Table 1. Effects of short-term fallowing and fumigation on subsequent performance of peach trees used to replant a cleared peach orchard site in 1998; Parlier, CA; data from Trout and Ajwa
|
|
Trunk diameter (mm)d |
Marketable yield (kg/tree) d |
||||||
|
Pre-plant treatmenta |
11/98 |
12/99 |
11/00 |
11/01 |
10/02 |
8/00 |
8/01 |
8/02 |
|
0-year fallow, non-fumigated |
22 c |
40 c |
63 c |
81 c |
104 c |
6.7 b |
17.1 a |
32.8 a |
|
1-year fallow, non-fumigated |
27 bc |
50 b |
74 bc |
88 bc |
113 bc |
7.2 b |
18.4 a |
35.5 a |
|
1-year fallow, Telone + Vapamb |
29 b |
53 b |
80 ab |
97 ab |
116 ab |
9.1 a |
20.4 a |
38.2 a |
|
0-year fallow, methyl bromide c |
37 a |
63 a |
89 a |
104 a |
126 a |
9.9 a |
18.8 a |
38.2 a |
aFor the fallow treatments, trees were removed in fall, either 0 year (4 mo) or 1 year (16 mo) before replanting. After tree removal, fallow plots were ripped to 76 cm depth and planted to Merced rye, which was mowed in spring. All treatments were planted simultaneously in February 1998.
b35 gal/A Telone II EC (310 lb/A 1,3-D) was applied by sub-drip in 100 mm water in fall 1997 with Vapam (26 gal/A) microsprayed on the soil surface.
cMethyl bromide (350 lb/A) was shank-injected in fall 1997, under HDPE plastic.
dMeans within a column and with letters in common are not significantly different (P=0.05).
Table 2. Effects of short-term fallowing and fumigation on subsequent performance of peach trees used to replant an old peach orchard site in 1999; Parlier, CA; data from Trout and Ajwa
|
|
Trunk diameter (mm)d |
Marketable yield,7/02 (kg/tree) d |
|||
|
Pre-plant treatmenta |
12/99 |
11/00 |
11/01 |
10/02 |
|
|
0-year fallow, non-fumigated |
17 c |
42 c |
61 b |
88 c |
22.6 c |
|
1-year fallow, non-fumigated |
19 b |
49 b |
69 b |
94 bc |
26.2 bc |
|
1-year fallow, Inline + Vapamb |
22 a |
58 a |
80 a |
106 a |
32.8 a |
|
0-year fallow, methyl bromide c |
23 a |
58 a |
79 a |
104 ab |
30.1 ab |
aFor the fallow treatments, trees were removed in fall, either 0 year (4 mo) or 1 year (16 mo) before replanting. After tree removal, fallow plots were ripped to 76 cm depth and planted to Merced rye, which was mowed in spring. All treatments were planted simultaneously in February 1998. b35 gal/A Inline (Telone C-35 EC) (320 lb/A 1,3-D+130 lb/A chloropicrin) was applied by sub drip in 76 mm water in fall 1998 with Vapam (13 gal/A) microsprayed on the soil surface.
cMethyl bromide (350 lb/A) was shank-injected fall 1998, covered with HDPE plastic.
dMeans within a column and with letters in common are not significantly different (P=0.05).
Table 3. Effects of short- to long-term pre-plant fallowing and pre-plant fumigation on performance of plum trees used to replant an old plum orchard site in 2000; Parlier, CA; after Trout and Ajwa
|
|
Trunk diameter (mm)d |
|
||
|
Pre-plant treatmenta |
10/00 |
11/01 |
10/02 |
Marketable yield (kg/tree) d |
|
0-year fallow, non-fumigated |
25 c |
52 c |
92 b |
4.7 b |
|
1-year fallow, non-fumigated |
29 b |
64 b |
108 a |
5.9 ab |
|
1-year fallow, non-fumigated, herbicide treatment of stumps b |
28 bc |
63 b |
109 a |
6.4 ab |
|
2-year fallow, non-fumigated |
30 ab |
67 ab |
111 a |
8.3 ab |
|
3-year fallow, non-fumigated |
34 a |
71 a |
115 a |
12.7 a |
|
0-year fallow, methyl bromide c |
34 a |
71 a |
115 a |
11.8 a |
aFor the fallow treatments, trees were removed in fall, either 0, 1, 2, or 3 year before replanting. After old tree removal, fallow plots were ripped to 76 cm depth and planted to Merced rye, which was mowed in spring. All plots were planted on the same day in February 2000.
bStumps of old trees treated with Roundup (50 ml/tree) immediately after cutting off tops in September, 16 mo before replanting.
cMethyl bromide (350 lb/A) was shank-injected fall 1999, covered with HDPE plastic.
dMeans within a column and with letters in common are not significantly different (P=0.05).
