| Common name |
Amount/Acre |
R.E.I.+ |
P.H.I.+ |
| (trade name) |
|
(hours) |
(days) |
|
| PREPLANT FUMIGATION |
| A. |
METAM SODIUM* |
| |
(Vapam, Sectagon) |
50–75 gal |
48 |
— |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 27 |
| |
COMMENTS: Metam is a water soluble, soil-applied biocide. For
best results, it should be applied to well tilled soil free of large clods
that was moistened by rainfall or preirrigated 2 weeks previously in order to
enhance germination of weed seeds. Typical application is with a subsurface
spray blade into premade beds. Set spray blades to cut 2–3 inches below
the soil surface with disc hillers following behind to form a 3- to 5-inch
soil cap over treated area. After 7–14 days, the caps are removed and
allowed to air before planting. Typically only a 6- to 12-inch band is
treated in order to reduce costs. It can be injected into the sprinkler
irrigation system and applied through drip irrigation tubes placed under a plastic
mulch. There have been numerous failures with metam, mostly because of
improper soil preparations. Fumigants such as metam sodium are a source of
volatile organic compounds (VOCs) but are minimally reactive with other air
contaminants that form ozone. Fumigate only as a last resort when other management strategies have not been successful or are not available. |
| |
| BEFORE PLANTING |
| A. |
BENSULIDE |
5–9 lb a.i. |
|
|
| |
(Prefar) 4E |
5–9 qt |
12 |
— |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 8 |
| |
COMMENTS: A narrow-spectrum herbicide applied before weed
seeds germinate; good for annual grasses and common purslane. Can be
mechanically incorporated shallowly (1–2 inches) before planting, or
applied after planting and incorporated with sprinkler irrigation. Can also
be applied by chemigation, through sprinkler, surface drip, or subsurface
drip irrigation. Very safe on all cucurbits. Also very persistent; check
label for plantback (rotational crop) restrictions. Use allowed under a Special Local Needs label. |
| |
| B. |
PARAQUAT* |
0.5–1 lb a.i. |
|
|
| |
(Gramoxone Inteon) |
2–4 pt |
12 |
0 |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 22 |
| |
COMMENTS: A nonselective foliar herbicide that kills emerged
weeds. Can be used before planting or after planting but before the crop
emerges. Any crop plants exposed to the spray will be killed, even
germinating seed in the crook stage. No soil residual activity. Use the lower
rate on small broadleaf weeds, the higher rate on larger weeds and grasses. A
nonionic surfactant must be added at the rate of 8–32 oz/100 gal, with
the higher surfactant rate needed for larger weeds and grasses. Wear
protective clothing as paraquat is highly toxic if ingested, inhaled, or
contacts the skin. Most active on warm, sunny days, particularly late afternoon. |
| |
| C. |
GLYPHOSATE |
1–4 lb a.i. |
|
|
| |
(Roundup Powermax, Touchdown, etc.) |
1.6–6.4 qt |
see comments |
— |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 9 |
| |
COMMENTS: A nonselective, foliar herbicide applied before
planting to premade beds to kill emerged weeds. Restricted entry interval
(R.E.I.) is 4 hours for Roundup and 12 hours for Touchdown. Allow 3 days
after treatment before planting. Use the lower rate for annual grasses and
weeds, the higher rate on perennial weeds. Add a nonionic surfactant for
difficult-to-control weeds. Consult the label for specific recommendations on
particular weed species. Do not apply to weeds stressed for moisture. For perennial weeds, allow 7 days after application before cultivating. |
| |
| D. |
OXYFLUORFEN |
0.25–0.5 lb a.i. |
|
|
| |
(GoalTender) |
0.5–1 pt |
24 |
— |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 14 |
| |
COMMENTS: Rate depends on weed size, but the rate used also
determines the minimum period between treatment and planting: Cantaloupe = 60
days for the low rate and 90 days for the high rate; watermelon = 60 days for
either rate; other cucurbits = 90 days for the low rate and 120 days for the
high rate. Provides control of annual broadleaves both before and after they
emerge. Incorporate with 2 inches of irrigation water and don't disturb soil
until planting time. Work beds with a rolling cultivator or similar tool to a
depth of 2.5 inches before planting to avoid crop injury or stand loss. Once
beds have been worked before planting, the herbicide is no longer effective.
