Transcript Broadleaf Weed Control in Sugarcane

Broadleaf Weed Control in
Sugarcane
Curtis Rainbolt
Sugarcane Extension Agent
Spiny pigweed
• Most common pigweed species
– Stickerweed
• Large, upright growth habit, entire leaves
• Very evident spines located at nodes
Alligatorweed
• Common in many areas
of the EAA
– Prefers wet areas
– Often spread by
cultivation
– Low growing
• Hollow stems when growing
in wet spots
• Opposite leaves
• Small white blooms
Common lambsquarters
• Common some years
– Usually during the cooler months (Dec, Jan)
– Can be difficult to control
• Waxy leaf surface
• Alternate leaves
• Medium size lobes on leaves
Common purslane
• Very common
– Probably not
competitive
– Prostrate growing
– Succulent
– Leaves small,
smooth, opposite
or alternate
– Red stems
– Controlled by most
herbicides
Common ragweed
• Often found on ditch banks
and field edges
– Deeply dissected leaves
– Many hairs on upper and
lower surfaces
– Long seedhead at top of plant
– Yellow flowers
Ragweed parthenium
• Primarily ditchbanks
– Less common than common ragweed
– Leaves less deeply dissected
• Divisions don’t go all the way to the stem
– White flowers
• Single, not multiples
Dayflower
• Common in open areas,
field edges
– Small, probably not
competitive
– Prostrate growth habit
– Parallel veins on leaves
• Actually a monocot, not a dicot
– Blue flowers
American black nightshade
• Occasional weed in EAA
– Problematic in vegetables
(tomato, pepper)
• Same family (Solanaceae)
• Resistant to paraquat in some
areas
– Alternate leaves
• Usually entire to somewhat
lobed
– Purple fruit
– Competitive
2,4-D Amine
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Very versatile, useful product
Controls most broadleaves
Can use lower rates on smaller weeds
At higher rates (2 lb ai) very good control
of alligatorweed
• Coverage is the key to good alligatorweed
control
Atrazine
• Backbone of sugarcane weed
control
– Used both PRE and POST
• PRE
– Good soil activity (2-4 qt/A)
– Controls most broadleaves
– Suppress/control many grasses
– Activity begins to fade 3-5 weeks after
application
– Broadleaf activity last longer than grass
activity
Diuron
(Karmex/Direx/Etc)
• Not used much
– Sand soils (binds very strongly on muck)
– Better control of broadleaves than grass
– Not much experience
• Crop injury?
• Rate
– 1.6 lb/A PRE
Envoke
• Excellent control of alligatorweed
• Partial (slow acting) control of prostrate
pigweeds
• Partial control of Dayflower
• Does not control American Black
Nightshade or related species
Evik
(Ametryn)
• Generally applied POST
– Some is applied PRE
• Controls many small grasses and
broadleaves
– Weeds need to be less than 4 inches
– Directed application
• Injury will be seen on treated foliage