Simultaneous effects of water and nitrogen stress on the vegetative and yield parameters of choy sum (Brassica chinensis var. parachinensis)
2016
Khairun N. K. | Teh, C. B. S. | Hawa Z. E. J.
Hypothetically, leafy vegetables need water and nitrogen (N) simultaneously in their applications for good growth. Therefore, this study was conducted to determine the effects of four watering frequencies (watering once a day, once a week and once in every twoweeks and no watering) and five levels of nitrogen (0, 34, 68, 136 and 272 kg N ha-1) onthe vegetative and yield parameters of choy sum over a period of four weeks. The choysum was grown in polyethylene bags under a rain shelter. The experimental design wasa split-split plot with four replications. Plant vegetative and yield parameters measuredweekly were plant height, leaf number, total leaf area, maximum root length, the variousplant part weights and total tissue nitrogen. Water stress detrimentally affected choy sum’sleaf growth more than root growth and the effect of water stress was more than nitrogenstress. Higher nitrogen rates in water-stressed condition increasingly reduced the numberof leaves and height of the choy sum. Choy sum grown under once-a-day watering andonce-a-week treatments did not experience water stress. The optimal soil water content andnitrogen application rate were 0.4 m3 m-3 and 30 to 40 kg N ha-1, respectively. The rate of34 kg N ha-1 and once-a-week watering treatment generally gave the highest values for allthe measured vegetative and yield parameters. Under lower and point of sufficient nitrogenrates, nitrogen was used for leaf thicknessand weight rather than for intercepting lightvia leaf area expansion
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