Yield and quality response of drip irrigated broccoli (Brassica oleracea L. var. italica) under different irrigation regimes, nitrogen applications and cultivation periods

摘要

The experiment aimed at evaluating the yield and quality response of broccoli (Brassica oleracea L. var. italica) to applied irrigation water and nitrogen by drip irrigation method during the spring and autumn cultivation periods of 2007. Irrigation water was applied based on a ratio of Class A pan evaporation (k cp =0.50, 0.75, 1.00 and 1.25) with 7 days interval. Also, the effect of four nitrogen levels (0kghap#, 150kghap#, 200kghap# and 250kghap#) was compared with each treatment. The seasonal evapotranspiration in the treatments varied from 233mm to 328mm during the spring period and from 276mm to 344mm during the autumn period. The highest broccoli yield was obtained in the spring period as 11.02thap# and in the autumn period as 4.55thap#. In general, there were statistical differences along nitrogen does with respect to yield and yield components while there were no statistically significant differences in the yield and yield components among irrigation regimes. Both yield and yield parameters in the spring period were found to be higher than that of the autumn period due to the low temperature and high rainy days in autumn. Irrigation water use efficiency (IWUE) ranged from 3.78kgmpd to 14.61kgmpd during the spring period and from 1.89kgmpd to 5.93kgmpd during the autumn period. On the other hand, nitrogen use efficiency (NUE) changed as 37.32-73.13% and 13.08-22.46% for spring and autumn season, respectively.