THE EFFECT OF NITROGENOUS FERTILIZER AND PLANT SPACING ON THE YIELD OF 3 CHINESE VEGETABLES - KAI-LAN, TSOI-SUM AND BAK-CHOY

The effect of nitrogenous (N) fertilizer and plant spacing on the yield of Kai lan (Brassica alboglabra, Bailey), Tsoi sum (Brassica parachinensis, Bailey) and Pak choi (Brassica chinensis L. Bailey) was studied. Decreasing inter-plant spacing result in the increase of marketable and total yields for all three Chinese vegetables. At the closer spacings, plant weights were similar or less than those at wide spacings. The yield increases were a result of the increased plant numbers per hectare. All vegetables responded to the addition of N fertilizer with increasing yields. Kai lan yields at the closest spacing, 0.1 × 03 m, were still increasing at the highest rate of N, 400 kg ha-1. At other spacings, the maximum yield was reached at 200 kg ha-1 N. Tsoi sum yields increased to 200 kg ha-1 N and then remained constant. Pak choi yield was maximized at 200 kg ha-1 N at the closest spacing. The addition of extra N fertilizer resulted in an increased incidence of soft rot damage and reduced yields in Pak choi. The treatments did not significantly affect the time for Tsoi sum, Pak choi or Kai lan to reach harvest maturity. © 1990.