Growth and Malondialdehyde Content of Salt-tolerant Grafted Rockmelon as Affected by Salinity Sources

Supplementation of additional salt is one of the feasible approaches to increase fruit quality in rockmelon. However, continuous supply through fertigation could lead to salinity development and deleteriously affects rockmelon growth. In order to mitigate the salinity stress incidence at vegetative stage, the use of salt-tolerant grafted rockmelon (Rockmelon/bottle gourd) enable to utilize the beneficial impact of salinity sources for growth optimization. Thus, an experiment was conducted to evaluate the growth performances and MDA content of salt-tolerant grafted rockmelon under varying salinity sources; and further to select the most feasible salinity sources that can be used at vegetative stage. All grafted plants were arranged in Randomized Complete Block Design (RCBD) with 4 replications. Grafted rockmelon was then subjected to four types of salinity sources; basic nutrient solution (BNS) (EC=2.5 dS m^-1) as control, NaCl (50 mM)+BNS (EC=7.1 dS m^-1), KNO₃+BNS (EC=8.4 dS m^-1), and high strength nutrient solution (NS) (EC=7.1 dS m^-1) for 28 days. Data on the plant growth and samples for malondialdehyde (MDA) content in leaves were collected at 30 days after transplanting (DAT). Salinity induced using KNO₃+BNS were sustained the growth variables (Stem diameter and total leaf area) and malondialdehyde (MDA) content. On the other hand, application of NaCl+BNS reduces overall growth measurements. Furthermore, growth parameters as total leaf area was negatively correlated with MDA concentrations in the leaf. In conclusion, incorporation of KNO₃+BNS is the most suitable salinity source to be used to enhance growth in salt-tolerant grafted rockmelon at vegetative stage.