Table 4. Effects of short- to long-term pre-plant fallows and pre-plant fumigation on subsequent performance of peach trees used to replant an old peach orchard site in 2000; Parlier, CA; after Trout and Ajwa
|
|
Trunk diameter (mm)c |
|
||
|
Pre-plant treatmenta |
11/00 |
10/01 |
10/02 |
Marketable yield (kg/tree) c |
|
0-year fallow, non-fumigated |
20 b |
42 d |
62 c |
8.0 d |
|
1-year fallow, non-fumigated |
20 b |
44 cd |
72 b |
10.4 cd |
|
2-year fallow, non-fumigated |
22 b |
48 bc |
76 b |
14.0 bc |
|
3-year fallow, non-fumigated |
23 b |
50 b |
80 b |
16.0 b |
|
0-year fallow, methyl bromide b |
29 a |
58 a |
90 a |
18.2 a |
aFor the fallow treatments, trees were removed in fall, either 0, 1, 2, or 3 year before replanting. After old tree removal, fallow plots were ripped to 76 cm depth and planted to Merced rye, which was mowed in spring. All treatments & plots were planted on the same day in February 2000.
bMethyl bromide (350 lb/A) was shank-injected fall 1999, covered with HDPE plastic.
cMeans within a column and with letters in common are not significantly different (P=0.05).
Table 5. Effects of pre-plant cover crop and fumigation treatments on subsequent growth of peach seedlings in soil collected from an old peach orchard site near Parlier, CA
|
Pre-plant soil treatmentsa |
|
Performance of Nemaguard peach seedlingsb |
|||
|
Fumigation status |
Cover crop / fallow conditions |
Cover crop residue incorporated per 2-liter pot (range, g) |
Top fresh weight (g) |
Root fresh weight (g) |
Percentage of discolored rootsc |
|
Non-fumigated |
Bare fallow, moist soil |
0 |
115 |
75 |
46 |
|
Non-fumigated |
Bare fallow, dry soil |
0 |
118 |
98 |
46 |
|
Bucket-fumigatedd |
Bare fallow, moist soil |
0 |
113 |
82 |
26 |
|
Field-fumigatede |
Bare fallow, dry soil |
0 |
92 |
66 |
36 |
|
Non-fumigated |
Castor bean, Ricinus communis |
233-306 |
130 |
111 |
48 |
|
Non-fumigated |
Crotolaria |
107-141 |
117 |
78 |
52 |
|
Non-fumigated |
Sesbania, Sesbania exaltata |
88-131 |
107 |
76 |
52 |
|
Non-fumigated |
Sudangrass, Sorghum sudanensis |
134-182 |
117 |
80 |
42 |
|
Non-fumigated |
Sudex, Sorghum bicolor x sudanese |
124-206 |
122 |
94 |
41 |
|
Non-fumigated |
Sword bean, Canavalia ensiformis |
87-95 |
115 |
70 |
40 |
|
Non-fumigated |
Velvetbean, Mucuna pruriens var. utilis |
102-135 |
120 |
97 |
44 |
|
Non-fumigated |
Vetch, Vicia sativa |
3-26 |
110 |
75 |
44 |
|
Non-fumigated |
Wheat, Triticum aestivum, cv. ÔDawsÕ |
118-124 |
110 |
85 |
41 |
|
Non-fumigated |
Wheat, Triticum aestivum, cv. ÔSpragueÕ |
148-151 |
122 |
92 |
47 |
|
L.S.Df: |
|
|
NS |
NS |
14 |
aSoil was collected in summer 1999 from replicate MBr-fumigated and non-fumigated plots near Parlier, screened through a 1-cm mesh screen, placed in 2-liter pots in a greenhouse, and subjected to the cover crop / fallow treatments. The cover crops were allowed to grow 4 months, uprooted, chopped with a shredder, weighed, incorporated into the soil, and allowed to decompose for 2 months.
bAfter the decomposition period, three Nemaguard peach seedlings were planted per 2-liter pot (May 2000). Three months after transplanting, total top and root fresh weight was determined for the peach seedlings in each pot, and the roots were washed free from the soil and inspected for symptoms of disease. There were four replicate pots per treatment combination.
cVisual estimate of the percentage of total root length with brown-discolored cortex tissue or decay extending through the root cortex.
dFumigated 3 weeks before transplanting with peach seedlings (MBr : chloropicrin 67:33, 0.8 g per liter soil; in a sealed 19-liter bucket).
eFumigated fall 1998, approx. 9 mo before collection of soil (MBr, 350 lb/A, shank injected in the field under HDPE plastic).
fLeast significant difference among means, based on 95% confidence intervals; NS indicates no significant difference.
