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Globe artichoke is a native crop of the Mediterranean region with about 80% worldwide production. It is estimated that about 3,000 ha are grown in the U.S., mostly in California. Artichoke crop can be grown as a perennial, by vegetative cuttings, or as annual by seeds. Crop production can be limited by freezing winter temperatures leading to irreversible plant damage or by high summer temperatures causing poor head quality. Successful artichokes production, particularly in areas with constraining climatic conditions, requires proper selection of cultivars and planting dates. Cultivars with low vernalization requirements are more prone to a short growing season. The application of GA₃ to overcome the lack of low temperatures and fulfill the vernalization requirements of early cultivars is well known. The goal of this multi-year project is to select production strategies contributing to earliness, extension of harvesting period, and improved yield and head quality under a variety of environmental conditions in Croatia and Texas. Selecting cultivars with different maturity groups and planting dates enabled harvesting period from autumn to late spring depending on locations. When GA₃ was applied (12.5 to 125 ppm) on a naturally vernalized crop from autumn planting, early yield was substantially increased without affecting earliness. Conversely, application of GA₃ (30 or 45 ppm) on nonvernalized plants established during late spring or summer was necessary for fall harvest in the Croatian locations. Head quality evaluated as head weight and size, or crude protein and total fiber concentration, progressively decreased during late spring harvest in Texas. Shifting the harvesting period towards early spring may be essential for improving head quality and for increasing the market share. To achieve adequate yields, longer harvesting period, and superior head quality, it is necessary to develop and adjust cultural practices for the specific growing area.

In previous studies, baldcypress [Taxodium distichum (L.) Rich.] clones were selected for tolerance to high pH soils, drought and salt exposures, and ornamental characteristics. The objective of the current research was to determine the treatment combinations that yielded optimum root quantity (percentage) and rooted cutting quality (root number, length, dry mass, and shoot dry mass) on vegetative cuttings for a representative clone. Cuttings were treated with factorial combinations of one of four potassium salt of indole-3-butyric acid (K-IBA) concentrations [0, 5,000, 10,000, 15,000 mg·L⁻¹ (0, 20.72, 41.44, 62.16 mm, respectively)], wounded or not wounded (1-cm long basal incision), and rooted in one of three substrates (100% perlite, 100% peatmoss, or 50% perlite:50% peatmoss). Data indicated a tradeoff between potential rooting quantity and root quality measurements in response to different substrates. Although rooting percentages were affected by substrates only at P ≤ 0.10 (53% in 100% perlite versus 36% in 100% peatmoss), there were highly significant (P ≤ 0.0001) differences in rooted cutting potential among substrates as measured by the percentage of cuttings with basal callus. Cuttings placed in 100% perlite callused at 85%, whereas cuttings placed in 100% peatmoss callused at ≈53%. The 100% peatmoss treatment, however, yielded cuttings with significantly greater root quality for all measurements, except root number per cutting. Wounding cuttings proved to have deleterious effects on root quality measurements. Total root length was ≈14.5 cm for non-wounded cuttings and ≈10.8 cm for wounded cuttings. Increasing K-IBA concentrations did not significantly (P ≤ 0.05) affect rooting or callus percentages but did significantly affect root dry mass, total root length, and average root length per cutting. Total root length increased from 10.8 cm at 0 mg·L⁻¹ K-IBA to 16 cm at 15,000 mg·L⁻¹ K-IBA. Mean root number per cutting increased from ≈1.6 with wounded cuttings planted in 100% peatmoss to ≈3.1 with non-wounded cuttings planted in 100% perlite. Results suggested that high-quality softwood baldcypress cuttings should not be wounded, should be treated with 15,000 mg·L⁻¹ K-IBA, and grown in a substrate with intermediate water-holding capacity to achieve an acceptable balance between rooting percentage and rooted cutting quality objectives.