Study on in vitro propagation of Giao co lam (Gynostemma pentaphyllium Thunb.)

Abstract

There are many types of substrate used in soilless cultivation, but each substrate has differences in water holding capacity and aeration. Therefore, it is very important to determine the amount of water applied to cucumber grown in various substrates based on the estimated cucumber evapotranspiration requirements (ETc) that can enhance cucumber growth and development, improve yields but reduce costs. The experiment was carried out in the experiment site of Nong Lam University Ho Chi Minh City from June to August 2016 with four irrigation levels and four substrates that were arranged in a split-plot design with three replications. Four irrigation levels (60, 80, 100 and 120% of ETc) were allocated to main plots, and four substrates including 100% coconut coir, 50% coconut coir + 50% peanut shells, 50% coconut coir + 50% sand, and 50% sawdust + 50% sand were allocated to subplots. Growth attributes and yield components of cucumber were determined. The results showed that cucumber grown on the substrate 50% coconut coir + 50% sand and irrigated by 120% ETc (corresponding 226 mL/plant/day at 3 weeks after planting - WAP, 280 mL/plant/day at 3 - 5 WAP and 236 mL/plant/day at late 5 WAP) performed the highest absolute yield and commercial yield (7.50 kg/m2 and 7.48 kg/m2, respectively), and had the highest profit (71,738,746 VND 1,000/m2, and the profit ratio was 1.77).