Comparison of water bamboo qualities and quantities harvested in different growth environments from Puli area in Taiwan

Abstract As one of Taiwan’s important agricultural crops, the harvest time of water bamboos is limited by environmental conditions such as season and temperature. In order to increase the total annual harvest of white bamboo shoots and improve economic efficiency, the night light filling technology is used to shorten the harvest time of Water bamboos and promote the growth of Water bamboos.Puli, as the city with the largest area of Water bamboos planted in Taiwan, currently uses the most commonly used fill lighting fixtures for light-emitting diodes (LEDs) and high-pressure sodium lamps (HPS). This study aims to examine the differences in various quality parameters of water bamboo grown under different environmental conditions, including total plant weight, plant height, basal circumference, shoot yield ratio, moisture content, ascorbic acid content (AsA), 2,2- Diphenyl-1-picrylhydrazyl (DPPH) radical scavenging, 2,2′-Azinobis-3- ethylbenzthiazoline-6-sulphonate (ABTS) radical scavenging, total phenolic content, and flavonoid content. The samples of water bamboo were collected from real lands in Puli areas where water bamboos were cultivated in different season, supplementary light at night and farming practice conditions. The experimental results showed that in terms of the basic characteristics of water bamboo, there were no significant differences in plant height, basal circumference, and moisture content among water bamboos harvested under different supplementary lighting conditions and agricultural practices in the Puli area in 2022. Water bamboo yields under supplementary light irradiations at night were majorly higher than those harvested without supplementary lighting. Summer time (12.9±0.96cm/105.7±15.3g/31.1±2.85cm) got significantly higher yields than those of water bamboos harvested in Autumn (11.2±1.40cm/83.1±18.3g/29.4±2.63cm). For vitamin C content, water bamboos obtained using eco-friendly farming method (6.48±0.49mg/100g Sample) was significantly higher than that obtained by customary farming method (5.77±0.63mg/100g Sample) under the condition of no supplementary light. Under the eco-friendly farming method, terms of vitamin C contents in water bamboo obtained by LED irradiation and without supplementary light irradiation (6.92±0.81mg/100g Sample and 6.48±0.49mg/100g Sample) were significantly higher than that obtained by high-pressure sodium lamp irradiation (5.40±0.47mg/100g Sample). In terms of antioxidant properties, when comparing different harvest times in the water bamboo fields planted in Puli in 2022, water bamboo harvested in autumn exhibited significant differences in DPPH/ABTS radical scavenging efficiency compared to those harvested in spring. Water bamboos harvested in summer also got significantly higher levels of total phenolic content and flavonoid content compared to those harvested in spring.