Herbicide and Cover Crop Residue Integration Affect Weed Control and Yield in Conservation Tillage Peanut.

Peanut (Arachis hypogaea L.) is a high economic value crop in southeastern United States and is generally grown in conventionally tilled systems. However, interest in reduced tillage peanut production is increasing due to reduced production costs and increased environmental benefits. However, there are some concerns too for widespread adoption of conservation tillage systems for example, loss of effective weed control with tillage and PPI herbicides and shifts from annual weed species to perennial species. Therefore, weed control strategies need to be adapted in conjunction with the conservation tillage system utilized. Strip tillage has so far been the most popular conservation system utilized in peanut production in the southeastern United States. With strip tillage growers can have dual benefit of both conservation tillage and conventional tillage. Experiments were conducted in Alabama, Florida and Georgia to evaluate strip tillage systems, utilizing high residue rye (Secale cereale L.) cover crop for weed control and peanut yield in comparison to conventional tillage systems. A randomized complete block design experiment with four replications was conducted over two years at Alabama and Georgia and one year in Florida. Six herbicide systems were utilized: no herbicide, two preemergence (PRE) herbicides systems (prowl and prowl + dual magnum), two other herbicides systems included the aforementioned PRE systems followed by postemergence (POST) herbicides (gramoxone + basagran + 2,4-DB) and postemergence herbicide application only. Without herbicides weed control in all the experiments was less than 50% for all the weed species evaluated. Broadleaf weeds were effectively controlled (≥ 90%) by the postemergence herbicides alone however grasses required both premergence and postemergence herbicide applications for their adequate control. Without herbicide treatment yield was less in strip tillage system compared to conventional tillage systems.