Table 6. Effects of pre-plant cover crop and fumigation treatments on subsequent growth of peach seedlings in soil collected from an old plum orchard site near Parlier, CA
|
Pre-plant soil treatmentsa |
|
Performance of Nemaguard peach seedlingsb |
|||
|
Fumigation status |
Cover crop / fallow conditions |
Cover crop residue incorporated per 2-liter pot (range, g)a |
Top fresh weight (g) |
Root fresh weight (g) |
Percentage of discolored rootsc |
|
Non-fumigated |
Bare fallow, moist soil |
0 |
113 |
55 |
42 |
|
Non-fumigated |
Bare fallow, dry soil |
0 |
106 |
64 |
44 |
|
Bucket-fumigatedd |
Bare fallow, moist soil |
0 |
81 |
64 |
30 |
|
Non-fumigated |
Castor bean, Ricinus communis |
233-306 |
127 |
63 |
36 |
|
Non-fumigated |
Crotolaria |
107-141 |
108 |
54 |
48 |
|
Non-fumigated |
Sesbania, Sesbania exaltata |
88-131 |
111 |
60 |
44 |
|
Non-fumigated |
Sudan grass, Sorghum sudanensis |
134-182 |
123 |
84 |
39 |
|
Non-fumigated |
Sudex, Sorghum bicolor x sudanese |
124-206 |
121 |
84 |
42 |
|
Non-fumigated |
Sword bean, Canavalia ensiformis |
87-95 |
114 |
63 |
43 |
|
Non-fumigated |
Velvetbean, Mucuna pruriens var. utilis |
102-135 |
116 |
61 |
47 |
|
Non-fumigated |
Vetch, Vicia sativa |
3-26 |
111 |
48 |
42 |
|
Non-fumigated |
Wheat, Triticum aestivum, cv. ÔDawsÕ |
118-124 |
129 |
75 |
39 |
|
Non-fumigated |
Wheat, Triticum aestivum, cv. ÔSpragueÕ |
148-151 |
125 |
59 |
36 |
|
L.S.D.f: |
|
|
NS |
NS |
NS |
aSoil was collected in summer 1999 from replicate non-fumigated plots near Parlier, screened through a 1-cm mesh screen, placed in 2-liter pots in a greenhouse, and subjected to the cover crop / fallow treatments. The cover crops were allowed to grow 4 months, uprooted, chopped with a shredder, weighed, incorporated into the soil, and allowed to decompose for 2 months.
bAfter the decomposition period, three Nemaguard peach seedlings were planted per 2-liter pot (May 2000). Three months after transplanting, total top and root fresh weight was determined for the peach seedlings in each pot, and the roots were washed free from the soil and inspected for symptoms of disease. There were four replicate pots per treatment combination.
cVisual estimate of the percentage of total root length with brown-discolored cortex tissue or decay extending through the root cortex.
dFumigated 3 weeks before transplanting with peach seedlings (MBr : chloropicrin 67:33, 0.8 g per liter soil; in a sealed 19-liter bucket).
fLeast significant difference among means, based on 95% confidence intervals; NS indicates no significant difference.
Table 7. Effects of pre-plant cover crop and fumigation treatments on incidence of fungal genera associated with peach seedling roots grown in soil collected from an old peach orchard site near Parlier, CAa
|
Fumigation status |
Cover crop / fallow conditions |
Incidence of selected fungal genera on roots of Nemaguard peach seedlings (%) |
||||||
|
Cylindrocarpon |
Fusarium |
Mortierella |
Papulospora |
Pythium |
Rhizoctonia |
Trichoderma |
||
|
Non-fumigated |
Bare fallow, moist soil |
0 |
50 |
5 |
3 |
0 |
3 |
20 |
|
Non-fumigated |
Bare fallow, dry soil |
0 |
50 |
3 |
3 |
0 |
3 |
30 |
|
Bucket-fumigatedb |
Bare fallow, moist soil |
3 |
15 |
3 |
0 |
0 |
13 |
23 |
|
Field-fumigatedc |
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