Efficiency of salicylic acid and calcium chloride foliar application on the growth performance of pak choi (Brassica rapa subsp. chinensis) under nutrient film technique (NFT) hydroponic system

Abstract

Pak choi is the mustard species which have high consumer in Malaysia, however, it is still insufficient to fulfil the demand of the consumer. Plant hormone and inorganic chemicals such as salicylic acid (SA) and calcium chloride (CaCl2) were used to increase the fresh produce production in agriculture. However, their application as foliar application in the smart planting technique by using hydroponic system not fully studied. Therefore, the study was conducted to investigate the efficiency of SA and CaCl2 foliar application on the growth and yield of pak choi under Nutrient Film Technique (NFT) hydroponic system. The plants were treated with SA and CaCl2 as foliar application at spraying volume of 160 L/ha (equivalent to 45 ml/plant). Plants were treated with a series of concentration: T0 (0.0 mM SA+ 0.0 mM CaCl2); T1 (0.5 mM SA+20 mM CaCl2); T2 (1.0 mM SA+20 mM CaCl2) and T3 (1.5 mM SA+20 mM CaCl2). The results of this study showed that the plant height of pak choi plants at T2 and T3 were significantly increased by 10.5% to 17% and 17% to 23%, respectively as compared to T1 and T0. Similar to plant height, the leaves number and diameter of pak choi plants were also significantly increased at these two concentrations with the percentage value ranging from 12% to 32% and 18% to 30% increment, respectively. For the plant yield, T3 was found to give greater fresh weight (P≤0.05) with the mean value of 127 g as compared to the T1 (78 g) and T0 (57 g). However, plants that treated with T2 and T3 concentration did not give any significant difference in both growth and yield parameters. In term of chlorophyll content, the combination of SA and CaCl2 did not give any effect with the mean values ranging from 40 nm to 50 nm. The results suggest that T2 was found to be the optimum concentration that can be applied for the production of pak choi plants in economic ways since this low concentration of SA significantly increased the growth and yield of pak choi plants.