A few can be applied as late as early boot, although injury risk increases after jointing. To minimize risk of injury after jointing, use water as the carrier and do not apply more than a half pint of ester or 1 pint of amine. 2-4,D will not control chickweed or henbit and can be weak on smartweed and deadnettle. It's not as effective as 2-4,D on mustard species but is more effective on smartweed and weak on chickweed, deadnettle, henbit and wild garlic. Applying in fertilizer solution increases leaf burn.
Product is weak on most winter annuals, dandelion and wild garlic but is effective on ragweed.
Apply before flag leaf is visible and when weeds are less than 4 inches tall, or the rosette is less than 4 inches wide. Apply with a nonionic surfactant. Product is not as broad spectrum as Harmony Extra but is more effective on Canada thistle. Do not plant double crop soybeans in fields treated with Peak. Specific questions about livestock, crops, weeds, gardens, trees, insects, etc., should be referred to Cooperative Extension Service offices, which are located in every county in the United States.