However, crop injury can result if beds are not thoroughly worked before
planting. This herbicide lasts 4–8 weeks in the soil and has a 10-month
plantback restriction for nonlabeled crops. Apply in a minimum of 20 gallons of water per acre. |
| |
AT PLANTING
Before crop and weeds emerge |
| A. |
BENSULIDE |
4–6 lb a.i. |
|
|
| |
(Prefar) 4E |
4–6 qt |
12 |
— |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 8 |
| |
COMMENTS: A narrow spectrum herbicide, good for annual grasses
and common purslane. Can be mechanically incorporated shallowly (1–2
inches) before planting, or applied after planting and incorporated with
sprinkler irrigation. Very safe on all cucurbits. Also very persistent; check label for plantback (rotational crop) restrictions. |
| |
| B. |
ETHALFLURALIN |
1.12–1.6875 lb a.i. |
|
|
| |
(Curbit) EC |
3–4.5 pt |
24 |
— |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 3 |
| |
COMMENTS: Apply to the soil surface within 2 days after
planting and before crop and weeds emerge. In sprinkler-irrigated fields,
activate with a minimum of 0.5 inches of water; a rainfall after application
will also serve to activate it. Excessive irrigation or rainfall may move the
herbicide deep in the soil, and injury can occur. In furrow- or
drip-irrigated fields, a shallow cultivation will activate. Injury potential is greater if seeding depth is too shallow. |
| |
| AFTER
PLANTING
|
| After crop and weeds emerge |
| A. |
SETHOXYDIM |
0.09375–0.28125 lb a.i. |
|
|
| |
(Poast) 1.5 EC |
0.5–1.5 pt |
12 |
14 |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 1 |
| |
COMMENTS: A selective, foliar herbicide for control of
grasses. Addition of a surfactant (crop oil concentrate or nonionic
surfactant) is essential. Usually safe to the crop, except on very warm,
sunny days; this may be due to the surfactant. Injury observed has been small
necrotic spots on treated leaves. Not effective on drought stressed grasses or on certain species (e.g., annual bluegrass, sprangletop). |
| |
| B. |
HALOSULFURON |
0.37–0.75 lb a.i. |
|
|
| |
(Sandea) |
0.5–1 oz |
12 |
30: pumpkins, cucumbers, squash |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 2 |
|
57: melons |
| |
COMMENTS: For use on seed and transplant cucurbits for the
control of nutsedge. Apply over the top of direct-seeded cucumber,
cantaloupe, honeydew, Crenshaw melons, pumpkins, and winter squash from the 4-true
leaf stage through first bloom. Maximum use rates are lower for over-the-top
applications (see label). Following bloom, or in other cucurbits, including
watermelon and summer squash, applications must be made either as a directed
spray or with shields to minimize contact with the crop. Make applications to
transplanted cucurbits at least 14 days after transporting but before 1st
bloom. Following bloom, applications to transplanted cucurbits must be made
either as a directed spray or with shields to minimize contact with the crop.
Injury may result if the spray contacts the foliage. Use of 0.25 to 0.5% v/v
of nonionic surfactant is recommended. Use of crop oil concentrate or
silicone surfactants is not recommended because of increased risk of injury. Do
not apply if a soil application of an organophosphate insecticide has been
made. Do not apply a foliar organophosphate insecticide within 21 days before or 7 days after any halosulfuron treatment. |
| |
| C. |
DCPA |
4.5–10.5 lb a.i. |
12 |
0 |
| |
(Dacthal) 75W |
6–14 lb |
|
|
| |
WSSA MODE OF ACTION GROUP NUMBER1: 3 |
| |
COMMENTS: Apply at layby, when cucurbits have 4-5 true leaves,
as a banded spray to control annual grasses and some annual broadleaf weeds. In sandy loam soils, maximum preemergent rate of 10 lb/acre is recommended. |
| |
| D. |
CLETHODIM |
0.098–0.121 lb a.i. |
|
|
| |
(Select Max) |
13–16 fl oz |
24 |
14 |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 1 |
| |
COMMENTS: Controls actively growing small grasses except for
bromes and fescues. Apply to annual bluegrass at 4-leaf stage. Repeat treatments
are necessary for perennial grasses, but a minimum of 14 days is required
between applications. Do not apply a postemergent broadleaf herbicide within
one day of clethodim or reduced grass control will occur. Symptoms appear in
7 to 14 days, depending on species and environmental conditions. Apply in 10
to 40 gal water/acre. Always add a crop oil concentrate at 1% v/v in the finished spray solution. |
| |
| LAYBY (Postthinning) |
| A. |
TRIFLURALIN |
0.5–1 lb a.i. |
12 |
60: watermelon |
| |
(Treflan, etc.) |
Label rates |
|
30: all others |
| |
WSSA MODE OF ACTION GROUP NUMBER1: 3 |
| |
COMMENTS: Rate is dependent on soil type. Apply as a directed
spray to clean cultivated soil when the crop has 3–4 leaves. Immediate
mechanical incorporation into the top 2–3 inches of soil is required.
Leaves and runners contacted by trifluralin may be stunted temporarily; lobes
on leaves may be thickened and veins constricted. Controls annual grasses and broadleaf weeds. |
| |
| B. |
ETHALFLURALIN |
1.12–1.6875 lb a.i. |
24 |
0 |
| |
(Curbit) EC |
3–4.5 pt |
|
|
| |
WSSA MODE OF ACTION GROUP NUMBER1: 3 |
| |
COMMENTS: Apply as a directed spray to avoid contact with the
growing tips. Use when field is free of emerged weeds and incorporate with a
sectioned rolling cultivator within 1–2 hours after application. Similar to trifluralin but also controls nightshades. |
| |
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