dimethenamid-P (Outlook)
Rate 0.56 to 0.98 lb ai/A (12 to 21 fl oz /A Outlook)
Time Early postemergence on corn up to 12 inches tall.
Remarks Consult label for application rate in relation to soil type. Use lower rates on coarse soils with low organic matter or low cation exchange capacity. May be tank mixed with other herbicides to provide burndown with residual control. PHI 50 days.
Caution Consult label for instructions on applications made through some irrigation systems. Regional experience indicates that corn may be injured by postemergence applications made during very hot weather. Do not apply on sweet corn grown for seed.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Chloroacetamide
pendimethalin (Prowl 3.3 EC, Prowl H2O, Stealth)
Rate 0.74 to 1.98 lb ai/A (1.8 to 4.8 pints/A Prowl 3.3) or 0.95 to 1.9 lb ai/A (2 to 4 pints/A Prowl H2O), depending on soil texture and organic matter content
Time Apply to emerged corn until 20 to 24 inches tall or at V8 growth stage, whichever is more restrictive.
Remarks Does not control emerged weeds. Note rates listed on label for different soil types and organic-matter content. Tank mix with other postemergent herbicides to control emerged weeds. Use drop nozzles if the corn canopy intercepts the spray and prevents it from uniformly reaching the soil.
Caution Do not incorporate. Use only shallow cultivation to reduce soil mixing at or near seed.
Site of action Group 3: microtubule assembly inhibitor
Chemical family Dinitroaniline
pyroxasulfone (Zidua SC or WDG)
Rate 0.057 to 0.21 lb ai/A (1.75 to 6.5 fl oz/A Zidua SC) depending on soil texture.
Time May be applied early postemergence to corn from spiking to V4 for residual preemergence control of susceptible weeds.
Remarks PHI is 37 days. Residual control of annual ryegrass and rattail fescue and many broadleaved weeds.
Caution Crop rotation intervals are 18 months for grasses grown for seed, and 11 months for small grains, snap beans, and peas. May injure corn on gravelly loams at 3 oz/A, especially if tankmixed with another preemergence herbicide.
Site of action Group 15: Very long chain fatty acid synthesis inhibitor
Chemical family Chloroacetamide
S-metolachlor (Dual Magnum or Dual II Magnum with corn safener) or metolachlor (Parallel)
Rate Consult labels to adjust rates for soil types and organic matter content.
Time Apply early postemergence before weeds germinate or yellow nutsedge emerges.
Remarks Activate with shallow incorporation or overhead moisture. Dual II has a safener to reduce potential injury. Suppresses yellow nutsedge.
Caution Consult label for specific rates, depending on soil texture and especially organic matter, or for restrictions on planting sensitive crops within 4 to 5 months. Inhibits roots and shoots.
Site of action Group 15: inhibits very long chain fatty acid synthesis
Chemical family Chloroacetamide