Factors affecting growth of perennial wall rocket and annual garden rocket.

摘要

Popularity of baby leaf salad crops has increased and is likely to continue. Despite their commercial importance, cultivation of these crops is limited by a lack of appropriate production systems. It is important to establish abiotic constraints for efficient production of these crops to improve supply and quality. In separate experiments, responses of perennial wall rocket (Diplotaxis tenuifolia [L.] DC.) and annual garden rocket (Eruca sativa Mill.) to harvest number, seasonal conditions, and fertilizer level were measured. The yield of perennial wall rocket was influenced by the interaction between the cultivar, harvest number, and season. No clear response between these factors was identified, with the highest yields for the cvs. European wild rocket [DT1] and Apollo [DT2] for the first harvest summer crop (2.7 and 2.8 kg/m2, respectively) and the cv. Nature [DT3] for the second harvest summer and spring crops (2.5 kg/m2, respectively). For annual garden rocket, there was an interaction between the yield and season with the highest yield during summer (3.3 kg/m2), followed by winter (2.7 kg/m2) and spring (1.9 kg/m2). Nitrogen rate did not affect yield or dry weight for either crop, meaning that the species require only little additional nitrogen for efficient growth, and crops may currently be overfertilized. Optimal production is achieved during spring and summer for perennial wall rocket and summer and winter for annual garden rocket, allowing for the interchangeable use of species throughout the growing seasons. The growth of perennial wall rocket improves from first to second harvest but decreases for annual garden rocket, meaning that the perennial species is better suited to at least two harvests.