This research included studies for transplant and field crop management with thepurpose of optimizing stand establishment, crop performance and nutritional quality ofartichoke (Cynara scolymus L.) grown in southwest Texas.Post-transplanting heat (35/20oC vs. 25/10oC, day/night temperatures) or drought[30% Water holding capacity (WHC) vs. 60% WHC] stress alone or in combinationsignificantly reduced shoot or/and root growth of artichoke seedlings. Combined heatand drought stresses strongly affected shoot water status and root growth. Results fromthis study imply that it is desirable to improve stand establishment by either conditioningthe seedlings to improve root growth or by preventing leaf dehydration by these stresses.Therefore, effects of plant growth regulators (PGR) on root growth and shoot waterstatus were examined.Ethylene regulators, including precursors or a releasing compound [DLmethionine(MET), 1-aminocyclopropane-1-carboxylic acid (ACC) and ethephone(ETH)], and inhibitors [amino-ethoxyvinylglycine (AVG) and 1-methylcyclopropene (1-MCP)] were applied to seedlings to evaluate their effect on root growth and development. ACC and ETH (1-100 M·L-1) enhanced root hair, root area and lateralroots (only with ETH at 30 M·L-1).The effects of film-forming antitranspirants and abscisic acid (ABA, 500-2000mg·L-1) foliar application on physiological responses, water status and hardiness ofartichoke transplants were examined under drought stress. ABA at 1000 mg·L-1enhanced drought tolerance of transplants which was associated with the maintenance ofshoot water status via stomatal closure. Film-forming antitranspirants were not effectiveto mitigate drought stress. These results suggest that ACC and ETH as root enhancers,and ABA as a plant water conditioner, could be useful PGR’s to enhance standestablishment in artichoke seedlings.Field artichoke performance in response to irrigation [50, 75 and 100% cropevapotranspiration (ETc)] and N (0-180 kg·ha-1) rates were investigated during threeseasons at Texas A&M AgriLife Research in Uvalde, TX. Irrigation was more effectivethan N rates to optimize artichoke yield. Yield reduction by 50% ETc was associatedwith a decrease in head number and weight. The highest yield was obtained with 100%ETc and 120 kg·ha-1 N. This study also showed that deficit irrigation significantlyimproved artichoke head quality, such as phenolic content, but with significant yieldlosses.
| Identifer | oai:union.ndltd.org:TEXASAandM/oai:repository.tamu.edu:1969.1/ETD-TAMU-3181 |
| Date | 15 May 2009 |
| Creators | Shinohara, Togo |
| Contributors | Leskovar, Daniel I., Patil, Bhimanagouda S., Piccinni, Giovanni |
| Source Sets | Texas A and M University |
| Language | en_US |
| Detected Language | English |
| Type | thesis, text |
| Format | electronic, application/pdf, born digital |
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