Effect of Terraflow and Glucan Tri on Plant Growth of Ri 6 Varieties

This field study examined the effects of two biostimulants, Terraflow and Glucan Tri, individually or in combination with Amistim, on vegetative physiology and root development of Ri6 durian under tropical orchard conditions in Vietnam. Five treatments were evaluated using randomized complete block design, assessing soil characteristics, leaf parameters, shoot initiation, canopy formation, and root regeneration across 0, 30, 60, 90, and 180 days after application (DAA). The Terraflow + Amistim combination produced the strongest physiological responses, increasing photosynthetic rate to 22.5 µmol CO₂ m⁻² s⁻¹ and SPAD values to 56.2 at 180 DAA. Leaf cycle duration was reduced to 18.3 days, while new shoot emergence reached 11.2 shoots/branch at 90 DAA. Leaf morphology also improved markedly, with maximal dimensions of 19.1 × 7.0 cm. Root initiation increased from 35.4 to 52.7 units from 30 to 60 DAA, significantly exceeding single-product treatments. The untreated control consistently declined across all measured indicators. These findings demonstrate the synergistic effectiveness of Terraflow and Amistim in restoring soil–plant functionality, enhancing physiological vigor, and promoting resilient vegetative growth. Integrating biostimulants into durian management presents a sustainable pathway to improve orchard productivity and long-term soil health.