Sunflower
Therefore, early season weed control is essential
for good yields. Annual weeds have been the primary focus of weed control research.
Perennial weeds can also present problems but are usually not specific to sunflower.
Successful weed control should include a combination of cultural and chemical methods.
Almost all North American sunflower plantings are cultivated and/or harrowed for weed
control, and over 2/3 are treated with herbicides. Postemergence cultivation with a
coilspring harrow, spike tooth harrow or rotary hoe is possible with as little as 5 to 7%
stand loss when sunflowers are at the four to six leaf stage (beyond cotyledon), preferably
in dry afternoons when the plants are less turgid. One or two between row cultivations are
common after the plants are at least 6 in. tall.
Several herbicides are currently approved for weed control in sunflowers. Information on
chemical weed control in sunflowers is available at most county extension offices.
G. Diseases:
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