Sampling and growth analysis.
In each accession plot for each planting date, two randomly selected plants of each accession from each planting were harvested at 30 day intervals after transplanting into the field. The harvested plants were separated into leaves, stems (including branches and inflor-escences) and roots. The separated plant parts were weighed and then dried to a constant weight in a forced air drying
oven at 21oC. Due to a lack of maturity in the transplanted plants, only those plants transplanted in April, were suitable for harvest and separation into parts at 120
days after transplanting. The shorter growing season of the transplantings in May and June could only be sampled at 30, 60, and 90 days after the transplanting for extraction of essential oils and chemical profiling. The harvest times corresponded to early vegetative, early flowering, and seed forming growth stages of the
plants. Plants in accession PI 652056 from the May planting only had adequate shoot (leaf and stem) growth at 30 DATP for essential oil extraction and
constituent determination.