 a–c
11 e
62 de
0 a
7 ab
7
Oxyfluorfen
2240 ai
66 ef
5
3 ab
8 de
61 ef
3 a
2 ab
9 c–e
67 e
1 a
2 a
4
Sulfometuron
26 ai
33 bc
7
12 c
10 e
45 c–e
5 ab
15 d–f
10 de
47 c–e
4 bc
14 a–c
5
Sulfometuron
53 ai
47 cd
5
11 c
5 cd
54 c–f
2 a
19 e–g
6 c–e
51 c–e
1 a
19 b–d
4
Sulfometuron
105 ai
27 ab
4
13 c
3 bc
23 ab
3 a
32 gh
5 cd
21 ab
1 ab
40 de
3
Nontreated control
65 ef
5
10 c
11 e
72 f
2 a
8 b–d
10 de
61 de
1 a
16 bc
6
Complete weed control
0
0
1
0
1
0
0
6
0
0
0
4
LS-means within a column followed by the same letter for PRE or POST applications are not significantly different at using Fisher’s protected LSD. Means are for the two E. urograndis clones combined, since clone effects were not significant. LS-means for the complete weed control treatment were not included in LSD comparisons, because this treatment was applied repeatedly to provide as close to 100% bare ground as possible and was intended for comparisons of eucalyptus growth response to weed control. 2The effect of treatment was not significant for sedge cover at 30 DAT for PRE or POST applications and for vine cover at 90 DAT for POST applications. 3PRE weed emergence treatments were applied April 29, 2009. POST weed emergence treatments were applied May 30, 2009. Seedlings were planted April 14, 2009. 4A nonionic surfactant was added at 0.25% (v/v) for POST applications of imazapic and imazamox as directed by herbicide label.
