Management Effects On Yield in Organically Grown American Skullcap (Scutellaria lateriflora).

Information on management effects such as pruning regime and timing of harvest is lacking in American skullcap (Scutellaria lateriflora). A field experiment was conducted in Shorter, Alabama in Marvyn loamy sand with 0-2% slope in 2008 and 2009. Seedlings were transplanted on a 10 cm deep mulch of composted cotton gin, wood chips and cattle manure overlaying a flattened cover crop of rye. An organic fertilizer (Nature Safe 8-5-5 Agriculture Fertilizer) supplied 67kg N ha-1, 37.5kg P ha-1 and 37.5kg K ha-1 per year via irrigation. The experimental design was a randomized complete block design with four replications in the first year and a 2X2 split plot factorial in randomized complete block design in the second year. The main factor was number of harvests in first season (2008): one harvest per season and two harvests per season and sub factors were number of harvests in second season (2009): two harvests per season and three harvests per season. Powdery mildew was controlled with foliar applications of neem oil fungicide (Trilogy). In year 1, two harvests per season gave significantly higher yield than one harvest. In year 2, a third harvest was not possible because of pythium infection, so both treatments were harvested twice but at different dates. Treatment differences were not significant. Late harvest gave significantly higher yield in the first harvest of the year 2 and early harvest gave significantly higher yield in the second harvest. No residual effect from the first season was found.