engleski

Antitranspirant efficacy on stress tolerance of artichoke transplants

Vegetable transplants are often exposed to environmental stresses during growth in the nursery, transport, and after field transplanting. Artichoke is a new potential crop for the Wintergarden region of Texas. Our previous studies confirmed the feasibility of artichoke production with high yields and quality during spring, while the next step is to determine the possibility of extending the harvest season during fall. To achieve that objective, planting should occur during late spring or summer, times when seedling growth could be impaired by high temperature and drought stresses. Antitranspirants, both metabolic and physical compounds, have been widely tested in horticultural crops to mitigate environmental constrains. However, the efficacy of antitranspirants in artichoke transplants is unknown. Greenhouse experiments were conducted to investigate the effect of foliarly applied abscisic acid (ABA) at various concentrations (0, 500, 1000 or 2000 mgL-1) and film-forming materials (trade names: Antistress, Transfilm, and Vapor Gard) on drought tolerance of artichoke seedlings (cv. Green Globe) exposed to withholding water. ABA at 1000 mgL-1 had a stronger impact on imparting drought stress tolerance, due to induced stomatal closure, transient decline of photosynthetic rates, and increased leaf water potential as compared to lower ABA concentrations or film-forming materials. Even though mature leaves showed signs of chlorosis when ABA was applied at 2000 mgL-1, ABA resulted in higher survival than control and film-forming materials. ABA may be a useful tool for conditioning artichoke seedlings to withstand transient water deficit stress, and thus improve stand establishment during summer, which is a prerequisite to optimize subsequent field growth and yield for fall production.

abscisic acid; Cynara scolymus; drought; gas exchange

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