Herbicides*

Use By Cropping System

Herbicide activity type

Products

Direct seeded

Transplanted

Plastic mulch

Postemergence non-selective systemic – controls emerged and actively growing plants.

Roundup

Prior to planting

Prior to transplanting

Between mulch strips

Postemergence non-selective contact – burn-down control of green foliage.

Gramoxone-Max

Scythe

Prior to planting

Prior to transplanting

Between mulch strips

Postemergence selective – control of emerged grasses.

Poast

Prism

Prior to or after planting

Prior to or after planting

At plant holes and between plastic strips

Preemergence – applied to soil surface without mechanical incorporation; irrigation or rainfall after application often improves weed control; weeds are controlled as they germinate.

Curbit EC

Alanap L

Prefar 4EC

Command 3ME

After seeding and before crop emerges

Before or after transplanting, depending on product used.

At edges of plastic and between plastic strips.

Preplant incorporated – applied and mixed into soil; controls weeds as seed germinate and seedlings emerge.

Prefar 4E

Prior to seeding.

Use very shallow incorporation with Prefar.

Prior to transplanting.

Use very shallow incorporation with Prefar.

Prefar 4E may be used under plastic.  

Directed application – apply to weed-free soil, avoiding contact with crop plants; some must be mixed into soil with cultivation.

Treflan

Dacthal W-75

Curbit EC

Sandea

Strategy

Check label for crop growth stage

Check label for crop growth stage

At edges of plastic and between plastic strips

Postemergence selective - controls some broadleaf weeds.  Not for watermelon.

Sandea

Check label for crop growth stage and weed sizes.

Check label for crop growth stage and weed sizes.

Check label for crop growth stage and weed sizes.

Postemergence selective - controls some broadleaf weeds; apply to weed-free soil; may stunt emerged weeds.

Alanap L

After crop emergence and when vines begin to run

When vines begin to run

At edges of plastic and between plastic strips