Partial root-zone irrigation effects on growth, metabolism and calcium status of Mangosteen seedling (Garcinia mangostana L.)

Abstract

Efficient irrigation technique for mangosteen seedling was evaluated, from October 2016 to May 2017, in order to determine the growth and morphophysiology of both the conventional deficit irrigation (CD) and partial root-zone irrigation (PR). A set of randomized block design, with 4 replicates each, was applied on 100% field capacity (control), 50% field capacity (CD1), 30% field capacity (CD2), and ratios of 100:50% field capacity (PR1), 100%:30% field capacity (PR2) and 50:30% field capacity (PR3). The results showed a restriction in mangosteen growth, except control, as indicated by decrease in total dry mass, which due to decrement in leaf number, photosynthetic rate and root growth. Malondialdehyde (MDA) level and glutathione peroxidase (GPX) activity was higher while proline accumulation was lower in PR compared to those of both CD and control treatments. Secondary metabolites content changes in treatments, such as octacosane, cysteamine sulfonic acid, propyl oleate, 1-nanodecene, and 2-butyn-1-ol-4metoxy were synthesized in the low soil moisture conditions. Leaf Ca-pectate, Ca-phosphate and dissolved Ca tended to increase in low soil moisture. The PR1 treated plant had the highest water use efficiency. Therefore, PR technique could be applied when the soil moisture level represents 50% (or more) of the field capacity